Features n Pulse Width Modulation (PWM) Controlled by Simple to Analog Input n Four Available Options Define Duty Cycle Limits Minimum Duty Cycle at % or % Maximum Duty Cycle at 9% or % n Frequency Range:.8Hz to MHz n Configured with to Resistors n <.7% Maximum Frequency Error n PWM Duty Cycle Error <.7% Maximum n Frequency Modulation (CO) Capability n. to. Single Supply Operation n μa Supply Current at khz n μs Start-Up Time n CMOS Output Driver Sources/Sinks ma n C to C Operating Temperature Range n Available in Low Profile (mm) SOT- (ThinSOT ) and mm mm DFN Applications n PWM Servo Loops n Heater Control n LED Dimming Control n High ibration, High Acceleration Environments n Portable and Battery-Powered Equipment L, LT, LTC and LTM, Linear Technology, TimerBlox and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. LTC699-/LTC699-/ TimerBlox: oltage-controlled Pulse Width Modulator (PWM) Description The LTC 699 is a silicon oscillator with an easy-to-use analog voltage-controlled pulse width modulation (PWM) capability. The LTC699 is part of the TimerBlox family of versatile silicon timing devices. A single resistor, R, programs the LTC699 s internal master oscillator frequency. The output frequency is determined by this master oscillator and an internal frequency divider, N, programmable to eight settings from to 68. f = MHz N kω R,N =,,6 68 Applying a voltage between and on the MOD pin sets the duty cycle. The four versions differ in their minimum/maximum duty cycle. Note that a minimum duty cycle limit of % or maximum duty cycle limit of % allows oscillations to stop at the extreme duty cycle settings. DEICE NAME PWM DUTY CYCLE RANGE LTC699- % to % LTC699- % to 9% LTC699- % to 9% LTC699- % to % For easy configuration of the LTC699, download the TimerBlox Designer tool at www.linear.com/timerblox. Typical Application MHz Pulse Width Modulator ANALOG PWM DUTY CYCLE CONTROL ( TO ) MOD LTC699. C.µF MOD./ / R k 699 TAa µs/ 699 TAb
LTC699-/LTC699-/ Absolute Maximum Ratings Supply oltage ( ) to....6 Maximum oltage On Any Pin...(.) PIN ( +.) Operating Temperature Range (Note ) LTC699C... C to 8 C LTC699I... C to 8 C LTC699H... C to C LTC699MP... C to C Pin Configuration (Note ) Specified Temperature Range (Note ) LTC699C... C to 7 C LTC699I... C to 8 C LTC699H... C to C LTC699MP... C to C Junction Temperature... C Storage Temperature Range... 6 C to C Lead Temperature (Soldering, sec) S6 Package... C TOP IEW + 7 6 MOD MOD TOP IEW 6 DCB PACKAGE 6-LEAD (mm mm) PLASTIC DFN T JMAX = C, θ JA = 6 C/W, θ JC =.6 C/W EXPOSED PAD (PIN 7) IS, PCB CONNECTION IS OPTIONAL S6 PACKAGE 6-LEAD PLASTIC TSOT- T JMAX = C, θ JA = 9 C/W, θ JC = C/W Order Information Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LTC699CDCB-#TRMPBF LTC699CDCB-#TRPBF LDXC 6-Lead (mm mm) Plastic DFN C to 7 C LTC699IDCB-#TRMPBF LTC699IDCB-#TRPBF LDXC 6-Lead (mm mm) Plastic DFN C to 8 C LTC699HDCB-#TRMPBF LTC699HDCB-#TRPBF LDXC 6-Lead (mm mm) Plastic DFN C to C LTC699CS6-#TRMPBF LTC699CS6-#TRPBF LTDXB 6-Lead Plastic TSOT- C to 7 C LTC699IS6-#TRMPBF LTC699IS6-#TRPBF LTDXB 6-Lead Plastic TSOT- C to 8 C LTC699HS6-#TRMPBF LTC699HS6-#TRPBF LTDXB 6-Lead Plastic TSOT- C to C LTC699CDCB-#TRMPBF LTC699CDCB-#TRPBF LDXF 6-Lead (mm mm) Plastic DFN C to 7 C LTC699IDCB-#TRMPBF LTC699IDCB-#TRPBF LDXF 6-Lead (mm mm) Plastic DFN C to 8 C LTC699HDCB-#TRMPBF LTC699HDCB-#TRPBF LDXF 6-Lead (mm mm) Plastic DFN C to C LTC699CS6-#TRMPBF LTC699CS6-#TRPBF LTDXD 6-Lead Plastic TSOT- C to 7 C LTC699IS6-#TRMPBF LTC699IS6-#TRPBF LTDXD 6-Lead Plastic TSOT- C to 8 C LTC699HS6-#TRMPBF LTC699HS6-#TRPBF LTDXD 6-Lead Plastic TSOT- C to C LTC699CDCB-#TRMPBF LTC699CDCB-#TRPBF LFCP 6-Lead (mm mm) Plastic DFN C to 7 C LTC699IDCB-#TRMPBF LTC699IDCB-#TRPBF LFCP 6-Lead (mm mm) Plastic DFN C to 8 C LTC699HDCB-#TRMPBF LTC699HDCB-#TRPBF LFCP 6-Lead (mm mm) Plastic DFN C to C LTC699CS6-#TRMPBF LTC699CS6-#TRPBF LTFCQ 6-Lead Plastic TSOT- C to 7 C LTC699IS6-#TRMPBF LTC699IS6-#TRPBF LTFCQ 6-Lead Plastic TSOT- C to 8 C LTC699HS6-#TRMPBF LTC699HS6-#TRPBF LTFCQ 6-Lead Plastic TSOT- C to C
ORDER INFORMATION LTC699-/LTC699-/ Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LTC699CDCB-#TRMPBF LTC699CDCB-#TRPBF LFCR 6-Lead (mm mm) Plastic DFN C to 7 C LTC699IDCB-#TRMPBF LTC699IDCB-#TRPBF LFCR 6-Lead (mm mm) Plastic DFN C to 8 C LTC699HDCB-#TRMPBF LTC699HDCB-#TRPBF LFCR 6-Lead (mm mm) Plastic DFN C to C LTC699CS6-#TRMPBF LTC699CS6-#TRPBF LTFCS 6-Lead Plastic TSOT- C to 7 C LTC699IS6-#TRMPBF LTC699IS6-#TRPBF LTFCS 6-Lead Plastic TSOT- C to 8 C LTC699HS6-#TRMPBF LTC699HS6-#TRPBF LTFCS 6-Lead Plastic TSOT- C to C LTC699MPS6-#TRMPBF LTC699MPS6-#TRPBF LTDXB 6-Lead Plastic TSOT- C to C LTC699MPS6-#TRMPBF LTC699MPS6-#TRPBF LTDXD 6-Lead Plastic TSOT- C to C LTC699MPS6-#TRMPBF LTC699MPS6-#TRPBF LTFCQ 6-Lead Plastic TSOT- C to C LTC699MPS6-#TRMPBF LTC699MPS6-#TRPBF LTFCS 6-Lead Plastic TSOT- C to C TRM = pieces. *Temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T A = C. Test conditions are =. to., MOD = to, CODE = to (N = to 6,8), R = k to 8k, R LOAD = k, C LOAD = pf unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Oscillation Frequency f Output Frequency.8 Hz f Frequency Accuracy (Note ).8Hz f MHz ±.8 ±.7 % l ±. % f / T Frequency Drift Over Temperature l ±. %/ C f / Frequency Drift Over Supply =. to. =. to. Long-Term Frequency Stability (Note ) 9 ppm/ khr Period Jitter (Note 9) N =. % P-P l l..8 N =..7 N = 6...6.8 %/ %/ % P-P % RMS % P-P % RMS Pulse Width Modulation D PWM Duty Cycle Accuracy MOD =. to.8 ±. ±.7 % MOD =. to.8 MOD <. or MOD >.8 l l ±. ±.9 % % D MAX Maximum Duty Cycle Limit LTC699-/LTC699-, POL =, MOD = l % LTC699-/LTC699-, POL =, MOD = l 9. 9 99 % D MIN Minimum Duty Cycle Limit LTC699-/LTC699-, POL =, MOD = l % LTC699-/LTC699-, POL =, MOD = l 9. % t S,PWM Duty Cycle Settling Time (Note 6) t MASTER = t /N 8 t MASTER µs
LTC699-/LTC699-/ Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T A = C. Test conditions are =. to., MOD = to, CODE = to (N = to 6,8), R = k to 8k, R LOAD = k, C LOAD = pf unless otherwise noted..96 SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Power Supply Operating Supply oltage Range l.. Power-On Reset oltage l.9 I S Supply Current R L =, R = k, =. l 6 µa N = =. l 8 µa R L =, R = k, =. l µa N = =. l 8 µa R L =, R = k, =. l 9 µa N 6 =. l 6 µa R L =, R = 8k, =. l 7 µa N = to 6,8 =. l µa Analog Inputs oltage at Pin l.97.. / T Drift Over Temperature l ±7 µ/ C R Frequency-Setting Resistor l 8 kω MOD Pin Input Capacitance. pf MOD Pin Input Current l ± na MOD,HI MOD oltage for Maximum LTC699-/LTC699-, POL =, D = % l.9 Duty Cycle LTC699-/LTC699-, POL =, D = 9%.86 MOD,LO MOD oltage for Minimum Duty Cycle LTC699-/LTC699-, POL =, D = % LTC699-/LTC699-, POL =, D = % l.6.. Pin oltage l / Pin alid Code Range (Note ) Deviation from Ideal l ±. % / = (CODE +.)/6 Pin Input Current l ±na Digital Output I (MAX) Output Current =.7 to. ± ma OH High Level Output oltage (Note 7) =. I = ma I = 6mA =. I = ma I = ma =. I = ma I = -8mA OL Low Level Output oltage (Note 7) =. I = ma I = 6mA =. I = ma I = ma =. I = ma I = 8mA t r Output Rise Time (Note 8) =., R LOAD = =., R LOAD = =., R LOAD = t f Output Fall Time (Note 8) =., R LOAD = =., R LOAD = =., R LOAD = l l l l l l l l l l l l..8..7.7.8.8..7.99..88..6....6..7.7..6.....6.7. ns ns ns ns ns ns
Electrical Characteristics Note : Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note : The LTC699C is guaranteed functional over the operating temperature range of C to 8 C. Note : The LTC699C is guaranteed to meet specified performance from C to 7 C. The LTC699C is designed, characterized and expected to meet specified performance from C to 8 C but it is not tested or QA sampled at these temperatures. The LTC699I is guaranteed to meet specified performance from C to 8 C. The LTC699H is guaranteed to meet specified performance from C to C. The LTC699MP is guaranteed to meet specified performance from C to C. Note : Frequency accuracy is defined as the deviation from the f equation, assuming R is used to program the frequency. Note : See Operation section, Table and Figure for a full explanation of how the pin voltage selects the value of CODE. Note 6: Duty cycle settling time is the amount of time required for the output to settle within ±% of the final duty cycle after a ±% change in the setting (±8m step in MOD ). LTC699-/LTC699-/ Note 7: To conform to the Logic IC Standard, current out of a pin is arbitrarily given a negative value. Note 8: Output rise and fall times are measured between the % and the 9% power supply levels with pf output load. These specifications are based on characterization. Note 9: Jitter is the ratio of the peak-to-peak deviation of the period to the mean of the period. This specification is based on characterization and is not % tested. Note : Long-term drift of silicon oscillators is primarily due to the movement of ions and impurities within the silicon and is tested at C under otherwise nominal operating conditions. Long-term drift is specified as ppm/ khr due to the typically nonlinear nature of the drift. To calculate drift for a set time period, translate that time into thousands of hours, take the square root and multiply by the typical drift number. For instance, a year is 8.77kHr and would yield a drift of 66ppm at 9ppm/ khr. Drift without power applied to the device may be approximated as /th of the drift with power, or 9ppm/ khr for a 9ppm/ khr device. Typical Performance Characteristics otherwise noted. =., R = k, and T A = C, unless Frequency Error vs Temperature Frequency Error vs Temperature Frequency Error vs Temperature GUARANTEED MAX OER TEMPERATURE R = k PARTS GUARANTEED MAX OER TEMPERATURE R = k PARTS GUARANTEED MAX OER TEMPERATURE R = 8k PARTS GUARANTEED MIN OER TEMPERATURE 7 TEMPERATURE ( C) GUARANTEED MIN OER TEMPERATURE 7 TEMPERATURE ( C) GUARANTEED MIN OER TEMPERATURE 7 TEMPERATURE ( C) 699 G 699 G 699 G
LTC699-/LTC699-/ Typical Performance Characteristics =., R = k, and T A = C, unless otherwise noted. Frequency Error vs R Frequency Drift vs Supply oltage Typical Distribution PARTS GUARANTEED MAX OER TEMPERATURE GUARANTEED MIN OER TEMPERATURE 8 R (k) 699 G DRIFT (%).......... R = k R = k R = 8k REFERENCED TO =. 6 SUPPLY OLTAGE () 699 G NUMBER OF UNITS.98 LOTS DFN AND SOT- 7 UNITS.988.996... () 699 G6 (m)..8.6.....6.8. Drift vs I Drift vs Supply vs Temperature REFERENCED TO I = µa I (µa) 699 G7 DRIFT (m)..8.6.....6.8. REFERENCED TO = 6 SUPPLY () 699 G8 ()......99.99.98.98 PARTS 7 TEMPERATURE ( C) 699 G9 N = Duty Cycle Error vs R N = Duty Cycle Error vs R N = Duty Cycle Error vs R MOD / =. (.%) CODE = PARTS 8 R (k) MOD / =. (%) CODE = PARTS 8 R (k) MOD / =.8 (87.%) CODE = PARTS 8 R (k) 699 G 699 G 699 G 6
Typical Performance Characteristics otherwise noted. LTC699-/LTC699-/ =., R = k, and T A = C, unless N > Duty Cycle Error vs R N > Duty Cycle Error vs R N > Duty Cycle Error vs R MOD / =. (.%) CODE = PARTS 8 R (k) 699 G MOD / =. (%) CODE = PARTS 8 R (k) 699 G MOD / =.8 (87.%) CODE = PARTS 8 R (k) 699 G 97 96 9 9 9 9 8 7 6 N = Duty Cycle Clamps vs R CODE = PARTS LTC699-/LTC699- MOD = LTC699-/LTC699- MOD = 8 R (k) 97 96 9 9 9 9 8 7 6 N > Duty Cycle Error vs R CODE = PARTS LTC699-/LTC699- MOD = LTC699-/LTC699- MOD = 8 R (k) N = Duty Cycle Error vs Temperature GUARANTEED MAX MOD / =. (.%) CODE = PARTS GUARANTEED MIN 7 TEMPERATURE ( C) 699 G6 699 G7 699 G8 N = Duty Cycle Error vs Temperature N = Duty Cycle Error vs Temperature N > Duty Cycle Error vs Temperature MOD / =. (%) CODE = PARTS GUARANTEED MAX GUARANTEED MAX MOD / =.8 (87.%) CODE = PARTS GUARANTEED MAX MOD / =. (.%) CODE = PARTS GUARANTEED MIN 7 TEMPERATURE ( C) GUARANTEED MIN 7 TEMPERATURE ( C) GUARANTEED MIN 7 TEMPERATURE ( C) 699 G9 699 G 699 G 7
LTC699-/LTC699-/ Typical Performance Characteristics otherwise noted. =., R = k, and T A = C, unless N > Duty Cycle Error vs Temperature MOD / =. (%) CODE = PARTS GUARANTEED MAX GUARANTEED MIN 7 TEMPERATURE ( C) 699 G N > Duty Cycle Error vs Temperature GUARANTEED MAX MOD / =.8 (87.%) CODE = PARTS GUARANTEED MIN 7 TEMPERATURE ( C) 699 G 97 96 9 9 9 9 N = Duty Cycle Clamps vs Temperature CODE = PARTS 8 7 6 LTC699-/LTC699- MOD = LTC699-/LTC699- MOD = 7 TEMPERATURE ( C) 699 G DUTY CYCLE (%) 97 96 9 9 9 9 N > Duty Cycle Clamps vs Temperature CODE = PARTS 8 7 6 LTC699-/LTC699- MOD = LTC699-/LTC699- MOD = 7 TEMPERATURE ( C) 699 G Duty Cycle Error vs CODE MOD / =. (.%) PARTS 6 8 CODE 699 G6 Duty Cycle Error vs CODE MOD / =. (%) PARTS 6 8 CODE 699 G7 Duty Cycle Error vs CODE MOD / =.8 (87.%) PARTS 6 8 CODE 699 G8 DUTY CYCLE (%) 9 8 7 6 N = Duty Cycle vs MOD / CODE = PARTS LTC699-/ LTC699-. LTC699-/ LTC699- LTC699-/LTC699- LTC699-/ LTC699-..6.8 MOD / (/) 699 G9 DUTY CYCLE (%) 9 8 7 6 N > Duty Cycle vs MOD / CODE = PARTS LTC699-/ LTC699-. LTC699-/ LTC699- LTC699-/LTC699- LTC699-/ LTC699-..6.8 MOD / (/) 699 G 8
Typical Performance Characteristics otherwise noted. LTC699-/LTC699-/ =., R = k, and T A = C, unless DUTY CYCLE (%) 9 8 7 6 N > Duty Cycle vs MOD / N = Duty Cycle Error vs Ideal N > Duty Cycle Error vs Ideal LTC699-/ LTC699- CODE = PARTS. LTC699-/LTC699- LTC699-/ LTC699- LTC699-/ LTC699-..6.8 MOD / (/) 699 G CODE = PARTS PART B PART A PART C 7 IDEAL DUTY CYCLE (%) 699 G CODE = PARTS PART B PART A PART C 7 IDEAL DUTY CYCLE (%) 699 G N > Duty Cycle Error vs Ideal CODE = PARTS PART C PART A PART B 7 IDEAL DUTY CYCLE (%) 699 G DUTY CYCLE (%) Linearity Near % Duty Cycle CODE = 99 LTC699-/LTC699-98 PARTS 97 96 9 9 9 9 9 9 89 88.8.86.868.9 MOD / (/) 699 G DUTY CYCLE (%) Linearity Near 9% Duty Cycle CODE = 99 LTC699-/LTC699-98 PARTS 97 96 9 9 9 9 9 9 89 88.8.86.868.9 MOD / (/) 699 G6 DUTY CYCLE (%) 7 7 7 69 68 67 66 6 6 6 Linearity Near 67% Duty Cycle CODE = PARTS 6.96.6.68.6.66.676 MOD / (/) 699 G7 DUTY CYCLE (%) Linearity Near % Duty Cycle CODE = LTC699-/LTC699- PARTS 9 8 7 6.8.6.8.8 MOD / (/) 699 G8 DUTY CYCLE (%) Linearity Near % Duty Cycle CODE = LTC699-/LTC699- PARTS 9 8 7 6.8.6.8.8 MOD / (/) 699 G9 9
LTC699-/LTC699-/ Typical Performance Characteristics otherwise noted. =., R = k, and T A = C, unless DUTY CYCLE (%) 6 9 8 7 Linearity Near % Duty Cycle CODE = PARTS 6.8...6.7.88 MOD / (/) 699 G DRIFT (%)........ N = Duty Cycle Drift vs Supply CODE = % CLAMP 9% CLAMP MOD / =.8 MOD / =. MOD / =.. REFERENCED TO =. 6 SUPPLY () 699 G DRIFT (%) N > Duty Cycle Drift vs Supply. CODE =.... % CLAMP MOD / =. 9% CLAMP. MOD / =.. MOD / =.8.. REFERENCED TO =. 6 SUPPLY () 699 G POWER SUPPLY CURRENT (µa) Supply Current vs MOD LTC699- R = k, R = k, 6 R = k, R = 8k, POWER SUPPLY CURRENT (µa) Supply Current vs Supply oltage R = k, R = k, R = k, 6 R = k, R = 8k, POWER SUPPLY CURRENT (µa) Supply Current vs Temperature., R = k,., R = k, 6., R = k,., R = 8k,., R = 8k,...6.8 MOD () 6 SUPPLY OLTAGE () 7 TEMPERATURE ( C) 699 G 699 G 699 G JITTER (% P-P )..8.6....8.6... Jitter vs Frequency PEAK-TO-PEAK PERIOD DEIATION MEASURED OER s INTERALS MOD / =. 6, =., =, =. 6, =. FREQUENCY (khz) 699 G6 POWER SUPPLY CURRENT (µa). Supply Current vs Frequency, Supply Current vs Frequency,. = 6,8.. FREQUENCY (khz) 699 G7 POWER SUPPLY CURRENT (µa) =.. 6,8.. FREQUENCY (khz) 699 G8
Typical Performance Characteristics otherwise noted. LTC699-/LTC699-/ =., R = k, and T A = C, unless DELTA FREQUENCY (ppm) Typical Frequency Error vs Time (Long-Term Drift) 6 UNITS SOT- AND DFN PARTS T A = C PUT RESISTANCE (Ω) Output Resistance vs Supply oltage PUT SOURCING CURRENT PUT SINKING CURRENT RISE/FALL TIME (ns)...... Rise and Fall Time vs Supply oltage t RISE t FALL C LOAD = pf 8 6 8 TIME (h) 699 G8a 6 SUPPLY OLTAGE () 699 G 6 SUPPLY OLTAGE () 699 G Typical I Current Limit vs PIN SHORTED TO Typical Start-Up, POL = I (µa) 8 6 / / µs 6 SUPPLY OLTAGE () 699 G µs/ =. CODE = ( 6) R = k MOD =. (~% DUTY CYCLE) 699 G / Typical Start-Up, POL = khz Full Modulation LTC699- MOD./ / µs / µs/ =. CODE = ( 6, POL = ) R = k MOD =. (~87.% DUTY CYCLE) 699 G =. CODE = R = k µs/ 699 G
LTC699-/LTC699-/ Pin Functions (DCB/S6) (Pin /Pin ): Supply oltage (. to.). This supply should be kept free from noise and ripple. It should be bypassed directly to the pin with a.μf capacitor. (Pin /Pin ): Programmable Divider and Polarity Input. The pin voltage ( ) is internally converted into a -bit result (CODE). may be generated by a resistor divider between and. Use % resistors to ensure an accurate result. The pin and resistors should be shielded from the pin or any other traces that have fast edges. Limit the capacitance on the pin to less than pf so that settles quickly. The MSB of CODE (POL) determines if the PWM signal is inverted before driving the output. When POL = the transfer function is inverted (duty cycle decreasing as MOD increases). (Pin /Pin ): Frequency-Setting Input. The voltage on the pin ( ) is regulated to above. The amount of current sourced from the pin (I ) programs the master oscillator frequency. The I current range is.μa to μa. The output oscillation will stop if I drops below approximately na. A resistor connected between and is the most accurate way to set the frequency. For best performance, use a precision metal or thin film resistor of.% or better tolerance and ppm/ C or better temperature coefficient. For lower accuracy applications an inexpensive % thick film resistor may be used. Limit the capacitance on the pin to less than pf to minimize jitter and ensure stability. Capacitance less than pf maintains the stability of the feedback circuit regulating the voltage. R MOD LTC699 699 PF C.µF MOD (Pin /Pin ): Pulse-Width Modulation Input. The voltage on the MOD pin controls the output duty cycle. The linear control range is between. and.9 (approximately m to 9m). Beyond those limits, the output will either clamp at % or 9%, or stop oscillating (% or % duty cycle), depending on the version. (Pin /Pin ): Ground. Tie to a low inductance ground plane for best performance. (Pin 6/Pin 6): Oscillator Output. The pin swings from to with an output resistance of approximately Ω. The duty cycle is determined by the voltage on the MOD pin. When driving an LED or other low-impedance load a series output resistor should be used to limit the source/sink current to ma. R R
+ LTC699-/LTC699-/ Block Diagram (S6 Package Pin Numbers Shown) R R -BIT A/D CONERTER DIGITAL FILTER POL PUT POLARITY MASTER OSCILLATOR I f OSC = MHz kω MCLK PROGRAMMABLE IDER,, 6, 6, 6,, 96, 68 PULSE WIDTH MODULATOR DUTY CYCLE = MOD(LIM)..8 6 t ON HALT OSCILLATOR IF I < na DISABLE PUT UNTIL TLED MOD(LIM) D = t ON t t POR OLTAGE LIMITER = + REF MOD I MOD 699 BD R
LTC699-/LTC699-/ Operation The LTC699 is built around a master oscillator with a MHz maximum frequency. The oscillator is controlled by the pin current (I ) and voltage ( ), with a MHz k conversion factor that is accurate to ±.8% under typical conditions. f MASTER = = MHz k I t MASTER A feedback loop maintains at ±m, leaving I as the primary means of controlling the output frequency. The simplest way to generate I is to connect a resistor (R ) between and, such that I = /R. The master oscillator equation reduces to: f MASTER = t MASTER = MHz k R From this equation, it is clear that drift will not affect the output frequency when using a single program resistor (R ). Error sources are limited to R tolerance and the inherent frequency accuracy Δf of the LTC699. R may range from k to 8k (equivalent to I between.μa and μa). The LTC699 includes a programmable frequency divider which can further divide the frequency by,, 6, 6, 6,, 96 or 68 before driving the pin. The divider ratio N is set by a resistor divider attached to the pin. f = MHz k = I t N CODE The pin connects to an internal, referenced -bit A/D converter that determines the CODE value. CODE programs two settings on the LTC699:. CODE determines the output frequency divider setting, N.. CODE determines the output polarity, via the POL bit. may be generated by a resistor divider between and as shown in Figure. LTC699 699 F. TO. Figure. Simple Technique for Setting CODE R R With R in place of /I the equation reduces to: f = MHz k = t N R
LTC699-/LTC699-/ Operation Table. CODE Programming CODE POL N RECOMMENDED f R (kω) R (kω) / 6.kHz to MHz Open Short. ±..6kHz to khz 976.97 ±. 6.96kHz to 6.kHz 976 8.6 ±. 6 976.6Hz to.6khz 8.87 ±. 6.Hz to.96khz 9.8 ±. 6.Hz to 976.6Hz.7 ±. 6 96.6Hz to.hz 68.6 ±. 7 68.8Hz to 6.Hz 887.687 ±. 8 68.8Hz to 6.Hz 887. ±. 9 96.6Hz to.hz 68.97 ±. 6.Hz to 976.6Hz.66 ±. 6.Hz to.96khz 9.787 ±. 6 976.6Hz to.6khz 8.78 ±. 6.96kHz to 6.kHz 8 976.87 ±..6kHz to khz 976.96 ±. 6.kHz to MHz Short Open.9687 ±. Table offers recommended % resistor values that accurately produce the correct voltage division as well as the corresponding N and POL values for the recommended resistor pairs. Other values may be used as long as:. The / ratio is accurate to ±.% (including resistor tolerances and temperature effects).. The driving impedance (R R) does not exceed kω. If the voltage is generated by other means (i.e. the output of a DAC) it must track the supply voltage. The last column in Table shows the ideal ratio of to the supply voltage, which can also be calculated as: CODE +. = ±.% + 6 For example, if the supply is. and the desired CODE is, =.8. = 98m ± m. Figure illustrates the information in Table, showing that N is symmetric around the CODE midpoint. POL BIT = POL BIT = f (khz).. 6 9 7 8.. INCREASING + Figure. Frequency Range and POL Bit vs CODE 699 F
LTC699-/LTC699-/ Operation Pulse Width (Duty Cycle) Modulation The MOD pin is a high impedance analog input providing direct control of the output duty cycle. The duty cycle is proportional to the voltage applied to the MOD pin, MOD. Duty Cycle = D = MOD.8 8 The PWM duty cycle accuracy ΔD specifies that the above equation is valid to within ±.% for MOD between. and.8 (.% to 87.% duty cycle). Since = ±m, the duty cycle equation may be approximated by the following equation. Duty Cycle = D MOD m 8m The MOD control range is approximately. to.9. Driving MOD beyond that range (towards or ) will have no further affect on the duty cycle. Duty Cycle Limits The only difference between the four versions of the LTC699 is the limits, or clamps, placed on the output duty cycle. The LTC699- generates output duty cycles ranging from % to %. At % or % the output will stop oscillating and rest at or, respectively. The LTC699- will never stop oscillating, regardless of the MOD level. Internal clamping circuits limit its duty cycle to a % to 9% range (% to 99% guaranteed). Therefore, its MOD control range is. to.86 (approximately. to.86). The LTC699- and LTC699- complete the family by providing one-sided clamping. The LTC699- allows % to 9% duty cycle, and the LTC699- allows % to % duty cycle. Output Polarity (POL Bit) The duty cycle equation describes a proportional transfer function, where duty cycle increases as MOD increases. The LTC699 includes a POL bit (determined by the CODE as described earlier) that inverts the output signal. This makes the duty cycle gain negative, reducing duty cycle as MOD increases. POL = POL = D t t D t t Figure. POL Bit Functionality MOD D =.8 8 D = MOD.8 8 699 F 6
Operation POL = forces a simple logic inversion, so it changes the duty cycle range of the LTC699- (making it % to %) and LTC699- (making it 9% to %). These transfer functions are detailed in Figure. LTC699-/LTC699-/ Table. Duty Cycle Ranges DUTY CYCLE RANGE vs MOD = PART NUMBER POL = POL = LTC699- % to % % to % LTC699- % to 9% 9% to % LTC699- % to 9% % to % LTC699- % to % 9% to % 9 8 MOD / =. 9 8 MOD / =. DUTY CYCLE (%) 7 6 POL = POL = DUTY CYCLE (%) 7 6 POL = POL = MOD / =.9......6.7.8.9 MOD / (/) 699 Fa MOD / =.86......6.7.8.9 MOD / (/) 699 Fb LTC699- LTC699-9 8 MOD / =. 9 8 MOD / =. DUTY CYCLE (%) 7 6 POL = POL = DUTY CYCLE (%) 7 6 POL = POL = MOD / =.86 MOD / =.9......6.7.8.9 MOD / (/) 699 Fc......6.7.8.9 MOD / (/) 699 Fd LTC699- LTC699- Figure. PWM Transfer Functions for All LTC699 Family Parts 7
LTC699-/LTC699-/ Operation Changing CODE After Start-Up Following start-up, the A/D converter will continue monitoring for changes. Changes to CODE will be recognized slowly, as the LTC699 places a priority on eliminating any wandering in the CODE. The typical delay depends on the difference between the old and new CODE settings and is proportional to the master oscillator period. t CODE = 6 ( CODE + 6) t MASTER A change in CODE will not be recognized until it is stable, and will not pass through intermediate codes. A digital filter is used to guarantee the CODE has settled to a new value before making changes to the output. Then the output will make a clean (glitchless) transition to the new divider setting../ µs Start-Up Time When power is first applied, the power-on reset (POR) circuit will initiate the start-up time, t START. The pin is held low during this time. The typical value for t START ranges from.ms to 8ms depending on the master oscillator frequency (independent of N ): t START(TYP) = t MASTER The output will begin oscillating after t START. If POL = the first pulse has the correct width. If POL = (CODE 8), the first pulse width can be shorter or longer than expected, depending on the duty cycle setting, and will never be less than % of t. During start-up, the pin A/D converter must determine the correct CODE before the output is enabled. The start-up time may increase if the supply or pin voltages are not stable. For this reason, it is recommended to minimize the capacitance on the pin so it will properly track. Less than pf will not affect performance. / =. R = k MOD =. µs/ 699 F STABLE t CODE t START Figure. CODE Change from to ST PULSE WIDTH MAY BE INACCURATE 699 F6 Figure 6. Start-Up Timing Diagram 8
LTC699-/LTC699-/ Applications Information Basic Operation The simplest and most accurate method to program the LTC699 is to use a single resistor, R, between the and pins. The design procedure is a four step process. After choosing the proper LTC699 version and POL bit setting, select the N value and then calculate the value for the R resistor. Alternatively, Linear Technology offers the easy to use TimerBlox Designer tool to quickly design any LTC699 based circuit. Download the free TimerBlox Designer software at www.linear.com/timerblox. Step : Selecting the POL Bit Setting Most applications will use POL =, resulting in a positive transfer function. However, some applications may require a negative transfer function, where increasing MOD reduces the output duty cycle. For example, if the LTC699 is used in a feedback loop, POL = may be required to achieve negative feedback. Step : Selecting the LTC699 ersion The difference between the LTC699 versions is observed at the endpoints of the duty cycle control range. Applications that require the output to never stop oscillating should use the LTC699-. On the other hand, if the output should be allowed to rest at or (% or % duty cycle), select the LTC699-. The LTC699- and LTC699- clamp the duty cycle at only one end of the control range, allowing the output to stop oscillating at the other extreme. If POL = the clamp will swap from low duty cycle to high, or vice-versa. Refer to Table and Figure for assistance in selecting the proper version. Step : Selecting the N Frequency Divider alue As explained earlier, the voltage on the pin sets the CODE which determines both the POL bit and the N value. For a given output frequency, N should be selected to be within the following range. 6.kHz f N MHz f (a) To minimize supply current, choose the lowest N value (generally recommended). For faster start-up or decreased jitter, choose a higher N setting. Alternatively, use Table as a guide to select the best N value for the given application. With POL already chosen, this completes the selection of CODE. Use Table to select the proper resistor divider or / ratio to apply to the pin. Step : Calculate and Select R The final step is to calculate the correct value for R using the following equation. MHz k R = (b) N f Select the standard resistor value closest to the calculated value. Example: Design a PWM circuit that satisfies the following requirements: f = khz Positive MOD to duty cycle response Output can reach % duty cycle, but not % Minimum power consumption Step : Selecting the POL Bit Setting For positive transfer function (duty cycle increases with MOD ), choose POL =. Step : Selecting the LTC699 ersion To limit the minimum duty cycle, but allow the maximum duty cycle to reach %, choose LTC699-. (Note that if POL = the LTC699- would be the correct choice.) Step : Selecting the N Frequency Divider alue Choose an N value that meets the requirements of Equation (a).. N Potential settings for N include and 6. N = is the best choice, as it minimizes supply current by us- 9
LTC699-/LTC699-/ applications information ing a large R resistor. POL = and N = requires CODE =. Using Table, choose the R and R values to program CODE =. Step : Select R Calculate the correct value for R using Equation (b). MHz k R = khz = 6k Since 6k is not available as a standard % resistor, substitute 69k if a.97% frequency shift is acceptable. Otherwise, select a parallel or series pair of resistors such as 9k and 6k to attain a more precise resistance. The completed design is shown in Figure 7. MOD R 6k MOD LTC699-699 F7. TO. Figure 7. khz PWM Oscillator R 976k CODE = R k Figure 8 demonstrates the worst-case impact of this variation (if is at its.97 or. limits). This error is in addition to the inherent PWM duty cycle accuracy spec ΔD (±.%), so care should be taken if accuracy at high duty cycles ( MOD near.9) is critical. Sensitivity to Δ can be eliminated by making MOD proportional to. For example, Figure 9 shows a simple circuit for generating an arbitrary duty cycle. The equation for duty cycle does not depend on at all. DUTY CYCLE (%) 9 8 7 6. = m = m = m..6.8 MOD () 699 F8 Figure 8. Duty Cycle ariation Due to Duty Cycle Sensitivity to Δ The output duty cycle is proportional to the ratio of MOD /. Since can vary up to ±m from it can effectively gain or attenuate MOD, as shown below when Δ is added to the equation. MOD D =.8 + ( ) 8 For many designs, the absolute MOD to duty cycle accuracy is not critical. For others, making the simplifying assumption of Δ = creates the potential for additional duty cycle error, which increases with MOD, reaching a maximum of.% if Δ = m. D MOD 8m D IDEAL + 8 R R MOD LTC699-X 699 F9 D = R R +R 8. TO. Figure 9. Fixed-Frequency, Arbitrary Duty Cycle Oscillator R R
Applications Information I Extremes (Master Oscillator Frequency Extremes) When operating with I outside of the recommended.μa to μa range, the master oscillator operates outside of the 6.kHz to MHz range in which it is most accurate. The oscillator will still function with reduced accuracy for I <.µa. At approximately na, the oscillator output will be frozen in its current state. The output could halt in a high or low state. This avoids introducing short pulses while frequency modulating a very low frequency output. At the other extreme, it is not recommended to operate the master oscillator beyond MHz because the accuracy of the pin ADC will suffer. LTC699-/LTC699-/ Pulse Width Modulation Bandwidth and Settling Time The LTC699 has a wide PWM bandwith, making it suitable for a variety of feedback applications. Figure shows that the frequency response is flat for modulation frequencies up to nearly / of the output frequency. Beyond that point, some peaking may occur (depending on N and average duty cycle setting). Duty cycle settling time depends on the master oscillator frequency. Following a ±8m step change in MOD, the duty cycle takes approximately eight master clock cycles (8 t MASTER ) to settle to within % of the final value. Examples are shown in Figures a and b. D(f MOD )/ D(Hz) (db), %, %, 8%, % 6... f MOD /f (Hz/Hz) 699 F Figure. PWM Frequency Response MOD./ MOD./ / / DUTY CYCLE % DUTY CYCLE % µs/ =. CODE = R = k MOD =. ±m 699 Fa µs/ =. CODE = R = k MOD =. ±m 699 Fb Figure a. PWM Settling Time, % Duty Cycle Figure b. PWM Settling Time, % Duty Cycle
LTC699-/LTC699-/ applications information Power Supply Current The power supply current varies with frequency, supply voltage and output loading. It can be estimated under any condition using the following equation: If N = (CODE = or ): I S(TYP) f ( 9pF + C LOAD ) + + kω + + Duty Cycle +. I R + 8µA LOAD If N > (CODE = or ): I S(TYP) N f 7pF + f ( 8pF + C LOAD ) + + kω + + Duty Cycle R LOAD +.6 I + 9µA Supply Bypassing and PCB Layout Guidelines The LTC699 is a.% accurate silicon oscillator when used in the appropriate manner. The part is simple to use and by following a few rules, the expected performance is easily achieved. Adequate supply bypassing and proper PCB layout are important to ensure this. Figure shows example PCB layouts for both the TSOT- and DFN packages using 6 sized passive components. The layouts assume a two layer board with a ground plane layer beneath and around the LTC699. These layouts are a guide and need not be followed exactly.. Connect the bypass capacitor, C, directly to the and pins using a low inductance path. The connection from C to the pin is easily done directly on the top layer. For the DFN package, C s connection to is also simply done on the top layer. For the TSOT-, can be routed through the C pads to allow a good C connection. If the PCB design rules do not allow that, C s connection can be accomplished through multiple vias to the ground plane. Multiple vias for both the pin connection to the ground plane and the C connection to the ground plane are recommended to minimize the inductance. Capacitor C should be a.μf ceramic capacitor.. Place all passive components on the top side of the board. This minimizes trace inductance.. Place R as close as possible to the pin and make a direct, short connection. The pin is a current summing node and currents injected into this pin directly modulate the operating frequency. Having a short connection minimizes the exposure to signal pickup.. Connect R directly to the pin. Using a long path or vias to the ground plane will not have a significant affect on accuracy, but a direct, short connection is recommended and easy to apply.. Use a ground trace to shield the pin. This provides another layer of protection from radiated signals. 6. Place R and R close to the pin. A direct, short connection to the pin minimizes the external signal coupling.
LTC699-/LTC699-/ applications information MOD LTC699 C.µF R R R R C C MOD R MOD R R R R DFN PACKAGE TSOT- PACKAGE 699 F Figure. Supply Bypassing and PCB Layout Typical Applications Constant On-Time Modulator IN TO R IN *.8k CTRL R M.k R.k MOD R M 9.k MOD LTC699-699 TA C.µF CC R 8k CODE = ( 6, POL = ) R 976k *OPTIONAL RESISTOR ADJUSTS FOR DESIRED IN RANGE. R IF M =.9 THEN t ON = N.µs R R M +R M k AS IN INCREASES, t INCREASES AND DUTY CYCLE DECREASES (BECAUSE POL = ) TO MAINTAIN A CONSTANT t ON. FOR CONSTANT OFF-TIME, JUST CHANGE CODE SO POL =.
LTC699-/LTC699-/ typical applications Digitally Controlled Duty Cycle with Internal REF Reference ariation Eliminated.µF MOD LTC699-X C.µF R / LTC678 + R 699 TA R.µF REF CC D IN LTC69 CLK µp CS/LD Programming N Using an 8-Bit DAC ANALOG PWM DUTY CYCLE CONTROL ( TO ) R MOD LTC699-X C.µF CC SDI LTC6-LZ8 SCK µp. TO. CS/LD C.µF CODE 6 7 8 9 DAC CODE 6 7 88 6 68 8 6 699 TA
+ LTC699-/LTC699-/ typical applications Changing Between Two Frequencies ANALOG PWM DUTY CYCLE CONTROL ( TO ) MOD LTC699-X ANALOG PWM DUTY CYCLE CONTROL ( TO ) MOD LTC699-X f MIN f MAX HC R CO R.µF R R f MIN R R.µF R R f MAX HC N7 699 TA NOTES WHILE THIS CIRCUIT IS SIMPLER THAN THE CIRCUIT TO THE RIGHT, ITS FREQUENCY ACCURACY IS WORSE DUE TO THE EFFECT OF SUPPLY ARIATION FROM SYSTEM TO SYSTEM AND OER TEMPERATURE. NOTES. WHEN THE NMOSFET IS OFF, THE FREQUENCY IS BY R = R.. WHEN THE NMOSFET IS ON, THE FREQUENCY IS BY R = R R.. SUPPLY ARIATION IS NOT A FACTOR AS THE SWITCHING RESISTOR IS EITHER FLOATING OR CONNECTED TO GROUND. Simple Diode Temperature Sensor R6.k D N8 R7 6.9k R8 8.k.µF LT6 +m/c MOD LTC699- R9 6Ω MOC7M D Q.µF R k 699 TA6 R k R 86k.µF R Ω PUT C µf ADJUST FOR % DUTY CYCLE AT C R k R k N = 6 f = khz PWM PUT FOR ISOLATED MEASUREMENT +% DUTY CYCLE CHANGE PER DEGREE C C TO 6 C RANGE WITH OPTO-ISOLATOR (DC: % TO 9%)
LTC699-/LTC699-/ typical applications Motor Speed/Direction Control for Full H-Bridge (Locked Anti-Phase Drive) S.6kHz, % TO 9% PWM % DC = CLOCKWISE % DC = STOPPED 9% DC = COUNTER CLOCKWISE A CW CURRENT FLOW INPUT TO R k MOD LTC699- R k R 8k.µF A MOTOR POWER H-BRIDGE HIGH = SWITCH ON 699 TA7 Motor Speed/Direction Control for Full H-Bridge (Sign/Magnitude Drive) S A A.6kHz, % TO 9% PWM % DC = SLOW 9% DC = FAST CW CURRENT FLOW INPUT TO MOD LTC699- MOTOR R k R k R 8k.µF POWER H-BRIDGE HIGH = SWITCH ON DIRECTION H = CCW, L = CW A 699 TA8 6
+ + typical applications Ratiometric Sensor to Pulse Width, Non-Inverting Response LTC699-/LTC699-/ R6 9.9k S.µF C.µF R 9.9k R M C.µF S =. TO. R K = k R SENSOR K = K S LT9 R 6k MOD LTC699-699 TA9 N = 6 f = khz R k R 86k PUT DUTY CYCLE = K % S.µF Ratiometric Sensor to Pulse Width, Inverting Response R6 9.9k S =. TO. K = R SENSOR K = S R k K S R k R6 9.9k R k S.µF LT9 C.µF R 6k C.µF MOD LTC699-699 TA N = 6 f = khz R k R 86k PUT DUTY CYCLE = ( K) % S.µF 7
+ LTC699-/LTC699-/ typical applications Radio Control Servo Pulse Generator R6 9.9k R6 9.9k C µf C.µF S =. TO. S.µF SERO CONTROL POT k R k R6 8.66k ms ms LT9 R 96k MOD LTC699-699 TA R k R 68k N = 96 f = 6.Hz, 6ms PERIOD PUT ms TO ms PULSE EERY 6ms.µF S Direct oltage Controlled PWM Dimming ( to Cd/m Intensity) DIMMING R k MOD LTC699-699 TA R 9.9Ω R M R 8k C.µF D HIGH INTENSITY LED SSL-LX9XUWC f = 7.kHz N = 6 8
+ + typical applications Wide Range LED Dimming ( to 8 Cd/m Brightness) LTC699-/LTC699-/ R 7.k LT6 R k.µf LT6 FAST MOD LTC699- FAST PWM CONTROLS 6 TO 8 Cd/m BRIGHTNESS R 7.k R k REF R M C.µF.. IN P IN R 6.9k % N = 6 f =.6kHz R 8k A PWM LT8UF LED + D D DIMMING TO.6 SLOW MOD LTC699- SLOW PWM CONTROLS TO 6 Cd/m BRIGHTNESS LUMILEDS LXHL-BW R M C.µF R k % N = 96 f = Hz R 68k 699 TA 9
+ + LTC699-/LTC699-/ typical applications Isolated PWM (% to 9%) Controller khz SOURCE PWM R k R k.µf LT.µF + R k C µf R k LT66 R 99k MOD LTC699- khz INTERMEDIATE PWM R9 ISOLATION k BARRIER T L L.µF CONCEPT DESIGN USING SIMPLE R-C FILTERING FOR PWM CONTROL. NOT OPTIMIZED FOR OFFS. R k C µf R6.99k R6 k R7 k R8 k ISO.µF R7 k LT R8 k C pf + R k R k LT66 C.µF R 787k MOD LTC699- ISO.µF khz ISOLATED PWM ISOPWM R M R 8k 699 TA ISO.µF T: PCA EPF89S ETHERNET TRANSFORMER
Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. DCB Package 6-Lead Plastic DFN (mm mm) (Reference LTC DWG # -8-7 Rev A) LTC699-/LTC699-/.7 ±..6 ±.. ±. ( SIDES). ±. PACKAGE LINE. ±.. BSC. ±. ( SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS. ±. ( SIDES) R =. TYP R =. TYP 6. ±.. ±. ( SIDES).6 ±. ( SIDES) PIN BAR TOP MARK (SEE NOTE 6). REF.7 ±... PIN NOTCH R. OR. CHAMFER (DCB6) DFN. ±.. BSC. ±. ( SIDES) BOTTOM IEW EXPOSED PAD NOTE:. DRAWING TO BE MADE A JEDEC PACKAGE LINE M-9 ARIATION OF (TBD). DRAWING NOT TO SCALE. ALL DIMENSIONS ARE IN MILLIMETERS. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED.mm ON ANY SIDE. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN LOCATION ON THE TOP AND BOTTOM OF PACKAGE
LTC699-/LTC699-/ Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. S6 Package 6-Lead Plastic TSOT- (Reference LTC DWG # -8-66 Rev B).6 MAX.9 REF.9 BSC (NOTE ). REF.8 MAX.6 REF. MIN.8 BSC..7 (NOTE ) PIN ONE ID RECOMMENDED SOLDER PAD LAY PER IPC CALCULATOR.9 BSC.. 6 PLCS (NOTE ).8.9. BSC DATUM A. MAX.... REF.9. (NOTE ) NOTE:. DIMENSIONS ARE IN MILLIMETERS. DRAWING NOT TO SCALE. DIMENSIONS ARE INCLUSIE OF PLATING. DIMENSIONS ARE EXCLUSIE OF MOLD FLASH AND METAL BURR. MOLD FLASH SHALL NOT EXCEED.mm 6. JEDEC PACKAGE REFERENCE IS MO-9.9 BSC S6 TSOT- RE B
LTC699-/LTC699-/ Revision History RE DATE DESCRIPTION PAGE NUMBER A / Revised θ JA value for TSOT package in the Pin Configuration. Added Note 7 for OH and OL in the Electrical Characteristics table. Minor edit to the Block Diagram. Minor edit to the equation in the Duty Cycle Sensitivity to section. Revised Typical Applications drawings. 9 B 7/ Revised Description and Order Information sections Added additional information to f / and included Note in Electrical Characteristics section Added Typical Frequency Error vs Time curve to Typical Performance Characteristics section Added text to Basic Operation paragraph in Applications Information section Corrected f value in Typical Applications drawing 669 TA to, 9 9 C / Added MP-Grade,,, Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
LTC699-/LTC699-/ Typical Application PWM Controller for LED Driver ANALOG PWM DUTY CYCLE MOD CONTROL ( TO ) LTC699- IN 8 TO 6.µF M C.µF PWM TGEN REF CTRL SYNC L 6.8µH SHDN IN SW FB LT7 ISP ISN TG D R.9M R k ma R SENSE mω C.7µF C.µF k 68k C.µF C R T 6.k MHz R T C.µF SS 699 TA C: KEMET C86CKRAC C: KEMET C6C7KRAC C, C: MURATA GRMBR7HKAB C: MURATA GRMBR7HKAB D: DIODE DFLS6 L: TOKO B99AS-6R8N LEDS: LUXEON I (WHITE) M: ZETEX ZXMP6AFTA Related Parts PART NUMBER DESCRIPTION COMMENTS LTC799 MHz to MHz ThinSOT Silicon Oscillator Wide Frequency Range LTC69 MHz to MHz ThinSOT Silicon Oscillator Low Power, Wide Frequency Range LTC696/LTC697 khz to MHz or khz ThinSOT Silicon Oscillator Micropower, I SUPPLY = µa at khz LTC69 Fixed Frequency Oscillator,.768kHz to 8.9MHz.9% Accuracy, µs Start-Up Time, µa at khz LTC699 TimerBlox, oltage Controlled Oscillator Frequency from 88Hz to MHz, No Caps,.% Accurate LTC699 TimerBlox, ery Low Frequency Clock with Reset Cycle Time from ms to 9. Hours, No Caps,.% Accurate LTC699 TimerBlox, Monostable Pulse Generator Resistor Set Pulse Width from µs to sec, No Caps, % Accurate LTC699 TimerBlox, Delay Block/Debouncer Resistor Set Delay from µs to sec, No Caps Required, % Accurate LT RE C PRINTED IN USA Linear Technology Corporation 6 McCarthy Blvd., Milpitas, CA 9-77 (8) -9 FAX: (8) -7 www.linear.com LINEAR TECHNOLOGY CORPORATION