LT1121/LT /LT Micropower Low Dropout Regulators with Shutdown FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION

Transcription

1 Micropower Low Dropout Reguators with Shutdown FEATURES n. Dropout otage n 1mA Output Current n µa Quiescent Current n No Protection Diodes Needed n Adjustabe Output from.7 to n. and Fixed Output otages n Controed Quiescent Current in Dropout n Shutdown n 16µA Quiescent Current in Shutdown n Stabe with.µf Output Capacitor n Reverse Battery Protection n No Reverse Current with Input Low n Therma Limiting n Avaiabe in the 8-Lead SO, 8-Lead PDIP, -Lead SOT- and -Lead TO-9 Packages APPLICATIONS n Low Current Reguator n Reguator for Battery-Powered Systems n Post Reguator for Switching Suppies DESCRIPTION The LT 111/LT111-./LT111- are micropower ow dropout reguators with shutdown. These devices are capabe of suppying 1mA of output current with a dropout votage of.. Designed for use in battery-powered systems, the ow quiescent current, µa operating and 16µA in shutdown, makes them an idea choice. The quiescent current is we-controed; it does not rise in dropout as it does with many other ow dropout PNP reguators. Other features of the LT111/LT111-./LT111- incude the abiity to operate with very sma output capacitors. They are stabe with ony.µf on the output whie most oder devices require between 1µF and 1µF for stabiity. Sma ceramic capacitors can be used, enhancing manufacturabiity. Aso the input may be connected to ground or a reverse votage without reverse current fow from output to input. This makes the LT111 series idea for backup power situations where the output is hed high and the input is at ground or reversed. Under these conditions ony 16µA wi fow from the output pin to ground. L, LT, LTC, LTM, Linear Technoogy and the Linear ogo are registered trademarks of Linear Technoogy Corporation. A other trademarks are the property of their respective owners. TYPICAL APPLICATION Battery-Powered Suppy with Shutdown Dropout otage. 8 IN LT111-. SHDN GND OUT 1 +. OUT 1mA 1μF SOLID TANTALUM DROPOUT OLTAGE ()... SHDN (PIN ) <. >.8 NC OUTPUT OFF ON ON LT111 TA OUTPUT CURRENT (ma) LT111 TA 1

2 ABSOLUTE MAXIMUM RATINGS (Note 1) Input otage LT ± LT111H... +6, Output Pin Reverse Current... 1mA Adjust Pin Current... 1mA Shutdown Pin Input otage (Note )... 6.,.6 Shutdown Pin Input Current (Note )... ma Output Short-Circuit Duration... Indefinite Operating Junction Temperature Range (Note ) LT111C-X... C to 1 C LT111I-X... C to 1 C Storage Temperature Range... 6 C to 1 C Lead Temperature (Sodering, 1 sec)... C PIN CONFIGURATION OUT NC/ADJ* GND NC 1 TOP IEW N8 PACKAGE 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO T JMAX = 1 C, θ JA = 1 C/W (N8, S8) T JMAX = 1 C, θ JA = 7 C/W (AS8) IN NC** NC** SHDN * PIN = NC FOR LT111-./LT111- = ADJ FOR LT111 ** PINS 6 AND 7 ARE FLOATING (NO INTERNAL CONNECTION) ON THE STANDARD S8 PACKAGE. PINS 6 AND 7 CONNECTED TO GROUND ON THE A ERSION OF THE LT111 (S8 ONLY). CONNECTING PINS 6 AND 7 TO THE GROUND PLANE WILL REDUCE THERMAL RESISTANCE. SEE THERMAL RESISTANCE TABLES IN THE APPLICATIONS INFORMATION SECTION. TAB IS GND FRONT IEW OUTPUT GND 1 IN ST PACKAGE -LEAD PLASTIC SOT- T JMAX = 1 C, θ JA = C/W BOTTOM IEW IN GND OUT Z PACKAGE -LEAD PLASTIC TO-9 T JMAX = 1 C, θ JA = 1 C/W ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT111CN8#PBF LT111CN8#TRPBF LT111CN8 8-Lead Pastic PDIP C to 1 C LT111CN8-.#PBF LT111CN8-.#TRPBF LT111CN8-. 8-Lead Pastic PDIP C to 1 C LT111CN8-#PBF LT111CN8-#TRPBF LT111CN8-8-Lead Pastic PDIP C to 1 C LT111IN8#PBF LT111IN8#TRPBF LT111IN8 8-Lead Pastic PDIP C to 1 C LT111IN8-.#PBF LT111IN8-.#TRPBF LT111IN8-. 8-Lead Pastic PDIP C to 1 C LT111IN8-#PBF LT111IN8-#TRPBF LT111IN8-8-Lead Pastic PDIP C to 1 C LT111CS8#PBF LT111CS8#TRPBF Lead Pastic S C to 1 C LT111CS8-.#PBF LT111CS8-.#TRPBF Lead Pastic S C to 1 C LT111CS8-#PBF LT111CS8-#TRPBF Lead Pastic S C to 1 C LT111HCS8#PBF LT111HCS8#TRPBF 111H 8-Lead Pastic S C to 1 C LT111IS8#PBF LT111IS8#TRPBF 111I 8-Lead Pastic S C to 1 C LT111IS8-.#PBF LT111IS8-.#TRPBF 11I 8-Lead Pastic S C to 1 C LT111IS8-#PBF LT111IS8-#TRPBF 11I 8-Lead Pastic S C to 1 C LT111HIS8#PBF LT111HIS8#TRPBF 11HI 8-Lead Pastic S C to 1 C LT111ACS8#PBF LT111ACS8#TRPBF 111A 8-Lead Pastic S C to 1 C LT111ACS8-.#PBF LT111ACS8-.#TRPBF 111A 8-Lead Pastic S C to 1 C LT111ACS8-#PBF LT111ACS8-#TRPBF 111A 8-Lead Pastic S C to 1 C

3 ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LT111AHCS8#PBF LT111AHCS8#TRPBF 11AH 8-Lead Pastic S C to 1 C LT111AIS8#PBF LT111AIS8#TRPBF 11AI 8-Lead Pastic S C to 1 C LT111AIS8-.#PBF LT111AIS8-.#TRPBF 11AI 8-Lead Pastic S C to 1 C LT111AIS8-#PBF LT111AIS8-#TRPBF 11AI 8-Lead Pastic S C to 1 C LT111AHIS8#PBF LT111AHIS8#TRPBF 1AHI 8-Lead Pastic S C to 1 C LT111CST-.#PBF LT111CST-.#TRPBF 111 -Lead Pastic SOT- C to 1 C LT111IST-.#PBF LT111IST-.#TRPBF 11I -Lead Pastic SOT- C to 1 C LT111CST-#PBF LT111CST-#TRPBF 111 -Lead Pastic SOT- C to 1 C LT111IST-#PBF LT111IST-#TRPBF 111I -Lead Pastic SOT- C to 1 C LT111CZ-#PBF LT111CZ-#TRPBF LT111CZ- -Lead Pastic TO-9 C to 1 C LT111IZ-#PBF LT111IZ-#TRPBF LT111IZ- -Lead Pastic TO-9 C to 1 C LT111CZ-#PBF LT111CZ-#TRPBF LT111CZ- -Lead Pastic TO-9 C to 1 C LT111IZ-#PBF LT111IZ-#TRPBF LT111IZ- -Lead Pastic TO-9 C to 1 C Consut LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a abe on the shipping container. Consut LTC Marketing for information on nonstandard ead based finish parts. For more information on ead free part marking, go to: For more information on tape and ree specifications, go to: ELECTRICAL CHARACTERISTICS The denotes the specifications which appy over the fu operating temperature range, otherwise specifications are at T A = C. PARAMETER CONDITIONS MIN TYP MAX UNITS Reguated Output otage (Note ) LT111-. IN =.8, I OUT = 1mA, T J = ºC. < IN <, 1mA < I OUT < 1mA LT111- IN =., I OUT = 1mA, T J = ºC 6 < IN <, 1mA < I OUT < 1mA LT111 (Note ) IN =., I OUT = 1mA, T J = ºC.8 < IN <, 1mA < I OUT < 1mA Line Reguation LT111-. Δ IN =.8 TO, I OUT = 1mA LT111- Δ IN =. TO, I OUT = 1mA LT111 (Note ) Δ IN =. TO, I OUT = 1mA Load Reguation LT111-. ΔI LOAD = 1mA to 1mA, T J = ºC ΔI LOAD = 1mA to 1mA LT111- ΔI LOAD = 1mA to 1mA, T J = ºC ΔI LOAD = 1mA to 1mA LT111 (Note ) ΔI LOAD = 1mA to 1mA, T J = ºC ΔI LOAD = 1mA to 1mA Dropout otage (Note 6) I LOAD = 1mA, T J = ºC I LOAD = 1mA I LOAD = ma, T J = ºC I LOAD = ma I LOAD = 1mA, T J = ºC I LOAD = 1mA I LOAD = 1mA, T J = ºC I LOAD = 1mA m m m m m m m m m

4 ELECTRICAL CHARACTERISTICS The denotes the specifications which appy over the fu operating temperature range, otherwise specifications are at T A = C. PARAMETER CONDITIONS MIN TYP MAX UNITS Ground Pin Current (Note 7) I LOAD = ma I LOAD = 1mA I LOAD = 1mA I LOAD = ma I LOAD = 1mA I LOAD = 1mA µa µa µa ma ma ma Adjust Pin Bias Current (Notes, 8) T J = ºC 1 na Shutdown Threshod OUT = Off to On OUT = On to Off Shutdown Pin Current (Note 9) SHDN = 6 1 µa Quiescent Current in Shutdown (Note 1) IN = 6, SHDN = 16 µa Rippe Rejection IN OUT = 1 (Avg), RIPPLE =. P-P, f RIPPLE = 1Hz, 8 db I LOAD =.1A Current Limit IN OUT = 7, T J = ºC ma Input Reverse Leakage Current IN =, OUT = 1 ma Reverse Output Current (Note 11) LT111-. OUT =., IN = 16 µa LT111- OUT =, IN = 16 µa LT111 (Note ) OUT =.8, IN = 16 µa Note 1: Stresses beyond those isted under Absoute Maximum Ratings may cause permanent damage to the device. Exposure to any Absoute Maximum Rating condition for extended periods may affect device reiabiity and ifetime. Note : The shutdown pin input votage rating is required for a ow impedance source. Interna protection devices connected to the shutdown pin wi turn on and camp the pin to approximatey 7 or.6. This range aows the use of ogic devices to drive the pin directy. For high impedance sources or ogic running on suppy votages greater than., the maximum current driven into the shutdown pin must be imited to ess than ma. Note : For junction temperatures greater than 11 C, a minimum oad of 1mA is recommended. For T J > 11 C and I OUT < 1mA, output votage may increase by 1%. Note : Operating conditions are imited by maximum junction temperature. The reguated output votage specification wi not appy for a possibe combinations of input votage and output current. When operating at maximum input votage, the output current range must be imited. When operating at maximum output current the input votage range must be imited. Note : The LT111 (adjustabe version) is tested and specified with the adjust pin connected to the output pin. Note 6: Dropout votage is the minimum input/output votage required to maintain reguation at the specified output current. In dropout the output votage wi be equa to: ( IN DROPOUT ). Note 7: Ground pin current is tested with IN = OUT (nomina) and a current source oad. This means that the device is tested whie operating in its dropout region. This is the worst case ground pin current. The ground pin current wi decrease sighty at higher input votages. Note 8: Adjust pin bias current fows into the adjust pin. Note 9: Shutdown pin current at SHDN = fows out of the shutdown pin. Note 1: Quiescent current in shutdown is equa to the sum tota of the shutdown pin current (6µA) and the ground pin current (9µA). Note 11: Reverse output current is tested with the input pin grounded and the output pin forced to the rated output votage. This current fows into the output pin and out of the ground pin.

5 TYPICAL PERFORMANCE CHARACTERISTICS LT111/LT111-./LT111- DROPOUT OLTAGE () Guaranteed Dropout otage Dropout otage Quiescent Current T J 1 C T J C.1 = TEST POINTS OUTPUT CURRENT (ma) DROPOUT OLTAGE () I LOAD = 1mA I LOAD = 1mA I LOAD = ma I LOAD = 1mA QUIESCENT CURRENT (μa) 1 IN = 6 R LOAD = SHDN = OPEN SHDN = G1 111 G 111 G QUIESCENT CURRENT (μa) LT111-. Quiescent Current SHDN = OPEN SHDN = R LOAD = QUIESCENT CURRENT (μa) LT111- Quiescent Current SHDN = OPEN R LOAD = SHDN = QUIESCENT CURRENT (μa) LT111 Quiescent Current SHDN = OPEN SHDN = R LOAD = OUT = ADJ INPUT OLTAGE () INPUT OLTAGE () INPUT OLTAGE () 111 G 111 G 111 G6.8.6 LT111-. Output otage I OUT = 1mA.8.6 LT111- Output otage I OUT = 1mA.8.81 LT111 Adjust Pin otage I OUT = 1mA OUTPUT OLTAGE () OUTPUT OLTAGE () ADJ PIN OLTAGE () G7 111 G8 111 G9

6 TYPICAL PERFORMANCE CHARACTERISTICS GROUND PIN CURRENT (μa) LT111-. Ground Pin Current *FOR OUT =. R LOAD = 1Ω I LOAD = ma* R LOAD = Ω I LOAD = 1mA* R LOAD =.k I LOAD = 1mA* GROUND PIN CURRENT (μa) LT111- Ground Pin Current R LOAD = Ω I LOAD = ma* R LOAD = Ω I LOAD = 1mA* *FOR OUT = R LOAD = k I LOAD = 1mA* GROUND PIN CURRENT (μa) LT111 Ground Pin Current OUT = ADJ R LOAD = 1Ω I LOAD = ma* R LOAD = 8Ω I LOAD = 1mA* *FOR OUT =.7 R LOAD =.8k I LOAD = 1mA* INPUT OLTAGE () INPUT OLTAGE () INPUT OLTAGE () 111 G1 111 G G1 LT111-. Ground Pin Current LT111- Ground Pin Current 1 9 LT111 Ground Pin Current OUT = ADJ GROUND PIN CURRENT (ma) R LOAD = Ω I LOAD = 1mA* R LOAD = Ω I LOAD = 1mA* R LOAD = 66Ω I LOAD = ma* *FOR OUT = INPUT OLTAGE () GROUND PIN CURRENT (ma) *FOR OUT = R LOAD = Ω I LOAD = 1mA* R LOAD = Ω I LOAD = 1mA* R LOAD = 1Ω I LOAD = ma* INPUT OLTAGE () GROUND PIN CURRENT (ma) R LOAD = Ω I LOAD = 1mA* R LOAD = 8Ω I LOAD = 1mA* R LOAD = 7Ω I LOAD = ma* *FOR OUT = INPUT OLTAGE () 111 G1 111 G1 111 G1 GROUND PIN CURRENT (ma) 6 Ground Pin Current 1 IN =. (LT111-.) IN = (LT111-) 1 IN =.7 (LT111) DEICE IS OPERATING 1 IN DROPOUT T 8 J = 1 C T J = C SHUTDOWN THRESHOLD () Shutdown Pin Threshod (On-to-Off). I LOAD = 1mA SHUTDOWN THRESHOLD () Shutdown Pin Threshod (Off-to-On) I LOAD = 1mA I LOAD = 1mA OUTPUT CURRENT (ma) G G G18 6

7 TYPICAL PERFORMANCE CHARACTERISTICS LT111/LT111-./LT111- SHUTDOWN PIN CURRENT (μa) Shutdown Pin Current 1 SHDN = SHUTDOWN PIN INPUT CURRENT (ma) 1 1 Shutdown Pin Input Current ADJUST PIN BIAS CURRENT (na) 1 1 LT111 Adjust Pin Bias Current SHUTDOWN PIN OLTAGE () G G 111 G1 OUTPUT PIN CURRENT (μa) 1 1 Reverse Output Current Current Limit Current Limit IN = OUT = (LT111-) OUT =. (LT111-.) OUT =.8 (LT111) SHORT-CIRCUIT CURRENT (ma) 1 1 OUT = CURRENT LIMIT (ma) 1 1 IN = 7 OUT = INPUT OLTAGE () G 111 G 111 G OUTPUT PIN CURRENT (μa) Reverse Output Current Rippe Rejection Rippe Rejection IN = CURRENT FLOWS INTO OUTPUT PIN LT111 ( OUT = ADJ ) LT111-. LT OUTPUT OLTAGE () 111 G RIPPLE REJECTION (db) IN = OUT (NOMINAL) P-P RIPPLE AT f = 1Hz I OUT = 1mA G6 RIPPLE REJECTION (db) 1 I OUT = 1mA 9 IN = 6 + m RMS RIPPLE 8 7 C OUT = 7μF SOLID TANTALUM 6 C OUT = 1μF SOLID TANTALUM k 1k 1k 1M FREQUENCY (Hz) 111 G7 7

8 TYPICAL PERFORMANCE CHARACTERISTICS LOAD REGULATION (m) 1 1 Load Reguation ΔI LOAD = 1mA TO 1mA * ADJ PIN TIED TO OUTPUT PIN LT111* LT111-. LT OUTPUT OLTAGE DEIATION () LOAD CURRENT (ma) LT111- Load Transient Response IN = 6 C IN =.1μF C OUT = 1μF TIME (ms) OUTPUT OLTAGE DEIATION () LOAD CURRENT (ma) LT111- Load Transient Response IN = 6 C IN =.1μF C OUT =.μf TIME (ms) 111 G8 111 G9 111 G PIN FUNCTIONS Input Pin: Power is suppied to the device through the input pin. The input pin shoud be bypassed to ground if the device is more than six inches away from the main input fiter capacitor. In genera the output impedance of a battery rises with frequency so it is usuay adviseabe to incude a bypass capacitor in battery-powered circuits. A bypass capacitor in the range of.1µf to 1µF is sufficient. The LT111 is designed to withstand reverse votages on the input pin with respect to both ground and the output pin. In the case of a reversed input, which can happen if a battery is pugged in backwards, the LT111 wi act as if there is a diode in series with its input. There wi be no reverse current fow into the LT111 and no reverse votage wi appear at the oad. The device wi protect both itsef and the oad. Output Pin: The output pin suppies power to the oad. An output capacitor is required to prevent osciations. See the Appications Information section for recommended vaue of output capacitance and information on reverse output characteristics. Shutdown Pin: This pin is used to put the device into shutdown. In shutdown the output of the device is turned off. This pin is active ow. The device wi be shut down if the shutdown pin is pued ow. The shutdown pin current with the pin pued to ground wi be 6µA. The shutdown pin is internay camped to 7 and.6 (one BE ). This aows the shutdown pin to be driven directy by ogic or by open coector ogic with a pu-up resistor. The pu-up resistor is ony required to suppy the eakage current of the open coector gate, normay severa microamperes. Pu-up current must be imited to a maximum of ma. A curve of shutdown pin input current as a function of votage appears in the Typica Performance Characteristics. If the shutdown pin is not used it can be eft open circuit. The device wi be active, output on, if the shutdown pin is not connected. Adjust Pin: For the adjustabe LT111, the adjust pin is the input to the error ampifier. This pin is internay camped to 6 and.6 (one BE ). It has a bias current of 1nA which fows into the pin. See Bias Current curve in the Typica Performance Characteristics. The adjust pin reference votage is.7 referenced to ground. The output votage range that can be produced by this device is.7 to. 8

9 APPLICATIONS INFORMATION The LT111 is a micropower ow dropout reguator with shutdown, capabe of suppying up to 1mA of output current at a dropout votage of.. The device operates with very ow quiescent current (µa). In shutdown the quiescent current drops to ony 16µA. In addition to the ow quiescent current the LT111 incorporates severa protection features which make it idea for use in batterypowered systems. The device is protected against both reverse input votages and reverse output votages. In battery backup appications where the output can be hed up by a backup battery when the input is pued to ground, the LT111 acts ike it has a diode in series with its output and prevents reverse current fow. Adjustabe Operation The adjustabe version of the LT111 has an output votage range of.7 to. The output votage is set by the ratio of two externa resistors as shown in Figure 1. The device servos the output votage to maintain the votage at the adjust pin at.7. The current in R1 is then equa to.7/r1. The current in R is equa to the sum of the current in R1 and the adjust pin bias current. The adjust pin bias current, 1nA at C, fows through R into the adjust pin. The output votage can be cacuated according to the formua in Figure 1. The vaue of R1 shoud be ess than k to minimize errors in the output votage caused by the adjust pin bias current. Note that in shutdown the output is turned off and the divider current wi be zero. Curves of Adjust Pin otage vs Temperature and Adjust Pin Bias Current vs Temperature appear in the Typica Performance Characteristics. The reference votage at the adjust pin has a sight positive temperature coefficient of IN SHDN OUT LT111 GND ADJ ( ) ( ) OUT = R + I ADJ R R1 ADJ =.7 I ADJ = 1nA AT C OUTPUT RANGE =.7 TO R R F1 Figure 1. Adjustabe Operation OUT LT111/LT111-./LT111- approximatey 1ppm/ C. The adjust pin bias current has a negative temperature coefficient. These effects are sma and wi tend to cance each other. The adjustabe device is specified with the adjust pin tied to the output pin. This sets the output votage to.7. Specifications for output votage greater than.7 wi be proportiona to the ratio of the desired output votage to.7 ( OUT /.7). For exampe: oad reguation for an output current change of 1mA to 1mA is 1m typica at OUT =.7. At OUT = 1, oad reguation woud be: 1.7 ( 1m )= ( 8m ) Therma Considerations Power handing capabiity wi be imited by maximum rated junction temperature (1 C). Power dissipated by the device wi be made up of two components: 1. Output current mutipied by the input/output votage differentia: I OUT ( IN OUT ), and. Ground pin current mutipied by the input votage: I GND IN. The ground pin current can be found by examining the Ground Pin Current curves in the Typica Performance Characteristics. Power dissipation wi be equa to the sum of the two components isted above. The LT111 series reguators have interna therma imiting designed to protect the device during overoad conditions. For continuous norma oad conditions the maximum junction temperature rating of 1 C must not be exceeded. It is important to give carefu consideration to a sources of therma resistance from junction to ambient. Additiona heat sources mounted nearby must aso be considered. Heat sinking, for surface mount devices, is accompished by using the heat spreading capabiities of the PC board and its copper traces. Copper board stiffeners and pated through hoes can aso be used to spread the heat generated by power devices. Tabes 1 through ist therma resistances for each package. Measured vaues of therma resistance for severa different board sizes and copper areas are isted for each package. A measurements were taken in sti air, on /" FR- board with 1oz copper. A 9

10 APPLICATIONS INFORMATION NC eads were connected to the ground pane. Tabe 1. N8 Package* 1 COPPER AREA TOPSIDE BACKSIDE BOARD AREA THERMAL RESISTANCE JUNCTION TO AMBIENT sq mm sq mm sq mm 8ºC/W 1 sq mm sq mm sq mm 8ºC/W sq mm sq mm sq mm 8ºC/W 1 sq mm 1 sq mm 1 sq mm 91ºC/W * Device is mounted on topside. Leads are through hoe and are sodered to both sides of board. Tabe. S8 Package COPPER AREA THERMAL RESISTANCE TOPSIDE* BACKSIDE BOARD AREA JUNCTION TO AMBIENT sq mm sq mm sq mm 1ºC/W 1 sq mm sq mm sq mm 1ºC/W sq mm sq mm sq mm 1ºC/W 1 sq mm 1 sq mm 1 sq mm 11ºC/W * Device is mounted on topside. Tabe. AS8 Package* COPPER AREA THERMAL RESISTANCE TOPSIDE** BACKSIDE BOARD AREA JUNCTION TO AMBIENT sq mm sq mm sq mm 6ºC/W 1 sq mm sq mm sq mm 6ºC/W sq mm sq mm sq mm 68ºC/W 1 sq mm sq mm sq mm 7ºC/W * Pins, 6 and 7 are ground. ** Device is mounted on topside. Tabe. SOT- Package (Therma Resistance Junction-to-Tab ºC/W) COPPER AREA THERMAL RESISTANCE TOPSIDE* BACKSIDE BOARD AREA JUNCTION TO AMBIENT sq mm sq mm sq mm ºC/W 1 sq mm sq mm sq mm ºC/W sq mm sq mm sq mm 8ºC/W 1 sq mm sq mm sq mm 6ºC/W 1 sq mm sq mm 1 sq mm 7ºC/W 1 sq mm 1 sq mm 6ºC/W * Tab of device attached to topside copper. Tabe. TO-9 Package THERMAL RESISTANCE Package aone Package sodered into PC board with pated through hoes ony Package sodered into PC board with 1/ sq. inch of copper trace per ead Package sodered into PC board with pated through hoes in board, no extra copper trace, and a cip-on type heat sink: Thermaoy type B Aavid type 7 Cacuating Junction Temperature ºC/W 17ºC/W 1ºC/W 16ºC/W 1ºC/W Exampe: given an output votage of., an input votage range of. to 7, an output current range of ma to 1mA, and a maximum ambient temperature of C, what wi the maximum junction temperature be? Power dissipated by the device wi be equa to: I OUT MAX ( IN MAX OUT ) + (I GND IN ) where, I OUT MAX = 1mA IN MAX = 7 I GND at (I OUT = 1mA, IN = 7) = ma so, P = 1mA (7.) + (ma 7) =.W If we use an SOT- package, then the therma resistance wi be in the range of C/W to 6 C/W depending on copper area. So the junction temperature rise above ambient wi be ess than or equa to:.w 6 C/W = C The maximum junction temperature wi then be equa to the maximum junction temperature rise above ambient pus the maximum ambient temperature or: T JMAX = C + C = 7 C Output Capacitance and Transient Performance The LT111 is designed to be stabe with a wide range of output capacitors. The minimum recommended vaue is 1µF with an ESR of Ω or ess. For appications where space is very imited, capacitors as ow as.µf can be used if combined with a sma series resistor. Assuming that the ESR of the capacitor is ow (ceramic) the suggested series

11 APPLICATIONS INFORMATION resistor is shown in Tabe 6. The LT111 is a micropower device and output transient response wi be a function of output capacitance. See the Transient Response curves in the Typica Performance Characteristics. Larger vaues of output capacitance wi decrease the peak deviations and provide improved output transient response. Bypass capacitors, used to decoupe individua components powered by the LT111, wi increase the effective vaue of the output capacitor. Tabe 6. Suggested Series Resistor aues OUTPUT CAPACITANCE SUGGESTED SERIES RESISTOR.µF Ω.7µF 1Ω.68µF 1Ω >1µF None Needed Protection Features The LT111 incorporates severa protection features which make it idea for use in battery-powered circuits. In addition to the norma protection features associated with monoithic reguators, such as current imiting and therma imiting, the device is protected against reverse input votages, reverse output votages, and reverse votages from output to input. Current imit protection and therma overoad protection are intended to protect the device against current overoad conditions at the output of the device. For norma operation, the junction temperature shoud not exceed 1 C. The input of the device wi withstand reverse votages of. Current fow into the device wi be imited to ess than 1mA (typicay ess than 1µA) and no negative votage wi appear at the output. The device wi protect both itsef and the oad. This provides protection against batteries that can be pugged in backwards. For fixed votage versions of the device, the output can be pued beow ground without damaging the device. If the input is open circuit or grounded the output can be pued beow ground by. The output wi act ike an open circuit, no current wi fow out of the pin. If the input is powered by a votage source, the output wi source the short-circuit current of the device and wi protect itsef by therma imiting. For the adjustabe version of the device, the output pin is internay camped at one diode drop beow ground. Reverse current for the adjustabe device must be imited to ma. In circuits where a backup battery is required, severa different input/output conditions can occur. The output votage may be hed up whie the input is either pued to ground, pued to some intermediate votage, or is eft open circuit. Current fow back into the output wi vary depending on the conditions. Many battery-powered circuits incorporate some form of power management. The foowing information wi hep optimize battery ife. Tabe 7 summarizes the foowing information. The reverse output current wi foow the curve in Figure when the input pin is pued to ground. This current fows through the output pin to ground. The state of the shutdown pin wi have no effect on output current when the input pin is pued to ground. In some appications it may be necessary to eave the input to the LT111 unconnected when the output is hed high. This can happen when the LT111 is powered from a rectified AC source. If the AC source is removed, then the input of the LT111 is effectivey eft foating. The reverse output current aso foows the curve in Figure if the input pin is eft open. The state of the shutdown pin wi have no effect on the reverse output current when the input pin is foating. OUTPUT PIN CURRENT (μa) IN < OUT CURRENT FLOWS INTO OUTPUT PIN TO GROUND LT111 ( OUT = ADJ ) LT111-. LT OUTPUT OLTAGE () 111 F Figure. Reverse Output Current 11

12 APPLICATIONS INFORMATION When the input of the LT111 is forced to a votage beow its nomina output votage and its output is hed high, the reverse output current wi sti foow the curve in Figure. This condition can occur if the input of the LT111 is connected to a discharged (ow votage) battery and the output is hed up by either a backup battery or by a second reguator circuit. When the input pin is forced beow the output pin or the output pin is pued above the input pin, the input current wi typicay drop to ess than µa (see Figure ). The state of the shutdown pin wi have no effect on the reverse output current when the output is pued above the input. INPUT CURRENT (μa) 1 OUT =. (LT111-.) OUT = (LT111-) 1 INPUT OLTAGE () Figure. Input Current 111 F Tabe 7. Faut Conditions INPUT PIN SHDN PIN OUTPUT PIN < OUT (Nomina) Open (Hi) Forced to OUT (Nomina) Reverse Output Current 1µA (See Figure ) Input Current 1µA (See Figure ) < OUT (Nomina) Grounded Forced to OUT (Nomina) Reverse Output Current 1µA (See Figure ) Input Current 1µA (See Figure ) Open Open (Hi) Forced to OUT (Nomina) Reverse Output Current 1µA (See Figure ) Open Grounded Forced to OUT (Nomina) Reverse Output Current 1µA (See Figure ).8 Open (Hi) Output Current =.8 Grounded Output Current = >1. Open (Hi) Output Current = Short-Circuit Current < IN < Grounded Output Current = 1

13 PACKAGE DESCRIPTION Pease refer to for the most recent package drawings. N Package 8-Lead PDIP (Narrow. Inch) (Reference LTC DWG # Rev I) LT111/LT111-./LT (7.6 8.)..6 ( ).1 ±. (. ±.17).* (1.16) MAX (..81) ( ).6 (1.61) TYP.1 (.) BSC NOTE: INCHES 1. DIMENSIONS ARE MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED.1 INCH (.mm).1 (.8) MIN.18 ±. (.7 ±.76). (.8) MIN N8 RE I 711. ±.1* (6.77 ±.81) 1 S8 Package 8-Lead Pastic Sma Outine (Narrow.1 Inch) (Reference LTC DWG # Rev G). BSC. ± (.81.) NOTE MIN.16 ±..8. ( ).1.17 ( ) NOTE. ±. TYP RECOMMENDED SOLDER PAD LAYOUT (..).1. (..8) 8 TYP..69 ( )..1 (.11.).16. (.6 1.7) NOTE: INCHES 1. DIMENSIONS IN (MILLIMETERS).1.19 (..8) TYP. DRAWING NOT TO SCALE. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED.6" (.1mm). PIN 1 CAN BE BEEL EDGE OR A DIMPLE. (1.7) BSC SO8 RE G 1 1

14 PACKAGE DESCRIPTION Pease refer to for the most recent package drawings. ST Package -Lead Pastic SOT- (Reference LTC DWG # -8-16).8.6 ( ).11.1 (.9.1).9 MAX.19 MAX.6.87 (6.7 7.).1.16 (..71).9 MAX.8 BSC.9 MAX.9 (.) BSC..1 (.8 1.).181 MAX.9 BSC RECOMMENDED SOLDER PAD LAYOUT.71 (1.8) MAX 1 MAX (..6).. (.6.8).181 (.6) BSC.1 (.1) MIN.8. (..116) 1 16 ST (SOT-) Z Package -Lead Pastic TO-9 (Simiar to TO-6) (Reference LTC DWG # Rev C) 1.6 ±.1 (1. ±.).1 ±.1 (.6 ±.17).6 ±. (1.±.17) DIA.18 ±. (.7 ±.17).18 ±. (.7 ±.17).9 (.86) NOM 1 NOM. (1.7) MIN. UNCONTROLLED (1.7) LEAD DIMENSION MAX NOM. (1.7) BSC BULK PACK.16 ±. (.6 ±.76).1 ±. Z (TO-9) 18 RE C (.81 ±.1) /. (. +./.1) PLCS TO-9 TAPE AND REEL REFER TO TAPE AND REEL SECTION OF LTC DATA BOOK FOR ADDITIONAL INFORMATION 1

15 REISION HISTORY (Revision history begins at Rev G) RE DATE DESCRIPTION PAGE NUMBER G /1 Changed Order Information top marking for 8-ead SO. and options, C-grade Information furnished by Linear Technoogy Corporation is beieved to be accurate and reiabe. However, no responsibiity is assumed for its use. Linear Technoogy Corporation makes no representation that the interconnection of its circuits as described herein wi not infringe on existing patent rights. 1

16 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT11 1mA Low Dropout Reguator with µa I Q Incudes. Reference and Comparator LT119 7mA Micropower Low Dropout Reguator µa Quiescent Current LT117 ma Negative Low Dropout Micropower Reguator µa I Q,.6 Dropout otage, SOT- Package LT11 ma Low Dropout Micropower Reguator with Shutdown 1µA, I Q, Reverse Battery Protection LT19 A Low Dropout Reguator with µa I Q m Dropout otage LT1611 Inverting 1.MHz Switching Reguator to at 1mA, Low Output Noise, SOT- Package LT161 1.MHz Singe-Ce Micropower DC/DC Converter SOT- Package, Internay Compensated LT167 High Efficiency Synchronous Step-Down Switching Reguator Burst Mode Operation, Monoithic, 1% Duty Cyce LT168 Douber Charge Pump with Low Noise Linear Reguator Low Output Noise: 6µ RMS (1kHz BW) LT176 Series 1mA, Low Noise, LDO Micropower Reguator µa Quiescent Current, µ RMS Noise LT176 Series ma, Low Noise, LDO Micropower Reguator µa Quiescent Current, µ RMS Noise LT176 Series A Fast Transient Response LDO m Dropout, µ RMS Noise LT196 Series ma, Low Noise, LDO Micropower Reguator µa Quiescent Current, µ RMS Noise LT196 Series 1.A Fast Transient Response LDO m Dropout, µ RMS Noise Burst Mode is a trademark of Linear Technoogy Corporation. 16 LT 1 RE G PRINTED IN USA Linear Technoogy Corporation 16 McCarthy Bvd., Mipitas, CA (8) -19 FAX: (8) -7 LINEAR TECHNOLOGY CORPORATION 199