DESCRIPTIO APPLICATIO S TYPICAL APPLICATIO. LT5521 Very High Linearity Active Mixer FEATURES

Transcription

1 LT1 Very High Linearity Active Mixer FEATRES Wideband Output Frequency Range to.7ghz +.dbm at 1.9GHz RF Output Low LO Leakage: dbm Integrated LO Buffer: Low LO Drive Level Single-Ended LO Drive Wide Single Supply Range:.V to.v Double-Balanced Active Mixer Shutdown Function 1-Lead (mm mm) QFN Package APPLICATIO S Cellular, W-CDMA, P and MTS Infrastructure Cable Downlink Infrastructure Wireless Infrastructure Fixed Wireless Access Equipment High Linearity Mixer Applications DESCRIPTIO The LT 1 is a very high linearity mixer optimized for low distortion and low LO leakage applications. The chip includes a high speed LO buffer with single-ended input and a double-balanced active mixer. The LT1 requires only dbm LO input power to achieve excellent distortion and noise performance, while reducing external drive circuit requirements. The LO buffer is internally Ω matched for wideband operation. With a MHz input, a 1.7GHz LO and a 1.9GHz output frequency, the mixer has a typical of +.dbm,.db conversion gain and a 1.dB noise figure. The LT1 offers exceptional LO-RF isolation, greatly reducing the need for output filtering to meet LO suppression requirements. The device is designed to work over a supply voltage range from.v to.v., LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO IF INPT BPF 1pF 1:1 11Ω.pF 11Ω IN + IN BIAS LO INPT dbm LO.pF OT + OT EN V CC V CC V CC.7nH.7nH V DC 1µF 1 TA1 :1 pf pf BPF PA RF OTPT OTPT POWER (dbm) Fundamental, rd Order Intermodulation Distortion vs Input Power P FND IM f IF = MHz f LO = 1.7GHz f RF = 1.9GHz P LO = dbm T A = P IN (dbm) 1 TA 1f 1

2 LT1 ABSOLTE MAXIMM RATINGS W W W (Note 1) Power Supply Voltage....V Enable Voltage....V to V CC +.V LO Input Power... +1dBm LO Input DC Voltage... V to 1.V IF Input Power... +1dBm Difference Voltage Across Output Pins... ±1.V Maximum Pin or Pin Current... ma Operating Ambient Temperature Range.. C to Storage Temperature Range... C to 1 Maximum Junction Temperature... 1 PACKAGE/ORDER INFORMATION IN + IN 1 TOP VIEW LO EN VCC V CC VCC F PACKAGE 1-LEAD (mm mm) PLASTIC QFN T JMAX = 1, θ JA = 7 C/W EXPOSED PAD (PIN 17) IS MST BE SOLDERED TO PCB 9 OT + OT W ORDER PART NMBER LT1EF F PART MARKING 1 Consult LTC Marketing for parts specified with wider operating temperature ranges. DC ELECTRICAL CHARACTERISTICS Test circuit shown in Figure 1. (Note ) V CC = V, EN =.9V, T A = unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX NITS Supply Voltage.. V Supply Current 9 ma Shutdown Current EN =.V 1 µa Enable (EN) Low = Off, High = On Enable Mode EN = High.9 V Disable Mode EN = Low. V Enable Current EN = V 17 µa Shutdown Enable Current EN =.V.1 µa Turn-On Time (Note ) ns Turn-Off Time (Note ) ns LO Voltage (Pin ) Internally Biased.9 V Input Voltage (Pins, ) V CC = V, Internally Biased. V V CC =.V, Internally Biased. V AC ELECTRICAL CHARACTERISTICS Test circuit shown in Figure 1. (Note ) V CC = V, EN =.9V, T A = unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX NITS LO Frequency Range 1 to MHz Input Frequency Range 1 to MHz Output Frequency Range 1 to 7 MHz LO Input Power 1 dbm LO Return Loss Z O = Ω, f LO = 17MHz 1 db Output Return Loss Requires Matching 1 db Input Return Loss (Pins, ) Requires Matching db 1f

3 LT1 AC ELECTRICAL CHARACTERISTICS V CC = V, EN =.9V, f IF = MHz, P IF = 7dBm, f LO = 17MHz, P LO = dbm, f RF = MHz, T A =. Test circuit shown in Figure 1. PARAMETER CONDITIONS MIN TYP MAX NITS Conversion Gain. db Conversion Gain Variation vs Temperature.9 db/ C Input P1dB +1 dbm Single-Side Band Noise Figure 1. db Two Tones, f IF = MHz, P IF = 7dBm/Tone +. dbm IIP (Note ) Two Tones, f IF = MHz, P IF = 7dBm/Tone, +9 dbm f LO + f IF1 + f IF LO-RF Leakage dbm LO-IF Leakage dbm V CC = V, EN =.9V, f IF = MHz, P IF = 7dBm, f LO = 11MHz, P LO = dbm, f RF = MHz, T A =. PARAMETER CONDITIONS MIN TYP MAX NITS Conversion Gain. db Conversion Gain Variation vs Temperature.1 db/ C Input P1dB +1 dbm Single-Side Band Noise Figure 1. db Two Tones, f IF = MHz, P IF = 7dBm/Tone +. dbm IIP (Note ) Two Tones, f IF = MHz, P IF = 7dBm/Tone, +9 dbm f LO + f IF1 + f IF LO-RF Leakage dbm LO-IF Leakage 9 dbm V CC =.V, EN =.9V, f IF = MHz, P IF = 7dBm, f LO = 17MHz, P LO = dbm, f RF = MHz, T A =. (Note ) PARAMETER CONDITIONS MIN TYP MAX NITS Conversion Gain. db Conversion Gain Variation vs Temperature.1 db/ C Input P1dB +11 dbm Single-Side Band Noise Figure 1. db Two Tones, f IF = MHz, P IF = 7dBm/Tone +. dbm IIP (Note ) Two Tones, f IF = MHz, P IF = 7dBm/Tone, + dbm f LO + f IF1 + f IF LO-RF Leakage dbm LO-IF Leakage dbm Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note : Specifications over the to temperature range are assured by design, characterization and correlation with statistical process controls. Note : Interval from the rising edge of the Enable input to the time when the RF output is within 1dB of its steady-state output. Note : Interval from the falling edge of the Enable signal to a db drop in the RF output power. Note : R1 = R7 =.Ω, Z1 = Z7 = 1nH. Note : Second harmonic distortion measured at f LO + f IF1 + f IF. 1f

4 LT1 TYPICAL DC PERFOR A CE CHARACTERISTICS W Test circuit shown in Figure 1. 1 Supply Current vs Supply Voltage (V Application) 11 Supply Current vs Supply Voltage (.V Application) I CC (ma) ICC (ma) G1 1 G TYPICAL AC PERFOR A CE CHARACTERISTICS W f LO = 17MHz, f IF = MHz, f RF = MHz, P LO = dbm, V CC = V, EN =.9V, T A =, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.9GHz output frequency and V CC = V. Fundamental, nd and rd Order Intermodulation Distortion vs Input Power P FND Conversion Gain vs Input Power Conversion Gain and vs RF Frequency OTPT POWER (dbm) IM IM IM IM P IN (dbm) (db) P IN (dbm) GC (db) 17 1 RF OT (MHz) 1 (dbm) 1 G 1 G 1 G 1f

5 LT1 TYPICAL AC PERFOR A CE CHARACTERISTICS f LO = 17MHz, f IF = MHz, f RF = MHz, W P LO = dbm, V CC = V, EN =.9V, T A =, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.9GHz output frequency and V CC = V. LO-RF Leakage vs LO Frequency 1 Conversion Gain, and Noise Figure vs Supply Voltage 1 Conversion Gain and vs LO Power LEAKAGE (dbm) (db) NF 1 (dbm) AND NOISE FIGRE (db) GC (db) 1 (dbm) LO FREQENCY (MHz) G 1 G7 1 G LO LEAKAGE (dbm) LO-RF Leakage vs LO Power LO-RF Leakage vs Supply Voltage Noise Figure vs LO Power 1 1 LO LEAKAGE (dbm) NOISE FIGRE (db) G9 1 G1 1 G11 (db) 1 Low Side LO () and High Side LO () Comparison: Conversion Gain and vs RF Frequency : R1 = R7 = 11Ω : R1 = R7 = 11Ω f IF = MHz (dbm) NOISE FIGRE (db) Low Side LO () and High Side LO () Comparison: Noise Figure vs RF Frequency : R1 = R7 = 11Ω : R1 = R7 = 11Ω f IF = MHz 17 1 RF OT (MHz) RF OT (MHz) 1 G1 1 G1 1f

6 LT1 TYPICAL AC PERFOR A CE CHARACTERISTICS f LO = 11MHz, f IF = MHz, f RF = MHz, W P LO = dbm, V CC = V, EN =.9V, T A =, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.GHz output frequency. Fundamental, nd and rd Order Intermodulation Distortion vs Input Power 1. Conversion Gain vs Input Power 1 Conversion Gain and vs RF Frequency, Fixed IF OTPT POWER (dbm) IM P FND IM IM IM 1 1 INPT POWER (dbm) GC (db) P IN (dbm) (db) RF OT (MHz) 1 (dbm) 1 G 1 G1 1 G17 LEAKAGE (dbm) LO-RF Leakage vs LO Frequency LO FREQENCY (MHz) 1 GC (db) 1. Conversion Gain, and Noise Figure vs Supply Voltage NF (dbm) AND NOISE FIGRE (db) GC (db) 1 Conversion Gain and vs LO Power (dbm) 1 G1 1 G 1 G LO-RF Leakage vs LO Power LO-RF Leakage vs Supply Voltage LO LEAKAGE (dbm) LO LEAKAGE (dbm) G1 1 G 1f

7 LT1 TYPICAL AC PERFOR A CE CHARACTERISTICS f LO = 11MHz, f IF = MHz, f RF = MHz, W P LO = dbm, V CC = V, EN =.9V, T A =, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.GHz output frequency. NOISE FIGRE (db) Noise Figure vs LO Power (db) 1 1 Low Side LO () and High Side LO () Comparison: Conversion Gain and vs RF Frequency f IF = MHz 1 (dbm) NOISE FIGRE (db) Low Side LO () and High Side LO () Comparison: Noise Figure vs RF Frequency f IF = MHz RF OT (MHz) RF OT (MHz) 1 1 G 1 G 1 G f LO = 1.7GHz, f IF = MHz, f RF = 1.9GHz, P LO = dbm, V CC =.V, EN =.9V, T A =, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.9GHz output frequency and V CC =.V. P OT, IM and IM vs Input Power. Conversion Gain vs Input Power 1 Conversion Gain and vs RF Frequency 7 P OT OTPT POWER (dbm) IM IM IM (db) GC (db) 1 17 (dbm) 1 IM P IN (dbm) P IN (dbm) RF OT (MHz) 1 G 1 G 1 G7 1f 7

8 LT1 TYPICAL AC PERFOR A CE CHARACTERISTICS f LO = 1.7GHz, f IF = MHz, f RF = 1.9GHz, P LO W = dbm, V CC =.V, EN =.9V, T A =, unless otherwise noted. Test circuit shown in Figure 1 is tuned for 1.9GHz output frequency and V CC =.V. LEAKAGE (dbm) 7 9 LO-RF Leakage vs LO Frequency GC (db) Conversion Gain, and Noise Figure vs Supply Voltage NF 1 1 (dbm) AND NOISE FIGRE (db) (db) 1 Conversion Gain and vs LO Power (dbm) LO FREQENCY (MHz) G 1 G1 1 G9 LO-RF Leakage vs LO Power Noise Figure vs LO Power LO Leakage vs Supply Voltage LO LEAKAGE (dbm) NOISE FIGRE (db) LO LEAKAGE (dbm) G 1 G 1 G PI F CTIO S (Pins 1,, 1, 11, 1, 1, 1): Ground. These pins are internally connected to the Exposed Pad for improved isolation. They should be connected to RF ground on the printed circuit board, and are not intended to replace the primary grounding through the backside of the package. IN +, IN (Pins, ): Differential Input Pins. Each pin requires a resistive DC path to ground. See Applications Information for choosing the resistor value. External matching is required. EN (Pin ): Enable Input Pin. The enable voltage should be at least.9v to turn the chip on and less than.v to turn the chip off. V CC (Pins, 7, ): Power Supply Pins. Total current draw for these three pins is ma. OT +, OT (Pins 1, 9): RF Output Pins. These pins must have a DC connection to the supply voltage (see Applications Information). These pins draw ma each. External matching is required. LO (Pin ): Local Oscillator Input. This input is internally DC biased to.9v. Input signal must be AC coupled. Exposed Pad (Pin 17): Circuit Ground Return for the Entire IC. For best performance, this pin must be soldered to the printed circuit board. 1f

9 LT1 BLOCK DIAGRA W EXPOSED LO PAD 1 IN + IN OT OT 9 BIAS EN V CC V CC V CC 7 1 BD TEST CIRCITS IF IN Ω C Z Z1 C T1 LO IN Ω Z1 OPT R1 C1 R7 Z7 OPT 1 IN + IN EN C R L OT + 1 LT1 EXPOSED PAD (17) 11 1 OT 9 V CC V CC V CC 7 L1 C L.".17".17" V CC C11 ε r =. T RF DC C C1 RF OT Ω EN 1 F1 Figure 1. Demonstration Board Schematic Table 1. Demonstration Board Bill of Materials 1, REF R1, R7 Z1 Z L1, L T1 T C1, C1 C C1 C, C, C C11 Z1, Z7 f IF = MHz, f RF = 1.9GHz f LO = 1.7GHz, V CC = V 11Ω, 1% 1pF Ω.7nH M/A-COM MABACT1 M/A-COM ETC1.---.pF pf pf 1µF Ω f IF = MHz, f RF = 1.GHz f LO = 1.1GHz, V CC = V 11Ω, 1% 1nH pf 1nH M/A-COM MABACT1 M/A-COM ETC pF.9pF 1µF Ω f IF = MHz, f RF = 1.9GHz f LO = 1.7GHz, V CC =.V.Ω, 1% 1pF Ω.7nH M/A-COM MABACT1 M/A-COM ETC1.---.pF pf pf 1µF 1nH THIS COMPONENT CAN BE REPLACED BY PCB TRACE ON FINAL APPLICATION R 1k 1k 1k Note 1: Tabulated values are used for characterization measurements. Note : Components shown on the schematic are included for consistency with the demo board. If no value is shown for the component, the site is unpopulated. Note : T1 also M/A-COM ETC1-1-1 and Sprague Goodman GWM. These alternative transformers have been measured and have similar performance. 1f 9

10 LT1 APPLICATIO S I FOR ATIO 1 W The LT1 is a high linearity double-balanced active mixer. The chip consists of a double-balanced mixer core, a high performance LO buffer and associated bias and enable circuitry. The chip is designed to operate with a supply voltage ranging from.v to.v. Table. Port Impedance FREQENCY DIFFERENTIAL DIFFERENTIAL SINGLE-ENDED (MHz) INPT OTPT LO. + j.7. j j j.. j j j.. j j.9. + j1. 1. j j j.1. j1.. + j.. + j.. j.. + j.. + j..9 j j j9. 1. j7.. + j.. + j.1 1. j7.. + j j.. + j17.9. j1.. + j. Signal Input Interface Figure shows the signal inputs of the LT1. The signal input pins are connected to the common emitter nodes of the mixer quad differential pairs. The real part of the differential IN + /IN impedance is Ω. The mixer core current is set by external resistors R1 and R7. Setting their values at 11Ω, the nominal DC voltage at the inputs is.v with V CC = V. Figure shows the input return loss for a matched input at MHz. IF IN Ω C Z Z1 C T1 1:1 C1 Z1 OPT IN + V CC IN Figure. Signal Input with External Matching R1 R7 Z7 OPT LT1 1 F IF RETRN LOSS (db) 1 1 FREQENCY (MHz) 1 F Figure. IF Input Return Loss For input frequencies above 1MHz, a broadband impedance matching tranformer with a 1:1 impedance ratio is recommended. Table provides the component values necessary to match various IF frequencies using the M/A- COM CT1 transformer (T1, Figure 1). Table. Component Values for Input Matching sing the M/A-COM CT1 IF C Z1 Z MHz 1pF 1nH pf 9MHz pf pf 7nH 1MHz 1pF 7pF 1nH MHz pf pf 1nH 17MHz pf 1pF.nH MHz pf 1pF Ω MHz pf.9pf Ω MHz.pF.pF Ω MHz.pF nused Ω Below 1MHz, the Mini-Circuits TCM-1T or the Pulse CX are better choices for a wider input match. This configuration is shown in Figure. The series capacitors maintain differential symmetry while providing DC isolation between the inputs. This helps to improve LO suppression. Shunt capacitor C1 (Figure ) is an optional capacitor across the input pins that significantly improves LO suppression. Although this capacitor is optional, it is important to regulate LO suppression, mitigating part-to-part variation. This capacitor should be optimized depending 1f

11 LT1 APPLICATIO S I FOR ATIO IF IN Ω W on the IF input frequency and the LO frequency. Smaller C1 values have reduced impact on the LO output suppression; larger values will degrade the conversion gain. A single-ended Ω source can also be matched to the differential signal inputs of the LT1 without an input transformer. Figure shows an example topology for a discrete balun, and Table lists component values for several frequencies. The discrete input match is intrinsically narrowband. LO suppression to the output is degraded and noise figure degrades by db for input frequencies greater than MHz. Noise figure degradation is worse at lower input frequencies. IF IN Ω C C pf T1 :1 C1 L C1 C1 L R1 R7 Figure. Low Frequency Signal Input R1 11Ω C1 R7 11Ω LT1 Figure. Alternative Transformerless Input Circuit sing Low Cost Discrete Components LT1 IN + V CC IN IN + IN 1 F 1 F Table. Component Values for Discrete Bridge Balun Signal Input Matching IF (MHz) C1, C1 (pf) L, L (nh) Operation at Reduced Supply Voltage External resistors R1 and R7 (Figure ) set the current through the mixer core. For best distortion performance, these resistors should be chosen to maintain a total of ma through the mixer core (ma per side). At V supply, R1 and R7 should be 11Ω. Table shows recommended values for R1 and R7 at various supply voltages. Caution: sing values below the recommended resistance can adversely affect operation or damage the part. Table. Minimum External Resistor Values vs Supply Voltage R1, R7 (Ω) Excessive mismatch between the external resistors R1 and R7 will degrade performance, particularly LO suppression. Resistors with 1% mismatch are recommended for optimum performance. Figure shows RF chokes in series with R1 and R7. These inductors are optional. In general, the chokes improve the conversion gain and noise figure by db at.v (i.e., at the minimum values of R1 and R7). The DC resistance variation of the RF chokes must be considered in the 1% source resistance mismatch suggested for maintaining LO suppression performance. Figure indicates the typical performance of the LT1 as the external source resistance (R1, R7) is varied while keeping the supply current constant. Figure data was taken without the benefit of input chokes, and shows the gradual gain degradation for smaller values of the input resistors R1 and R7. Figure 7 shows the typical behavior when the supply voltage is fixed and the core current is varied by adjusting values of the external resistors R1 and R7. Decreasing the core current decreases the power consumption and improves noise figure but degrades distortion performance. Figure demonstrates the impact of the RF chokes in series with the source resistance at.v. There is a db improvement in conversion gain and noise figure and a corresponding decrease in. 1f 11

12 LT1 APPLICATIO S I FOR ATIO CONVERSION GAIN (db) W R1 AND R7 (Ω) Figure., and Noise Figure vs External Resistance, Constant Core Current (Variable Supply Voltage) CONVERSION GAIN (db) T A = f IF = MHz f LO = 1.7GHz f RF = 1.9GHz T A = f IF = MHz f LO = 1.7GHz f RF = 1.9GHz V CC = V CORE CRRENT (ma) Figure 7., and Noise Figure vs Core Current, Constant Supply Voltage NF NF 1 F 1 F7 1 1 (dbm) AND NOISE FIGRE (db) (dbm) AND NOISE FIGRE (db) The user can tailor the biasing of the LT1 to meet individual system requirements. It is recommended to choose a source resistance as large as possible to minimize sensitivity to power supply variation. Output Interface A DC connection to V CC must be provided on the PCB to the output pins. These pins will draw approximately ma each from the power supply. On-chip, there is a nominal Ω differential resistance between the output pins. Figure 9 shows a typical matching circuit using an external balun to provide differential to single-ended conversion. LO suppression and xlo suppression are influenced by the symmetry of the external output matching circuitry. PCB design must maintain the trace layout symmetry of the output pins as much as possible to minimize these signals. The M/A-COM ETC1.--- :1 transformer (T, Figure 9) is suitable for applications with output frequencies between MHz and 7MHz. Output matching at various frequencies is achieved by adding inductors in series with the output (L1, L) and DC blocking capacitor C, as shown in Figure 9. Table specifies center frequency and bandwidth of the output match for different matching configurations. Figure 1 shows the typical output return loss vs frequency for 1GHz and GHz applications. Capacitor C1 provides a solid AC ground at the RF output frequency. CONVERSION GAIN (db) T A = f IF = MHz f LO = 1.7GHz f RF = 1.9GHz V CC =.V RFC RFC CORE CRRENT (ma) RFC NF 1 (dbm) AND NOISE FIGRE (db) LT1 Ω OT + 1 V CC OT 9 L1 V CC L T :1 C C1 1 F9 OT 1 F Figure. Comparison of.v Performance With and Without Input RF Choke Figure 9. Simplified Output Circuit with External Matching Components 1 1f

13 LT1 APPLICATIO S I FOR ATIO W Table. Matching Values sing M/A-COM ETC1.--- Output Transformer f OT L1, L C C1 f (1dB RL).GHz nh pf pf MHz.GHz 1nH pf pf MHz.GHz.7nH pf pf MHz 1.7GHz.7nH pf pf MHz 1.GHz 1nH pf pf MHz 1.GHz 1nH.9pF MHz RETRN LOSS (db) 1.7 GHz 1GHz FREQENCY (GHz) Figure 1. Output Return Loss vs Frequency For applications with LO and output frequencies below 1GHz, the M/A-COM MABAES is recommended for the output component T. This transformer maintains better low frequency output symmetry. Table 7 lists components necessary for a 7MHz output match using the M/A-COM MABAES. Table 7. Matching Values sing M/A-COM MABAES Output Transformer f OT L1, L C C1 f (1dB RL) 7MHz nh pf MHz. 1 F1 Johanson Technology supplies the 7BLB1S hybrid balun for use between.ghz and GHz. With additional matching, this transformer can be used for applications between.ghz and.7ghz. Example LT1 performance is shown in Figure 11. CONVERSION GAIN (db) 1. T A = f IF = MHz NF FREQENCY (GHz) 1 F11 Figure 11. LT1 Performance for an Application Tuned to.ghz with Low Side () and High Side () LO Injection LO Interface The LO input pin is internally matched to Ω. It has an internal DC bias of 9mV. External AC coupling is required. Figure 1 shows a simplified schematic of the LO input. Overdriving the LO input will dramatically reduce the performance of the mixer. The LO input power should not exceed +1dBm for normal operation. Select C1 (Figure 1) only large enough to achieve the desired LO input return loss. This reduces external low frequency signal amplification through the LO buffer. For applications with LO frequency in the range of.1ghz to.ghz, the LT1 achieves improved distortion and (dbm) AND NOISE FIGRE (db) Hybrid baluns provide a low cost alternative for differential to single-ended conversion. The critical performance parameters of conversion gain,, noise figure and LO suppression are largely unaffected by these transformers. However, their limited bandwidth and reduced symmetry outside the frequency of operation degrades the suppression of higher order LO harmonics, particularly xlo. Murata LBD1 series hybrid balun transformers, for example, can be used for output frequencies as low as MHz and as high as.ghz. LO IN Ω LT1 V CC Ω C1 Ω Ω 1 F1 Figure 1. Simplified LO Input Circuit 1f 1

14 LT1 APPLICATIO S I FOR ATIO RETRN LOSS (db) 1 W C1 =.pf C1 =.7pF 1 FREQENCY (MHz) 1 F1 Figure 1. LO Port Return Loss noise performance with slightly reduced current through the mixer core. Accordingly, in a V application operating within this LO frequency range, the recommended source resistor value (R1 and R7) is increased to 11Ω. Enable Interface Figure 1 shows a simplified schematic of the EN pin interface. The voltage necessary to turn on the LT1 is.9v. To disable the chip, the enable voltage must be below.v. If the EN pin is not connected, the chip is disabled. It is not recommended, however, that any pins be left floating for normal operation. It is important that the voltage at the EN pin never exceed V CC, the power supply voltage, by more than.v. If this should occur, the supply current could be sourced through the EN pin ESD protection diodes, potentially damaging the IC. The resistor R (Figure 1) in series with the EN pin on the demo board is populated with a 1kΩ resistor to protect the EN pin to avoid inadvertant damage to the IC. For timing measurements, this resistor is replaced with a LT1 V CC Ω resistor. If the shutdown function is not required, then the EN pin should be wired directly to the V CC power supply on the PCB. Supply Decoupling The power supply decoupling shown in the schematic of Figure 1 is recommended to minimize spurious signal coupling into the output through the power supply. ACPR Performance Because of its high linearity and low noise, the LT1 offers outstanding ACPR performance in a variety of applications. For example, Figures and 1 show ACPR and Alternate Channel measurements for single channel and -channel DPCH W-CDMA signals at 1.9GHz output frequency. ACPR ACPR AND AltCPR (db) T A = f RF = 1.9GHz f IF = 7MHz f LO = 1.GHz ACPR 1 MHz OFFSET NOISE 1 1 OTPT CHANNEL POWER (dbm) 1 F Figure. Single Channel W-CDMA ACPR and MHz Offset Noise Performance 7 7 T A = f RF = 1.9GHz f IF = 7MHz f LO = 1.GHz AltCPR ACPR MHz OFFSET NOISE OTPT CHANNEL POWER, EACH CHANNEL (dbm) NOISE FLOOR (dbm/hz) NOISE FLOOR (dbm/hz) 1 EN 1 F1 Figure 1. Enable Input Circuit 1 G Figure 1. -Channel W-CDMA ACPR, AltCPR and MHz Offset Noise Floor 1f

15 LT1 APPLICATIO S I FOR ATIO W Figure 17. Top View of Demo Board PACKAGE DESCRIPTIO F Package 1-Lead Plastic QFN (mm mm) (Reference LTC DWG # --) BOTTOM VIEW EXPOSED PAD. ±.1 ( SIDES).7 ±. R =.1 TYP 1. ±..7 ±. PIN 1 TOP MARK (NOTE ) 1. ±.. ±. ( SIDES).9 ±.. ±.1 (-SIDES). ±.. BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS PACKAGE OTLINE. REF.. NOTE: 1. DRAWINONFORMS TO JEDEC PACKAGE OTLINE MO- VARIATION (WGGC). DRAWING NOT TO SCALE. ALL DIMENSIONS ARE IN MILLIMETERS. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED.mm ON ANY SIDE. EXPOSED PAD SHALL BE SOLDER PLATED. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE (F) QFN 11. ±.. BSC 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. 1f

16 LT1 RELATED PARTS PART NMBER DESCRIPTION COMMENTS Infrastructure LT11 High Linearity pconverting Mixer RF Output to GHz, 17dBm, Integrated LO Buffer LT1 DC-GHz High Signal Level Downconverting Mixer DC to GHz, 1dBm, Integrated LO Buffer LT1 ltralow Distortion, Wideband Digitally Controlled BW = MHz, OIP = 7dBm at 1MHz,.dB Gain Control Range Gain Amplifier/ADC Driver LT 1.GHz to.ghz Direct Conversion Quadrature Demodulator dbm, Integrated LO Quadrature Generator LT1.GHz to 1.GHz Direct Conversion Quadrature Demodulator 1.dBm, Integrated LO Quadrature Generator LT17 MHz to 9MHz Quadrature Demodulator 1dBm, Integrated LO Quadrature Generator LT.7GHz to 1.GHz High Linearity pconverting Mixer 17.1dBm at 1GHz, Integrated RF Output Transformer with Ω Matching, Single-Ended LO and RF Ports Operation LT 1.GHz to.ghz High Linearity pconverting Mixer.9dBm at 1.9GHz, Integrated RF Output Transformer with Ω Matching, Single-Ended LO and RF Ports Operation LT MHz to.7ghz High Signal Level Downconverting Mixer.V to.v Supply, dbm at 9MHz, NF = 1.dB, Ω Single-Ended RF and LO Ports RF Power Detectors LT MHz to.7ghz RF Measuring Receiver db Dynamic Range, Temperature Compensated,.7V to.v Supply LTC RF Power Detectors with >db Dynamic Range MHz to GHz, Temperature Compensated,.7V to V Supply LTC7 1kHz to 1MHz RF Power Detector 1kHz to 1GHz, Temperature Compensated,.7V to V Supply LTC MHz to 7GHz RF Power Detector db Dynamic Range, Temperature Compensated, SC7 Package LTC9 MHz to GHz RF Power Detector db Linear Dynamic Range, Low Power Consumption, SC7 Package LTC MHz to 7GHz Precision RF Power Detector Precision V OT Offset Control, Shutdown, Adjustable Gain LTC1 MHz to 7GHz Precision RF Power Detector Precision V OT Offset Control, Shutdown, Adjustable Offset LTC MHz to 7GHz Precision RF Power Detector Precision V OT Offset Control, Adjustable Gain and Offset LT MHz to GHz RF Power Detector db Dynamic Range, Temperature Compensated, SC7 Package Low Voltage RF Building Blocks LT 1.GHz to.7ghz Receiver Front End 1.V to.v Supply, Dual-Gain LNA, Mixer, LO Buffer LT MHz Quadrature IF Demodulator with RSSI 1.V to.v Supply, 7MHz to MHz IF, db Limiting Gain, 9dB RSSI Range LT 1.GHz to.7ghz Direct IQ Modulator and 1.V to.v Supply, Four-Step RF Power Control, pconverting Mixer 1MHz Modulation Bandwidth LT MHz Quadrature IF Demodulator with VGA 1.V to.v Supply, MHz to MHz IF, db to 7dB Linear Power Gain,.MHz Baseband Bandwidth LT MHz Ouadrature IF Demodulator with 17MHz Baseband Bandwidth, MHz to MHz IF, 1.V to.v VGA and 17MHz Baseband Bandwidth Supply, 7dB to db Linear Power Gain RF Power Controllers LTC177A RF Power Controller Multiband GSM/DCS/GPRS Mobile Phones LTC17 RF Power Controller Multiband GSM/DCS/GPRS Mobile Phones LTC7 RF Power Controller Multiband GSM/DCS/GPRS Mobile Phones LTC SOT- RF PA Controller Multiband GSM/DCS/GPRS Phones, db Dynamic Range, khz Loop BW LTC1 SOT- RF PA Controller Multiband GSM/DCS/GPRS Phones, db Dynamic Range, khz Loop BW LTC RF Power Controller for EDGE/TDMA Multiband GSM/GPRS/EDGE Mobile Phones 1 Linear Technology Corporation 1 McCarthy Blvd., Milpitas, CA () - FAX: () f LT/TP 1K PRINTED IN THE SA LINEAR TECHNOLOGY CORPORATION