LTC5542 1.6GHz to 2.7GHz High Dynamic Range Downconverting Mixer DESCRIPTION FEATURES n n n n n n n n n n n n Conversion Gain: 8dB at 2.4GHz IIP3: 26.8dBm at 2.4GHz Noise Figure: 9.9dB at 2.4GHz 17.3dB NF Under +5dBm Blocking High Input P1dB 3.3V Supply, 660mW Power Consumption Shutdown Pin 50 Single-Ended RF and LO Inputs LO Inputs 50 Matched when Shutdown High Isolation LO Switch 0dBm LO Drive Level High LO-RF and LO-IF Isolation Small Solution Size 20-Lead (5mm x 5mm) QFN package The LTC(R)5542 is part of a family of high dynamic range, high gain, passive downconverting mixers covering the 600MHz to 4GHz frequency range. The LTC5542 is optimized for 1.6GHz to 2.7GHz RF applications. The LO frequency must fall within the 1.7GHz to 2.5GHz range for optimum performance. A typical application is a LTE or WiMAX receiver with a 2.3GHz to 2.7GHz RF input and low-side LO. The LTC5542 is designed for 3.3V operation, however; the IF amplifier can be powered by 5V for the highest P1dB. An integrated SPDT LO switch with fast switching accepts two active LO signals, while providing high isolation. APPLICATIONS The LTC5542's high conversion gain and high dynamic range enable the use of lossy IF filters in high-selectivity receiver designs, while minimizing the total solution cost, board space and system-level variation. n High Dynamic Range Downconverting Mixer Family n n n n Wireless Infrastructure Receivers (LTE, W-CDMA. TD-SCDMA, WiMAX, GSM1800) Point-to-Point Microwave Links High Dynamic Range Downmixer Applications L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. PART# RF RANGE LO RANGE LTC5540 600MHz -1.3GHz 700MHz - 1.2GHz LTC5541 1.3GHz - 2.3GHz 1.4GHz - 2.0GHz LTC5542 1.6GHz - 2.7GHz 1.7GHz - 2.5GHz LTC5543 2.3GHz - 4GHz 2.4GHz - 3.6GHz TYPICAL APPLICATION Wideband Receiver 190MHz SAW 1nF VCCIF 3.3V or 5V 1F 22pF 150nH 11.0 ADC IF - RF 2300MHz TO 2400MHz LO2 LTC5542 IF RF LNA ALTERNATE LO FOR FREQUENCY-HOPPING LO 0.7pF SYNTH 2 BIAS SHDN VCC2 VCC 3.3V 1F VCC1 22pF VCC3 LO1 LOSEL LO SELECT (0V/3.3V) IIP3 26 24 22 9.0 20 8.5 18 8.0 GC 7.5 16 30MHz 14 7.0 4.7pF SHDN (0V/3.3V) GC (dB) 4.7pF IMAGE BPF 22pF 28 10.5 RF = 2350 50MHz LO = 2160MHz 10.0 P = 0dBm LO 9.5 TEST CIRCUIT IN FIGURE 1 SYNTH 1 LO 2160MHz IIP3 (dBm), SSB NF (dB) IF+ 190MHz BPF IF AMP 1nF 150nH Wideband Conversion Gain, IIP3 and NF vs IF Output Frequency 12 6.5 10 NF 6.0 8 140 150 160 170 180 190 200 210 220 230 240 IF OUTPUT FREQUENCY (MHz) 5542 TA01a 5542 TA01 5542f 1 LTC5542 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) IFGND GND IF- IFBIAS IF+ TOP VIEW Mixer Supply Voltage (VCC1, VCC2)...........................3.8V LO Switch Supply Voltage (VCC3).............................3.8V IF Supply Voltage (IF+, IF -) ......................................5.5V Shutdown Voltage (SHDN) ................-0.3V to VCC +0.3V LO Select Voltage (LOSEL)................-0.3V to VCC +0.3V LO1, LO2 Input Power (1GHz to 3GHz) ...................9dBm LO1, LO2 Input DC Voltage ....................................0.5V RF Input Power (1GHz to 3GHz) ...........................15dBm RF Input DC Voltage ............................................... 0.1V Operating Temperature Range .................-40C to 85C Storage Temperature Range .................. -65C to 150C Junction Temperature (TJ) .................................... 150C 20 19 18 17 16 15 LO2 NC 1 14 VCC3 RF 2 21 GND CT 3 13 GND 7 8 9 10 LOSEL GND 6 VCC1 11 LO1 VCC2 12 GND SHDN 5 LOBIAS GND 4 UH PACKAGE 20-LEAD (5mm s 5mm) PLASTIC QFN TJMAX = 150C, JA = 34C/W, JC = 3C/W EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC5542IUH#PBF LTC5542IUH#TRPBF 5542 20-Lead (5mm x 5mm) Plastic QFN -40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard 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/ AC ELECTRICAL CHARACTERISTICS VCC = 3.3V, VCCIF = 3.3V, SHDN = Low, TA = 25C, PLO = 0dBm, unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3, 4) PARAMETER CONDITIONS MIN LO Input Frequency Range RF Input Frequency Range Low-Side LO High-Side LO TYP MAX UNITS 1700 to 2500 MHz 1900 to 2700 1600 to 2300 MHz MHz 5 to 500 MHz IF Output Frequency Range Requires External Matching RF Input Return Loss ZO = 50, 1600MHz to 2700MHz >12 dB LO Input Return Loss ZO = 50, 1700MHz to 2500MHz >12 dB IF Output Return Loss Requires External Matching >12 dB LO Input Power fLO = 1700MHz to 2500MHz LO to RF Leakage fLO = 1700MHz to 2500MHz <-32 dBm LO to IF Leakage fLO = 1700MHz to 2500MHz <-40 dBm LO Switch Isolation LO1 Selected, 1700MHz < fLO < 2500MHz LO2 Selected, 1700MHz < fLO < 2500MHz 49 52 dB dB RF to LO Isolation fRF = 1600MHz to 2700MHz >49 dB RF to IF Isolation fRF = 1600MHz to 2700MHz >35 -4 0 6 dBm dB 5542f 2 LTC5542 AC ELECTRICAL CHARACTERISTICS VCC = 3.3V, VCCIF = 3.3V, SHDN = Low, TA = 25C, PLO = 0dBm, PRF = -3dBm (f = 2MHz for two-tone IIP3 tests),unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3, 4) Low-Side LO Downmixer Application: RF = 1900 to 2700MHz, IF = 190MHz, fLO = fRF -fIF PARAMETER CONDITIONS Conversion Gain RF = 2150MHz RF = 2400MHz RF = 2650MHz MIN TYP 6.5 8.5 8.0 7.4 MAX UNITS dB Conversion Gain Flatness RF = 2350 30MHz, LO = 2160MHz, IF=190 30MHz 0.15 dB Conversion Gain vs Temperature TA = -40C to +85C, RF = 2400MHz -0.006 dB/C Input 3rd Order Intercept RF = 2150MHz RF = 2400MHz RF = 2650MHz 27.2 26.8 25.3 dBm RF = 2150MHz RF = 2400MHz RF = 2650MHz 9.9 9.9 10.2 dB SSB Noise Figure Under Blocking fRF = 2400MHz, fLO = 2210MHz, fBLOCK = 2500MHz, PBLOCK = 5dBm 17.3 dB 2RF - 2LO Output Spurious Product (fRF = fLO + fIF/2) fRF = 2305MHz at -10dBm, fLO = 2210MHz, fIF = 190MHz -62 dBc 3RF - 3LO Output Spurious Product (fRF = fLO + fIF/3) fRF = 2273.33MHz at -10dBm, fLO = 2210MHz, fIF = 190MHz -73 dBc Input 1dB Compression RF = 2400MHz, VCCIF = 3.3V RF = 2400MHz, VCCIF = 5V 11.3 14.7 dBm SSB Noise Figure 24.0 High-Side LO Downmixer Application: RF = 1600-2300MHz, IF = 190MHz, fLO = fRF +fIF PARAMETER CONDITIONS Conversion Gain RF = 1750MHz RF = 1950MHz RF = 2150MHz MIN TYP 6.5 8.8 8.5 8.0 MAX UNITS dB Conversion Gain Flatness RF = 1950MHz 30MHz, LO = 2140MHz, IF = 190 30MHz 0.20 dB Conversion Gain vs Temperature TA = -40C to 85C, RF = 1950MHz -0.006 dB/C Input 3rd Order Intercept RF = 1750MHz RF = 1950MHz RF = 2150MHz 25.1 25.2 24.6 dBm SSB Noise Figure 23.0 RF = 1750MHz RF = 1950MHz RF = 2150MHz 9.0 9.4 10.3 SSB Noise Figure Under Blocking fRF = 1950MHz, fLO = 2140MHz, fIF = 190MHz fBLOCK = 1850MHz, PBLOCK = 5dBm 17.5 dB 2LO - 2RF Output Spurious Product (fRF = fLO - fIF/2) fRF = 2045MHz at -10dBm, fLO = 2140MHz fIF = 190MHz -67 dBc 3LO - 3RF Output Spurious Product (fRF = fLO - fIF/3) fRF = 2076.67MHz at -10dBm, fLO = 2140MHz fIF = 190MHz -73 dBc Input 1dB Compression RF = 1950MHz, VCCIF = 3.3V RF = 1950MHz, VCCIF = 5V 11.0 14.4 dBm 11.0 dB 5542f 3 LTC5542 DC ELECTRICAL CHARACTERISTICS noted. Test circuit shown in Figure 1. (Note 2) PARAMETER VCC = 3.3V, VCCIF = 3.3V, SHDN = Low, TA = 25C, unless otherwise CONDITIONS MIN TYP MAX UNITS VCC Supply Voltage (Pins 6, 8 and 14) 3.1 3.3 3.5 V VCCIF Supply Voltage (Pins 18 and 19) 3.1 3.3 5.3 V 99 100 199 116 120 236 mA 500 A Power Supply Requirements (VCC, VCCIF) VCC Supply Current (Pins 6 + 8 + 14) VCCIF Supply Current (Pins 18 + 19) Total Supply Current (VCC + VCCIF) Total Supply Current - Shutdown SHDN = High Shutdown Logic Input (SHDN) Low = On, High = Off SHDN Input High Voltage (Off) 3 V SHDN Input Low Voltage (On) -0.3V to VCC + 0.3V SHDN Input Current -20 0.3 V 30 A Turn On Time 1 s Turn Off Time 1.5 s LO Select Logic Input (LOSEL) Low = LO1 Selected, High = LO2 Selected LOSEL Input High Voltage 3 V LOSEL Input Low Voltage -0.3V to VCC + 0.3V LOSEL Input Current -20 LO Switching Time 0.3 V 30 A 50 Note 1: 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 2: The LTC5542 is guaranteed functional over the operating temperature range from -40C to 85C. TYPICAL DC PERFORMANCE CHARACTERISTICS VCC Supply Current vs Supply Voltage (Mixer and LO Switch) SHDN = Low, Test circuit shown in Figure 1. VCCIF Supply Current vs Supply Voltage (IF Amplifier) Total Supply Current vs Temperature (VCC + VCCIF) 130 110 ns Note 3: SSB Noise Figure measured with a small-signal noise source, bandpass filter and 6dB matching pad on RF input, bandpass filter and 6dB matching pad on the LO input, and no other RF signals applied. Note 4: LO switch isolation is measured at the IF output port at the IF frequency with fLO1 and fLO2 offset by 2MHz. 230 108 120 104 102 85C 25C 100 98 -40C 96 94 220 85C 110 100 25C 90 210 VCC = 3.3V, VCCIF = 5V (DUAL SUPPLY) 200 VCC = VCCIF = 3.3V (SINGLE SUPPLY) 190 180 80 -40C 92 90 3.0 SUPPLY CURRENT(mA) SUPPLY CURRENT (mA) SUPPLY CURRENT(mA) 106 3.1 3.2 3.3 3.5 3.4 VCC SUPPLY VOLTAGE (V) 3.6 5542 G01 70 3.0 3.3 3.6 3.9 4.2 4.5 4.8 5.1 VCCIF SUPPLY VOLTAGE (V) 5.4 5542 G02 170 -45 -25 55 -5 15 35 TEMPERATURE (C) 75 95 5542 G03 5542f 4 LTC5542 TYPICAL AC PERFORMANCE CHARACTERISTICS Low-Side LO VCC = 3.3V, VCCIF = 3.3V, SHDN = Low, TA = 25C, PLO = 0dBm, PRF = -3dBm (-3dBm/tone for two-tone IIP3 tests, f = 2MHz), IF = 190MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Gain, IIP3 and NF vs RF Frequency 28 26 LO Leakage vs LO Frequency IIP3 60 LO LEAKAGE (dBm) 20 18 16 14 12 LO-RF -40 LO-IF 10 RF-IF 40 35 GC 2.1 2.2 2.3 2.4 2.5 RF FREQUENCY (GHz) 2.6 -60 1.5 2.7 1.7 1.9 2.1 2.3 LO FREQUENCY (GHz) 2.5 5542 G04 25 1.5 2.7 1.7 1.9 2.1 2.3 RF FREQUENCY (GHz) 2.5 5542 G05 2150MHz Conversion Gain, IIP3 and NF vs LO Power 2.7 5541 G06 2400MHz Conversion Gain, IIP3 and NF vs LO Power 2650MHz Conversion Gain, IIP3 and NF vs LO Power 26 18 24 19 24 23 22 85C 17 25C -40C 15 20 85C 16 25C -40C 14 12 18 10 8 NF 14 6 12 10 GC 8 -6 -4 4 -2 0 2 LO INPUT POWER (dBm) 19 12 17 10 NF 15 10 2 9 2 8 0 7 0 6 -6 -4 4 -2 0 2 LO INPUT POWER (dBm) 27 85C 16 25C -40C 14 25 17 10 9 7 3.0 8 6 RF = 2400MHz VCC = VCCIF 4 GC 2 3.1 3.2 3.3 3.4 3.5 VCC, VCCIF SUPPLY VOLTAGE (V) 0 3.6 5542 G10 -4 4 -2 0 2 LO INPUT POWER (dBm) IIP3 2400MHz Conversion Gain, IIP3 and RF Input P1dB vs Temperature 22 28 20 26 18 85C 25C 16 -40C 14 23 21 19 12 NF 17 10 15 8 13 RF = 2400MHz 6 VCC = 3.3V 4 11 9 7 3.0 GC 3.3 2 3.6 3.9 4.2 4.5 4.8 5.1 VCCIF SUPPLY VOLTAGE (V) 6 5542 G09 0 5.4 5542 G11 SSB NF (dB) 12 SSB NF (dB) 19 GC (dB), IIP3 (dBm) 29 18 11 3 1 -6 6 Conversion Gain, IIP3 and NF vs IF Supply Voltage (Dual Supply) 20 13 5 GC 5542 G08 25 IIP3 NF 7 4 27 15 9 12 11 6 11 14 4 GC 13 NF 16 6 Conversion Gain, IIP3 and NF vs Supply Voltage (Single Supply) 21 18 13 5542 G07 23 8 20 SSB NF (dB) 16 21 85C 16 25C -40C 14 21 IIP3 GC (dB), IIP3 (dBm), P1dB (dBm) 22 IIP3 GC (dB), IIP3 (dBm) 20 25 GC (dB), IIP3 (dBm) 27 18 IIP3 SSB NF (dB) 20 26 SSB NF (dB) GC (dB), IIP3 (dBm) 45 30 6 1.9 2.0 28 50 -50 NF RF-LO 55 -30 22 ISOLATION (dB) GC (dB), IIP3 (dBm), NF (dB) 24 8 GC (dB), IIP3 (dBm) RF Isolation vs RF Frequency 65 -20 IIP3 24 22 RF = 2400MHz VCCIF = 5.0V VCCIF = 3.3V 20 18 16 P1dB 14 12 10 GC 8 6 -45 -25 -5 15 35 55 TEMPERATURE (C) 75 95 5542 G12 5542f 5 LTC5542 TYPICAL AC PERFORMANCE CHARACTERISTICS Low-Side LO VCC = 3.3V, VCCIF = 3.3V, SHDN = Low, TA = 25C, PLO = 0dBm, PRF = -3dBm (-3dBm/tone for 2-tone IIP3 tests, f = 2MHz), IF = 190MHz, unless otherwise noted. Test circuit shown in Figure 1. 2-Tone IF Output Power, IM3 and IM5 vs RF Input Power Single-Tone IF Output Power, 2 x 2 and 3 x 3 Spur vs RF Input Power 20 IFOUT 10 (RF = 2400MHz) IFOUT TA = 25C RF1 = 2399MHz RF2 = 2401MHz LO = 2210MHz -10 -20 0 -30 -40 -50 -60 LO = 2210MHz -10 -20 -30 2RF-2LO (RF = 2305MHz) -40 -50 3RF-3LO (RF = 2273.3MHz) -60 IM3 -70 -80 -12 -9 -6 -3 0 3 RF INPUT POWER (dBm/TONE) -80 -12 -9 6 12 -6 15 -4 4 -2 0 2 LO INPUT POWER (dBm) 6 5542 G15 LO Switch Isolation vs LO Frequency-LO2 Selected PLO2 = -3dBm PLO = -3dBm PLO = 0dBm 12 50 PLO2 = 0dBm 45 11 LOSEL = LOW PLO1 = 0dBm 40 1.5 5 1.7 PLO1 = 0dBm 50 PLO1 = 3dBm 45 PLO2 = 3dBm PLO = 3dBm -20 -15 -10 -5 0 RF BLOCKER POWER (dBm) 55 ISOLATION (dB) ISOLATION (dB) SSB NF (dB) 3RF-3LO (RF = 2273.3MHz) 60 55 9 -25 -70 PLO1 = -3dBm 16 10 2RF-2LO (RF = 2305MHz) -80 -6 -3 0 3 6 9 RF INPUT POWER (dBm) 60 17 13 -65 LO Switch Isolation vs LO Frequency-LO1 Selected RF = 2400MHz BLOCKER = 2500MHz 14 -60 5542 G14 SSB Noise Figure vs RF Blocker Level 15 -55 -75 5542 G13 18 RF = 2400MHz PRF = -10dBm LO = 2210MHz -70 IM5 19 RELATIVE SPUR LEVEL (dBc) 0 -50 20 OUTPUT POWER (dBm) OUTPUT POWER (dBm/TONE) 10 2 x 2 and 3 x 3 Spur Suppression vs LO Power 1.9 2.1 2.3 LO FREQUENCY (GHz) 5542 G16 2.5 40 1.5 2.7 LOSEL = HIGH PLO2 = 0dBm 1.7 1.9 2.1 2.3 LO FREQUENCY (GHz) 2.5 2.7 5542 G17 5542 G18 High-Side LO Conversion Gain Distribution DISTRIBUTION (%) 30 RF = 1950MHz SSB Noise Figure Distribution 40 RF = 1950MHz 18 85C 25C -40C 16 25 20 15 10 14 85C 25C -40C 12 10 8 6 5542 G18a 20 15 5 0 0 7.5 7.7 7.9 8.1 8.3 8.5 8.7 8.9 9.1 CONVERSION GAIN (dB) 25 10 2 0 RF = 1950MHz 30 4 5 85C 25C -40C 35 DISTRIBUTION (%) 35 IIP3 Distribution 20 DISTRIBUTION (%) 40 23.8 24.2 24.6 25 25.4 IIP3 (dBm) 25.8 5542 G18b 8.2 8.6 9.0 9.4 9.8 10.2 SSB NOISE FIGURE (dB) 10.6 5542 G18c 5542f 6 LTC5542 TYPICAL AC PERFORMANCE CHARACTERISTICS High-Side LO VCC = 3.3V, VCCIF = 3.3V, SHDN = Low, TA = 25C, PLO = 0dBm, PRF = -3dBm (-3dBm/tone for 2-tone IIP3 tests, f = 2MHz), IF = 190MHz, unless otherwise noted. Test circuit shown in Figure 1. 1950MHz SSB Noise Figure vs RF Blocker Level Conversion Gain, IIP3 and NF vs RF Frequency 15 23 13 18 21 12 17 19 11 17 10 9 14 13 8 11 7 11 6 10 GC 7 1.5 1.6 1.7 1.8 1.9 2.0 2.1 RF FREQUENCY (GHz) PLO = 0dBm 12 5 2.3 2.2 PLO = -3dBm 15 13 9 24 16 SSB NF (dB) 9 -25 0 -20 -15 -10 -5 RF BLOCKER POWER (dBm) 25 23 22 14 22 14 21 20 12 20 12 GC 8 -4 -6 -2 0 2 4 LO INPUT POWER (dBm) 18 10 16 8 14 85C 6 25C -40C 4 12 2 10 0 8 6 GC -6 -4 4 -2 0 2 LO INPUT POWER (dBm) 5542 G22 OUTPUT POWER (dBm) 0 RF1 = 1949MHz -20 RF2 = 1951MHz -30 LO = 2140MHz -40 -50 IM3 8 13 85C 6 25C -40C 4 2 9 0 7 3 -9 -6 -3 0 RF INPUT POWER (dBm/TONE) GC 2 0 -6 6 -4 4 -2 0 2 LO INPUT POWER (dBm) 6 2 x 2 and 3 x 3 Spur Suppression vs LO Power -50 LO = 2140MHz -20 -30 2LO-2RF -40 (RF = 2045MHz) -50 5542 G24 -80 -12 -9 6 5542 G23 -10 -70 12 10 11 -60 IM5 -70 -80 -12 14 NF 15 IFOUT 10 (RF = 1950MHz) -10 -60 18 17 20 IFOUT 95 16 Single-Tone IF Output Power, 2 x 2 and 3 x 3 Spurs vs RF Input Power 20 0 75 IIP3 5542 G22b 2-Tone IF Output Power, IM3 and IM5 vs RF Input Power 10 55 -5 15 35 TEMPERATURE (C) 19 RELATIVE SPUR LEVEL (dBc) 10 NF SSB NF (dB) 8 85C 6 25C -40C 4 GC (dB), IIP3 (dBm) 16 14 -25 SSB NF (dB) 24 12 OUTPUT POWER (dBm/TONE) 18 16 16 GC 5542 G21 24 10 P1dB 12 8 -45 IIP3 18 14 2150MHz Conversion Gain, IIP3 and NF vs LO Power 26 SSB NF (dB) GC (dB), IIP3 (dBm) 18 NF 16 10 1950MHz Conversion Gain, IIP3 and NF vs LO Power IIP3 18 5542 G20 1750MHz Conversion Gain, IIP3 and NF vs LO Power 26 RF = 1950MHz VCCIF = 5.0V VCCIF = 3.3V 20 5 5542 G19 IIP3 22 PLO = 3dBm GC (dB), IIP3 (dBm) GC (dB), IIP3 (dBm) 15 SSB NF (dB) RF = 1950MHz 19 BLOCKER = 1850MHz NF 26 20 14 IIP3 25 GC (dB), IIP3 (dBm), P1dB (dBm) 27 1950MHz Conversion Gain, IIP3 and RF Input P1dB vs Temperature RF = 1950MHz PRF = -10dBm LO = 2140MHz -55 -60 2LO-2RF (RF = 2045MHz) -65 -70 3LO-3RF (RF = 2076.67MHz) -75 3LO-3RF (RF = 2076.67MHz) -80 3 6 9 -6 -3 0 RF INPUT POWER (dBm) 12 15 5542 G25 -6 -4 4 -2 0 2 LO INPUT POWER (dBm) 6 5542 G26 5542f 7 LTC5542 PIN FUNCTIONS NC (Pin 1): This pin is not connected internally. It can be left floating, connected to ground or to VCC . LOBIAS (Pin 7): This Pin Allows Adjustment of the LO Buffer Current. Typical DC voltage is 2.2V. RF (Pin 2): Single-Ended Input for the RF Signal. This pin is internally connected to the primary side of the RF input transformer, which has low DC resistance to ground. A series DC-blocking capacitor should be used to avoid damage to the integrated transformer. The RF input is impedance matched, as long as the selected LO input is driven with a 0dBm 6dB source between 1.7GHz and 2.5GHz. LOSEL (Pin 9): LO1/LO2 Select Pin. When the input voltage is less than 0.3V, the LO1 port is selected. When the input voltage is greater than 3V, the LO2 port is selected. Typical input current is 11A for LOSEL = 3.3V. This pin must not be allowed to float. CT (Pin 3): RF Transformer Secondary Center-Tap. This pin may require a bypass capacitor to ground. See the Applications Information section. This pin has an internally generated bias voltage of 1.2V. It must be DC-isolated from ground and VCC. GND (Pins 4, 10, 12, 13, 17, Exposed Pad Pin 21): Ground. These pins must be soldered to the RF ground plane on the circuit board. The exposed pad metal of the package provides both electrical contact to ground and good thermal contact to the printed circuit board. SHDN (Pin 5): Shutdown Pin. When the input voltage is less than 0.3V, the internal circuits supplied through pins 6, 8, 14, 18 and 19 are enabled. When the input voltage is greater than 3V, all circuits are disabled. Typical input current is less than 10A. This pin must not be allowed to float. VCC2 (Pin 6) and VCC1 (Pin 8): Power Supply Pins for the LO Buffer and Bias Circuits. These pins are internally connected and must be externally connected to a regulated 3.3V supply, with bypass capacitors located close to the pin. Typical current consumption is 99mA. LO1 (Pin 11) and LO2 (Pin 15): Single-Ended Inputs for the Local Oscillators. These pins are internally biased at 0V and require external DC blocking capacitors. Both inputs are internally matched to 50, even when the chip is disabled (SHDN = high). VCC3 (Pin 14): Power Supply Pin for the LO Switch. This pin must be connected to a regulated 3.3V supply and bypassed to ground with a capacitor near the pin. Typical DC current consumption is less than 100A. IFGND (Pin 16): DC Ground Return for the IF Amplifier. This pin must be connected to ground to complete the IF amplifier's DC current path. Typical DC current is 100mA. IF - (Pin 18) and IF + (Pin 19): Open-Collector Differential Outputs for the IF Amplifier. These pins must be connected to a DC supply through impedance matching inductors, or a transformer center-tap. Typical DC current consumption is 50mA into each pin. IFBIAS (Pin 20): This Pin Allows Adjustment of the IF Amplifier Current. Typical DC voltage is 2.1V. 5542f 8 LTC5542 BLOCK DIAGRAM 20 19 18 16 21 IF+ IFBIAS IF - IFGND EXPOSED PAD IF AMP VCC3 14 RF 2 LO AMP LOSEL PASSIVE MIXER CT 3 5 LO2 15 SHDN 9 LO1 11 BIAS VCC2 VCC1 6 8 7 LOBIAS GND PINS ARE NOT SHOWN 5542 BD TEST CIRCUIT IFOUT 190MHz 50 4:1 T1 L1 VCCIF 3.1V TO 5.3V 100mA C9 L1, L2 vs IF Frequencies C10 IF (MHz) L1, L2 (nH) L2 140 270 190 150 240 100 300 56 380 33 C8 20 19 18 IFBIAS IF+ IF - 17 GND 16 IFGND 1 NC LO2 15 2 RF VCC3 14 C4 LO2IN 50 C1 RFIN 50 C11 LTC5542 3 CT C7 GND 13 4 GND GND 12 C3 SHDN (0V/3.3V) 5 SHDN VCC2 LOBIAS 7 6 VCC 3.1V TO 3.5V 99mA C5 0.015" 0.062" 0.015" VCC1 LOSEL 9 8 LO1IN 50 LO1 11 GND 10 REF DES VALUE SIZE COMMENTS C1, C6, C7, C8 22pF 0402 AVX C3, C4 4.7pF 0402 AVX C5, C9 1F 0603 AVX C10 1000pF 0402 AVX C11 0.7pF 0402 AVX L1, L2 150nH 0603 Coilcraft 0603CS T1 (Alternate) TC4-1W-7ALN+ (WBC4-6TLB) Mini-Circuits (Coilcraft) 5541 TC C6 LOSEL (0V/3.3V) RF GND DC1431A BOARD BIAS STACK-UP GND (NELCO N4000-13) Figure 1. Standard Downmixer Test Circuit Schematic (190MHz IF) 5542f 9 LTC5542 APPLICATIONS INFORMATION Introduction The LTC5542 consists of a high linearity passive doublebalanced mixer core, IF buffer amplifier, high speed singlepole double-throw (SPDT) LO switch, LO buffer amplifier and bias/shutdown circuits. See Block Diagram section for a description of each pin function. The RF and LO inputs are single-ended. The IF output is differential. Low-side or high-side LO injection can be used. The evaluation circuit, shown in Figure 1, utilizes bandpass IF output matching and an IF transformer to realize a 50 single-ended IF output. The evaluation board layout is shown in Figure 2. is LO frequency-dependent and is not required for most applications. When used, C2 should be located within 2mm of pin 3 for proper high-frequency decoupling. The nominal DC voltage on the CT pin is 1.2V. For the RF input to be matched, the selected LO input must be driven. The measured RF input return loss is shown in Figure 4 for LO frequencies of 1.7GHz, 2.1GHz and 2.5GHz. These LO frequencies correspond to the lower, middle and upper values of the LO range. As shown in Figure 4, the RF input impedance is somewhat dependent on LO frequency. TO MIXER RFIN C1 2 RF C11 3 CT C2 LTC5542 5542 F03 5541 5542 F02 F02 Figure 3. RF Input Schematic Figure 2. Evaluation Board Layout 0 RF Input The secondary winding of the RF transformer is internally connected to the passive mixer. The center-tap of the transformer secondary is connected to pin 3 (CT) to allow the connection of bypass capacitor, C2. The value of C2 -5 RETURN LOSS (dB) The mixer's RF input, shown in Figure 3, is connected to the primary winding of an integrated transformer. A 50 match is realized when a series capacitor C1 and shunt capacitor C11, are connected to the RF input. C1 is also needed for DC blocking if the RF source has DC voltage present, since the primary side of the RF transformer is DC-grounded internally. The DC resistance of the primary is approximately 3.6. LO = 2.5GHz C1 = 22pF C11 = 0.7pF LO = 2.1GHz LO = 1.75GHz -10 -15 -20 -25 -30 1.2 1.7 2.7 2.2 FREQUENCY (GHz) 3.2 5542 F04 Figure 4. RF Input Return Loss 5542f 10 LTC5542 APPLICATIONS INFORMATION The RF input impedance and input reflection coefficient, versus RF frequency, is listed in Table 1. The reference plane for this data is pin 2 of the IC, with no external matching, and the LO is driven at 2.1GHz. Table 1. RF Input Impedance and S11 (at Pin 2, No External Matching, LO Input Driven at 2.1GHz) S11 The LO switch is designed for high isolation and fast (<50ns) switching. This allows the use of two active synthesizers in frequency-hopping applications. If only one synthesizer is used, then the unused LO input may be grounded. The LO switch is powered by VCC3 (Pin 14) and controlled by the LOSEL logic input (Pin 9). The LO1 and LO2 inputs are always 50-matched when VCC is applied to the chip, even when the chip is shutdown. The DC resistance of the selected LO input is approximately 23 and the unselected input is approximately 50. A logic table for the LO switch is shown in Table 2. Measured LO input return loss is shown in Figure 6. FREQUENCY (GHz) INPUT IMPEDANCE MAG ANGLE 1.2 23.3 + j32.1 0.53 106.4 1.4 30.7 + j33.6 0.45 97.2 1.6 38.4 + j30.0 0.35 92.4 1.8 41.8 + j23.6 0.27 94.7 2.0 42.5 + j14.5 0.18 107.8 2.2 26.2 + j12.8 0.35 142.1 LOSEL ACTIVE LO INPUT 2.4 27.7 + j20.2 0.38 123.1 Low LO1 2.6 28.4 + j22.5 0.39 117.6 High LO2 2.8 29.6 + j25.2 0.39 111.4 3.0 32.9 + j25.9 0.36 106.3 3.2 34.2 + j23.6 0.33 108.2 LTC5542 LO2 C4 LO2IN 15 LO BUFFER VCC3 14 TO MIXER Table 2. LO Switch Logic Table The LO amplifiers are powered by VCC1 and VCC2 (pin 8 and pin 6). When the chip is enabled (SHDN = low), the internal bias circuit provides a regulated 4mA current to the amplifier's bias input, which in turn causes the amplifiers to draw approximately 88mA of DC current. This 4mA reference current is also connected to LOBIAS (Pin 7) to allow modification of the amplifier's DC bias current for special applications. The recommended application circuits require no LO amplifier bias modification, so this pin should be left open-circuited. 5 BIAS 7 LOBIAS 6 VCC2 8 VCC1 9 LOSEL 5542 F05 Figure 5. LO Input Schematic LO Inputs The mixer's LO input circuit, shown in Figure 5, consists of an integrated SPDT switch, a balun transformer, and a two-stage high-speed limiting differential amplifier to drive the mixer core. The LTC5542's LO amplifiers are optimized for the 1.7GHz to 2.5GHz LO frequency range. LO frequencies above or below this frequency range may be used with degraded performance. C3 = C4 = 4.7pF 0 RETURN LOSS (dB) LO1 11 4mA C3 LO1IN -5 -10 -15 SELECTED -20 -25 NOT SELECTED OR SHUTDOWN -30 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 FREQUENCY (GHz) 5542 F06 Figure 6. LO Input Return loss 5542f 11 LTC5542 APPLICATIONS INFORMATION The nominal LO input level is 0dBm although the limiting amplifiers will deliver excellent performance over a 6dB input power range. LO input power greater than 6dBm may cause conduction of the internal ESD diodes. Series capacitors C3 and C4 optimize the input match and provide DC blocking. T1 C10 R1 (OPTION TO REDUCE DC POWER) IFBIAS The LO1 input impedance and input reflection coefficient, versus frequency, is shown in Table 3. The LO2 port is identical due to the symmetric device layout and packaging. IFOUT 4:1 20 L1 L2 VCCIF 100mA L3 (OR SHORT) C8 19 IF+ IF - 18 16 IFGND VCC IF AMP 4mA Table 3. LO1 Input Impedance vs Frequency (at Pin 11, No External Matching, LOSEL = Low) LTC5542 BIAS S11 FREQUENCY (GHz) INPUT IMPEDANCE MAG ANGLE 1.0 53.3 - j15.4 0.15 -69.3 1.2 36.3 - j9.7 0.19 -138.2 1.4 29.9 - j1.6 0.25 -174.4 1.6 29.0 + j5.7 0.27 +160.3 1.8 30.5 + j10.5 0.27 +144.1 2.0 32.3 + j13.4 0.27 +133.4 2.2 33.6 + j15.7 0.27 +125.3 2.4 34.7 + j17.8 0.27 +118.7 2.6 35.7 + j19.7 0.28 +112.8 2.8 36.4 + j21.4 0.29 +108.6 3.0 36.7 + j22.9 0.30 +105.3 IF Output The IF amplifier, shown in Figure 7, has differential opencollector outputs (IF+ and IF -), a DC ground return pin (IFGND), and a pin for modifying the internal bias (IFBIAS). The IF outputs must be biased at the supply voltage (VCCIF), which is applied through matching inductors L1 and L2. Alternatively, the IF outputs can be biased through the center tap of a transformer. Each IF output pin draws approximately 50mA of DC supply current (100mA total). IFGND (pin 16) must be grounded or the amplifier will not draw DC current. Grounding through inductor L3 may improve LO-IF and RF-IF leakage performance in some applications, but is otherwise not necessary. High DC resistance in L3 will reduce the IF amplifier supply current, which will degrade RF performance. 5542 F07 Figure 7. IF Amplifier Schematic with Bandpass Match transformer or discrete IF balun circuit. The evaluation board (see Figures 1 and 2) uses a 4:1 ratio IF transformer for impedance transformation and differential to singleended transformation. It is also possible to eliminate the IF transformer and drive differential filters or amplifiers directly. The IF output impedance can be modeled as 300 in parallel with 2.1pF at IF frequencies. An equivalent smallsignal model (including bondwire inductance) is shown in Figure 8. Frequency-dependent differential IF output impedance is listed in Table 4. This data is referenced to the package pins (with no external components) and includes the effects of IC and package parasitics. 19 18 IF+ 0.9nH IF - 0.9nH RIF CIF LTC5542 5542 F08 Figure 8. IF Output Small-Signal Model For optimum single-ended performance, the differential IF outputs must be combined through an external IF 5542f 12 LTC5542 APPLICATIONS INFORMATION Bandpass IF Matching 4:1 The IF output can be matched for IF frequencies as low as 90MHz or as high as 500MHz using the bandpass IF matching shown in Figure 1 and Figure 7. L1 and L2 resonate with the internal IF output capacitance at the desired IF frequency. The value of L1, L2 is calculated as follows: VCCIF 3.1-5.3V C9 1F L1 82nH 19 R2 1k IF + where CIF is the internal IF capacitance (listed in Table 4). L2 82nH 18 IF - LTC5542 5542 F09 Figure 9. IF Output with Lowpass Matching 0 -5 RETURN LOSS (dB) Table 4. IF Output Impedance vs Frequency C8 22pF C13 1.5pF L1, L2 = 1/[(2 fIF)2 * 2 * CIF] Values of L1 and L2 are tabulated in Figure 1 for various IF frequencies. For IF frequencies below 90MHz, the values of L1, L2 become unreasonably high and the lowpass topology shown in Figure 9 is preferred. Measured IF output return loss for bandpass IF matching is plotted in Figure 10. IFOUT 50 T1 -10 FREQUENCY (MHz) DIFFERENTIAL OUTPUT IMPEDANCE (RIF || XIF (CIF)) 90 320 || -j842 (2.1pF) 140 312 || -j541 (2.1pF) -20 190 300 || -j419 (2.0pF) 240 294 || -j301 (2.2pF) 300 287 || -j221 (2.4pF) 33nH 100nH -25 50 100 150 200 250 300 350 400 450 500 550 FREQUENCY (MHz) 380 280 || -j161 (2.6pF) 500 269 || -j120 (2.65pF) -15 270nH 150nH 5542 F10 Figure 10. IF Output Return Loss - Bandpass Matching Lowpass IF Matching IF Amplifier Bias An alternative IF matching network shown in Figure 9 uses a lowpass topology, which provides excellent RF to IF and LO to IF isolation. VCCIF is supplied through the center tap of the 4:1 transformer. A 250 to 200 lowpass impedance transformation is realized by shunt elements R2 and C13 (in parallel with the internal RIF and CIF), and series inductors L1 and L2. Resistor R2 is selected to reduce the IF output resistance to 250, or it can be deleted for the highest conversion gain. The final impedance transformation to 50 is realized by transformer T1. The matching element values shown in Figure 9 are optimized for a wideband 30MHz to 150MHz IF match.The demo board (see Figure 2) has been laid out to accommodate this matching topology with very few modifications. The IF amplifier delivers excellent performance with VCCIF = 3.3V, which allows the VCC and VCCIF supplies to be common. With VCCIF increased to 5V, the RF input P1dB increases by more than 3dB, at the expense of higher power consumption. Mixer performance at 2400MHz is shown in Table 5 with VCCIF = 3.3V and 5V. For the highest conversion gain, high-Q wire-wound chip inductors are recommended for L1 and L2, especially when using VCCIF = 3.3V. Low-cost multilayer chip inductors may be substituted, with a slight reduction in conversion gain. 5542f 13 LTC5542 APPLICATIONS INFORMATION Table 5. Performance Comparison with VCCIF = 3.3V and 5V (RF = 2400MHz, Low-Side LO, IF = 190MHz) VCCIF ICCIF (mA) GC (dB) P1dB (dBm) IIP3 (dBm) NF (dB) 3.3V 100 8.0 11.3 26.8 9.9 5V 103 7.9 14.7 27.3 10.0 The IFBIAS pin (pin 20) is available for reducing the DC current consumption of the IF amplifier, at the expense of IIP3. This pin should be left open-circuited for optimum performance. The internal bias circuit produces a 4mA reference for the IF amplifier, which causes the amplifier to draw approximately 100mA. If resistor R1 is connected to pin 20 as shown in Figure 7, a portion of the reference current can be shunted to ground, resulting in reduced IF amplifier current. For example, R1 = 1k will shunt away 1.5mA from pin 20 and the IF amplifier current will be reduced by 38% to approximately 62mA. The nominal, open-circuit DC voltage at pin 20 is 2.1V. Table 6 lists RF performance versus IF amplifier current. Table 6. Mixer Performance with Reduced IF Amplifier Current (RF = 2400MHz, Low-Side LO, IF = 190MHz, VCC = VCCIF = 3.3V) R1 (k) ICCIF (mA) GC (dB) IIP3 (dBm) P1dB (dBm) NF (dB) OPEN 100 8.0 26.8 11.3 9.9 4.7 90 7.7 26.3 11.4 9.9 2.2 81 7.4 25.4 11.6 9.9 1 62 6.9 23.4 11.6 10.0 Shutdown Interface Figure 11 shows a simplified schematic of the SHDN pin interface. To disable the chip, the SHDN voltage must be higher than 3.0V. If the shutdown function is not required, the SHDN pin should be connected directly to GND. The voltage at the SHDN pin should never exceed the power supply voltage (VCC) by more than 0.3V. If this should occur, the supply current could be sourced through the ESD diode, potentially damaging the IC. The SHDN pin must be pulled high or low. If left floating, then the on/off state of the IC will be indeterminate. If a three-state condition can exist at the SHDN pin, then a pull-up or pull-down resistor must be used. LTC5542 VCC2 6 SHDN 500 5 (RF = 1950MHz, High-Side LO, IF = 190MHz, VCC = VCCIF = 3.3V) R1 (k) ICCIF (mA) GC (dB) IIP3 (dBm) P1dB (dBm) NF (dB) OPEN 100 8.5 25.2 11.0 9.4 4.7 90 8.3 24.9 11.1 9.3 2.2 81 8.0 24.3 11.3 9.3 1 62 7.6 22.8 11.3 9.4 5542 F11 Figure 11. Shutdown Input Circuit Supply Voltage Ramping Fast ramping of the supply voltage can cause a current glitch in the internal ESD protection circuits. Depending on the supply inductance, this could result in a supply voltage transient that exceeds the maximum rating. A supply voltage ramp time of greater than 1ms is recommended. 5542f 14 LTC5542 PACKAGE DESCRIPTION UH Package 20-Lead Plastic QFN (5mm x 5mm) (Reference LTC DWG # 05-08-1818 Rev O) 0.70 p0.05 5.50 p 0.05 4.10 p 0.05 2.60 REF 2.70 p 0.05 2.70 p 0.05 PACKAGE OUTLINE 0.25 p0.05 0.65 BSC PIN 1 NOTCH R = 0.30 TYP OR 0.35 s 45o CHAMFER RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 0.75 p 0.05 5.00 p 0.10 R = 0.05 TYP R = 0.125 TYP 19 20 0.40 p 0.10 PIN 1 TOP MARK (NOTE 6) 1 2 2.70 p 0.10 5.00 p 0.10 2.60 REF 2.70 p 0.10 (UH20) QFN 0208 REV O 0.200 REF 0.00 - 0.05 0.25 p 0.05 0.65 BSC NOTE: BOTTOM VIEW--EXPOSED PAD 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.20mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 5542f 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. 15 LTC5542 TYPICAL APPLICATION Wideband, Low-Frequency IF using Lowpass IF Matching 4:1 Wideband Conversion Gain, IIP3 and IF Output Return Loss vs Output Frequency IFOUT 25 22pF 1F GC (dB), IIP3 (dBm) 82nH 1k IF+ LO2 LTC5542 IF 22pF RF IF - 4.7pF BIAS VCC2 VCC 3.3V 1F VCC1 -10 -15 15 13 IF RETURN LOSS GC -20 7 -25 30 40 50 60 70 80 90 100110 120130140150 IF OUTPUT FREQUENCY (MHz) LO SHDN -5 17 9 0.7pF SHDN (0V/3.3V) RF = 1950 60MHz 23 LO = 2040MHz 21 PLO = 0dBm VCC = VCCIF = 3.3V 19 TA = 25C 11 RF IIP3 IF RETURN LOSS (dB) 82nH 1.5pF 0 27 30MHz to 150MHz VCCIF 3.3V VCC3 LO 5542 TA03 LO1 LOSEL 22pF 5542 TA02 RELATED PARTS PART NUMBER Infrastructure LT5527 LT5557 LTC6400-X LTC6401-X LTC6416 LTC6412 LT5554 LT5575 DESCRIPTION COMMENTS 400MHz to 3.7GHz, 5V Downconverting Mixer 400MHz to 3.8GHz, 3.3V Downconverting Mixer 300MHz Low Distortion IF Amp/ADC Driver 140MHz Low Distortion IF Amp/ADC Driver 2GHz 16-Bit ADC Buffer 31dB Linear Analog VGA Ultralow Distort IF Digital VGA 700MHz to 2.7GHz Direct Conversion I/Q Demodulator LT5578 400MHz to 2.7GHz Upconverting Mixer LT5579 1.5GHz to 3.8GHz Upconverting Mixer LTC5598 5MHz to 1.6GHz I/Q Modulator RF Power Detectors LT5534 50MHz to 3GHz Log RF Power Detector with 60dB Dynamic Range LT5537 Wide Dynamic Range Log RF/IF Detector LT5570 2.7GHz Mean-Squared Detector LT5581 6GHz Low Power RMS Detector ADCs LTC2208 16-Bit, 130Msps ADC LTC2262-14 14-Bit, 150Msps ADC Ultralow Power LTC2242-12 12-Bit, 250Msps ADC 2.3dB Gain, 23.5dBm IIP3 and 12.5dB NF at 1900MHz, 5V/78mA Supply 2.9dB Gain, 24.7dBm IIP3 and 11.7dB NF at 1950MHz, 3.3V/82mA Supply Fixed Gain of 8dB, 14dB, 20dB and 26dB; >36dBm OIP3 at 300MHz, Differential I/O Fixed Gain of 8dB, 14dB, 20dB and 26dB; >40dBm OIP3 at 140MHz, Differential I/O 40.25dBm OIP3 to 300MHz, Programmable Fast Recovery Output Clamping 35dBm OIP3 at 240MHz, Continuous Gain Range -14dB to 17dB 48dBm OIP3 at 200MHz, 2dB to 18dB Gain Range, 0.125dB Gain Steps Integrated Baluns, 28dBm IIP3, 13dBm P1dB, 0.03dB I/Q Amplitude Match, 0.4 Phase Match 27dBm OIP3 at 900MHz, 24.2dBm at 1.95GHz, Integrated RF Transformer 27.3dBm OIP3 at 2.14GHz, NF = 9.9dB, 3.3V Supply, Single-Ended LO and RF Ports 27.7dBm OIP3 at 140MHz, 22.9dBm at 900MHz, -161.2dBm/Hz Noise Floor 1dB Output Variation over Temperature, 38ns Response Time, Log Linear Response Low Frequency to 1GHz, 83dB Log Linear Dynamic Range 0.5dB Accuracy Over Temperature and >50dB Dynamic Range, 500ns Rise Time 40dB Dynamic Range, 1dB Accuracy Over Temperature, 1.5mA Supply Current 78dBFS Noise Floor, >83dB SFDR at 250MHz 72.8dB SNR, 88dB SFDR, 149mW Power Consumption 65.4dB SNR, 78dB SFDR, 740mW Power Consumption 5542f 16 Linear Technology Corporation LT 0310 * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com (c) LINEAR TECHNOLOGY CORPORATION 2010