LTC5548 2GHz to 14GHz Microwave Mixer with Wideband DC– 6GHz IF Description Features Upconversion or Downconversion nn High IIP3: +24.4dBm at 5.8GHz +21.4dBm at 9GHz nn 7.1dB Conversion Loss at 5.8GHz nn +15.2dBm Input P1dB at 5.8GHz nn Integrated LO Buffer: 0dBm LO Drive nn Selectable Integrated LO Frequency Doubler nn Low LO-RF Leakage: <–30dBm nn 50Ω Wideband Matched RF and LO Ports nn 3.3V/120mA Supply nn Fast Turn ON/OFF for TDD Operation nn 3mm × 2mm, 12-Lead QFN Package nn Applications Microwave Transceivers Wireless Backhaul nn Point-to-Point Microwave nn Phased-Array Antennas nn C, X and Ku Band RADAR nn Test Equipment nn Satellite MODEMs nn nn The LTC®5548 is a high performance, microwave double balanced passive mixer that can be used for frequency upconversion or downconversion. The device is similar to the LTC5549, but with a broadband, differential DC to 6GHz IF port. The LTC5548 is recommended for applications where the IF frequency range extends below 500MHz. For applications where the IF frequency is always above 500MHz, the LTC5549 is recommended, since it includes an integrated IF balun. The LTC5548’s mixer and integrated RF balun are optimized to cover the 2GHz to 14GHz RF frequency range. The device includes an integrated LO amplifier optimized for the 1GHz to 12GHz frequency range, requiring only 0dBm drive. The device also includes an integrated LO frequency doubler, which can be enabled or disabled with a CMOS-compatible control pin. The LTC5548 delivers exceptionally high IIP3 and P1dB, in addition to very low LO to RF and LO to IF leakages. The part also offers high integration in a small package. 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. Typical Application Conversion Loss and IIP3 (Low Side LO, IF = 240MHz) LNA RF IF RX IFOUT LO RX LO DUPLEXER TX LO LO PA RF IF TX IFIN 30 CONVERSION LOSS (dB), IIP3 (dBm) LTC5548 28 26 IIP3 24 22 20 18 DOWNMIXING UPMIXING 16 14 12 10 CONVERSION LOSS 8 LTC5548 5548 TA01a 6 2 3 4 5 6 7 8 9 10 11 12 RF FREQUENCY (GHz) 5548 TA01b 5548f For more information www.linear.com/LTC5548 1 LTC5548 Absolute Maximum Ratings Pin Configuration (Note 1) IF + 2 IF – 3 LO GND 12 11 10 13 GND 4 5 6 GND 1 RF GND GND TOP VIEW GND Supply Voltage (VCC)...................................................4V Enable Input Voltage (EN).................–0.3V to VCC + 0.3V X2 Input Voltage (X2).......................–0.3V to VCC + 0.3V LO Input Power (1GHz to 12GHz)................... ….+10dBm LO Input DC Voltage ............................................. ±0.1V RF Power (2GHz to 14GHz).................................+20dBm RF DC Voltage ........................................................ ±0.1V IF+/IF – Input Power (LF to 6GHz)........................+20dBm IF+/IF – Input DC Voltage..........................................±0.3V Operating Temperature Range (TC)......... –40°C to 105°C Storage Temperature Range................... –65°C to 150°C Junction Temperature (TJ)..................................... 150°C 9 VCC 8 X2 7 EN UDB PACKAGE 12-LEAD (3mm × 2mm) PLASTIC QFN TJMAX = 150°C, θJC = 25°C/W EXPOSED PAD (PIN 13) IS GND, MUST BE SOLDERED TO PCB Order Information (http://www.linear.com/product/LTC5548#orderinfo) Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC5548IUDB#TRMPBF LTC5548IUDB#TRPBF LGXF 12-Lead (3mm × 2mm) Plastic QFN –40°C to 105°C TRM = 500 pieces. Consult LTC Marketing for parts specified with wider operating temperature ranges. 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/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. DC Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TC = 25°C. VCC = 3.3V, EN = High, unless otherwise noted. Test circuit shown in Figure 1. (Note 2) PARAMETER CONDITIONS MIN TYP MAX UNITS Power Supply Requirements Supply Voltage (VCC) l Supply Current Enabled X2 = Low (LO Doubler Off) X2 = High (LO Doubler On) Shutdown Current EN = Low 3.0 3.3 3.6 V 120 136 140 160 mA mA 100 μA Enable (EN) and LO Frequency Doubler (X2) Logic Inputs Input High Voltage (On) l Input Low Voltage (Off) l Input Current –0.3V to VCC + 0.3V 1.2 V –30 0.3 V 100 μA Chip Turn-On Time 0.2 μs Chip Turn-Off Time 0.1 μs 2 5548f For more information www.linear.com/LTC5548 LTC5548 AC Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TC = 25°C. VCC = 3.3V, EN = High, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for twotone IIP3 tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3) PARAMETER CONDITIONS MIN TYP MAX UNITS LO Frequency Range l 1 to 12 GHz RF Frequency Range l 2 to 14 GHz IF Frequency Range l DC to 6000 MHz RF Return Loss ZO = 50Ω, 2GHz to 13.6GHz >9 dB LO Input Return Loss ZO = 50Ω, 1GHz to 12GHz >10 dB LO Input Power X2 = Low X2 = High –6 –6 0 0 6 3 dBm dBm Downmixer Application with LO Doubler Off (X2 = Low), IF = 240MHz, Low Side LO Conversion Loss RF Input = 2GHz RF Input = 5.8GHz RF Input = 9GHz RF Input = 12GHz 6.0 7.1 8.5 10.2 dB dB dB dB Conversion Loss vs Temperature TC = –40°C to 105°C, RF Input = 5.8GHz 0.006 dB/°C 2-Tone Input 3rd Order Intercept (ΔfRF = 2MHz) RF Input = 2GHz RF Input = 5.8GHz RF Input = 9GHz RF Input = 12GHz 23.1 24.4 21.4 18.7 dBm dBm dBm dBm SSB Noise Figure RF Input = 2GHz RF Input = 5.8GHz RF Input = 8.5GHz 6.2 8.0 9.6 dB dB dB LO to RF Leakage fLO = 1GHz to 12GHz <–25 dBm LO to IF Leakage fLO = 1GHz to 12GHz <–26 dBm RF to LO Isolation fRF = 2GHz to 14GHz >40 dB l RF Input to IF Output Isolation fRF = 2GHz to 14GHz >35 dB Input 1dB Compression RF Input = 5.8GHz 15.2 dBm 7.3 9.2 11.8 dB dB dB 0.006 dB/°C Downmixer Application with LO Doubler On (X2 = High), IF = 240MHz, Low Side LO Conversion Loss RF Input = 5.8GHz RF Input = 9GHz RF Input = 12GHz Conversion Loss vs. Temperature TC = –40°C to 105°C, RF Input = 5.8GHz 2-Tone Input 3rd Order Intercept (ΔfRF = 2MHz) RF Input = 5.8GHz RF Input = 9GHz RF Input = 12GHz 23.9 20.9 18.3 dBm dBm dBm SSB Noise Figure RF Input = 5.8GHz RF Input = 8.5GHz 8.9 10.8 dB dB l LO to RF Input Leakage fLO = 1GHz to 5GHz <–30 dBm 2LO to RF Input Leakage fLO = 1GHz to 5GHz ≤–25 dBm LO to IF Output Leakage fLO = 1GHz to 5GHz <–36 dBm 2LO to IF Output Leakage fLO = 1GHz to 5GHz <–20 dBm Input 1dB Compression fRF = 5.8GHz 14.8 dBm 5548f For more information www.linear.com/LTC5548 3 LTC5548 AC Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TC = 25°C. VCC = 3.3V, EN = High, PLO = 0dBm, PIF = –5dBm (–5dBm/tone for twotone IIP3 tests), unless otherwise noted. Test circuit shown in Figure 1. (Notes 2, 3) PARAMETER CONDITIONS MIN TYP MAX UNITS Upmixer Application with LO Doubler Off (X2 = Low), IF = 240MHz, Low Side LO Conversion Loss RF Output = 2GHz RF Output = 5.8GHz RF Output = 9GHz RF Output = 12GHz 6.3 7.1 9.3 10.9 dB dB dB dB Conversion Loss vs Temperature TC = –40°C to 105°C, RF Output = 5.8GHz 0.006 dB/°C Input 3rd Order Intercept (ΔfIF = 2MHz) RF Output = 2GHz RF Output = 5.8GHz RF Output = 9GHz RF Output = 12GHz 26.3 24.9 21.5 17.2 dBm dBm dBm dBm SSB Noise Figure RF Output = 2GHz RF Output = 5.8GHz RF Output = 8.5GHz 7.8 8.7 10.4 dB dB dB LO to RF Output Leakage fLO = 1GHz to 12GHz <–25 dBm LO to IF Input Leakage fLO = 1GHz to 12GHz <–26 dBm IF to LO Isolation fIF = 500MHz to 6GHz >50 dB IF to RF Isolation fIF = 500MHz to 6GHz >40 dB Input 1dB Compression RF Output = 5.8GHz 15.7 dBm Upmixer Application with LO Doubler On (X2 = High), IF = 240MHz, Low Side LO Conversion Loss RF Output = 5.8GHz RF Output = 9GHz RF Output = 12GHz 7.4 9.6 12.1 dB dB dB Conversion Loss vs Temperature TC = –40°C to 105°C, RF Output = 5.8GHz 0.006 dB/°C 2-Tone Input 3rd Order Intercept (ΔfIF = 2MHz) RF Output = 5.8GHz RF Output = 9GHz RF Output = 12GHz 24.9 21.3 16.8 dBm dBm dBm SSB Noise Figure RF Output = 5.8GHz RF Output = 9GHz 10.4 12.4 dB dB LO to RF Output Leakage fLO = 1GHz to 5GHz <–30 dBm 2LO to RF Output Leakage fLO = 1GHz to 5GHz <–25 dBm LO to IF Input Leakage fLO = 1GHz to 5GHz <–36 dBm 2LO to IF Input Leakage fLO = 1GHz to 5GHz <–20 dBm Input 1dB Compression RF Output = 5.8GHz 14.8 dBm 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 LTC5548 is guaranteed functional over the –40°C to 105°C case temperature range (θJC = 25°C/W). 4 Note 3: SSB noise figure measurements performed with a small-signal noise source, bandpass filter and 2dB matching pad on input, with bandpass filters on LO, and output. 5548f For more information www.linear.com/LTC5548 LTC5548 Typical Performance Characteristics Supply Current vs Case Temperature Supply Current vs VCC 150 X2 = HIGH 140 140 130 130 120 120 110 ICC (mA) ICC (mA) 150 X2 = LOW 100 90 80 70 –40 –20 EN = high, test circuit shown in Figure 1. X2 = HIGH X2 = LOW 110 100 0 20 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 90 VCC = 3V VCC = 3.3V VCC = 3.6V 80 40 60 80 100 120 70 3.0 3.1 CASE TEMPERATURE (°C) 3.2 3.3 3.4 3.5 3.6 SUPPLY VOLTAGE (V) 5548 G01 5548 G02 5548f For more information www.linear.com/LTC5548 5 LTC5548 Typical Performance Characteristics 2GHz to 12GHz downmixer application. VCC = 3.3V, EN = high, X2 = low, TC = 25°C, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), IF = 240MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Loss and IIP3 vs RF Frequency (Low Side LO) Conversion Loss and IIP3 vs RF Frequency (High Side LO) 26 24 22 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 26 IIP3 20 18 16 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 14 12 10 8 6 4 CONVERSION LOSS 2 3 4 5 6 7 8 IIP3 22 20 18 16 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 14 12 10 8 6 4 10 11 12 9 24 CONVERSION LOSS 2 3 4 RF FREQUENCY (GHz) 5 6 7 8 10 11 12 9 RF FREQUENCY (GHz) 5548 G03 5548 G04 Conversion Loss and IIP3 vs RF Frequency (High Side LO) Conversion Loss and IIP3 vs RF Frequency (Low Side LO) 26 24 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 26 IIP3 22 20 18 16 PLO = –6dBm PLO = 0dBm PLO = 6dBm 14 12 10 8 CONVERSION LOSS 6 4 2 3 4 5 6 7 8 9 24 20 18 16 PLO = –6dBm PLO = 0dBm PLO = 6dBm 14 12 10 8 CONVERSION LOSS 6 4 10 11 12 IIP3 22 2 3 4 RF FREQUENCY (GHz) 5 6 7 8 10 11 12 9 RF FREQUENCY (GHz) 5548 G05 5548 G06 Conversion Loss and IIP3 vs RF Frequency (Low Side LO) Conversion Loss and IIP3 vs RF Frequency (High Side LO) 26 24 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 26 IIP3 22 20 18 16 VCC = 3V VCC = 3.3V VCC = 3.6V 14 12 10 8 6 4 CONVERSION LOSS 2 3 4 5 6 7 8 9 10 11 12 24 IIP3 22 20 18 16 VCC = 3V VCC = 3.3V VCC = 3.6V 14 12 10 8 CONVERSION LOSS 6 4 2 3 RF FREQUENCY (GHz) 5 6 7 8 9 10 11 12 RF FREQUENCY (GHz) 5548 G07 6 4 5548 G08 5548f For more information www.linear.com/LTC5548 LTC5548 2GHz to 12GHz downmixer application. Typical Performance Characteristics VCC = 3.3V, EN = high, X2 = low, TC = 25°C, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), IF = 240MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Loss and IIP3 vs IF Frequency (Low Side LO) Input P1dB vs RF Frequency 16 26 15 IIP3 24 14 22 INPUT P1dB (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 28 20 18 RF = 5.8GHz RF = 9.8GHz 16 14 12 11 HIGH SIDE LO LOW SIDE LO 9 8 6 12 10 CONVERSION LOSS 10 13 0 0.5 1 1.5 2 8 3 2.5 2 3 4 IF FREQUENCY (GHz) 5 6 7 8 9 5548 G09 5548 G10 LO Leakage RF Isolation –10 65 –20 LO-IF –30 LO-RF RF ISOLATION (dB) 60 LO LEAKAGE (dBm) 10 11 12 RF FREQUENCY (GHz) –40 RF-LO 55 50 45 RF-IF 40 35 –50 1 2 3 4 5 6 7 8 30 9 10 11 12 2 3 LO FREQUENCY (GHz) 4 5 6 7 8 5548 G11 30 60 DISTRIBUTION (%) DISTRIBUTION (%) 5.8GHz IIP3 Histogram 35 85°C 25°C –40°C 70 10 11 12 5548 G12 5.8GHz Conversion Loss Histogram 80 9 RF FREQUENCY (GHz) 50 40 30 20 85°C 25°C –40°C 25 20 15 10 5 10 0 6.6 6.7 6.8 6.9 7.0 7.1 7.2 7.3 7.4 7.5 7.6 0 22.8 23.2 23.6 CONVERSION LOSS (dB) 24 24.4 24.8 25.2 25.6 IIP3 (dBm) 5548 G13 5548 G14 5548f For more information www.linear.com/LTC5548 7 LTC5548 Typical Performance Characteristics 2GHz to 12GHz downmixer application with LO frequency doubler enabled. VCC = 3.3V, EN = high, X2 = high, TC = 25°C, PLO = 0dBm, PRF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), IF = 240MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Loss and IIP3 vs RF Frequency (Low Side LO) 26 24 24 IIP3 22 20 18 16 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 14 12 10 8 CONVERSION LOSS 6 4 2 3 4 5 6 7 8 9 10 11 12 26 IIP3 22 20 18 16 PLO = –6dBm PLO = 0dBm PLO = 3dBm 14 12 10 8 CONVERSION LOSS 6 4 2 3 4 5 6 7 8 IIP3 20 18 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 8 CONVERSION LOSS 6 4 2 3 4 5 6 7 8 9 20 18 16 PLO = –6dBm PLO = 0dBm PLO = 3dBm 14 12 10 8 CONVERSION LOSS 6 4 10 11 12 IIP3 22 2 3 4 8 6 CONVERSION LOSS 2 3 4 5 6 7 8 10 11 12 9 Conversion Loss and IIP3 vs RF Frequency (High Side LO) 5 6 7 8 9 24 20 18 16 VCC = 3V VCC = 3.3V VCC = 3.6V 14 12 10 8 6 4 10 11 12 IIP3 22 CONVERSION LOSS 2 3 4 5 6 7 8 10 11 12 9 RF FREQUENCY (GHz) 5548 G18 5548 G17 Conversion Loss and IIP3 vs IF Frequency (Low Side LO) Input P1dB vs RF Frequency LO and 2LO Leakage to IF 16 26 –10 IIP3 24 20 18 RF = 5.8GHz RF = 9.8GHz 16 14 12 10 8 6 0.5 1 1.5 14 13 12 11 10 CONVERSION LOSS 0 LO AND 2LO LEAKAGE (dBm) 15 22 INPUT P1dB (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 10 RF FREQUENCY (GHz) 5548 G16 2 2.5 3 9 5548 G19 –20 2LO-IF –30 LO-IF –40 HIGH SIDE LO LOW SIDE LO 2 3 4 5 6 7 8 9 10 11 12 RF FREQUENCY (GHz) IF FREQUENCY (GHz) 8 12 26 RF FREQUENCY (GHz) 4 VCC = 3V VCC = 3.3V VCC = 3.6V 14 5548 G15 CONVERSION LOSS (dB), IIP3 (dBm) 24 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 26 24 10 16 Conversion Loss and IIP3 vs RF Frequency (High Side LO) 26 12 18 5548 G14 Conversion Loss and IIP3 vs RF Frequency (High Side LO) 14 20 RF FREQUENCY (GHz) 5548 G15 16 IIP3 22 4 10 11 12 9 24 RF FREQUENCY (GHz) RF FREQUENCY (GHz) 22 Conversion Loss and IIP3 vs RF Frequency (Low Side LO) CONVERSION LOSS (dB), IIP3 (dBm) 26 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) Conversion Loss and IIP3 vs RF Frequency (Low Side LO) –50 1 2 3 4 5 LO FREQUENCY (GHz) 5548 G20 5548 G21 5548f For more information www.linear.com/LTC5548 LTC5548 2GHz to 12GHz upmixer application. Typical Performance Characteristics VCC = 3.3V, EN = high, X2 = low, TC = 25°C, PLO = 0dBm, PIF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), IF = 240MHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Loss and IIP3 vs RF Frequency (Low Side LO) 28 26 26 IIP3 24 22 20 18 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 16 14 12 10 CONVERSION LOSS 8 6 2 3 4 5 6 7 8 9 28 IIP3 24 22 20 PLO = –6dBm PLO = 0dBm PLO = 6dBm 18 16 14 12 10 CONVERSION LOSS 8 6 10 11 12 2 3 4 RF FREQUENCY (GHz) 5 6 7 8 9 IIP3 22 20 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 10 CONVERSION LOSS 8 6 2 3 4 5 6 7 8 9 22 20 18 14 12 10 CONVERSION LOSS 8 6 10 11 12 PLO = –6dBm PLO = 0dBm PLO = 6dBm 16 2 3 4 2 3 4 5 6 7 3 IF FREQUENCY (GHz) 8 9 7 8 9 10 11 12 IIP3 24 22 20 VCC = 3V VCC = 3.3V VCC = 3.6V 18 16 14 12 10 CONVERSION LOSS 8 6 10 11 12 2 3 4 5 6 7 8 9 10 11 12 RF FREQUENCY (GHz) 5548 G27 IF Isolation 90 16 80 15 70 14 13 12 10 0 0.5 1 1.5 2 2.5 IF-LO 60 50 IF-RF 40 30 LS LO, RF = 5.8GHz LS LO, RF = 9.8GHz 3 IF FREQUENCY (GHz) 5548 G28 6 26 17 11 2.5 5 5548 G24 IF ISOLATION (dB) INPUT P1dB (dBm) CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS 2 CONVERSION LOSS 8 Input P1dB vs IF Frequency RF = 5.8GHz RF = 9.8GHz 1.5 10 5548 G26 IIP3 1 12 RF FREQUENCY (GHz) Conversion Loss and IIP3 vs IF Frequency (Low Side LO) 0.5 14 Conversion Loss and IIP3 vs RF Frequency (High Side LO) IIP3 24 5548 G25 0 VCC = 3V VCC = 3.3V VCC = 3.6V 16 28 RF FREQUENCY (GHz) 32 30 28 26 24 22 20 18 16 14 12 10 8 6 18 RF FREQUENCY (GHz) CONVERSION LOSS (dB), IIP3 (dBm) 26 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 28 12 20 Conversion Loss and IIP3 vs RF Frequency (High Side LO) 26 14 22 5548 G23 28 16 IIP3 24 RF FREQUENCY (GHz) Conversion Loss and IIP3 vs RF Frequency (High Side LO) 18 26 6 10 11 12 5548 G22 24 Conversion Loss and IIP3 vs RF Frequency (Low Side LO) CONVERSION LOSS (dB), IIP3 (dBm) 28 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) Conversion Loss and IIP3 vs RF Frequency (Low Side LO) 20 0 0.5 1 1.5 2 2.5 3 IF FREQUENCY (GHz) 5548 G29 5548 G30 5548f For more information www.linear.com/LTC5548 9 LTC5548 Typical Performance Characteristics 2GHz to 12GHz upmixer application with LO frequency doubler enabled. VCC = 3.3V, EN = high, X2 = high, TC = 25°C, PLO = 0dBm, PIF = –5dBm (–5dBm/tone for two-tone IIP3 tests, Δf = 2MHz), output measured at 5.8GHz, unless otherwise noted. Test circuit shown in Figure 1. Conversion Loss and IIP3 vs RF Frequency (Low Side LO) 28 26 26 IIP3 24 22 20 18 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 16 14 12 10 CONVERSION LOSS 8 6 2 3 4 5 6 7 8 9 28 IIP3 24 22 20 PLO = –6dBm PLO = 0dBm PLO = 3dBm 18 16 14 12 10 CONVERSION LOSS 8 6 10 11 12 2 3 4 RF FREQUENCY (GHz) 5 6 7 8 9 20 TC = –40°C TC = 25°C TC = 85°C TC = 105°C 12 CONVERSION LOSS 8 2 3 4 5 6 7 8 9 24 18 PLO = –6dBm PLO = 0dBm PLO = 3dBm 16 14 12 CONVERSION LOSS 10 8 6 10 11 12 IIP3 20 2 3 4 5 6 7 8 9 3 4 5 6 7 8 24 9 10 11 12 IIP3 22 20 18 VCC = 3V VCC = 3.3V VCC = 3.6V 16 14 12 CONVERSION LOSS 10 8 2 3 4 5 6 7 8 9 10 11 12 RF FREQUENCY (GHz) 5548 G33 Input P1dB vs IF Frequency LO and 2LO Leakage to RF –10 RF = 5.8GHz RF = 9.8GHz CONVERSION LOSS LO AND 2LO LEAKAGE (dBm) 16 INPUT P1dB (dBm) CONVERSION LOSS (dB), IIP3 (dBm) 2 5548 G35 IIP3 15 14 13 12 11 1.5 2 2.5 3 IF FREQUENCY (GHz) 10 LS LO, RF = 5.8GHz LS LO, RF = 9.8GHz 0 0.5 1 1.5 2 2.5 3 IF FREQUENCY (GHz) 5548 G37 10 CONVERSION LOSS 8 6 10 11 12 17 1 10 RF FREQUENCY (GHz) Conversion Loss and IIP3 vs IF Frequency (Low Side LO) 0.5 12 Conversion Loss and IIP3 vs RF Frequency (High Side LO) 22 5548 G34 0 14 26 RF FREQUENCY (GHz) 32 30 28 26 24 22 20 18 16 14 12 10 8 6 VCC = 3V VCC = 3.3V VCC = 3.6V 16 5548 G33 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) IIP3 10 18 Conversion Loss and IIP3 vs RF Frequency (High Side LO) 22 14 20 RF FREQUENCY (GHz) 26 16 22 5548 G32 26 18 IIP3 24 RF FREQUENCY (GHz) Conversion Loss and IIP3 vs RF Frequency (High Side LO) 24 26 6 10 11 12 5548 G31 6 Conversion Loss and IIP3 vs RF Frequency (Low Side LO) CONVERSION LOSS (dB), IIP3 (dBm) 28 CONVERSION LOSS (dB), IIP3 (dBm) CONVERSION LOSS (dB), IIP3 (dBm) Conversion Loss and IIP3 vs RF Frequency (Low Side LO) –20 2LO-RF –30 –40 –50 LO-RF 1 2 3 4 5 6 LO FREQUENCY (GHz) 5548 G38 5548 G39 5548f For more information www.linear.com/LTC5548 LTC5548 Pin Functions GND (Pins 1, 4, 6, 10, 12, Exposed Pad Pin 13): Ground. These pins must be soldered to the RF ground 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. EN (Pin 7): Enable Pin. When the voltage applied to this pin is greater than 1.2V, the mixer is enabled. When the voltage is less than 0.3V, the mixer is disabled. Typical input current is less than 30μA. This pin has an internal 376kΩ pull-down resistor. IF+, IF– (Pins 2, 3): Differential Terminals for the IF. These pins may be used for a differential IF or connected to an external balun if a single-ended IF port is needed. The IF port can be used from DC up to 6GHz depending on the external balun bandwidth. X2 (Pin 8): Digital Control Pin for LO Frequency Doubler. When the voltage applied to this pin is greater than 1.2V, the LO frequency doubler is enabled. When the voltage DC is less than 0.3V, the LO frequency doubler is disabled. Typical input current is less than 30μA. This pin has an internal 376kΩ pull-down resistor. RF (Pin 5): Single-Ended Terminal for the RF Port. This pin is internally connected to the primary side of the RF transformer, which has low DC resistance to ground. A series DC blocking capacitor must be used to avoid damage to the integrated transformer if DC voltage is present. The RF port is impedance matched from 2GHz to 14GHz as long as the LO is driven with a 0 ±6dBm source between 1GHz and 12GHz. VCC (Pin 9): Power Supply Pin. This pin must be externally connected to a regulated 3.3V supply, with a bypass capacitor located close to the pin. Typical current consumption is 120mA when the part is enabled. LO (Pin 11): Input for the Local Oscillator (LO). A series DC blocking capacitor must be used. Typical DC voltage at this pin is 1.6V. Block Diagram 3 LTC5548 2 IF – IF + X2 5 LO AMP RF 11 LO MIXER CORE REF/BIAS 7 EN 8 X2 9 VCC GND PINS ARE NOT SHOWN. 5548 BD 5548f For more information www.linear.com/LTC5548 11 LTC5548 Test Circuit IF 50Ω • T1 • 3 2 1 IF – IF+ GND 4 GND LTC5548 GND 12 C4 RF 50Ω 13 GND 5 RF C1 ZO = 50Ω L = 1.4mm 6 GND LO 11 ZO = 50Ω L = 3.55mm C3 LO 50Ω GND 10 EN X2 VCC 7 8 9 VCC (3.0V TO 3.6V) EN X2 C2 C5 5548 F01 REF DES VALUE SIZE VENDOR COMMENT C1, C3 0.15pF 0402 AVX ACCU-P 04021JR15ZBS C2, C4 22pF 0402 AVX 0402A220JAT2A C5 1µF 0603 Murata GRM188R71A105KA61 T1 TC1-1-13M+* Mini Circuits IF = 4.5MHz to 3GHz TCM1-83X+ Mini Circuits IF = 10MHz to 6GHz * Standard Evaluation Board Configuration Figure 1. Standard Test Circuit Schematic 12 5548f For more information www.linear.com/LTC5548 LTC5548 Applications Information Introduction The LTC5548 consists of a high linearity double-balanced mixer core, LO buffer amplifier, LO frequency doubler and bias/enable circuits. See the Block Diagram section for a description of each pin function. The RF and LO are singleended terminals. The IF is differential. An external balun is needed if a single-ended IF signal is desired. The LTC5548 can be used as a frequency downconverter where the RF is used as an input and IF is used as an output. It can also be used as a frequency upconverter where the IF is used as an input and RF is used as an output. Low side or high side LO injection can be used. The evaluation circuit and the evaluation board layout are shown in Figure 1 and Figure 2, respectively. LTC5548 RF 50Ω 5 RF C1 ZO = 50Ω L = 1.4mm 5548 F03 Figure 3. Simplified RF Port Interface Schematic 0 IF = 240MHz IF = 1890MHz IF = 4000MHz RF RETURN LOSS (dB) 5 10 15 20 25 30 35 40 2 3 4 5 6 7 8 9 10 11 12 13 14 RF FREQUENCY (GHz) 5548 F04a (a) 0 IF = 240MHz IF = 1890MHz IF = 4000MHz Figure 2. Evaluation Board Layout RF Port The mixer’s RF port, shown in Figure 3, is connected to the primary winding of an integrated transformer. The primary side of the RF transformer is DC-grounded internally and the DC resistance of the primary side is approximately 3.2Ω. A DC blocking capacitor is needed if the RF source has DC voltage present. The secondary winding of the RF transformer is internally connected to the mixer core. RF RETURN LOSS (dB) 5 10 15 20 25 30 35 2 3 4 5 6 7 8 9 10 11 RF FREQUENCY (GHz) (b) 5548 F04b Figure 4. RF Port Return Loss (a) C1 = 0.15pF (b) C1 Open 5548f For more information www.linear.com/LTC5548 13 LTC5548 Applications Information The RF port is broadband matched to 50Ω from 2GHz to 14GHz with a 0.15pF shunt capacitor (C1) located 1.4mm away from the RF pin. The RF port is 50Ω matched from 2GHz to 10GHz without C1. An LO between –6dBm and 6dBm is required for good RF impedance matching. The measured RF input return loss is shown in Figure 4 for IF frequencies of 240MHz, 1890MHz and 4GHz with low side LO. The RF input impedance and input reflection coefficient versus RF frequency is listed in Table 1. The reference plane for this data is Pin 5 of the IC, with no external matching, and the LO is driven at 7.5GHz. Table 1. RF Input Impedance and S11 (at Pin 5, No External Matching, LO Input Driven at 7.5GHz) S11 FREQUENCY (GHz) INPUT IMPEDANCE MAG ANGLE 2 34.3+j28.9 0.37 99.6 3 49.4+j24.7 0.24 77.4 4 57.2-j3.8 0.08 –25.8 5 37.7+j4.4 0.15 157.4 6 43.4+j2.2 0.07 160.2 7 46.2-j1.9 0.04 –152.3 8 47.8-j1.1 0.02 –155.0 Table 1. RF Input Impedance and S11 (at Pin 5, No External Matching, LO Input Driven at 7.5GHz) 9 48.8+j0.6 0.01 152.8 10 46.1+j9.1 0.10 107.8 11 35.8+j3.2 0.17 165.2 12 16.3+j4.1 0.51 169.5 13 10.9+j2.3 0.64 174.5 14 12.9-j3.5 0.59 –171.4 LO Input The mixer’s LO input, shown in Figure 5, consists of a single-ended to differential conversion, high speed limiting differential amplifier and an LO frequency doubler. The LO amplifier is optimized for the 1GHz to 12GHz LO frequency range. LO frequencies above or below this frequency range may be used with degraded performance. The LO frequency doubler is controlled by a digital voltage input at X2 (Pin 8). When the X2 voltage is higher than 1.2V, the LO frequency doubler is enabled. When X2 is left open or its voltage is lower than 0.3V, the LO frequency doubler is disabled. The DC voltage at the LO input is about 1.6V. A DC blocking capacitor (C4) is required. LTC5548 Z0 = 50Ω L = 3.55mm X2 LO C4 LO 11 C3 8 X2 9 VCC 5548 F05 Figure 5. Simplified LO Input Schematic 14 5548f For more information www.linear.com/LTC5548 LTC5548 Applications Information The LO is 50Ω matched from 1GHz to 12GHz, with a 0.15pF shunt capacitor (C3) located 3.55mm away from the LO pin. External matching components may be needed for extended LO operating frequency range. The measured LO input return loss is shown in Figure 6. The LO return loss does not change when LO frequency double is enabled. The nominal LO input level is 0dBm, although the limiting amplifiers will deliver excellent performance over a ±6dBm input power range. 0 X2 = LOW, EN = HIGH X2 = LOW, EN = LOW X2 = HIGH, EN = HIGH LO RETURN LOSS (dB) 5 10 15 20 25 30 1 2 3 4 5 6 7 8 The LO input impedance and input reflection coefficient versus frequency, is shown in Table 2. Table 2. LO Input Impedance vs Frequency (at Pin 11, No External Matching) S11 FREQUENCY (GHz) INPUT IMPEDANCE MAG ANGLE 1 63.8-j17.4 0.19 –42.9 2 58.1-j12.7 0.14 –50.8 3 50.5-j10.8 0.11 –81.2 4 43.4-j9.1 0.12 –120.4 5 36.7+j4.6 0.16 157.9 6 30.9-j6.8 0.25 –155.6 7 28.1-j6.3 0.29 –159.3 8 28.7-j5.1 0.28 –162.8 9 28.9-j2.2 0.27 –172.5 10 26.4+j2.6 0.31 171.8 11 24.1+j3.1 0.35 170.8 12 24.3+j0.3 0.35 179.1 9 10 11 12 13 LO FREQUENCY (GHz) 5548 F06a (a) C3 = 0.15pF 0 X2 = LOW, EN = HIGH X2 = LOW, EN = LOW X2 = HIGH, EN = HIGH LO RETURN LOSS (dB) 5 10 15 20 25 30 1 2 3 4 5 6 7 8 9 10 11 12 13 LO FREQUENCY (GHz) 5548 F06b (b) C3 Open Figure 6. LO Input Return Loss 5548f For more information www.linear.com/LTC5548 15 LTC5548 Applications Information IF Port The measured IF port return loss is shown in Figure 8. The mixer’s IF port is differential as shown in Figure 7. ESD protection diodes are connected to both of these ports. The differential IF output of the LTC5548 is suitable for directly driving a wideband differential amplifier or filter. Figure 9 shows a schematic for the evaluation of LTC5548 with a differential IF at very low IF frequency. The impedance of the IF+ and IF– terminals is approximately 25Ω in parallel with 0.25pF. An external 1:1 balun is required for a 50Ω single-ended IF. Using a TC1-1-13M+ balun, for example, the IF port is broadband matched from 4.5MHz to 3GHz, when the LO is applied. IF – 3 2 5 IF RETURN LOSS (dB) LTC5548 0 IF + 10 TCM1-83X+ 15 TC1-1-13M+ 20 25 30 35 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 IF FREQUENCY (GHz) 5548 F07 5548 F08 Figure 7. Simplified IF Port Schematic Figure 8. IF Port Return Loss L-PADS AND 180° COMBINER FOR 50Ω SINGLE-ENDED MEASUREMENT 34.8Ω IF – 50Ω 10kHz TO 20MHz COMBINER 0° 35.7Ω + 34.8Ω 50Ω 3 LTC5548 Z0 = 50Ω L = 1.4mm IF 50Ω 35.7Ω 2 IF – IF + X2 LO AMP RF 0.15pF IF 50Ω OUT 180° Z0 = 50Ω L = 3.55mm 5 RF ZMSCJ-2-2 22pF 11 LO LO 0.15pF MIXER CORE REF/BIAS 7 EN 8 X2 9 VCC 5548 F09 VCC 3.3V EN X2 22pF 1µF Figure 9. Test Circuit for Wideband Differential Output at IF Frequency of 10kHz to 20MHz 16 For more information www.linear.com/LTC5548 5548f LTC5548 Applications Information The complete test circuit, shown in Figure 9, uses resistive impedance matching attenuators (L-pads) on an evaluation board to transform each 25Ω IF output to 50Ω. An external 0°/180° power combiner is then used to convert the 100Ω differential output to 50Ω single-ended to facilitate measurement. The measured performance is shown in Figure 10. The measured results do not include the loss of the L-pads and external 180° combiner. CONVERSION LOSS (dB), IIP3 (dBm) Figure 11 shows a simplified schematic of the EN pin interface. To enable the chip, the EN voltage must be higher than 1.2V. The voltage at the EN pin should never exceed VCC by more than 0.3V. If this should occur, the supply current could be sourced through the ESD diode, potentially damaging the IC. If the EN pin is left floating, its voltage will be pulled low by the internal pull-down resistor and the chip will be disabled. X2 Interface 25 IIP3 23 15 13 RF = 5.8GHz LS LO 11 9 CONVERSION LOSS 7 5 Enable Interface 0 4000 8000 12000 20000 16000 IF FREQUENCY (kHz) 5548 F10 Figure 10. Conversion Gain and IIP3 for Differential IF Frequency of 10kHz to 20MHz 9 7 VCC EN Figure 12 shows a simplified schematic of the X2 pin interface. To enable the integrated LO frequency doubler, the X2 voltage must be higher than 1.2V. The X2 voltage at the pin should never exceed VCC by more than 0.3V. If this should occur, the supply current could be sourced through the ESD diode, potentially damaging the IC. If the X2 pin is left floating, its voltage will be pulled low by the internal pull-down resistor and the LO frequency doubler will be disabled. 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. LTC5548 9 BIAS 8 5548 F11 Figure 11. Simplified Enable Input Circuit VCC LTC5548 X2 5548 F12 Figure 12. Simplified X2 Interface Circuit 5548f For more information www.linear.com/LTC5548 17 LTC5548 Applications Information Spurious Output Levels Mixer spurious output levels versus harmonics of the RF and LO are tabulated in Table 3. The spur levels were measured on a standard evaluation board using the test circuit shown in Figure 1. The spur frequencies can be calculated using the following equation: Frequency Downconversion: fSPUR = (M • fRF)±(N • fLO) Frequency Upconversion: fSPUR = (M • fIF)±(N • fLO) Table 3a. Downconversion IF Output Spur Levels (dBc): LO Frequency Doubler Off (X2 = Low): fSPUR = (M • fRF) – (N • fLO) RF = 5250MHz, PRF = –6dBm, PLO = 0dBm, LO = 4900MHz N 0 1 0 M 2 3 4 5 –25 –5 –37 –45 * 1 –51 0 –42 –16 –59 –56 2 –72 –69 –81 –77 –71 –75 3 –75 –72 –78 –61 –79 –69 4 * –75 –77 –79 –81 –78 5 * * –74 –78 –77 –81 *Out of the test equipment range. Table 3b. Downconversion IF Output Spur Levels (dBc): LO Frequency Doubler On (X2 = High): fSPUR = (M • fRF) – (N • fLO) RF = 5252MHz, PRF = –6dBm, PLO = 0dBm, LO = 2450MHz N 0 0 M 1 2 3 4 5 6 7 8 –24 –14 –8 –5 –22 –32 –32 –51 1 –25 –18 0 –18 –29 –28 –18 –29 –43 2 –67 –77 –64 –61 –60 –61 –68 –70 –65 3 –75 –74 –72 –78 –72 –76 –63 –69 –78 4 * –76 –74 –74 –74 –76 –67 –77 –68 5 * * * –75 –75 –74 –69 –66 –70 *Out of the test equipment range. 18 5548f For more information www.linear.com/LTC5548 LTC5548 Package Description Please refer to http://www.linear.com/product/LTC5548#packaging for the most recent package drawings. UDB Package Variation A 12-LeadUDB Plastic QFN (3mm × 2mm) Package (Reference Variation: LTC DWG # 05-08-1985 Rev Ø) A 12-Lead Plastic QFN (3mm × 2mm) (Reference LTC DWG # 05-08-1985 Rev Ø) 0.25 ±0.05 0.85 ±0.05 0.65 ±0.05 0.77 ±0.05 0.05 REF 2.50 ±0.05 DETAIL B DETAIL B 0.25 ±0.10 PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC 0.75 ±0.05 0.77 ±0.10 0.05 REF DETAIL A 3.50 ±0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED R = 0.13 TYP 10 12 0.15 REF 0.60 ±0.10 0.40 ±0.10 9 1 0.40 REF 7 0.40 ±0.10 3 2.00 ±0.10 6 3.00 ±0.10 0.50 ±0.10 0.75 ±0.05 0.20 REF DETAIL A 4 0.50 ±0.10 (UDB12) DFN 0814 REV 0 0.25 ±0.05 0.50 BSC BOTTOM VIEW—EXPOSED PAD SIDE VIEW 0.00 – 0.05 NOTE: 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 0.15mm 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 5548f 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. For more information www.linear.com/LTC5548 19 LTC5548 Typical Application Wideband 10MHz to 6GHz Upconversion to 6.5GHz Conversion Loss and IIP3 vs Input Frequency (High Side LO) TCM1-83X+ LTC5548 • • 10MHz TO 6GHz IF + RF IF – 6.5GHz LO ZO = 50Ω L = 3.55mm 22pF 0.15pF CONVERSION LOSS (dB), IIP3 (dBm) 28 26 24 20 RFOUT = 6.5GHz LO DOUBLER OFF TC = 25°C 18 16 14 12 10 CONVERSION LOSS 8 6 6.51GHz to 12.5GHz IIP3 22 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 5548 TA02a INPUT FREQUENCY (GHz) 5548 TA02b Related Parts PART NUMBER DESCRIPTION COMMENTS Mixers, Modulators and Demodulators LTC5549 2GHz to 14GHz Microwave Mixer 8dB Conversion Loss, 24dBm IIP3, 500MHz to 6GHz Single-Ended IF with Integrated Balun LTC5544 4GHz to 6GHz Downconverting Mixer 7.5dB Gain, >25dBm IIP3 and 10dB NF, 3.3V/200mA Supply LTC5576 3GHz to 8GHz High Linearity Active Upconverting Mixer 25dBm OIP3, –0.6dB Gain, 14.1dB NF, –154dBm/Hz Output Noise Floor, –28dBm LO Leakage at 8GHz LTC5551 300MHz to 3.5GHz Ultrahigh Dynamic Range Downconverting Mixer +36dBm IIP3; 2.4dB Gain, <10dB NF, 0dBm LO Drive, +18dBm P1dB, 670mW Power Consumption LTC5567 400MHz to 4GHz, Active Downconverting Mixer 1.9dB Gain, 26.9dBm IIP3 and 11.8dB NF at 1950MHz, 3.3V/89mA Supply LTC5577 300MHz to 6GHz High Signal Level Active Downconverting Mixer 50Ω Matched Input from 1.3GHz to 4.3GHz, 30dBm IIP3, 0dB Gain, >40dB LO-RF Isolation, 0dBm LO Drive LTC5510 1MHz to 6GHz Wideband High Linearity Active Mixer 50Ω Matched Input from 30MHz to 6GHz, 27dBm OIP3, 1.5dB Gain, Up- or Down-Conversion LTC5585 4GHz Wideband I/Q Demodulator 400MHz to 4GHz Direct Conversion, 25.7dBm IIP3; 60dBm, IIP2 Adjustable to >85dBm, DC Offset Cancellation, >500MHz I & Q Bandwidth LTC5588-1 6GHz I/Q Modulator 200MHz to 6GHz Direct Conversion, 31dBm OIP3 Adjustable to 34dBm, –160dBm/Hz Output Noise Floor, Excellent ACPR Amplifiers LTC6430-20 High Linearity Differential IF Amp 20MHz to 2GHz Bandwidth, 20.8dB Gain, 51dBm OIP3, 2.9dB NF at 240MHz LTC6431-20 High Linearity Single-Ended IF Amp 20MHz to 1.4GHz Bandwidth, 20.8dB Gain, 46.2dBm OIP3, 2.6dB NF at 240MHz RF Power Detectors LTC5564 15GHz Ultra Fast 7ns Response Time RF Detector with Comparator 600MHz to 15GHz, –24dB to 16dBm Input Power Range, 9ns Comparator Response Time, 125°C Version LT5581 6GHz Low Power RMS Detector 40dB Dynamic Range, ±1dB Accuracy Over Temperature, 1.5mA Supply Current LTC5582 40MHz to 10GHz RMS Detector ±0.5dB Accuracy Over Temperature, ±0.2dB Linearity Error, 57dB Dynamic Range LTC5583 Dual 6GHz RMS Power Detector Up to 60dB Dynamic Range, ±0.5dB Accuracy Over Temperature, >50dB Isolation RF PLL/Synthesizer with VCO LTC6948 Ultralow Noise, Low Spurious Frac-N PLL with Integrated VCO 20 Linear Technology Corporation 373MHz to 6.39GHz, –157dBc/Hz WB Phase Noise Floor, –274dBc/Hz Normalized In-Band 1/f Noise 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LTC5548 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTC5548 5548f LT 0216 • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2016