LTC6430-20 High Linearity Differential RF/IF Amplifier/ADC Driver DESCRIPTION FEATURES 51.0dBm OIP3 at 240MHz into a 100Ω Diff Load n NF = 2.9dB at 240MHz n 20MHz to 2060MHz –3dB Bandwidth n 20.8dB Gain n A-Grade 100% OIP3 Tested at 380MHz n0.6nV/√Hz Total Input Noise n S11 < –10dB Up to 1.4GHz n S22 < –10dB Up to 1.4GHz n>2.75V P-P Linear Output Swing n P1dB = 24.0dBm n Insensitive to V CC Variation n100Ω Differential Gain-Block Operation n Input/Output Internally Matched to 100Ω Diff n Single 5V Supply n DC Power = 850mW n4mm × 4mm, 24-Lead QFN Package n The LTC®6430-20 is a differential gain block amplifier designed to drive high resolution, high speed ADCs with excellent linearity beyond 1000MHz and with low associated output noise. The LTC6430-20 operates from a single 5V power supply and consumes only 850mW. In its differential configuration, the LTC6430-20 can directly drive the differential inputs of an ADC. Using 1:2 baluns, the device makes an excellent 50Ω wideband balanced amplifier. While using 1:1.33 baluns, the device creates a high fidelity 40MHz to 1000MHz 75Ω CATV amplifier. The LTC6430-20 is designed for ease of use, requiring a minimum of support components. The device is internally matched to 100Ω differential source/load impedance. Onchip bias and temperature compensation ensure consistent performance over environmental changes. The LTC6430-20 uses a high performance SiGe BiCMOS process for excellent repeatability compared with similar GaAs amplifiers. All A-grade LTC6430-20 devices are tested and guaranteed for OIP3 at 380MHz. The LTC6430-20 is housed in a 4mm × 4mm, 24-lead, QFN package with an exposed pad for thermal management and low inductance. A single-ended 50Ω IF gain block with similar performance is also available, see the related LTC6431-20. APPLICATIONS Differential ADC Driver Differential IF Amplifier n OFDM Signal Chain Amplifier n50Ω Balanced IF Amplifier n75Ω CATV Amplifier n700MHz to 800MHz LTE Amplifier n Low Phase Noise Clock or LO Amplifier n n 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 OIP3 vs Frequency 55 Differential 16-Bit ADC Driver 5V VCM 1:2 BALUN OIP3 (dBm) RF CHOKES VCC = 5V ADC LTC6430-20 50Ω RSOURCE = 100Ω DIFFERENTIAL RLOAD = 100Ω DIFFERENTIAL 50 FILTER 643020 TA01a 45 40 V = 5V 35 PCC = 3dBm/TONE OUT ZIN = ZOUT = 100Ω DIFF. TA = 25°C 30 200 400 600 0 FREQUENCY (MHz) 800 1000 643020 TA01b 643020f For more information www.linear.com/LTC6430-20 1 LTC6430-20 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) Total Supply Voltage (VCC to GND)...........................5.5V Amplifier Output Current (+OUT)..........................120mA Amplifier Output Current (–OUT)..........................120mA RF Input Power, Continuous, 50Ω (Note 2)........ +15dBm RF Input Power, 100µs Pulse, 50Ω (Note 2).......+20dBm Operating Temperature Range (TCASE) ....–40°C to 85°C Storage Temperature Range................... –65°C to 150°C Junction Temperature (TJ)..................................... 150°C DNC DNC DNC VCC GND +IN TOP VIEW 24 23 22 21 20 19 DNC 1 18 +OUT DNC 2 17 GND DNC 3 16 T_DIODE 25 GND DNC 4 15 DNC 13 –OUT DNC DNC 9 10 11 12 VCC 8 DNC 7 –IN 14 GND DNC 6 GND DNC 5 UF PACKAGE 24-LEAD (4mm × 4mm) PLASTIC QFN TJMAX = 150°C, θJC = 40°C/W* EXPOSED PAD (PIN 25) IS GND, MUST BE SOLDERED TO PCB *Measured from Junction to the back of a PCB with natural convection. ORDER INFORMATION The LTC6430-20 is available in two grades. The A-grade guarantees a minimum OIP3 at 380MHz while the B-grade does not. LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC6430AIUF-20#PBF LTC6430AIUF-20#TRPBF 43020 24-Lead (4mm × 4mm) Plastic QFN –40°C to 85°C LTC6430BIUF-20#PBF LTC6430BIUF-20#TRPBF 43020 24-Lead (4mm × 4mm) Plastic QFN –40°C to 85°C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on nonstandard 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/ DC ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VCC = 5V, ZSOURCE = ZLOAD = 100Ω. Typical measured DC electrical performance using Test Circuit A (Note 3). SYMBOL PARAMETER VS Operating Supply Range IS,TOT Total Supply Current IS,OUT ICC Total Supply Current to OUT Pins Current to VCC Pin CONDITIONS MIN TYP MAX UNITS 4.75 5.0 5.25 V 117 113 170 l 213 220 mA mA 102.9 99 152 l 199 206 mA mA 14.1 14.0 18 l 22.5 22.5 mA mA All VCC Pins Plus +OUT and –OUT Current to +OUT and –OUT Either VCC Pin May Be Used 643020f 2 For more information www.linear.com/LTC6430-20 LTC6430-20 AC ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VCC = 5V, ZSOURCE = ZLOAD = 100Ω, unless otherwise noted (Note 3). Measurements are performed using Test Circuit A, measuring from 50Ω SMA to 50Ω SMA without de-embedding (Note 4). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Small Signal BW –3dB Bandwidth De-Embedded to Package (Low Frequency Cut-Off, 20MHz) 2060 MHz S11 Differential Input Match De-Embedded to Package, 25MHz to 2200MHz –10 dB S21 Forward Differential Power Gain De-Embedded to Package, 100MHz to 400MHz 20.8 dB S12 Reverse Differential Isolation De-Embedded to Package, 25MHz to 4000MHz –23 dB S22 Differential Output Match De-Embedded to Package, 25MHz to 1400MHz –10 dB Frequency = 50MHz S21 Differential Power Gain De-Embedded to Package 21.1 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 47.9 45.9 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –91.8 –87.8 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –82.6 dBc HD3 Third Harmonic Distortion POUT = 8dBm –93.1 dBc P1dB Output 1dB Compression Point 23.0 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 2.9 dB Frequency = 140MHz S21 Differential Power Gain De-Embedded to Package 20.9 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 48.0 46.0 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –92.0 –88.0 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –82.1 dBc HD3 Third Harmonic Distortion POUT = 8dBm –94.9 dBc P1dB Output 1dB Compression Point 23.3 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 2.9 dB Frequency = 240MHz S21 Differential Power Gain De-Embedded to Package 20.8 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 8MHz, ZO = 100Ω A-Grade B-Grade 51.0 47.0 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 8MHz, ZO = 100Ω A-Grade B-Grade –98.0 –90.0 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –79.8 dBc HD3 Third Harmonic Distortion POUT = 8dBm –80.9 dBc P1dB Output 1dB Compression Point 23.9 dBm NF Noise Figure 2.9 dB De-Embedded to Package for Balun Input Loss 643020f For more information www.linear.com/LTC6430-20 3 LTC6430-20 AC ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VCC = 5V, ZSOURCE = ZLOAD = 100Ω, unless otherwise noted (Note 3). Measurements are performed using Test Circuit A, measuring from 50Ω SMA to 50Ω SMA without de-embedding (Note 4). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Frequency = 300MHz S21 Differential Power Gain De-Embedded to Package 20.8 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 50.1 47.1 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –96.2 –90.2 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –75.5 dBc HD3 Third Harmonic Distortion POUT = 8dBm –77.2 dBc P1dB Output 1dB Compression Point 24.7 dBm NF Noise Figure 3.0 dB De-Embedded to Package for Balun Input Loss Frequency = 380MHz 19.6 20.8 POUT = 3dBm/Tone, Δf = 8MHz, ZO = 100Ω A-Grade B-Grade 44.8 48.3 46.3 dBm dBm Third-Order Intermodulation POUT = 3dBm/Tone, Δf = 8MHz, ZO = 100Ω A-Grade B-Grade –83.6 –90.6 –86.6 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –70.3 dBc HD3 Third Harmonic Distortion POUT = 8dBm –74.3 dBc P1dB Output 1dB Compression Point 24.7 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 3.05 dB S21 Differential Power Gain De-Embedded to Package OIP3 Output Third-Order Intercept Point IM3 l 22.1 dB Frequency = 500MHz S21 Differential Power Gain De-Embedded to Package 20.7 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 48.9 46.9 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –93.8 –89.8 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –68.9 dBc HD3 Third Harmonic Distortion POUT = 8dBm –82.8 dBc P1dB Output 1dB Compression Point 24.3 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 3.30 dB Frequency = 600MHz S21 Differential Power Gain De-Embedded to Package 20.7 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 48.7 45.7 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –93.4 –87.4 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –65.9 dBc HD3 Third Harmonic Distortion POUT = 8dBm –73.1 dBc P1dB Output 1dB Compression Point 24.0 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 3.44 dB De-Embedded to Package 20.7 dB Frequency = 700MHz S21 Differential Power Gain 643020f 4 For more information www.linear.com/LTC6430-20 LTC6430-20 AC ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VCC = 5V, ZSOURCE = ZLOAD = 100Ω, unless otherwise noted (Note 3). Measurements are performed using Test Circuit A, measuring from 50Ω SMA to 50Ω SMA without de-embedding (Note 4). SYMBOL PARAMETER CONDITIONS OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade MIN 48.6 45.6 TYP MAX UNITS dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –93.2 –87.2 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –58.0 dBc HD3 Third Harmonic Distortion POUT = 8dBm –74.5 dBc P1dB Output 1dB Compression Point 23.6 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 3.68 dB Frequency = 800MHz S21 Differential Power Gain De-Embedded to Package 20.7 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 46.5 43.5 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –89.0 –83.0 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –51.4 dBc HD3 Third Harmonic Distortion POUT = 8dBm –71.2 dBc P1dB Output 1dB Compression Point 22.9 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 3.93 dB Frequency = 900MHz S21 Differential Power Gain De-Embedded to Package 20.7 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 45.1 43.1 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –86.2 –82.2 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –48.9 dBc HD3 Third Harmonic Distortion POUT = 8dBm –68.4 dBc P1dB Output 1dB Compression Point 22.3 dBm NF Noise Figure De-Embedded to Package for Balun Input Loss 4.0 dB Frequency = 1000MHz S21 Differential Power Gain De-Embedded to Package 20.6 dB OIP3 Output Third-Order Intercept Point POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade 43.7 41.7 dBm dBm IM3 Third-Order Intermodulation POUT = 2dBm/Tone, Δf = 1MHz, ZO = 100Ω A-Grade B-Grade –83.4 –79.4 dBc dBc HD2 Second Harmonic Distortion POUT = 8dBm –55.2 dBc HD3 Third Harmonic Distortion POUT = 8dBm –65.8 dBc P1dB Output 1dB Compression Point 22.5 dBm NF Noise Figure 4.27 dB De-Embedded to Package for Balun Input Loss 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: Guaranteed by design and characterization. This parameter is not tested. Note 3: The LTC6430-20 is guaranteed functional over the case operating temperature range of –40°C to 85°C. Note 4: Small signal parameters S and noise are de-embedded to the package pins, while large signal parameters are measured directly from the test circuit. 643020f For more information www.linear.com/LTC6430-20 5 LTC6430-20 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, VCC = 5V, ZSOURCE = ZLOAD = 100Ω, unless otherwise noted (Note 3). Measurements are performed using Test Circuit A, measuring from 50Ω SMA to 50Ω SMA without de-embedding (Note 4). 10 7 6 5 0 500 1000 1500 2000 FREQUENCY (MHz) 2500 4 3 643020 G01 0 1000 3000 4000 2000 FREQUENCY (MHz) 0 5000 50 450 850 650 FREQUENCY (MHz) 250 643020 G02 1050 1250 643020 G03 Differential Reverse Isolation (S12DD) vs Frequency Over Temperature 0 TCASE = 100°C 85°C 50°C –10 30°C 0°C –20°C –15 –40°C –5 –20 500 3 1 25 –15 0 4 Differential Gain (S21DD) vs Frequency Over Temperature MAG S21DD (dB) –10 5 2 2 0 3000 TCASE = 100°C 85°C 50°C 30°C 0°C –20°C –40°C –5 MAG S11DD (dB) 6 1 0 TCASE = –40°C 30°C 85°C 7 NOISE FIGURE (dB) 8 Differential Input Match (S11DD) vs Frequency Over Temperature –25 8 TCASE = 100°C 85°C 50°C 30°C 0°C –20°C –40°C 9 S11 S21 S12 S22 Noise Figure vs Frequency Over Temperature 1000 1500 FREQUENCY (MHz) 2000 643020 G04 20 TCASE = 100°C 85°C 15 50°C 30°C 0°C –20°C –40°C 10 1000 1500 0 500 FREQUENCY (MHz) Differential Output Match (S22DD) vs Frequency Over Temperature MAG S12DD (dB) 35 30 25 20 15 10 5 0 –5 –10 –15 –20 –25 –30 Differential Stability Factor K vs Frequency Over Temperature STABILITY FACTOR K (UNITLESS) MAG (dB) Differential S Parameters vs Frequency –20 –25 –30 –35 2000 Common Mode Gain (S21CC) vs Frequency Over Temperature 0 0 643020 G05 500 1000 1500 FREQUENCY (MHz) 2000 643020 G06 CM-DM Gain (S21DC) vs Frequency Over Temperature 22 5 21 –15 –20 0 500 1000 1500 FREQUENCY (MHz) 2000 643020 G07 18 MAG S21DC (dB) TCASE = 100°C 85°C 50°C 30°C 0°C –20°C –40°C MAG S21CC (dB) MAG S22DD (dB) 19 –10 –25 0 20 –5 17 16 TCASE = 15 100°C 85°C 14 50°C 13 30°C 12 0°C –20°C 11 –40°C 10 1000 1500 0 500 FREQUENCY (MHz) –5 –10 TCASE = 100°C 85°C 50°C 30°C 0°C –20°C –40°C –15 –20 –25 2000 643020 G08 –30 0 500 1500 1000 FREQUENCY (MHz) 2000 643020 G09 643020f 6 For more information www.linear.com/LTC6430-20 LTC6430-20 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, VCC = 5V, ZSOURCE = ZLOAD = 100Ω, unless otherwise noted (Note 3). Measurements are performed using Test Circuit A, measuring from 50Ω SMA to 50Ω SMA without de-embedding (Note 4). OIP3 vs Frequency OIP3 vs RF Power Out/Tone Over Frequency 52 55 54 VCC = 5V 50 ZIN = ZOUT = 100Ω TA = 25°C 48 50 52 50 48 40 46 OIP3 (dBm) OIP3 (dBm) OIP3 (dBm) 46 45 44 42 40 V = 5V 35 PCC = 3dBm/ TONE OUT ZIN = ZOUT = 100Ω DIFF. TA = 25°C 30 200 400 600 0 FREQUENCY (MHz) 50MHz 100MHz 200MHz 300MHz 36 643020 G10 OIP3 vs Tone Spacing Over Frequency OIP3 (dBm) 43 41 50MHz 140MHz 200MHz 240MHz 37 0 30 40 20 TONE SPACING (MHz) VCC = 5V ZIN = ZOUT = 100Ω POUT = 2dBm/TONE TA = 25°C 400 600 FREQUENCY (MHz) 1000 800 643020 G12 40 TCASE = 85°C 70°C 50°C 30°C 0°C –20°C –40°C 35 50 20 0 200 643020 G13 POUT = 2dBm/TONE ZIN = ZOUT = 100Ω TA = 25°C 400 600 FREQUENCY (MHz) OIP2 vs Frequency 0 100 –50 –60 60 –40 50 40 30 20 –80 10 –90 0 1200 643020 G15 HD3 vs Frequency Over POUT 70 –70 400 200 600 800 1000 2ND HARMONIC FREQUENCY (MHz) 1000 643020 G14 POUT = 6dBm POUT = 8dBm –20 VCC = 5V ZIN = ZOUT = 100Ω –30 TA = 25°C 80 –40 800 –10 90 OIP2 (dBm) HD2 (dBc) 200 OIP3 vs Frequency Over Temperature 25 10 POUT = 6dBm POUT = 8dBm VCC = 5V ZIN = ZOUT = 100Ω TA = 25°C 0 0 643020 G11 30 400MHz 600MHz 800MHz 1000MHz HD2 vs Frequency Over POUT –30 30 10 HD3 (dBc) OIP3 (dBm) 45 39 –20 8 45 47 –10 32 50 49 0 POUT = 2dBm/TONE ZIN = ZOUT = 100Ω TA = 25°C 34 6 55 51 35 VCC = 4.5V VCC = 4.75V VCC = 5V VCC = 5.25V VCC = 5.5V 42 40 36 400MHz 600MHz 800MHz 1000MHz 34 –10 –8 –6 –4 –2 0 2 4 RF POUT (dBm/TONE) 1000 44 38 38 800 OIP3 vs Frequency Over VCC Voltage –60 –70 VCC = 5V ZIN = ZOUT = 100Ω POUT = 8dBm TA = 25°C 0 –50 –80 –90 400 200 600 800 1000 FUNDAMENTAL FREQUENCY (MHz) 1200 643020 G22 –100 0 1000 1500 500 3RD HARMONIC FREQUENCY (MHz) 643020 G16 643020f For more information www.linear.com/LTC6430-20 7 LTC6430-20 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, VCC = 5V, ZSOURCE = ZLOAD = 100Ω, unless otherwise noted (Note 3). Measurements are performed using Test Circuit A, measuring from 50Ω SMA to 50Ω SMA without de-embedding (Note 4). 26 Output P1dB vs Frequency 180 25 24 22 21 20 19 8 16 10 200 0 643020 G17 150 140 130 120 VCC = 5V ZIN = ZOUT = 100Ω TA = 25°C 17 6 –2 0 2 4 INPUT POWER (dBm) TCASE = 25°C 160 23 18 –4 Total Current (ITOT) vs VCC 170 ITOT (mA) 25 24 23 22 21 20 19 18 17 16 15 14 13 12 –6 OUTPUT P1dB (dBm) OUTPUT POWER (dBm) Output Power vs Input Power Over Frequency 110 400 600 FREQUENCY (MHz) 800 1000 100 3 643020 G18 3.5 4 4.5 VCC (V) 5 5.5 6 643020 G19 100MHz, P1dB = 23.2dBm 200MHz, P1dB = 23.7dBm 400MHz, P1dB = 24.7dBm 600MHz, P1dB = 23.9dBm 800MHz, P1dB = 22.9dBm 1000MHz, P1dB = 22.4dBm Total Current (ITOT) vs Case Temperature Total Current vs RF Input Power 190 200 180 160 150 140 ITOT (mA) TOTAL CURRENT (mA) 170 130 110 120 100 80 60 90 70 VCC = 5V TA = 25°C 50 0 5 10 –20 –15 –10 –5 RF INPUT POWER (dBm) 40 20 15 20 643020 G20 VCC = 5V 0 –60 –40 –20 0 20 40 60 80 100 120 CASE TEMPERATURE (°C) 643020 G21 643020f 8 For more information www.linear.com/LTC6430-20 LTC6430-20 PIN FUNCTIONS GND (Pins 8, 14, 17, 23, Exposed Pad Pin 25): Ground. For best RF performance, all ground pins should be connected to the printed circuit board ground plane. The exposed pad (Pin 25) should have multiple via holes to an underlying ground plane for low inductance and good thermal dissipation. +OUT (Pin 18): Positive Amplifier Output Pin. A transformer with a center tap tied to VCC or a choke inductor tied to 5V supply is required to provide DC current and RF isolation. For best performance select a choke with low loss and high self resonant frequency (SRF). See the Applications Information section for more information. +IN (Pin 24): Positive Signal Input Pin. This pin has an internally generated 1.8V DC bias. A DC-blocking capacitor is required. See the Applications Information section for specific recommendations. –OUT (Pin 13): Negative Amplifier Output Pin. A transformer with a center tap tied to VCC or a choke inductor is required to provide DC current and RF isolation. For best performance select a choke with low loss and high SRF. –IN (Pin 7): Negative Signal Input Pin. This pin has an internally generated 1.8V DC bias. A DC-blocking capacitor is required. See the Applications Information section for specific recommendations. DNC (Pins 1 to 6, 10 to 12, 15, 19 to 21): Do Not Connect. Do not connect these pins, allow them to float. Failure to float these pins may impair the performance of the LTC6430-20. VCC (Pins 9, 22): Positive Power Supply. Either or both VCC pins should be connected to the 5V supply. Both VCC pins are internally connected within the package. Bypass the VCC pin with 1000pF and 0.1µF capacitors. The 1000pF capacitor should be physically close to a VCC pin. T_DIODE (Pin 16): Optional. A diode which can be forward biased to ground with up to 1mA of current. The measured voltage will be an indicator of the chip temperature. BLOCK DIAGRAM VCC 9, 22 BIAS AND TEMPERATURE COMPENSATION 24 +IN 20dB GAIN +OUT T_DIODE 7 –IN 20dB GAIN –OUT 18 16 13 GND 8, 14, 17, 23 AND PADDLE 25 643020 BD 643020f For more information www.linear.com/LTC6430-20 9 LTC6430-20 Differential Application Test Circuit A (Balanced Amp) RFIN 50Ω, SMA +OUT DNC GND DNC –OUT DNC DNC VCC GND R2 350Ω T2 2:1 DNC DNC –IN C2 1000pF C3 1000pF T_DIODE LTC6430-20 DNC C8 60pF DNC DNC DNC DNC BALUN_A L1 560nH DNC T1 1:2 GND PORT INPUT +IN R1 350Ω VCC C7 60pF DNC C1 1000pF GND TEST CIRCUIT A C5 1nF C4 1000pF • • BALUN_A PORT OUTPUT RFOUT 50Ω, SMA L2 560nH C6 0.1µF VCC = 5V BALUN_A = ADT2-IT FOR 50MHz TO 300MHz BALUN_A = ADT2-1P FOR 300MHz TO 400MHz BALUN_A = ADTL2-18 FOR 400MHz TO 1000MHz ALL ARE MINI-CIRCUITS CD542 FOOTPRINT 643020 F01 Figure 1. Test Circuit A OPERATION The LTC6430-20 is a highly linear, fixed-gain amplifier for differential signals. It can be considered a pair of 50Ω single-ended devices operating 180 degrees apart. Its core signal path consists of a single amplifier stage minimizing stability issues. The input is a Darlington pair for high input impedance and high current gain. Additional circuit enhancements increase the output impedance commensurate with the input impedance and minimize the effects of internal Miller capacitance. The LTC6430-20 uses a classic RF gain block topology, with enhancements to achieve excellent linearity. Shunt and series feedback elements are added to lower the input/ output impedance and match them simultaneously to the source and load. An internal bias controller optimizes the bias point for peak linearity over environmental changes. This circuit architecture provides low noise, good RF power handling capability and wide bandwidth; characteristics that are desirable for IF signal-chain applications. 643020f 10 For more information www.linear.com/LTC6430-20 LTC6430-20 APPLICATIONS INFORMATION The LTC6430-20 is a highly linear fixed-gain amplifier which is designed for ease of use. Both the input and output are internally matched to 100Ω differential source and load impedance from 20MHz to 1400MHz. Biasing and temperature compensation are also handled internally to deliver optimized performance. The designer need only supply input/output blocking capacitors, RF chokes and decoupling capacitors for the 5V supply. However, because the device is capable of such wideband operation, a single application circuit will probably not result in optimized performance across the full frequency band. will drop the available voltage to the device. Also look for an inductor with high self resonant frequency (SRF) as this will limit the upper frequency where the choke is useful. Above the SRF, the parasitic capacitance dominates and the choke’s impedance will drop. For these reasons, wire-wound inductors are preferred, while multilayer ceramic chip inductors should be avoided for an RF choke if possible. Since the LTC6430-20 is capable of such wideband operation, a single choke value will not result in optimized performance across its full frequency band. Table 1 lists common frequency bands and suggested corresponding inductor values. Differential circuits minimize the common mode noise and 2nd harmonic distortion issues that plague many designs. Additionally, the LTC6430’s differential topology matches well with the differential inputs of an ADC. However, evaluation of these differential circuits is difficult, as high resolution, high frequency, differential test equipment is lacking. Table 1. Target Frequency and Suggested Inductor Value Our test circuit is designed for evaluation with standard single ended 50Ω test equipment. Therefore, 1:2 balun transformers have been added to the input and output to transform the LTC6430-20’s 100Ω differential source/load impedance to 50Ω single-ended impedance compatible with most test equipment. Other than the balun, the evaluation circuit requires a minimum of external components. Input and output DCblocking capacitors are required as this device is internally biased for optimal operation. A frequency appropriate choke and de-coupling capacitors provide DC bias to the RF ±OUT nodes. Only a single 5V supply is necessary to either of the VCC pins on the device. Both VCC pins are connected inside the package. Two VCC pins are provided for the convenience of supply routing on the PCB. An optional parallel 60pF, 350Ω input network has been added to ensure low frequency stability. The particular element values shown in Test Circuit A are chosen for wide bandwidth operation. Depending on the desired frequency, performance may be improved by custom selection of these supporting components. Choosing the Right RF Choke Not all choke inductors are created equal. It is always important to select an inductor with low RLOSS as resistance FREQUENCY BAND (MHz) INDUCTOR VALUE (nH) SRF (MHz) MODEL NUMBER 20 to 100 1500 100 0603LS 100 to 500 560 525 0603LS 500 t o 1000 100 1150 0603LS 1000 to 2000 51 1400 0603LS MANUFACTURER Coilcraft www.coilcraft.com DC-Blocking Capacitor The role of a DC-blocking capacitor is straightforward: block the path of DC current and allow a low series impedance path for the AC signal. Lower frequencies require a higher value of DC-blocking capacitance. Generally, 1000pF to 10,000pF will suffice for operation down to 20MHz. The LTC6430-20 linearity is insensitive to the choice of blocking capacitor. RF Bypass Capacitor RF bypass capacitors act to shunt the AC signals to ground with a low impedance path. They prevent the AC signal from getting into the DC bias supply. It is best to place the bypass capacitor as close as possible to the DC supply pins of the amplifier. Any extra distance translates into additional series inductance which lowers the effectiveness of the bypass capacitor network. The suggested bypass capacitor network consists of two capacitors: a low value 1000pF capacitor to shunt high frequencies and a larger 0.1µF capacitor to handle lower frequencies. Use ceramic capacitors of appropriate physical size for each capacitance value (e.g., 0402 for the 1000pF, 0805 for the 0.1µF) to minimize the equivalent series resistance (ESR) of the capacitor. 643020f For more information www.linear.com/LTC6430-20 11 LTC6430-20 APPLICATIONS INFORMATION Low Frequency Stability Most RF gain blocks suffer from low frequency instability. To avoid stability issues, the LTC6430-20, contains an internal feedback network that lowers the gain and matches the input and output impedance of the intrinsic amplifier. This feedback network contains a series capacitor, whose value is limited by physical size. So, at some low frequencies, this feedback capacitor looks like an open circuit; the feedback fails, gain increases and gross impedance mismatches occur which can create instability. This situation is easily resolved with a parallel capacitor and a resistor network on the input. This is shown in Figure 1. This network provides resistive loss at low frequencies and is bypassed by the capacitor at the desired band of operation. However, if the LTC6430-20 is preceded by a low frequency termination, such as a choke or balun transformer, the input stability network is not required. A choke at the output can also terminate low frequencies out-of-band and stabilize the device. Exposed Pad and Ground Plane Considerations As with any RF device, minimizing the ground inductance is critical. Care should be taken with PC board layouts using exposed pad packages, as the exposed pad provides the lowest inductive path to ground. The maximum allowable number of minimum diameter via holes should be placed underneath the exposed pad and connected to as many ground plane layers as possible. This will provide good RF ground and low thermal impedance. Maximizing the copper ground plane at the signal and microstrip ground will also improve the heat spreading and lower inductance. It is a good idea to cover the via holes with solder mask on the backside of the PCB to prevent the solder from wicking away from the critical PCB to exposed pad interface. One to two ounces of copper plating is suggested to improve heat spreading from the device. Frequency Limitations The LTC6430-20 is a wide bandwidth amplifier but it is not intended for operation down to DC. The lower frequency cutoff is limited by on-chip matching elements. The cutoff may be arbitrarily pushed lower with off chip elements; however, the translation between the low fixed DC common mode input voltage and the higher open collector 12 DC common mode output bias point make DC-coupled operation impractical. Using the On-Chip Diode to Sense Temperature An on-chip temperature diode is accessible through the T_DIODE pin. This is an optional feature to determine the on-chip temperature. Forward bias this pin with 0.01mA to 1mA of current and the voltage drop will indicate the temperature on the die. With this temperature, the user can determine the thermal impedance of the chip to PCB and get an indicator of the exposed pad solder attach quality. For best accuracy the user needs to perform a temperature calibration at their desired current to accurately determine the absolute temperature. At 1mA the diode voltage slope is –1.2mV/°C. Test Circuit A Test Circuit A, shown in Figure 1, is designed to allow for the evaluation of the LTC6430-20 with standard singleended 50Ω test equipment. This allows the designer to verify the performance when the device is operated differentially. This evaluation circuit requires a minimum of external components. Since the LTC6430-20 operates over a very wide band, the evaluation test circuit is optimized for wideband operation. Obviously, for narrowband operation, the circuit can be further optimized. Input and output DC-blocking capacitors are required, as this device is internally DC biased for optimal performance. A frequency appropriate choke and decoupling capacitors are required to provide DC bias to the RF output nodes (+OUT and –OUT). A 5V supply should also be applied to one of the VCC pins on the device. Components for a suggested parallel 60pF, 350Ω stability network have been added to ensure low frequency stability. The 60pF capacitance can be increased to improve low frequency (<150 MHz) performance, however the designer needs to be sure that the impedance presented at low frequency will not create an instability. Balanced Amplifier Circuit, 50Ω Input and 50Ω Output This balanced amplifier circuit is a replica of Test Circuit A. It is useful for single-ended 50Ω amplifier requirements and is surprisingly wideband. Using this balanced arrangement For more information www.linear.com/LTC6430-20 643020f LTC6430-20 APPLICATIONS INFORMATION and the frequency appropriate baluns, one can achieve the intermodulation and harmonic performance listed in the AC Electrical Characteristics specifications of this data sheet. Besides its impressive intermodulation performance, the LTC6430-20 has impressive 2nd harmonic suppression as well. This makes it particularly well suited for multioctave applications where the 2nd harmonic cannot be filtered. Please note that a number of DNC pins are connected on the evaluation board. These connections are not necessary for normal circuit operation. The evaluation board also includes an optional back to back pair of baluns so that their losses may be measured. This allows the designer to de-embed the balun losses and more accurately predict the LTC6430-20 performance in a differential circuit. This balanced circuit example uses two Mini-Circuits 1:2 baluns. The baluns were chosen for their bandwidth and frequency options that utilize the same package footprint (see Table 2). A pair of these baluns, back-to-back has less than 1.5dB of loss, so the penalty for this level of performance is minimal. Any suitable 1:2 balun may be used to create a balanced amplifier with the LTC6430-20. Table 2. Target Frequency and Suggested 2:1 Balun The optional stability network is only required when the balun’s bandwidth reaches below 20MHz. It is included in the circuit as a comprehensive protection for any passive element placed at the LTC6430-20 input. Its performance degradation at low frequencies can be mitigated by increasing the 60pF capacitor’s value. 300 to 400 ADT2-1T-1P 400 to 1300 ADTL2-18 MANUFACTURER Mini-Circuits www.minicircuits.com Boasting high linearity, low associated noise and wide bandwidth, the LTC6430-20 is well suited to drive high speed, high resolution ADCs with over a GHz of input bandwidth. To demonstrate its performance, the LTC6430-20 was used to drive an LTC2158 14-bit, 310Msps ADC with DNC DNC GND DNC DNC DNC –OUT VCC GND DNC –IN 100Ω DIFFERENTIAL C4 • • 1000pF BALUN_A DNC DNC C3 1000pF T2 2:1 T_DIODE LTC6430-20 DNC C8 60pF DNC +OUT DNC DNC BALUN_A VCC +IN 100Ω DIFFERENTIAL L1 560nH DNC GND T1 1:2 GND R1 350Ω C2 1000pF ADT2-1T C7 60pF C1 1000pF RFIN 50Ω, SMA MODEL NUMBER 50 to 300 Driving the LTC2158, 14-Bit, 310Msps ADC with 1.25GHz of Bandwidth Demo Boards 2076A-A and 2076A-B implement this balanced amplifier circuit. It is shown in Figure 18. PORT INPUT FREQUENCY BAND (MHz) PORT OUTPUT RFOUT 50Ω, SMA L2 560nH R2 350Ω C5 1000pF C6 0.1µF OPTIONAL STABILITY NETWORK VCC = 5V 643020 F02 BALUN_A = ADT2-1T FOR 50MHz TO 300MHz BALUN_A = ADT2-1T-1P FOR 300MHz TO 400MHz BALUN_A = ADTL2-18 FOR 400MHz TO 1300MHz ALL ARE MINI-CIRCUITS CD542 FOOTPRINT Figure 2. Balanced Amplifier Circuit, 50Ω Input and 50Ω Output 643020f For more information www.linear.com/LTC6430-20 13 LTC6430-20 APPLICATIONS INFORMATION 1.25GHz of input bandwidth in an undersampling application. Typically, a filter is used between the ADC driver amplifier and ADC input to minimize the noise contribution from the amplifier. However, with the typical SNR of higher sample rate ADCs, the LTC6430-20 can drive them without any intervening filter, and with very little penalty in SNR. This system approach has the added benefit of allowing over two octaves of usable frequency range. The LTC6430-20 driving the LTC2158, as shown in the circuit of Figure 3, the bandwidth is limited only by the 1.25GHz input BW of the ADC, still produces 57dB SNR, and offers IM performance that varies little from 240MHz to 1GHz. At the lower end of this frequency range, the IM contribution of the ADC and amplifier are comparable, and the thirdorder IM products may be additive, or may see cancelation. At 1GHz input, the ADC is dominant in terms of IM and noise contribution, limited by internal clock jitter and high input signal amplitude. Table 3 shows noise and linearity performance. Example outputs at 500MHz and 1000MHz are shown in Figure 5, Figure 6, Figure 7, and Figure 8. The LTC6430-20 can directly drive the high speed ADC inputs and settles quickly. Most feedback amplifiers require protection from the sampling disturbances, the mixing products that result from direct sampling. This is in part due to the fact that unless the ADC input driving circuitry offers settling in less than one-half clock cycle, the ADC may not exhibit the expected linearity. If the ADC samples the recovery process of an amplifier it will be seen as distortion. If an amplifier exhibits envelope detection VCM 5V 560nH 0603 60pF GUANELLA BALUN 1nF 150Ω VCC = 5V 49.9Ω 1nF 350Ω • • 100nH 0402CS LTC6430-20 LTC2158 MA/COM ETC1-1-13 643020 F03 200ps Figure 3. Wideband ADC Driver, LTC6430-20 Directly Driving the LTC2158 ADC VCM 5V 560nH 0603 60pF MINI-CIRCUITS ADTL2-18 2:1 BALUN 1nF VCC = 5V 49.9Ω 1nF 350Ω • • LTC6430-20 100nH 0402CS LTC2158 643020 F04 200ps Figure 4. Wideband ADC Driver, LTC6430-20 Directly Driving the LTC2158 ADC—Alternative Using Mini-Circuits 2:1 Balun 643020f 14 For more information www.linear.com/LTC6430-20 LTC6430-20 APPLICATIONS INFORMATION Table 3. LTC6430-20 and LTC2158 Combined Performance Frequency (MHz) Sample Rate (Msps) IM3 (Low, Hi) (dBFS) HD3 (3rd Harmonic) (dBc) SFDR (dB) SNR (dB) 240 307.2 (–87, –87) –79.7 77.4 58.6 380 307.2 (–86, –86) –74.2 71.7 58.2 500 307.2 (–92, –92) –79.7 77.4 58.6 656 307.2 (–86, –85) –88.5 61.3 56.8 690 307.2 (–87, –87) –73.0 68.8 57.0 842 307.2 (–84, –85) –69.6 61.8 56.2 1000 307.2 (–83,–83) –70.8 67.5 55.5 in the presence of multi-GHz mixing products, it will also distort. A band limiting filter would provide suppression from those products beyond the capability of the amplifier, as well as limit the noise bandwidth, however the settling of the filter can be an issue. The LTC2158, at 310Msps only allows 1.5ns settling time for any driver that is disturbed by these transients. This approach of removing the filter between the ADC and driver amplifier offers many advantages. It opens the opportunity to precede the amplifier with switchable bandpass filters, without any need to change the critical network between the drive amplifier and ADC. The transmission line distances shown in the schematic are part of the design, and are devised such that there are no impedance discontinuities, and therefore no reflections, in the distances between 75ps to 200ps from the ADC. End termination can be immediately prior to, or preferably after the ADC, and the amplifier should either be within the 75ps inner boundary, or outside the 200ps distance. Similarly, any shunt capacitor or resonator incorporated into a filter, including the large pads required by some inductors with more than a small fraction of 1pF, should not be in this range of distances from the ADC where reflections will impair performance. Transformers with large pads should be avoided within these distances. A 100nH shunt inductor at the ADC input approximates the complex conjugate of the ADC sampling circuit, and in doing so, improves power transfer and suppresses the low frequency difference products produced by direct sampling ADCs. If the entire frequency range from 300MHz to 1GHz were of interest, a 100nH inductor at the input is acceptable, but if interest is only in higher frequencies, performance would be better if the input inductor is reduced in value. If lower frequencies are of interest, a higher value up to some 200nH may be practical, but beyond that range the SRF of the inductor becomes an issue. As this inductor is placed at different distances either before or after the ADC inputs, the optimal value may change. In all cases, it should be within 50ps of the ADC inputs. End termination may be more than 200ps distant if after the ADC. If the end termination were perfect, it could be at any distance after the ADC. To terminate the input path after the ADC, place the termination resistors on the back of the PCB. If the input signal path is buried or on the back of the PCB, termination resistors should be placed on the top of the PCB to properly terminate after the ADC. Although the ADC is isolated by a driver amplifier, care must be taken when filtering at the amplifier input. Much like MESFETs, high frequency mixing products are handled well by the LTC6430. However, if there is no band limiting after the LTC6430, these mixing products, reduced by reverse isolation but subsequently reflected from a filter prior to the LTC6430 and reamplified, can cause distortion. In such cases, the network will then be sensitive to transmission line lengths and impedance characteristics of the filter prior to the LTC6430. Diplexers or absorptive filters can produce more robust results. An absorptive filter or diplexer-like structure after the amplifier reduces the sensitivity to the network prior to the amplifier, but the same constraints previously outlined apply to the filter. 643020f For more information www.linear.com/LTC6430-20 15 LTC6430-20 APPLICATIONS INFORMATION Figure 5. ADC Output: 1-Tone Test at 500MHz with 307.2Msps Sampling Rate Undersampled in the Fourth Nyquist Zone Figure 6. ADC Output: 2-Tone Test at 500MHz with 307.2Msps Sampling Rate Undersampled in the Fourth Nyquist Zone 643020f 16 For more information www.linear.com/LTC6430-20 LTC6430-20 APPLICATIONS INFORMATION Figure 7. ADC Output: 1-Tone Test at 1000MHz with 307.2Msps Sampling Rate Undersampled in the Seventh Nyquist Zone Figure 8. ADC Output: 2-Tone Test at 1000MHz with 307.2Msps Sampling Rate Undersampled in the Seventh Nyquist Zone 643020f For more information www.linear.com/LTC6430-20 17 LTC6430-20 APPLICATIONS INFORMATION Figure 9. LTC6430-20 LTC2158 Combo Board CATV AMPLIFIER 40MHZ TO 1000MHZ Wide bandwidth, excellent linearity and low output noise makes the LTC6430-20 an exceptional candidate for CATV amplifier applications. As expected, the LTC6430-20 works well in a push-pull circuit to cover the entire 40MHz to 1000MHz CATV band. Using readily available SMT baluns, the LTC6430-20 offers high linearity and low noise across the whole CATV band. Remarkably, this performance is achieved with only 850mW of power at 5V. Its low power dissipation greatly reduces the heat sinking requirements relative to traditional “block” CATV amplifiers. The native LTC6430-20 device is well matched to 100Ω differential impedance at both the input and the output. Therefore, we can employ 1:1.33 surface mount (SMT) baluns to transform its native 100Ω impedance to the standard 75Ω CATV impedance, while retaining all the exceptional characteristics of the LTC6430-20. In addition, the balun’s excellent phase balance and the 2nd order linearity of the LTC6430-20 combine to further suppress 2nd order products across the entire CATV band. As with any wide bandwidth application, care must be taken when selecting a choke. An SMT wire wound ferrite core inductor was chosen for its low series resistance, high self resonant frequency (SRF) and compact size. An input stability network is not required for this application as the balun presents a low impedance to the LTC6430-20’s input at low frequencies. Our resulting push-pull CATV amplifier circuit is simple, compact, completely SMT and extremely power efficient. The LTC6430-20 push-pull circuit has 19.2dB of gain with ±0.58dB of flatness across the entire 40MHz to 1000MHz band. It sports an OIP3 of 46dBm. The CTB and CSO measurements have not been taken as of this writing. These characteristics make the LTC6430-20 an ideal amplifier for head-end cable modem applications or CATV distribution amplifiers. The circuit is shown in Figure 10, with 75Ω “F” connectors at both input and output. The evaluation board may be loaded with either 75Ω “F” connectors, or 75Ω BNC connectors, depending on the users preference. Please note that the use of substandard connectors can limit usable bandwidth of the circuit. 643020f 18 For more information www.linear.com/LTC6430-20 LTC6430-20 APPLICATIONS INFORMATION T1 1:1.33 DNC DNC DNC GND DNC T_DIODE LTC6430-20 DNC C3 0.047µF T2 1.33:1 C5 1000pF –IN BALUN_A = TC1.33-282+ FOR 40MHz TO 1000MHz MINI-CIRCUITS 1:1.33 BALUN • C4 0.047µF DNC –OUT DNC GND DNC C2 0.047µF 100Ω DIFFERENTIAL DNC DNC GND BALUN_A L1 560nH +OUT DNC 100Ω DIFFERENTIAL RFIN 75Ω, CONNECTOR VCC DNC VCC PORT INPUT DNC +IN GND C1 0.047µF PORT OUTPUT • BALUN_A RFOUT 75Ω, CONNECTOR L2 560nH C6 0.1µF VCC = 5V 643020 F10 Figure 10. CATV Amplifier: 75Ω Input and 75Ω Output –5 MAG (dB) S22 –15 10 20 8 15 10 –20 0 200 400 600 800 FREQUENCY (MHz) 1000 0 1200 0 200 643020 F11 Figure 11. CATV Circuit, Input and Output Return Loss vs Frequency 400 600 800 FREQUENCY (MHz) 6 4 1200 0 0 200 400 600 800 FREQUENCY (MHz) 643020 F12 1000 1200 643020 F13 Figure 13. CATV Amplifier Circuit, Noise Figure vs Frequency 0 VCC = 5V, T = 25°C –10 POUT = 6dBm/TONE –20 VCC = 5V, T = 25°C 50 P OUT = 2dBm/TONE 45 40 35 30 25 20 –30 –40 –50 HD2 –60 –70 HD3 –80 –90 15 10 1000 Figure 12. CATV Amplifier Circuit, Gain (S21) vs Frequency HD2 AND HD3 (dBc) –30 VCC = 5V, T = 25°C INCLUDES BALUN LOSS 2 5 S11 –25 OIP3 (dBm) MAG (dB) –10 25 NOISE FIGURE (dB) 0 –100 0 200 400 600 800 FREQUENCY (MHz) 1000 1200 643020 F14 Figure 14. CATV Amplifier Circuit, OIP3 vs Frequency –110 0 200 400 600 800 1000 1200 HARMONIC FREQUENCY (MHz) 643015 F15 Figure 15. HD2 and HD3 Products vs Frequency 643020f For more information www.linear.com/LTC6430-20 19 LTC6430-20 APPLICATIONS INFORMATION 5 4 3 2 1 D D C C B B A 5 4 TECHNOLOGY A CATV AMPLIFIER 3 2 1 Figure 16. LTC6430-20 CATV Circuit Schematic Figure 17. LTC6430-20 CATV Evaluation Board 643020f 20 For more information www.linear.com/LTC6430-20 LTC6430-20 APPLICATIONS INFORMATION 5 4 3 2 1 C B C D D B A 5 4 3 TECHNOLOGY A RF/IF AMP/ADC DRIVER 2 1 Figure 18. Demo Board 2076A Schematic A Low Phase Noise Amplifier Appropriate for Clock or LO Amplification Many wide band amplifiers are based on field effect devices (FET). CMOS, MesFET, PHEMT and GaN FETs devices are capable of wide bandwidth operation. On the other hand, the LTC6430-20 is based on a SiGe HBT device structure. The active junction of an HBT is sub-surface and not prone to the surface state effects that plague Field Effect Device. These surface charges have long lifetime and manifest themselves as low frequency (phase) noise contributors Great care was also taken with the bias circuitry surrounding the LTC6430-20 as to minimize low frequency noise. As a result the LTC6430-20 has very low residual phase noise. We have measured our amplifiers phase noise performance using an Agilent E5500. This noise measurement method uses two equivalent paths to the noise detector, where they are combined in quadrature to eliminate the noise from the synthesizer. Thus leaving only the residual noise of the amplifier. The residual phase noise of the LTC6430-20 is only –160dBc at 10kHz offset. See Figures 19 and 20. 643020f For more information www.linear.com/LTC6430-20 21 LTC6430-20 APPLICATIONS INFORMATION Figure 19. LTC6430-20 Residual Phase Noise at 380MHz and 24dBm POUT Figure 20. LTC6430-20 Residual Phase Noise at 600MHz and 23dBm POUT 643020f 22 For more information www.linear.com/LTC6430-20 LTC6430-20 APPLICATIONS INFORMATION Figure 21. Demo Board 2076A PCB 643020f For more information www.linear.com/LTC6430-20 23 LTC6430-20 DIFFERENTIAL S PARAMETERS ZDIFF = 100Ω, T = 25°C, De-Embedded to Package Pins, 5V, DD: Differential In to Differential Out FREQUENCY (MHz) S11DD (Mag) S11DD (Ph) S21DD (Mag) S21DD (Ph) S12DD (Mag) S12DD (Ph) S22DD (Mag) S22DD (Ph) GTU (Max) STABILITY (K) 13 –9.26 –90.51 23.80 175.00 –32.77 38.54 –10.95 –83.37 24.72 1.22 63 –15.14 –165.61 21.00 171.00 –23.30 –0.67 –19.70 –168.07 21.18 0.99 125 –15.42 –179.50 20.89 168.00 –23.31 –6.13 –20.63 163.80 21.06 1.00 188 –15.47 173.98 20.86 164.00 –23.33 –10.22 –20.76 146.05 21.02 1.00 250 –15.53 168.66 20.82 159.00 –23.35 –14.01 –20.62 130.46 20.98 1.00 313 –15.58 163.86 20.79 154.00 –23.36 –17.68 –20.40 115.73 20.95 1.00 375 –15.66 159.47 20.76 150.00 –23.37 –21.42 –20.10 102.10 20.92 1.00 438 –15.71 155.10 20.74 145.00 –23.38 –25.16 –19.71 89.32 20.90 1.00 500 –15.80 150.93 20.72 140.00 –23.39 –28.89 –19.31 76.53 20.89 1.00 563 –15.93 146.85 20.69 135.00 –23.41 –32.65 –18.85 63.92 20.86 1.00 625 –16.09 142.84 20.68 131.00 –23.43 –36.45 –18.36 51.44 20.85 1.00 688 –16.27 138.71 20.66 126.00 –23.45 –40.31 –17.77 39.16 20.84 1.00 750 –16.51 134.71 20.66 121.00 –23.48 –44.17 –17.16 26.91 20.84 1.00 813 –16.76 131.11 20.66 116.00 –23.51 –48.08 –16.54 14.95 20.85 1.00 875 –17.06 127.47 20.66 111.00 –23.54 –52.09 –15.83 3.31 20.86 1.00 938 –17.43 124.24 20.67 106.00 –23.59 –56.11 –15.12 –8.18 20.88 1.00 1000 –17.84 121.27 20.68 101.00 –23.65 –60.15 –14.40 –19.09 20.91 1.00 1063 –18.33 118.52 20.69 95.90 –23.71 –64.29 –13.68 –29.61 20.94 1.00 1125 –18.93 116.83 20.71 90.70 –23.80 –68.44 –12.95 –39.87 20.99 0.99 1188 –19.57 116.37 20.72 85.20 –23.89 –72.62 –12.26 –49.91 21.03 0.99 1250 –20.14 117.52 20.74 79.50 –24.00 –76.89 –11.55 –59.70 21.10 0.99 1313 –20.68 120.07 20.72 73.80 –24.11 –81.21 –10.88 –69.02 21.13 0.98 1375 –21.14 124.93 20.68 67.70 –24.26 –85.55 –10.22 –78.13 21.15 0.98 1438 –21.23 131.06 20.66 61.70 –24.41 –89.92 –9.62 –87.07 21.20 0.98 1500 –20.90 138.25 20.56 55.50 –24.60 –94.32 –9.04 –95.80 21.18 0.97 1563 –19.95 144.26 20.48 48.90 –24.81 –98.64 –8.48 –104.53 21.19 0.96 1625 –18.83 147.76 20.33 42.70 –25.03 –102.91 –8.01 –113.14 21.14 0.96 1688 –17.57 149.45 20.13 35.90 –25.25 –107.24 –7.55 –121.73 21.04 0.95 1750 –16.37 149.11 19.94 29.40 –25.52 –111.45 –7.15 –130.18 20.97 0.95 1813 –15.17 147.51 19.61 23.10 –25.80 –115.57 –6.78 –138.82 20.77 0.95 1875 –14.06 144.51 19.28 16.30 –26.10 –119.65 –6.44 –147.52 20.57 0.95 1938 –13.10 140.68 18.94 10.50 –26.38 –123.43 –6.19 –155.94 20.35 0.95 2000 –12.25 136.43 18.48 4.49 –26.69 –127.22 –5.93 –164.25 20.03 0.97 2063 –11.53 131.89 18.05 –1.39 –26.99 –131.08 –5.72 –172.58 19.72 0.99 2125 –10.87 127.16 17.58 –6.43 –27.27 –134.59 –5.54 179.33 19.37 1.02 2188 –10.31 122.28 17.04 –11.60 –27.59 –138.32 –5.39 171.30 18.95 1.07 2250 –9.81 117.46 16.62 –16.20 –27.86 –141.93 –5.26 163.58 18.63 1.11 2313 –9.37 112.41 16.10 –20.00 –28.21 –145.40 –5.17 156.00 18.21 1.18 2375 –9.01 107.65 15.68 –24.30 –28.44 –149.05 –5.09 148.51 17.87 1.23 643020f 24 For more information www.linear.com/LTC6430-20 LTC6430-20 TYPICAL APPLICATIONS 50Ω Input/Output Balanced Amplifier T1 1:2 DNC DNC VCC DNC GND DNC T_DIODE LTC6430-20 DNC BALUN_A = ADT2-1T FOR 50MHz TO 300MHz BALUN_A = ADT2-1T-1P FOR 300MHz TO 400MHz BALUN_A = ADTL2-18 FOR 400MHz TO 1300MHz ALL ARE MINI-CIRCUITS CD542 FOOTPRINT T2 2:1 GND DNC –OUT R2 350Ω 100Ω DIFFERENTIAL C4 • • 1000pF BALUN_A DNC DNC –IN C2 1000pF C3 1000pF DNC DNC C8 60pF DNC BALUN_A L1 560nH +OUT VCC 100Ω DIFFERENTIAL RFIN 50Ω, SMA DNC DNC GND PORT INPUT +IN R1 350Ω GND C7 60pF C1 1000pF PORT OUTPUT RFOUT 50Ω, SMA L2 560nH C6 0.1µF C5 1000pF VCC = 5V OPTIONAL STABILITY NETWORK 643020 TA02 16-Bit ADC Driver T1 1:2 +OUT GND DNC T_DIODE LTC6430-20 LOWPASS FILTER +IN –IN 14- TO 16-BIT ADC DNC DNC DNC –OUT VCC DNC GND GND C2 1000pF 100Ω DIFFERENTIAL C4 1000pF DNC DNC ETC1-1-13 1:1 TRANSFORMER M/A-COM • DNC DNC BALUN_A C3 1000pF • RFIN 50Ω, SMA L1 220nH DNC DNC VCC DNC GND DNC –IN PORT INPUT +IN C1 1000pF L2 220nH BALUN_A = ADT2-1T FOR 50MHz TO 300MHz BALUN_A = ADT2-1T-1P FOR 300MHz TO 400MHz BALUN_A = ADTL2-18 FOR 400MHz TO 1300MHz ALL ARE MINI-CIRCUITS CD542 FOOTPRINT C5 1000pF C6 0.1µF VCC = 5V 643020 TA03 643020f For more information www.linear.com/LTC6430-20 25 LTC6430-20 TYPICAL APPLICATIONS 75Ω 40MHz to 1000MHz CATV Amplifier DNC GND DNC T_DIODE LTC6430-20 T2 1.33:1 C4 0.047µF DNC DNC –OUT DNC GND DNC VCC 100Ω DIFFERENTIAL DNC DNC GND C2 0.047µF C3 0.047µF +OUT DNC BALUN_A L1 560nH DNC DNC DNC DNC 100Ω DIFFERENTIAL RFIN 75Ω, CONNECTOR VCC +IN T1 1:1.33 –IN PORT INPUT GND C1 0.047µF • • BALUN_A PORT OUTPUT RFOUT 75Ω, CONNECTOR L2 560nH BALUN_A = TC1.33-282+ FOR 40MHz TO 1000MHz C5 1000pF C6 0.1µF VCC = 5V MINI-CIRCUITS 1:1.33 643020 TA04 643020f 26 For more information www.linear.com/LTC6430-20 LTC6430-20 PACKAGE DESCRIPTION Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. UF Package 24-Lead Plastic QFN (4mm × 4mm) (Reference LTC DWG # 05-08-1697 Rev B) 0.70 ±0.05 4.50 ±0.05 2.45 ±0.05 3.10 ±0.05 (4 SIDES) PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 4.00 ±0.10 (4 SIDES) BOTTOM VIEW—EXPOSED PAD R = 0.115 TYP 0.75 ±0.05 PIN 1 NOTCH R = 0.20 TYP OR 0.35 × 45° CHAMFER 23 24 PIN 1 TOP MARK (NOTE 6) 0.40 ±0.10 1 2 2.45 ±0.10 (4-SIDES) (UF24) QFN 0105 REV B 0.200 REF 0.00 – 0.05 0.25 ±0.05 0.50 BSC NOTE: 1. DRAWING PROPOSED TO BE MADE A JEDEC PACKAGE OUTLINE MO-220 VARIATION (WGGD-X)—TO BE APPROVED 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, IF PRESENT 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 643020f 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 representaFor more www.linear.com/LTC6430-20 tion that the interconnection of itsinformation circuits as described herein will not infringe on existing patent rights. 27 LTC6430-20 TYPICAL APPLICATION Wideband Balanced Amplifier 5V VCC = 5V RF 1:2 TRANSFORMER VIN LTC6430-20 RS 50Ω RSOURCE = 100Ω DIFFERENTIAL RLOAD = 100Ω DIFFERENTIAL 2:1 TRANSFORMER RL 50Ω 643020 TA05 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS Fixed Gain IF Amplifiers/ADC Drivers LTC6431-20 50Ω 20dB Gain Block IF Amplifier Single-Ended Version of LTC6430-20, 20.8dB Gain, 46.2dBm OIP3 at 240MHz into a 50Ω Load LTC6431-15 50Ω 15dB Gain Block IF Amplifier Single-Ended Version of LTC6430-15, 15.5dB Gain, 47dBm OIP3 at 240MHz into a 50Ω Load LTC6430-15 100Ω Differential 15dB Gain Block IF Amplifier 20MHz to 2GHz 3.3dB NF 15.5dB Gain, 50dBm OIP3 at 240MHz into a 100Ω Differential Load LTC6417 1.6GHz Low Noise High Linearity Differential Buffer/ OIP3 = 41dBm at 300MHz, Can Drive 50Ω Differential Output High ADC Driver Speed Voltage Clamping Protects Subsequent Circuitry LTC6400-8/LTC6400-14/ LTC6400-20/LTC6400-26 1.8GHz Low Noise, Low Distortion Differential ADC Drivers –71dBc IM3 at 240MHz 2VP-P Composite, IS = 90mA, AV = 8dB, 14dB, 20dB, 26dB LTC6401-8/LTC6401-14/ LTC6401-20/LTC6401-26 1.3GHz Low Noise, Low Distortion Differential ADC Drivers –74dBc IM3 at 140MHz 2VP-P Composite, IS = 50mA, AV = 8dB, 14dB, 20dB, 26dB LT6402-6/LT6402-12/ LT6402-20 300MHz Differential Amplifier/ADC Drivers –71dBc IM3 at 20MHz 2VP-P Composite, AV = 6dB, 12dB, 20dB LTC6410-6 1.4GHz Differential IF Amplifier with Configurable Input Impedance OIP3 = 36dBm at 70MHz, Flexible Interface to Mixer IF Port LTC6420-20 Dual 1.8GHz Low Noise, Low Distortion Differential ADC Drivers Dual Version of the LTC6400-20, AV = 20dB Variable Gain IF Amplifiers/ADC Drivers LTC6412 800MHz, 31dB Range Analog-Controlled VGA OIP3 = 35dBm at 240MHz, Continuously Adjustable Gain Control Baseband Differential Amplifiers LTC6409 1.1nV/√Hz Single Supply Differential Amplifier/ADC Driver 88dB SFDR at 100MHz, AC- or DC-Coupled Inputs LTC6406 3GHz Rail-to-Rail Input Differential Amplifier/ ADC Driver –65dBc IM3 at 50MHz 2VP-P Composite, Rail-to-Rail Inputs, eN = 1.6nV/√Hz, 18mA LTC6404-1/LTC6404-2 Low Noise Rail-to-Rail Output Differential Amplifier/ 16-Bit SNR, SFDR at 10MHz, Rail-to-Rail Outputs, eN = 1.5nV/√Hz, ADC Driver LTC6404-1 Is Unity-Gain Stable, LTC6404-2 Is Gain-of-Two Stable High Speed ADCs LTC2208/LTC2209 16-Bit, 13Msps/160Msps ADC 74dBFS Noise Floor, SFDR > 89dB at 140MHz, 2.25VP-P Input LTC2259-16 16-Bit, 80Msps ADC, Ultralow Power 72dBFS Noise Floor, SFDR > 82dB at 140MHz, 2.00VP-P Input LTC2160-14/LTC2161-14/ 14-bit, 25Msps/40Msps/60Msps ADC Low Power LTC2162-14 76.2 dBFS Noise Floor, SFDR > 84dB at 140MHz, 2.00VP-P Input LTC2155-14/LTC2156-14/ 14-bit, 170Msps/210Msps/250Msps/310Msps LTC2157-14/LTC2158-14 ADC 2-Channel 69dBFS Noise Floor, SFDR > 80dB at 140MHz, 1.50VP-P Input, >1GHz Input BW LTC2216 79dBFS Noise Floor, SFDR > 91dB at 140MHz, 75VP-P Input 16-Bit, 80Msps ADC 643020f 28 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LTC6430-20 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LTC6430-20 LT 1014 • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2014