LT5524 Low Distortion IF Amplifier/ADC Driver with Digitally Controlled Gain FEATURES DESCRIPTIO Output IP3 at 100MHz: 40dBm The LT 5524 is a programmable gain amplifier (PGA) with Maximum Output Power: 16dBm bandwidth extending from low frequency (LF) to 540MHz. Bandwidth: LF to 540MHz It consists of a digitally controlled variable attenuator, Propagation Delay: 0.8ns followed by a high linearity amplifier. Four parallel digital Maximum Gain: 27dB inputs control the gain over a 22.5dB range with 1.5dB Gain Control Range: 22.5dB step resolution. An on-chip power supply regulator/filter Gain Control Step: 1.5dB helps isolate the amplifier signal path from external noise Gain Control Settling Time: 500ns sources. Noise Figure: 8.6dB at 100MHz (Max Gain) The LT5524s open-loop architecture offers stable opera- Output Noise Floor: 138dBm/Hz (Max Gain) tion for any practical load conditions, including peaking- Reverse Isolation: 92dB free AC response when driving capacitive loads, and Single Supply: 4.75V to 5.25V excellent reverse isolation. Shutdown Mode The LT5524 may be operated broadband, where the out- Enable/Disable Time: 1s put differential RC time constant sets the bandwidth, or it Differential I/O Interface may be used as a narrowband driver with the appropriate 20-Lead TSSOP Package output filter. U , LTC and LT are registered trademarks of Linear Technology Corporation. APPLICATIO S Patents Pending. High Linearity ADC Driver IF Sampling Receivers VGA IF Power Amplifier 50 Driver Instrumentation Applications TYPICAL APPLICATIO Output IP3 vs Frequency, R = 200 OUT 54 5V 51 CHOKE CHOKE 48 0.1F 0.1F 45 MAX GAIN RF IF IF LT5524 100 ADC INPUT BPF AMP 42 5524 TA01 39 LO 0.1F 0.1F 1.5dB GAIN CONTROL ATTENUATION 36 4 LINES STEP 33 30 0 50 100 150 200 FREQUENCY (MHz) 5524 TA02 5524f 1 OIP3 (dBm) U ULT5524 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Notes 1, 2) TOP VIEW Power Supply Voltage (V , V ) .......................... 6V ORDER PART CC1 CC2 + Output DC Voltage (OUT , OUT ) ............................. 7V NUMBER EN 1 20 NC Control Input Voltage (EN, PGAx) ............. 0.5V to V V 2 19 V CC1 CC2 CC LT5524EFE + GND 3 18 Signal Input Voltage (IN , IN ) ................... 0.5V to 3V GND GND 4 17 GND Operating Ambient Temperature Range .. 40C to 85C + IN 5 16 OUT Storage Temperature Range ................. 65C to 150C 21 + IN 6 15 OUT Lead Temperature (Soldering, 10 sec).................. 300C GND 7 14 GND GND 8 13 GND PGA0 9 12 PGA3 PGA1 10 11 PGA2 FE PACKAGE 20-LEAD PLASTIC TSSOP T = 150C, = 38C/W JMAX JA EXPOSED PAD (PIN 21) IS GND MUST BE SOLDERED TO PCB Consult LTC Marketing for parts specified with wider operating temperature ranges. PROGRA ABLE GAI SETTI GS ATTENUATION STEP POWER GAIN RELATIVE TO MAX GAIN PGA0 PGA1 PGA2 PGA3 * 1 0dB High High High High 27.0dB 2 1.5dB Low High High High 25.5dB 3 3.0dB High Low High High 24.0dB 4 4.5dB Low Low High High 22.5dB 5 6.0dB High High Low High 21.0dB 6 7.5dB Low High Low High 19.5dB 7 9.0dB High Low Low High 18.0dB 8 10.5dB Low Low Low High 16.5dB 9 12.0dB High High High Low 15.0dB 10 13.5dB Low High High Low 13.5dB 11 15.0dB High Low High Low 12.0dB 12 16.5dB Low Low High Low 10.5dB 13 18.0dB High High Low Low 9.0dB 14 19.5dB Low High Low Low 7.5dB 15 21.0dB High Low Low Low 6.0dB 16 22.5dB Low Low Low Low 4.5dB (Note 3) *R = 200 OUT 5524f 2 U U WW U W U U WWW