LT5514 Ultralow Distortion IF Amplifier/ADC Driver with Digitally Controlled Gain FEATURES DESCRIPTIO n Output IP3 at 100MHz: 47dBm The LT 5514 is a programmable gain amplifier (PGA) with n Maximum Output Power: 21dBm bandwidth extending from low frequency (LF) to 850MHz. n Bandwidth: LF to 850MHz It consists of a digitally controlled variable attenuator, n Propagation Delay: 0.8ns followed by a high linearity amplifier. The amplifier is n Maximum Gain: 33dB configured with two identical transconductance amplifi- n Noise Figure: 7.3dB (Max Gain) ers, hard wired in parallel with individual dedicated enable n Gain Control Range: 22.5dB pins. When both amplifiers are enabled (Standard mode), n Gain Control Step: 1.5dB the LT5514 offers an OIP3 of +47dBm (at 100MHz). n Gain Control Settling Time: 500ns Power dissipation can be reduced when a single amplifier n Output Noise Floor: 134dBm/Hz (Max Gain) is enabled (Low Power mode). Four parallel digital inputs n Reverse Isolation: 80dB control the gain over a 22.5dB range with 1.5dB step n Single Supply: 4.75V to 5.25V resolution. An on-chip power supply regulator/filter helps n Low Power Mode isolate the amplifier signal path from external noise sources. n Shutdown Mode The LT5514s open-loop architecture offers stable opera- n Enable/Disable Time: 1m s tion for any practical load conditions, including peaking- n Differential I/O Interface free AC response when driving capacitive loads, and n 20-Lead TSSOP Package excellent reverse isolation. U APPLICATIO S The LT5514 may be operated broadband, where the out- put differential RC time constant sets the bandwidth, or it n High Linearity ADC Driver may be used as a narrowband driver with the appropriate n IF Sampling Receivers output filter. n VGA IF Power Amplifier , LTC and LT are registered trademarks of Linear Technology Corporation. n 50W Driver n Instrumentation Applications TYPICAL APPLICATIO Output IP3 vs Frequency (Standard Mode) 56 5V 53 CHOKE CHOKE 0.1F 0.1F 50 R = 200 OUT 47 RF IF IF LT5514 100 ADC R = 100 INPUT AMP OUT BPF 44 5514 TA01 LO 0.1F 0.1F 41 GAIN CONTROL 4 LINES 38 35 0 50 100 150 200 5514 TA02 FREQUENCY (MHz) 5514f 1 OIP3 (dBm) U ULT5514 ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Notes 1, 2) TOP VIEW Power Supply Voltage (V , V ) .......................... 6V ORDER PART CC1 CC2 + Output Supply Voltage (OUT , OUT ) ....................... 8V NUMBER ENA 1 20 ENB Control Input Voltage (ENA, ENB, PGAx) .. 0.5V to V V 2 19 V CC1 CC2 CC LT5514EFE + GND 3 18 Signal Input Voltage (IN , IN ) ................... 0.5V to 3V GND GND 4 17 GND Operating Ambient Temperature Range .. 40 C to 85 C + IN 5 16 OUT Storage Temperature Range ................. 65 C to 150 C 21 + IN 6 15 OUT Lead Temperature (Soldering, 10 sec).................. 300 C GND 7 14 GND GND 8 13 GND PGA0 9 12 PGA3 PGA1 10 11 PGA2 FE PACKAGE 20-LEAD PLASTIC TSSOP T = 150 C, q = 38 C/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. ODES OF OPERATIO MODES ENA ENB AMP A AMP B LT5514 STATE 1 Full Power (Standard) High High On On Enable Amp A and Amp B 2 Low Power A High Low On Off Enable Amp A 3 Low Power B Low High Off On Enable Amp B 4 Shutdown Low Low Off Off Sleep, All Amps Disabled PROGRA ABLE GAI SETTI GS ATTENUATION STEP POWER GAIN RELATIVE TO MAX GAIN PGA0 PGA1 PGA2 PGA3 STANDARD MODE* LOW POWER MODE** 1 0dB High High High High 33.0dB 30.0dB 2 1.5dB Low High High High 31.5dB 28.5dB 3 3.0dB High Low High High 30.0dB 27.0dB 4 4.5dB Low Low High High 28.5dB 25.5dB 5 6.0dB High High Low High 27.0dB 24.0dB 6 7.5dB Low High Low High 25.5dB 22.5dB 7 9.0dB High Low Low High 24.0dB 21.0dB 8 10.5dB Low Low Low High 22.5dB 19.5dB 9 12.0dB High High High Low 21.0dB 18.0dB 10 13.5dB Low High High Low 19.5dB 16.5dB 11 15.0dB High Low High Low 18.0dB 15.0dB 12 16.5dB Low Low High Low 16.5dB 13.5dB 13 18.0dB High High Low Low 15.0dB 12.0dB 14 19.5dB Low High Low Low 13.5dB 10.5dB 15 21.0dB High Low Low Low 12.0dB 9.0dB 16 22.5dB Low Low Low Low 10.5dB (Note 3) 7.5dB (Note 3) *R = 200W **R = 400W OUT OUT 5514f 2 U U WW U W U W U U WWW