Variable Gain Amplifiers (VGA / DGVA) | National Semiconductor Home->Amplifiers

Variable Gain Amplifiers (VGAs)

National's VGAs feature high-frequency large signals and can drive heavy load currents. They additionally provide accurate device-to-device gain matching and excellent attenuation range, making them ideal for automatic gain control applications in communications infrastructure wireless basestation, industrial and video applications.

 

LMH6515 – 600 MHz, Digital Controlled, Variable Gain Amplifier

  • 8.3 dB noise figure, 40 dBm OIP3
  • 500 mW power dissipation
  • 26 dB maximum gain, RL = 200
  • 31 dB gain range in precise 1 dB steps
  • Gain step error < 0.05 dB at F = 100 MHz
  • Differential-to-differential and single-to-differential
  • Available in small LLP-16 packaging (4 mm x 4 mm)
  • Ideal match for 12/14-bit high-speed ADCs up to 300 MHz, such as the ADC14V155 and ADC14DS105
  • Reference board RD-146 with ADC14V155

LMH6518 – 900 MHz DVGA with 40 dB Adjustment Gain and 8.5 mdB Effective Gain-Step Resolution

  • Integrated bandwidth filters
  • Auxiliary output for trigger path
  • Gain range 40 dB
  • Gain step size 2 dB
  • Gain step size with ADC 8.5 mdB
  • SNR (VIN≥25 mVpp FS, 200 MHz BW) 52dBFS
  • HD2/HD3 at 100 MHz -50 dBc/-53 dBc
  • Input referred noise (max gain) 0.98 nV/√Hz
  • Power consumption 1.1W/0.75W

 

VGA Selection Table

Part Gain Adjust Range (dB) Signal Channel BW (MHz) Supply (Volt) Gain Control Interface Supply Current (mA) Output Current (mA) Offset Voltage max, 25C (mV) Max Input Bias Current (nA) Voltage Noise (nV/√Hz) Special Features
24 25 2.7 - 5 SPI-Microwire 5.5 20 300 0.3 12 Av x1 to x16; Shutdown
40 900 4.75 - 5.25 SPI-1 150   40 10000 0.98 Oscilloscope Front-end w/ Trigger & Filters
31 600 4 - 5 Parallel TTL/CMOS 100 20 30   1.8 1db Steps, Differential I/O
42 600 4 - 5 Parallel TTL/CMOS 107 20 30   18 6db Steps, Differential I/O
80 150 7 - 12 Voltage 11 80 55 3700 4.4  
70 135 5 - 12 Voltage 37 90 370 20000 6.6 Differential Input
70 130 5 - 12 Voltage 27 90 300 20000 7.7 Differential Input

View VGA parametric table

WHAT'S NEW
Op Amp Products
  • LMP8601/LMP8602/LMP8603 - 60V Common Mode 20x/50x/100x Gain Bidirectional Precision Current Sensing Amplifiers
  • LMV841Q
    CMOS Input, RRIO, Wide Supply Range Operational Amplifiers
  • LMV841/LMV842/LMV844Q
    CMOS Input, RRIO, Wide Supply Range Quad Operational Amplifiers
  • Nanopower, 1.8V, RRIO, CMOS Input, Operational Amplifier
  • Single/Dual Zero Drift, Low Noise, EMI Hardened Amplifier
  • Low Power, High Linearity IF and Baseband Dual 16 bit ADC Driver With Digitally Controlled Gain
  • 900 MHz Fully Differential Amplifier with Output Limiting Clamp
  • 2.9 nV/sqrt(Hz) Low Noise, Precision , RRIO Amplifier

 

Op Amp Application Notes
  • AN-1808 - LMH730033 Evaluation Board
  • AN-1803 - Design Considerations for a Transimpedance Amplifier
  • AN-1796 - LMP7721 Evaluation Board
  • AN-1784 - LMV1022 / LMV1023 Digital Output PDM Microphone Amplifier Demo Board User's Guide

 

Op Amp Evaluation Boards
  • 551012875-001 - $4.00 Description: 551012875-001 Evaluation Board
  • 551012876-001 - $4.00 Description: 551012876-001 Evaluation Board
  • 551012922-001 - $4.00 Description: SC-70 Amplifier Universal Evaluation Board
  • LMH2100EVAL - $99.00 Description: Evaluation Board for the LMH2100 Logarithmic Power Detector

 

Op Amp Models & Software

SPICE Models:

Software:

 



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