Ling Zhi electronic VCA821 programmable amplifier module V1.0
1 Module introduction
yes TI The company introduces DC coupling, broadband, low-noise, low distortion and linearity dB High gain precision voltage control VGA The chip is well suited for use as a high frequency variable gain control amplifier STM32 Etc. DA MCU system can achieve programmable amplification effect. The optimized layout, wiring and reasonable design greatly reduce interference and enhance the stability of the module. This module can be used for RF/IF Systematic VCA Circuit and video gain control, A/D Systems such as range expansion and signal measurement.
The main features of the module are as follows:
( 1 Module only One Broadband amplification A broadband gain alterable amplifier chip is adopted VCA821 .
( 2 Gain control: manual control and automatic control. In manual mode, the gain is adjusted by an onboard potentiometer, and the control voltage is 617mV~1220mV Automatic mode, by external connection DA Regulating gain, control voltage 617~1220mV . The whole board Default gain range: 0~20dB . Modify the 821 gain resistor to vary the gain range.
( 3 In) Small signal amplification output 1Vpp The case, the whole board -3dB The cutoff frequency is about 500MHz Left and right The gain fluctuation in the band is very small . The whole board -1dB The cutoff frequency is about 400MHz The gain fluctuation in the passband is very small.
( 4 Module Maximum input / Output voltage: maximum input voltage 250mVpp Maximum output voltage 2.5Vpp ;
( 5 Module usage ± 5V power supply .
( 6 ) The input / output interface is adopted SMA Interface The input and output impedance is 50Ω .
( 7 ) the right modules can be customized according to the user\'s actual requirements. As the debugging process is tedious, it needs to be charged a certain amount of customization fee.
2 Module interface
The interface of each module is shown in figure.
Schematic diagram of module interface
3 Module interface connecting method
The module manually adjusts gain, debug, and external connections DA Control gain, debug connection (with small core board and power module), as shown below (refer to figure).
Fig. 1 connection diagram of module manual adjustment of gain
External DA control gain, debug connection (with small core board and power module) connection diagram
4 Module debugging effect
Test condition: use RF line connection, “ VIN ” receive signal input, “ VOUT ” the output of the signal; the input signal amplitude is constant, and the signal source is loaded 50 Ω and there is no DC offset.
Module frequency characteristic diagram
5 Invoice list
VCA821 Programmable amplifier module
User manual, module diagram (PDF version) and chip manual
Baidu SkyDrive Download
- Type: Air Conditioner Parts
- Unit Type: piece
- Package Weight: 0.5kg (1.10lb.)
- Package Size: 10cm x 10cm x 10cm (3.94in x 3.94in x 3.94in)