Description

A, AD603 chip introduction

The AD603 is a low noise, voltage controlled amplifier for radio frequency (RF) and intermediate frequency (IF) automatic gain control (AGC) systems. It provides accurate pin selectable gains from −11 dB to +31 dB at 90 MHz bandwidth and +9 dB to +51 dB at 9 MHz bandwidth. Use an external resistor to obtain any intermediate gain range. The input referred noise spectral density is only 1.3 nV/√Hz, and the power consumption is 125 mW with the recommended ±5 V power supply.

The gain is linear in dB and is precisely calibrated and does not change with temperature and supply voltage. The gain is controlled by a high-impedance (50 MΩ), low-bias (200 nA) differential input; the scale factor is 25 mV/dB, so only 1 V of gain control voltage is needed to cover the mid-range of 40 dB of the gain range. Regardless of the range chosen, 1 dB over-range and under-range are available. For a 40 dB change, the gain control response time is less than 1 μs. The differential gain control interface allows differential or single-ended positive or single-ended negative control voltages. Several such amplifiers can be cascaded with their gain control gain bias to optimize the system signal-to-noise ratio (SNR).

The AD603 can drive load impedances as low as 100 Ω with low distortion. For a 500 Ω load with a 5 pF shunt, the total harmonic distortion of a ±1 V sine output is typically −60 dBc at 10 MHz. The peak rated output into a 500 Ω load is ±2.5 V (minimum).

The AD603 uses a proprietary, patented circuit structure, X-AMP®. The X-AMP contains a 0 dB to -42.14 dB variable attenuator followed by a fixed gain amplifier. Due to the presence of an attenuator, the amplifier never has to process a large input, and negative feedback can be used to define its (fixed) gain and dynamic performance. The attenuator has a 100 Ω input resistor that is laser trimmed to ±3% and contains a 7-stage R-2R ladder network, which provides a 6.021 dB attenuation between contacts. Using proprietary interpolation techniques, linear continuous gain control in dB is available.

The AD603 has an operating temperature range of −40°C to +85°C.

Two or Two Stage AD603-VCA (Voltage Control Gain) Module

1, the work of gain and frequency range: (see the schematic diagram of the specific configuration)

   -11dB -- +31dB 90MHz Bandwidth

9dB ​​-- +51dB 9MHz Bandwidth

-1dB -- +41dB 30MHz Bandwidth (default configuration mode, this is a Level 1 parameter)

2, the maximum gain can be amplified to 1000 times the small signal without distortion, the maximum power supply is ± 7.5V DC

3, 100MHz bandwidth, flatness test (maximum gain flatness less than 3dB in 30MHz)

Package List:

- 1pc module as frist picture show