AD603ARZ-REEL is a low – noise, voltage – controlled amplifier designed by Analog Devices Inc. (ADI) for precision adjustment in radio – frequency (RF) and intermediate – frequency (IF) automatic gain control (AGC) systems. Here is a detailed description of its functions:
Gain Characteristics
• Wide Gain Range: It offers a gain range of – 11 dB to + 31 dB with a 90 MHz bandwidth and + 9 dB to + 51 dB with a 9 MHz bandwidth. The gain is pin – programmable, and any intermediate gain range can be set using an external resistor.
• Linear – in – dB Gain Control: The decibel gain is linear in dB, accurately calibrated, and stable over temperature and supply. The gain is controlled at a high – impedance (50 MΩ), low – bias (200 nA) differential input, and the scaling is 25 mV/dB. It only requires a gain control voltage of 1 V to span the central 40 dB of the gain range.
Bandwidth Characteristics
The bandwidth of AD603ARZ – REEL is independent of the variable gain, which means that the amplifier can maintain a relatively stable bandwidth within the gain – adjustable range, facilitating its application in various frequency – band signal amplification scenarios.
Noise Performance
The input – referred noise spectral density of this chip is only 1.3 nV/√Hz, which is very low. This enables the amplifier to have excellent noise performance during signal amplification, minimizing the impact of noise on the signal and improving the signal – to – noise ratio of the system.
Output Capability
AD603ARZ – REEL can drive a load impedance as low as 100 Ω with low distortion. For a 500 Ω load in shunt with 5 pF, the total harmonic distortion for a ± 1 V sinusoidal output at 10 MHz is typically – 60 dBc. The peak – specified output is ± 2.5 V minimum into a 500 Ω load, which can meet the requirements of different load – driving applications.
Other Features
The differential gain control interface allows the use of either differential or single – ended positive or negative control voltages. Multiple amplifiers can be cascaded, and their gain control gains can be offset to optimize the system SNR. In addition, the gain control response time is less than 1 μs for a 40 dB change, which means that the amplifier can quickly respond to gain adjustments and adapt to changes in the input signal.
