This datasheet provides detailed information on the features of the AD8322, including support for the DOCSIS standard for reverse path transmission gain, programmable in 6 dB steps over a 42 dB range, low distortion, low noise, maintains 75 ohms output impedance, 180 MHz bandwidth, 5 V supply and support for SPI interfaces.
The AD8322 is a low‑cost, digitally controlled variable‑gain line driver optimized for coaxial cable‑driving applications such as DOCSIS upstream modems. It provides a programmable gain range of about 42 dB in 6 dB steps, low distortion, and maintains a constant 75 Ω output impedance during power‑up and power‑down.
The device operates from a single 5 V supply, supports SPI programming, and is packaged in a 28‑lead TSSOP. It is intended for use as the upstream power amplifier in cable modems and set‑top boxes, offering high output power (up to 60 dBmV) and low noise performance.
| Gain Range | 41.0 – 43.2 dB |
|---|---|
| Bandwidth (-3 dB) | 180 MHz |
| Output Noise (Max Gain, 10 MHz) | -32 dBmV in 160 kHz BW |
| Supply Voltage Operating Range | 4.75 V – 5.25 V |
| Quiescent Current (Power‑Up) | 100 mA – 126 mA |
| Operating Temperature | -40 °C to +85 °C |
| Differential Output Impedance | 75 Ω ±20 % |
| Input Resistance (Single‑Ended) | 210 Ω |
| Input Capacitance | 2 pF |
The gain can be programmed from about –12.64 dB to +29.5 dB, covering a total range of roughly 42 dB in 6.02 dB steps.
The device operates from a single 5 V supply with an acceptable range of 4.75 V to 5.25 V.
The differential output impedance is 75 Ω ±20 % and is maintained in both power‑up and power‑down conditions.