Overview
The AD8328ARQ-REEL, produced by Analog Devices Inc., is a low-cost, digitally controlled power amplifier designed primarily for use in Data Over Cable Service Interface Specification (DOCSIS) and EuroDOCSIS cable modems. This component is optimized for coaxial line driving and is well-suited for applications requiring precise gain control and low power consumption.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage | 5 | V |
| Upper Bandwidth | 107 | MHz |
| Output Impedance (Differential) | 300 | Ω |
| Input Impedance (Single-Ended) | 800 | Ω |
| Input Impedance (Differential) | 1.6 k | Ω |
| Gain Range | -28 dB to +31 dB | dB |
| Gain Steps | 1 dB per LSB | |
| Serial Interface | SPI (3 digital data lines: CLK, DATEN, SDATA) | |
| Low Power Sleep Mode Current | 20 μA | μA |
Key Features
- Digitally controlled gain with an 8-bit serial interface, allowing for precise gain adjustments in 1 dB steps over a 59 dB range (-28 dB to +31 dB).
- Supports SPI programming for gain adjustment and other control functions.
- Low power consumption with supply current scaling based on gain code, reducing power when operating in lower gain codes.
- Low power sleep mode with a supply current of 20 μA.
- Differential input and output configuration with 300 Ω differential output impedance, suitable for use with a 2:1 balun transformer to match 75 Ω coaxial lines.
- Vernier control in the input stage for fine 1 dB gain steps.
Applications
- DOCSIS and EuroDOCSIS cable modems.
- CATV set-top boxes.
- CATV telephony modems.
- Coaxial and twisted pair line drivers.
Q & A
- What is the primary application of the AD8328ARQ-REEL?
The AD8328ARQ-REEL is primarily intended for use in DOCSIS and EuroDOCSIS cable modems, as well as other CATV-related applications.
- What is the supply voltage of the AD8328ARQ-REEL?
The supply voltage is 5 V).
- What is the upper bandwidth of the AD8328ARQ-REEL?
The upper bandwidth is 107 MHz).
- How is the gain of the AD8328ARQ-REEL controlled?
The gain is digitally controlled through an 8-bit serial interface using SPI programming).
- What is the range of the gain adjustment?
The gain can be adjusted from -28 dB to +31 dB in 1 dB steps).
- What is the output impedance of the AD8328ARQ-REEL in differential configuration?
The output impedance is 300 Ω in differential configuration).
- How does the AD8328ARQ-REEL reduce power consumption?
The component reduces power consumption through supply current scaling based on the gain code, and it has a low power sleep mode with a current of 20 μA).
- What type of interface does the AD8328ARQ-REEL use for control?
The AD8328ARQ-REEL uses a serial peripheral interface (SPI) for control).
- What are some common applications of the AD8328ARQ-REEL besides DOCSIS cable modems?
Besides DOCSIS cable modems, it is used in CATV set-top boxes, CATV telephony modems, and as coaxial and twisted pair line drivers).
- Is the AD8328ARQ-REEL still in production?
No, the AD8328 is obsolete as indicated by the product discontinuance notice).
