Overview
The AD8324ACPZ, produced by Analog Devices Inc., is a low-cost amplifier specifically designed for coaxial line driving. It is ideally suited for applications in DOCSIS 2.0 and EuroDOCSIS cable modems, as well as CATV set-top boxes and telephony modems. This device operates on a 3.3 V supply and features a digitally controlled gain with an 8-bit resolution over a 59 dB range, allowing for fine 1 dB gain steps. The AD8324ACPZ supports both differential and single-ended input signals and is optimized for driving a 75 Ω load through a 1:1 transformer.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VCC) | 3.13 | 3.3 | 3.47 | V |
| Input Voltage | 1.5 | V p-p | ||
| Output Impedance | 75 | Ω | ||
| Bandwidth | 100 | MHz | ||
| Gain Range | 59 | dB | ||
| Gain Step | 1 | dB/LSB | ||
| Output Noise Level (min gain) | 1.3 | nV/√Hz | ||
| Operating Temperature Range | -40 | 85 | °C | |
| Package Type | 20-Lead QSOP, 20-Lead LFCSP |
Key Features
- Digitally controlled gain with 8-bit resolution over a 59 dB range, allowing for 1 dB gain steps.
- Supports both differential and single-ended input signals.
- Output specified for driving a 75 Ω load through a 1:1 transformer.
- Low distortion performance of –54 dBc at an output level up to 61 dBmV at 65 MHz bandwidth.
- Maintains 75 Ω output impedance in all power modes.
- Upper bandwidth of 100 MHz (full gain range).
- Supports SPI interfaces for gain programming.
- Low power sleep mode reducing supply current to 30 μA and full power-down function reducing power-down current to 2.5 mA.
Applications
The AD8324ACPZ is primarily intended for use as the upstream power amplifier (PA) in DOCSIS 2.0 and EuroDOCSIS certified cable modems and CATV set-top boxes. It is also suitable for CATV telephony modems, coaxial and twisted pair line drivers. The device is designed to handle the varying distances between the cable modem and the headend by adjusting the output power through gain or attenuation, ensuring the signal arrives at the headend with the proper level.
Q & A
- What is the primary application of the AD8324ACPZ?
The AD8324ACPZ is primarily used as the upstream power amplifier in DOCSIS 2.0 and EuroDOCSIS certified cable modems and CATV set-top boxes.
- What is the supply voltage range for the AD8324ACPZ?
The supply voltage range is from 3.13 V to 3.47 V.
- What is the output impedance of the AD8324ACPZ?
The output impedance is 75 Ω.
- What is the bandwidth of the AD8324ACPZ?
The upper bandwidth is 100 MHz over the full gain range.
- How is the gain controlled in the AD8324ACPZ?
The gain is digitally controlled with an 8-bit resolution over a 59 dB range, allowing for 1 dB gain steps.
- What is the distortion performance of the AD8324ACPZ?
The distortion performance is –54 dBc at an output level up to 61 dBmV at 65 MHz bandwidth.
- Does the AD8324ACPZ support sleep mode?
Yes, it has a low power sleep mode that reduces the supply current to 30 μA.
- What are the package options for the AD8324ACPZ?
The device is available in 20-Lead QSOP and 20-Lead LFCSP packages.
- What is the operating temperature range of the AD8324ACPZ?
The operating temperature range is from -40°C to +85°C.
- How does the AD8324ACPZ handle input signals?
The device accepts both differential and single-ended input signals. For differential inputs, the signals must be 180° out of phase and of equal amplitude.
