Overview
The AD8325ARUZ, produced by Analog Devices Inc., is a 5 V CATV (Cable Television) line driver with fine step output power control. This device is optimized for coaxial line driving applications, particularly in cable modems and other DOCSIS (Data Over Cable Service Interface Specification) compliant systems. It operates from a single 5 V supply and has an operational temperature range of –40°C to +85°C. The AD8325 is packaged in a low-cost 28-lead TSSOP (Thin Shrink Small Outline Package).
Key Specifications
| Parameter | Value |
|---|---|
| Amplifier Type | CATV Line Driver |
| Number of Channels | 1 Channel |
| Supply Voltage (Max) | 5.25 V |
| Supply Voltage (Min) | 4.75 V |
| Operating Supply Current | 133 mA |
| Operating Temperature Range | –40°C to +85°C |
| Control Step Size | 0.75 dB |
| Gain Control Range | 59 dB (–29.5 dB to 30 dB) |
| Second Order Harmonic Distortion (typ) | –60 dBc |
| Third Order Harmonic Distortion (typ) | –54 dBc |
| Bandwidth (-3 dB, typ) | 100 MHz |
| Package | 28-Lead TSSOP |
| RoHS Compliance | Compliant |
Key Features
- Digital control of gain with a fine step resolution of 0.75 dB, allowing for precise output power adjustment.
- Wide gain control range of 59 dB, from –29.5 dB to 30 dB, enabling the device to handle various signal levels.
- Low distortion performance with second and third order harmonic distortions of –60 dBc and –54 dBc, respectively, ensuring high signal quality.
- Differential input and output stages to improve power supply rejection ratio (PSRR) and linearity.
- Operates from a single 5 V supply, simplifying power management in the system.
- SPI (Serial Peripheral Interface) for gain programming, allowing for easy integration into digital systems.
- Low-cost 28-lead TSSOP package, suitable for cost-sensitive applications.
Applications
- Cable modems and DOCSIS compliant systems, where precise control over the upstream signal power is necessary.
- Coaxial line driving applications in CATV systems, requiring low distortion and high signal integrity.
- Other communication systems that require variable gain amplification with fine step control.
Q & A
- Q: What is the primary application of the AD8325?
A: The AD8325 is primarily used as the upstream power amplifier in DOCSIS compliant cable modems and other CATV line driving applications.
- Q: What is the gain control range of the AD8325?
A: The AD8325 has a gain control range of 59 dB, from –29.5 dB to 30 dB.
- Q: How is the gain of the AD8325 controlled?
A: The gain of the AD8325 is controlled using a serial peripheral interface (SPI).
- Q: What is the typical operating supply current of the AD8325?
A: The typical operating supply current of the AD8325 is 133 mA.
- Q: What is the bandwidth of the AD8325?
A: The bandwidth of the AD8325 is typically 100 MHz.
- Q: Is the AD8325 RoHS compliant?
A: Yes, the AD8325 is RoHS compliant.
- Q: What is the package type of the AD8325?
A: The AD8325 is packaged in a 28-lead TSSOP (Thin Shrink Small Outline Package).
- Q: What are the typical second and third order harmonic distortions of the AD8325?
A: The typical second and third order harmonic distortions are –60 dBc and –54 dBc, respectively.
- Q: How does the AD8325 handle differential inputs?
A: The AD8325 can handle differential inputs, and it is imperative that the input signals are 180 degrees out of phase and of equal amplitudes for proper gain accuracy and harmonic performance.
- Q: What is the operating temperature range of the AD8325?
A: The operating temperature range of the AD8325 is –40°C to +85°C.
