AD8323ARUZ

Overview

The AD8323ARUZ is a digitally controlled variable gain amplifier optimized for coaxial line driving applications. It operates from a single 5 V supply with an operating range of 4.75 V to 5.25 V and draws 133 mA quiescent current in power-up mode. The device provides a programmable gain range of 53.5 dB with a scaling factor of 0.7526 dB/LSB, achieving a maximum gain of 27.5 dB. It maintains a differential output impedance of 75 Ω and supports an upper bandwidth of 100 MHz across the full gain range.

Feature Summary

• Maintains constant 75 Ω differential output impedance during power-up and power-down conditions
• Features asynchronous sleep mode reducing supply current to approximately 4 mA
• Supports SPI interface for 8-bit serial gain control via DATEN, SDATA, and CLK pins

Applications

• Gain-programmable line drivers for CATV systems
• HFC high-speed data modems compliant with DOCSIS standards
• Interactive cable set-top boxes
• PC plug-in cable modems

Procurement Notes

Verify that the specific ordering suffix corresponds to the TSSOP-28 package variant required for the design. Confirm that the component meets all relevant RoHS directives before integration. Ensure that the serial interface timing requirements are compatible with the host controller logic levels. Validate that the thermal resistance characteristics align with the printed circuit board layout constraints.

Selection Notes

Select this component when a fixed 75 Ω output impedance is required without external termination resistors. Choose this device for applications needing fine-step gain adjustment over a wide dynamic range. Consider the low-power sleep mode for battery-operated or burst-transmission systems. Ensure the input signal can be AC-coupled to match the internal DC bias level.

Part Context

The AD8323ARUZ belongs to the Analog Devices AD8323 family of special purpose amplifiers. It is functionally similar to the AD8325 but offers a slightly different gain range and distortion profile. Both devices target upstream transmission in cable modem architectures. The ARUZ suffix indicates a lead-free TSSOP package option within the product line.

Replacement Considerations

Public documentation confirms that the MA/COM ETC-1-IT-15 transformer may substitute for the specified TOKO transformer in evaluation circuits. No direct pin-compatible amplifier replacements are explicitly confirmed in the provided source material.