MAX3518ETP+G2Z

Overview

The MAX3518ETP+G2Z is a DOCSIS 3.0 compliant CATV upstream amplifier IC operating from a single +5V supply. It covers a 5MHz to 85MHz input frequency range with a 275MHz, 3dB bandwidth. The device provides 63dB of gain control in 1dB steps via an SPI interface and supports four QPSK modulated carriers at +58dBmV simultaneously. Power consumption is 1.25W at 31dB gain, dropping to 25mW in transmit-disable mode. It features differential I/O, requiring an external balun, and operates within the -40°C to +85°C temperature range.

Feature Summary

• Integrated programmable-gain amplifier with differential Class A output stage for superior even-order distortion performance
• Four selectable power codes allow bias current reduction based on specific linearity requirements
• Ultra-low power dissipation in transmit-disable mode to minimize heat generation between bursts
• Low transient voltage during burst on/off switching to maintain signal integrity

Applications

• DOCSIS 3.0 Cable Modems
• VOIP Modems
• Set-Top Boxes

Procurement Notes

Verify that the ordering suffix G2Z corresponds to the standard lead-free/RoHS-compliant package configuration as indicated by the plus sign (+) in the base part number. Confirm the component is supplied in the 20-pin thin QFN format with exposed pad. Ensure the procurement documentation matches the Analog Devices/Maxim Integrated manufacturing origin.

Selection Notes

Select this component when designing systems requiring strict compliance with DOCSIS 3.0 upstream specifications. The integrated PGA simplifies design by reducing the need for external variable gain stages. Consider the requirement for an external 1:1 transformer to convert the differential output to single-ended signals for standard cable networks.

Part Context

This integrated circuit belongs to the Maxim Integrated product family, now part of Analog Devices Inc. It is specifically engineered for hybrid fiber-coaxial (HFC) network infrastructure. The device consolidates multiple functions into a compact footprint, replacing discrete amplifier solutions previously used in cable modem and set-top box architectures.

Replacement Considerations

MAX3518ETP+T

FAQ

How is the gain of the MAX3518 controlled?

The gain is controlled via a 3-wire SPI interface using a 6-bit gain code, allowing adjustments in 1dB steps over a 63dB range.

What is required for the output connection?

An external 1:1 transformer (balun) is required at the output port to convert the differential signal to a single-ended 75Ω load.