General Description

The MAX2038 8-channel variable-gain amplifier (VGA) and programmable octal mixer array is designed for high linearity, high dynamic range, and low noise performance targeting ultrasound imaging and Doppler applications. Each amplifier features differential inputs and outputs and a total gain range of 42dB (typ). In addition, the VGAs offer very low output-referred noise performance suitable for interfacing with 12-bit ADCs.

Features

♦ 8-Channel Configuration

♦ High Integration for Ultrasound Imaging

   Applications

♦ Pin Compatible with the MAX2037 Ultrasound VGA

VGA Features

♦ Maximum Gain, Gain Range, and Output-Referred

   Noise Optimized for Interfacing with 12-Bit ADCs

   Maximum Gain of 29.5dB

   Total Gain Range of 42dB

   22nV/√Hz Ultra-Low Output-Referred Noise at

   5MHz

♦ ±0.25dB Absolute Gain Error

♦ 120mW Consumption per Channel

♦ Switchable Output VGA Clamp Eliminating ADC

   Overdrive

♦ Fully Differential VGA Outputs for Direct ADC

   Drive

♦ Variable Gain Range Achieves 42dB Dynamic

   Range

♦ -70dBc HD2 at VOUT = 1.5VP-P and fIN = 5MHz

♦ Two-Tone Ultrasound-Specific* IMD3 of

   -52dBc at VOUT = 1.5VP-P and fIN = 5MHz

CW Doppler Mixer Features

♦ Low Mixer Noise of -155dBc/Hz at 1kHz Offset

   from 1.25MHz Carrier

♦ Serial-Programmable LO Phase Generator for 4, 8,

   16 LO Quadrature Phase Resolution

♦ Optional Individual Channel 4 x fLO LO Input

   Drive Capability

♦ 269mW Power Consumption per Channel (Normal

   Power Mode) and 226mW Power Consumption

   per Channel (Low-Power Mode)

Applications

   Ultrasound Imaging

   Sonar