Fully Integrated Octal Ultrasound LNA Delivers 29.5dB of Max Gain, 40dB of Dynamic Gain Range, -70dBc of HD2 Performance, and an Exceptionally Low Output-Referred Noise Level of Only 22nV/√Hz
The MAX2037 8-channel variable-gain amplifier (VGA) 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 typically 42dB. In addition, the VGAs offer very low output-referred noise performance suitable for interfacing with 12-bit ADCs.
The MAX2037 VGA is optimized for less than ±0.25dB absolute gain error to ensure minimal channel-to-channel ultrasound beamforming focus error. The device's differential outputs are designed to directly drive ultrasound ADCs through an external passive anti-aliasing filter. A switchable clamp is also provided at each amplifier's outputs to limit the output signals, thereby preventing ADC overdrive or saturation.
Dynamic performance of the device is optimized to reduce distortion to support second-harmonic imaging. The device achieves a second-harmonic distortion specification of -70dBc at VOUT = 1.5VP-P and fIN = 5MHz, and an ultrasound-specific* two-tone third-order intermodulation distortion specification of -52dBc at VOUT = 1.5VP-P and fIN = 5MHz.
The MAX2037 operates from a +5.0V power supply, consuming only 120mW/channel. The device is available in a 100-pin TQFP package with an exposed paddle. Electrical performance is guaranteed over a 0°C to +70°C temperature range.
MAX2034/MAX2035/MAX2037
EEPW Analog/Mixed-Signal IC Technical Innovation Award Winner 2006
Key Features
Applications/Uses
8-Channel Configuration
High Integration for Ultrasound Imaging Applications
Pin Compatible with the MAX2038 Ultrasound VGA Plus CW Doppler Beamformer
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
Pin-for-Pin 10-Bit Compatibility Supported By MAX2035/MAX2036