AD9238BST-40

Overview

The AD9238BST-40 is a dual-channel, 12-bit analog-to-digital converter (ADC) from Analog Devices Inc., operating at a maximum sampling rate of 40 MSPS. It utilizes a multistage differential pipelined architecture with output error correction logic to ensure no missing codes across the full industrial temperature range (-40°C to +85°C). The device features dual high-performance sample-and-hold amplifiers (SHAs) and an integrated voltage reference. It operates on a single 3 V supply (2.7 V to 3.6 V) with power consumption of 330 mW at 40 MSPS. The ADC supports flexible analog input ranges from 1 V p-p to 2 V p-p and offers offset binary or two's complement data formats.

Feature Summary

• Dual-channel architecture with exceptional crosstalk immunity exceeding 85 dB
• Integrated duty cycle stabilizer maintains performance over wide clock variations
• Multiplexed data output option enables single-port operation from either channel

Applications

• Ultrasound equipment
• Direct conversion or IF sampling receivers
• WB-CDMA, CDMA2000, WiMAX systems
• Battery-powered instruments
• Low cost digital oscilloscopes

Procurement Notes

Verify the specific speed grade suffix matches the required 40 MSPS performance level. Confirm package type availability, as the component is offered in both 64-lead LQFP and LFCSP configurations. Ensure environmental specifications align with the intended industrial operating temperature range requirements.

Selection Notes

Select this model for applications requiring dual-channel synchronization with low power consumption. Compare against the AD9238-20 for lower power needs or the AD9238-65 for higher bandwidth requirements. Consider the pin-compatible AD9248 if 14-bit resolution is necessary for the design.

Part Context

The AD9238 series includes variants rated for 20 MSPS, 40 MSPS, and 65 MSPS. The BST-40 variant specifically targets the mid-range performance tier, balancing power efficiency with sufficient throughput for intermediate frequency sampling. It shares the same physical footprint and pinout as other speed grades within the family.

Replacement Considerations

The AD9238BST-20 and AD9238BST-65 are pin-compatible alternatives within the same family. The AD9248 series offers 14-bit resolution with identical pinouts. Verify that the replacement meets the specific timing and power constraints of the existing circuit design.