AD9238BST-20

Overview

The AD9238BST-20 is a dual-channel, 12-bit analog-to-digital converter (ADC) from Analog Devices Inc., operating at a maximum sampling rate of 20 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), an integrated voltage reference, and supports flexible analog input ranges from 1 V p-p to 2 V p-p. It operates on a single 3 V supply (2.7 V to 3.6 V) and offers low power consumption of 180 mW at 20 MSPS. Digital outputs are available in offset binary or two's complement formats.

Feature Summary

• Dual-channel architecture with exceptional crosstalk immunity exceeding 85 dB.
• Integrated duty cycle stabilizer maintains performance over wide clock variations.
• Flexible analog input support for differential or single-ended applications.
• Multiplexed data output option enables single-port operation.

Applications

• Ultrasound equipment
• Direct conversion or IF sampling receivers
• WB-CDMA, CDMA2000, WiMAX systems

Procurement Notes

Verify the specific speed grade suffix '-20' corresponds to the required 20 MSPS sampling rate during procurement. Confirm package availability in LQFP-64 format. Ensure component authenticity through authorized distributors. Check RoHS compliance status if required by local regulations. Validate that the ordering code matches the exact pinout and electrical specifications needed for the design.

Selection Notes

Select the AD9238BST-20 when a 20 MSPS sampling rate meets system requirements, offering lower power consumption compared to higher-speed variants. Consider the AD9238-40 or AD9238-65 if higher bandwidth or dynamic performance is necessary. Ensure the application can accommodate the 3 V single-supply requirement. Verify that the parallel digital interface aligns with the downstream processing logic or FPGA capabilities.

Part Context

The AD9238 series includes speed grades -20, -40, and -65, all sharing identical pinouts and functional blocks. The AD9238 is pin-compatible with the 14-bit AD9248, allowing for resolution upgrades without board redesign. This component belongs to Analog Devices' portfolio of high-performance, low-power ADCs designed for demanding signal processing applications.

Replacement Considerations

Public confirmed substitute part numbers: AD9238BSTZ-20, AD9238BCPZ-20, AD9238BSTZ-40, AD9238BSTZ-65.