AD7988-1BRMZ-RL7

Overview

The AD7988-1BRMZ-RL7 is a 16-bit, low-power PulSAR analog-to-digital converter (ADC) manufactured by Analog Devices Inc. It operates at a throughput of 100 kSPS with a single 2.5 V supply and supports logic interfaces from 1.8 V to 5 V. The device features a pseudo-differential input range of 0 V to VREF, where VREF can be set between 2.4 V and 5.1 V. Key performance metrics include a typical Signal-to-Noise Ratio (SNR) of 91.5 dB, Integral Nonlinearity (INL) of ±1.25 LSB maximum, and Differential Nonlinearity (DNL) of ±0.9 LSB maximum. Total power dissipation is 700 µW at 100 kSPS. It utilizes a versatile serial interface compatible with SPI, Microwire, and DSP protocols, housed in a 10-lead MSOP package.

Feature Summary

• Zero latency architecture providing immediate data availability after conversion completion without pipeline delay.
• Versatile serial interface supporting daisy-chaining capabilities via the SDI input for multi-device configurations.
• Low power consumption with independent digital interface supply allowing operation across various logic voltage levels.

Applications

• Automated test equipment
• Data acquisition systems
• Medical instruments
• Machine automation

Procurement Notes

Verify the specific suffix RL7 indicates reel packaging when sourcing components. Confirm that the BRMZ designation corresponds to the MSOP-10 package variant rather than the LFCSP option. Ensure compatibility with the required operating temperature range of -40°C to +125°C for the intended application environment.

Selection Notes

Select this component for applications requiring high resolution with minimal power draw at moderate sampling rates. The pseudo-differential input architecture simplifies front-end design compared to fully differential counterparts. Consider the external reference requirement and ensure the host system provides a stable VREF within the specified 2.4 V to 5.1 V range for optimal accuracy.

Part Context

This part belongs to the AD7988-1/AD7988-5 family of 16-bit PulSAR ADCs. The AD7988-1 variant specifically targets lower throughput requirements compared to the AD7988-5, which offers 500 kSPS. Both share identical pinouts and architectural features, differing primarily in conversion speed and associated power dissipation characteristics under full load conditions.

Replacement Considerations

The AD7988-5BRMZ serves as a higher-speed alternative within the same package and pinout configuration. For applications requiring fully differential inputs, the AD7680 series may be considered, though it differs in input architecture and supply voltage ranges. Verify pin compatibility before substituting any related devices.

FAQ

How does the CNV pin function in chain mode?

In chain mode, the SDI pin must be held low during the rising edge of CNV. This allows multiple ADCs to be daisy-chained on a single SDO line, with data shifting out sequentially based on the SCK clock cycles following the CNV pulse.

What is the impact of VREF on dynamic performance?

The reference voltage directly influences the signal-to-noise ratio and total harmonic distortion. Higher VREF values generally improve SNR and SINAD, with specifications typically measured at VREF = 5 V for optimal dynamic range performance.

Can the digital interface operate independently of the analog supply?

Yes, the device features a separate VIO pin that powers the digital I/O interface. This allows the logic levels to range from 1.8 V to 5 V, independent of the 2.5 V analog supply (VDD), facilitating interfacing with various microcontrollers and DSPs.