AD7870SQ

Overview

The AD7870SQ is a complete monolithic 12-bit analog-to-digital converter featuring an integrated track-and-hold amplifier, successive approximation ADC, and laser-trimmed internal clock. It operates from ±5 V power supplies with a typical power dissipation of 60 mW. The device provides a 3 V on-chip reference and supports input ranges of ±3 V. Key performance metrics include a maximum conversion time of 9 µs using the internal clock, a data access time of 70 ns, and a signal-to-noise ratio of 69 dB minimum at +25°C. It utilizes a 24-pin dual-in-line package.

Feature Summary

• Integrates a 12-bit successive approximation ADC with a 2 µs track-and-hold amplifier and a laser-trimmed internal clock oscillator.
• Offers versatile digital interface options including parallel 12-bit word output, two-byte mode, and serial data transfer modes.
• Contains an on-chip temperature-compensated buried Zener reference providing a stable 3 V output for internal or external use.

Applications

• Data acquisition systems requiring high-speed sampling
• Digital signal processing (DSP) front-ends
• Industrial process control instrumentation

Procurement Notes

Verify the specific suffix 'SQ' against the manufacturer's current ordering guide to confirm package type and temperature range availability. Ensure compatibility with ±5 V supply rails and check for lead-free compliance requirements if applicable to the target assembly process.

Selection Notes

Select this component when a self-contained 12-bit ADC with an internal clock is required to minimize external component count. The AD7870 variant specifically suits applications needing a ±3 V bipolar input range. Consider the 24-pin DIP package constraints for board layout and thermal management during system design.

Part Context

This part belongs to the AD7870/AD7875/AD7876 family of LC2MOS 12-bit sampling ADCs. While sharing core architecture, the AD7870 is distinguished by its ±3 V input range capability compared to the unipolar AD7875 or wide-range AD7876. The 'SQ' designation typically indicates a specific military-grade or hermetic packaging variant within the broader product line.

Replacement Considerations

Direct pin-compatible replacements within the same family include the AD7875 and AD7876, provided the input voltage range requirements are adjusted accordingly. Verify that the replacement part supports the necessary operating temperature range and interface timing specifications.