AD7893AR-3

Overview

The AD7893AR-3 is a 12-bit successive approximation analog-to-digital converter housed in an 8-pin SOIC package. It operates from a single +5 V supply and features an on-chip track/hold amplifier with a conversion time of 6 μs. The device supports a ±2.5 V input voltage range and utilizes a two-wire serial interface for data output. Key electrical specifications include a typical power dissipation of 25 mW, a signal-to-noise ratio of 70 dB at a 117 kHz sampling rate, and a maximum differential nonlinearity of ±1 LSB.

Feature Summary

• Integrated on-chip track/hold amplifier ensures accurate signal acquisition for high-speed conversions.
• Two-wire serial interface simplifies connection to microcontrollers and DSP processors.
• Single +5 V supply operation enables low-power performance suitable for portable applications.

Applications

• Battery-powered instrumentation systems
• Portable data acquisition devices
• Industrial process control monitoring

Procurement Notes

Verify the specific suffix 'AR-3' against the manufacturer's current ordering guide to confirm the SOIC package and ±2.5 V input range. Ensure compatibility with external reference requirements, as the part requires an external +2.5 V reference source for correct operation. Check for RoHS compliance status if required by your manufacturing standards.

Selection Notes

Select this component when a compact 12-bit ADC with a ±2.5 V bipolar input range is required. It is suitable for designs constrained by board space due to its 8-pin footprint. Consider the 6 μs conversion time and 117 kHz throughput rate against system speed requirements. Verify that the host processor can support the required serial clock timing for data retrieval.

Part Context

The AD7893 belongs to Analog Devices' family of fast, low-power serial ADCs. The AR-3 variant specifically denotes the industrial temperature range (-40°C to +85°C), SOIC package, and ±2.5 V input capability. It shares architectural similarities with other models in the series but differs in input scaling and packaging options.

Replacement Considerations

Direct pin-compatible replacements within the same family include the AD7893AR-2 (0 V to +2.5 V range) or AD7893AR-5 (0 V to +5 V range). For higher resolution needs, consider the AD7894 series, though pin counts and interfaces may differ. Always verify thermal and electrical specifications before substitution.

FAQ

What is the output coding format for the AD7893AR-3?

The AD7893AR-3 uses Two's Complement binary output coding because it supports a bipolar input voltage range of ±2.5 V.

How is the conversion cycle initiated?

Conversion is initiated by applying a rising edge pulse to the CONVST (Convert Start) pin. This triggers the track/hold amplifier to enter hold mode and begins the internal conversion sequence.

What is the minimum acquisition time required between conversions?

To achieve optimum performance, a minimum of 600 ns should be allowed after the read operation ends and before the next rising edge of CONVST to ensure the track/hold amplifier settles correctly.