AD7893ARZ-2REEL7

Overview

The AD7893ARZ-2REEL7 is a 12-bit successive approximation analog-to-digital converter (ADC) housed in an 8-pin SOIC package. It operates from a single +5 V supply and features an on-chip track/hold amplifier, internal clock, and high-speed serial interface. The device accepts a unipolar analog input range of 0 V to +2.5 V and requires an external +2.5 V reference voltage. Key electrical specifications include a maximum conversion time of 6 μs, a typical power dissipation of 25 mW, and a signal-to-noise ratio of 70 dB at a sampling rate of 117 kHz. The component supports an operating temperature range of -40 °C to +85 °C.

Feature Summary

• Integrates a 12-bit ADC, track/hold amplifier, and control logic within a compact 8-pin package for space-efficient designs.
• Operates from a single +5 V supply with low power consumption, making it suitable for battery-powered applications.
• Features a high-speed two-wire serial interface utilizing SCLK and SDATA lines for straightforward microcontroller connectivity.

Applications

• Battery-powered portable instrumentation
• Industrial process control systems
• Data acquisition modules

Procurement Notes

Verify the specific suffix 'REEL7' indicates tape-and-reel packaging when sourcing components. Confirm that the '-2' designation corresponds to the 0 V to +2.5 V input range variant. Ensure the ordering documentation matches the exact Analog Devices part number to avoid confusion with other input range versions such as the AD7893-3 or AD7893-5.

Selection Notes

Select this component when a 12-bit resolution and 0 V to +2.5 V input range are required in an 8-pin form factor. Consider the 6 μs conversion time and 117 kHz throughput rate against system timing constraints. Verify compatibility with the required external +2.5 V reference source, as the device does not contain an internal reference generator.

Part Context

The AD7893 series comprises four variants differentiated by input voltage ranges: ±10 V, ±2.5 V, 0 V to +5 V, and 0 V to +2.5 V. All variants share identical architecture, pinout, and performance characteristics regarding speed and power. The AD7893ARZ-2REEL7 specifically addresses applications requiring unipolar signals within the lower voltage range while maintaining the standard 12-bit accuracy of the family.

Replacement Considerations

Direct functional substitutes within the same family include the AD7893ARZ-3, AD7893ARZ-5, and AD7893ARZ-10, provided the input voltage range differences are accommodated in the circuit design. Other packages such as mini-DIP (N-8) or cerdip (Q-8) offer equivalent electrical performance but require footprint adjustments.

FAQ

How is the output data formatted for the AD7893-2 variant?

The AD7893-2 outputs straight (natural) binary code. The serial interface provides four leading zeros followed by the 12-bit conversion result starting with the most significant bit.

What is the minimum time required between conversions for optimal performance?

To achieve specified performance, a minimum of 600 ns must elapse after the read operation ends before the next rising edge of CONVST. This allows the track/hold amplifier sufficient time to acquire the input signal.

Can the AD7893 operate at throughput rates higher than 117 kHz?

Yes, the device can operate at throughput rates up to 133 kHz by reading data during the conversion phase. However, this results in slightly degraded performance, including a potential reduction in signal-to-noise ratio and increased code flicker.