AD7828CQ

Overview

The AD7828CQ is an 8-bit, 8-channel analog-to-digital converter utilizing a half-flash architecture. It operates on a single 5 V supply with a typical power dissipation of 50 mW. The device features a built-in track-and-hold function capable of handling signals up to 10 kHz. Conversion time is 2.5 µs per channel, allowing a maximum sampling rate of 50 kHz for the eight channels. Total unadjusted error is ±1/2 LSB max. It interfaces via standard parallel data outputs controlled by Chip Select and Read signals.

Feature Summary

• Half-flash conversion technique eliminates the need for an external clock signal
• Built-in track-and-hold function supports high slew rate inputs without external components
• Parallel digital interface compatible with standard microprocessor memory cycles
• Integrated multiplexer selects from eight single-ended analog input channels

Applications

• Speech analysis systems using real-time filtering
• Fast infinite sample-and-hold circuits
• Industrial process control monitoring
• Data acquisition systems requiring multi-channel sensing

Procurement Notes

Verify the specific suffix CQ indicates industrial temperature range operation (-40°C to +85°C) and the Q-28 package option. Confirm availability status as this component may be discontinued or subject to limited supply constraints. Ensure the ordering documentation matches the required total unadjusted error specification of ±1/2 LSB.

Selection Notes

Select the AD7828CQ when eight channels are required with a 50 kHz aggregate sampling rate. This model suits applications needing a simple parallel interface without complex serial protocols. Consider the ±1/2 LSB accuracy for precision requirements. Verify that the source impedance of the driving circuitry remains below 100 Ω to ensure proper charging of internal capacitors during the tracking phase.

Part Context

The AD7828CQ belongs to the AD7824/AD7828 family of high-speed multichannel ADCs. While the AD7824 offers four channels, the AD7828 provides eight channels in a 28-lead package. Both share the same LC2MOS fabrication process and half-flash conversion methodology. The CQ suffix specifically denotes the industrial temperature grade and plastic DIP/SOIC/SSOP packaging options.

Replacement Considerations

Public confirmed substitutes include the AD7828BQ for industrial range with ±1 LSB error, or the AD7828LN for commercial range. Surface mount equivalents such as the AD7828LP or AD7828KP are available for different package requirements.