AD7828LRS

Overview

The AD7828LRS is an 8-bit, 8-channel analog-to-digital converter (ADC) utilizing a half-flash architecture. It features a built-in track-and-hold function capable of handling 10 kHz signals with a slew rate up to 157 mV/µs. The device operates on a single 5 V supply and achieves a conversion time of 2.5 µs per channel. Total unadjusted error is specified at ±1/2 LSB maximum. It interfaces via standard Chip Select (CS) and Read (RD) signals without requiring an external clock. The RS-28 package supports surface-mount installation.

Feature Summary

• Half-flash conversion technique enables high-speed digitization without external clocking.
• Integrated multiplexer and track-and-hold circuitry simplify multi-channel signal acquisition.
• Standard microprocessor interface allows direct connection using common control signals.
• Flexible reference inputs support both unipolar and bipolar input voltage ranges.

Applications

• Industrial process control systems requiring multi-channel data acquisition
• Speech analysis applications utilizing real-time filtering techniques
• Fast infinite sample-and-hold circuits for signal conditioning

Procurement Notes

Verify the specific ordering suffix RS-28 corresponds to the required surface-mount package configuration. Confirm that the commercial temperature range (0°C to 70°C) aligns with the operational environment requirements. Ensure the ±1/2 LSB total unadjusted error specification meets the system accuracy needs. Check for availability as this component may be subject to discontinuation or long lead times from Analog Devices.

Selection Notes

Select the AD7828LRS when an 8-bit resolution and 8-channel multiplexing capability are required for moderate-speed applications. This model is suitable for designs needing a simple parallel interface without complex timing logic. Consider alternative models if higher resolution, lower power consumption, or industrial temperature ranges (-40°C to +85°C) are necessary. Evaluate the source impedance constraints, as low output impedance amplifiers are recommended to drive the internal sampling capacitors effectively.

Part Context

The AD7828LRS belongs to the AD7824/AD7828 family of high-speed multichannel ADCs manufactured by Analog Devices. While the AD7824 offers four channels, the AD7828 provides eight channels in a similar form factor. The L version denotes the commercial temperature grade with tighter linearity specifications compared to the K version. The RS-28 indicates a specific 28-lead surface-mount package option within this product line.

Replacement Considerations

Direct replacements include other variants within the AD7828 series such as AD7828LN or AD7828BR depending on package and temperature requirements. Cross-vendor alternatives like the MAX1020B offer similar functionality but require interface adaptation. Verify pin compatibility and electrical specifications before substituting.