AD7827BRZ

Overview

The AD7827BRZ is an 8-bit, single-channel analog-to-digital converter (ADC) featuring a half-flash architecture and a maximum throughput of 1 MSPS. It operates from a single 3 V or 5 V supply with an input range of 0 V to 2 V or 0 V to 2.5 V respectively. The device integrates a track-and-hold amplifier, a 2.5 V reference with 2% tolerance, and a serial interface compatible with DSPs. Key electrical parameters include a conversion time of 420 ns, integral nonlinearity of ±0.5 LSB max, and differential nonlinearity of ±0.5 LSB max. Normal operation current is typically 8 mA at 3 V, reducing to 1 μA in power-down mode.

Feature Summary

• Integrates a high-speed half-flash ADC with on-chip track-and-hold amplifier for precise signal acquisition.
• Features automatic power-down functionality controlled by the CONVST pin state to optimize energy efficiency.
• Includes an internal 2.5 V voltage reference with specified tolerance, eliminating external reference requirements.
• Provides a three-wire serial interface optimized for direct connection to digital signal processors without additional logic.

Applications

• Direct interfacing with TMS320C5x and ADSP-21xx family digital signal processors.
• High-speed data acquisition systems requiring low power consumption.
• Subsampling applications utilizing the track-and-hold capability for input frequencies up to 10 MHz.

Procurement Notes

Verify the specific package variant against the ordering guide; the BR suffix denotes the Small Outline IC (SOIC-8) package. Confirm that the required linearity error specification matches the ±0.5 LSB guarantee provided for this model. Ensure the design accommodates the industrial temperature range of -40°C to +105°C as specified for the Version B part.

Selection Notes

Select this component when a single-ended 8-bit resolution is sufficient for the application's dynamic range requirements. Consider the 420 ns conversion time and 200 ns acquisition time constraints when designing the system clock and timing sequences. Evaluate the power consumption trade-offs between continuous sampling mode and automatic power-down mode based on the required throughput rate.

Part Context

The AD7827 belongs to Analog Devices' series of low-power, high-speed serial interface ADCs. It utilizes a half-flash architecture where a 4-bit flash ADC performs coarse conversion followed by a fine conversion to achieve full 8-bit resolution. This structure balances speed and power consumption, making it suitable for battery-operated portable instruments and industrial control systems.

Replacement Considerations

The AD7827BN is the plastic DIP equivalent within the same product family. Verify pin compatibility and thermal characteristics if transitioning between the SOIC-8 and Plastic DIP packages. No other cross-model substitutes are confirmed in the provided documentation.