Analog Devices Inc. AD7827BRZ

Overview

AD7827BRZ from Analog Devices is an 8-bit, 1 MSPS serial-output sampling ADC with on-chip track-and-hold and 2.5 V reference (±2% tolerance), operating from single 3 V ±10% or 5 V ±10% supply. It delivers 420 ns conversion time, 200 ns acquisition time, and supports 0 V–2 V input range at 3 V supply or 0 V–2.5 V at 5 V supply-ideal for real-time DSP interfacing in industrial data acquisition systems.

For engineers reviewing the AD7827BRZ datasheet, AD7827BRZ pinout, AD7827BRZ application, or AD7827BRZ equivalent, key selection considerations include its automatic power-down via CONVST pin, DSP/microcontroller-compatible three-wire serial interface (RFS/DOUT/SCLK), guaranteed 8-bit no-missing-codes performance, ±0.5 LSB INL/DNL, and SOIC-8 package compatibility with high-speed subsampling up to 10 MHz analog inputs.

Technical Context

The AD7827BRZ employs a half-flash architecture: a 4-bit flash ADC generates MSBs, followed by a second flash stage for LSBs, achieving full 8-bit resolution in ≤420 ns. Its track-and-hold acquires input within 200 ns and holds for 120 ns during conversion, enabling precise timing control via the falling edge of CONVST.

Conversion initiation and power-state control are unified on the CONVST pin: falling edge starts conversion; logic level sampled ~530 ns after that edge determines automatic power-down. The serial interface uses continuous SCLK, frame-synced RFS output, and MSB-first DOUT-fully compatible with TMS320C5x, ADSP-21xx, and DSP560xx serial ports without glue logic.

Key Specifications

Pinout & Package

AD7827BRZ is housed in an 8-lead small outline IC (SOIC) package, 3.9 mm × 4.9 mm body, 1.27 mm lead pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit, serial-interface sampling ADC applications.

Compared with AD7827BRZ, AD7823BRZ removes 5 V support and on-chip reference but retains identical timing and pinout-ideal for cost-optimized 3 V-only systems. MAX1112CSA+ offers higher throughput and SPI compatibility but sacrifices the deterministic frame-sync and auto-ranging advantages critical for DSP-centric real-time control.

Availability

AD7827BRZ is available at Aetrix Electronics and suitable for industrial process monitoring, DSP-based motor control, portable test equipment, and high-speed data logging requiring stable component supply across extended temperature ranges (–40°C to +105°C).

Supply support for AD7827BRZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD7827BRZ belongs to Analog Devices' precision high-speed sampling ADC product line, designed specifically for real-time data acquisition in DSP- and microcontroller-based systems demanding low latency, low power, and minimal external component count.

FAQ

What is the maximum analog input frequency supported by the AD7827BRZ?

The AD7827BRZ's on-chip track-and-hold supports analog input frequencies up to 10 MHz while maintaining specified SNR (>42 dB at 1 MSPS). This makes it suitable for subsampling applications where high-frequency signals are intentionally aliased into baseband for digitization-provided the Nyquist criterion is satisfied relative to the desired band of interest.

Does the AD7827BRZ require an external reference, or can it operate with its internal reference?

The AD7827BRZ can operate with its internal 2.5 V ±2% reference enabled by default, eliminating the need for external components. However, the VREF pin also accepts an external 2.5 V reference for improved initial accuracy and temperature stability-particularly valuable in precision measurement applications where ±0.1% reference drift is unacceptable.

How does the automatic power-down feature of the AD7827BRZ work, and how is it controlled?

The AD7827BRZ implements automatic power-down by sampling the logic level on the CONVST pin approximately 530 ns after its falling edge. If CONVST remains low at that instant, the device powers down, reducing supply current to 1 µA. Power-up occurs on the next rising edge of CONVST-enabling precise, firmware-controlled duty cycling without external enable circuitry.

Is the AD7827BRZ pin-compatible with other members of the AD782x family, such as the AD7823BRZ?

Yes, the AD7827BRZ and AD7823BRZ share identical SOIC-8 pinout, timing behavior, and serial interface protocol. They differ only in supply voltage range (AD7827BRZ supports both 3 V and 5 V; AD7823BRZ is 3 V only) and reference architecture (AD7827BRZ includes on-chip reference; AD7823BRZ requires external reference). This enables direct substitution in 3 V designs with minor schematic updates.

What is the purpose of the RFS (Receive Frame Sync) signal in the AD7827BRZ serial interface?

The RFS signal in the AD7827BRZ provides hardware-level frame synchronization for the serial data stream: its falling edge marks the start of valid 8-bit data transmission on DOUT, aligning precisely with the first rising edge of SCLK after conversion completion. This eliminates software-based bit counting and ensures robust, jitter-immune data capture in high-speed DSP interfaces like TMS320C5x SPORT.