Analog Devices Inc. AD7825BRUZ-REEL7

Overview

AD7825BRUZ-REEL7 from Analog Devices is a high-speed, 4-channel, 8-bit parallel-output analog-to-digital converter (ADC) with 2 MSPS throughput, 420 ns conversion time, on-chip 2.5 V reference, and track-and-hold - designed for DSP front ends and subsampling in mobile communication systems.

For engineers reviewing the AD7825BRUZ-REEL7 datasheet, AD7825BRUZ-REEL7 pinout, AD7825BRUZ-REEL7 application, or AD7825BRUZ-REEL7 equivalent, this page delivers verified technical context, real-world interface behavior, channel selection logic, power-down timing, and design-meaningful specifications - all confirmed for the AD7825BRUZ-REEL7 variant in 24-lead TSSOP packaging.

Technical Context

The AD7825BRUZ-REEL7 implements a half-flash ADC architecture with two-stage conversion: a 4-bit coarse flash followed by a 4-bit fine flash, achieving full 8-bit resolution in ≤420 ns. It integrates a track-and-hold amplifier with 200 ns acquisition time and supports automatic power-down triggered by CONVST logic level sampling at EOC assertion.

Channel selection uses dedicated A0/A1 address inputs (not register writes), enabling immediate multiplexer reconfiguration before conversion start. The parallel interface operates with CS/RD-controlled 3-state data bus (DB0–DB7), EOC pulse signaling, and dual-supply compatibility (3 V ±10% or 5 V ±10%), with separate PD pin for explicit low-power mode control.

Key Specifications

Pinout & Package

AD7825BRUZ-REEL7 is packaged in a 24-lead, 0.15 mm pitch, thin shrink small outline package (TSSOP) with exposed pad for thermal performance - compatible with automated SMT assembly and space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit, multi-channel, parallel-output ADC applications.

Compared with AD7822BRUZ-REEL7 and AD7829BRUZ-REEL7, the AD7825BRUZ-REEL7 uniquely balances channel count (4), package size (24-lead TSSOP), and pin compatibility - making it optimal for mid-channel-count, space-sensitive applications where adding external MUX would increase latency or cost.

Availability

AD7825BRUZ-REEL7 is available at Aetrix Electronics and suitable for mobile communications, disk drive electronics, and portable data acquisition systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AD7825BRUZ-REEL7 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, headquartered in Norwood, MA, with design centers worldwide and ISO 9001-certified manufacturing.

The AD7822/AD7825/AD7829 family was engineered for high-speed, low-power, microprocessor-compatible data acquisition - targeting cost-sensitive, size-constrained applications in communications, storage, and portable instrumentation where 2 MSPS throughput and hardware channel selection deliver decisive system-level advantages.

FAQ

What is the maximum sampling rate supported by the AD7825BRUZ-REEL7?

The AD7825BRUZ-REEL7 supports a maximum throughput of 2 MSPS, with a guaranteed conversion time of ≤420 ns. This rate is achievable across the full industrial temperature range (−40°C to +85°C) and both supply voltages (3 V ±10% and 5 V ±10%). At 2 MSPS, the device delivers full 8-bit resolution with ±0.75 LSB INL/DNL, making it suitable for real-time baseband sampling and DSP front ends where latency and determinism are critical. The AD7825BRUZ-REEL7 achieves this performance using a half-flash architecture that balances speed, power, and silicon area.

Does the AD7825BRUZ-REEL7 require an external reference voltage?

No, the AD7825BRUZ-REEL7 does not require an external reference voltage because it integrates a precision 2.5 V on-chip reference with ±50 mV initial error and 50 ppm/°C temperature coefficient. The VREF IN/OUT pin can be left unconnected to use the internal reference, or it can accept an external 2.5 V source for higher accuracy. When using the internal reference, the AD7825BRUZ-REEL7 maintains full specified performance including SNR (48 dB min), THD (−55 dB max), and DC accuracy - eliminating BOM cost and layout area associated with external references while retaining design flexibility.

How does channel selection work on the AD7825BRUZ-REEL7?

Channel selection on the AD7825BRUZ-REEL7 is implemented via dedicated hardware pins A0 and A1 - no register writes or serial configuration are needed. These inputs are sampled on the falling edge of the RD signal, and the selected channel (VIN1–VIN4) is converted on the subsequent falling edge of CONVST. This synchronous, pin-driven method ensures deterministic timing, eliminates firmware overhead, and avoids race conditions common in software-configured MUX schemes. The AD7825BRUZ-REEL7's functional block diagram and timing diagrams confirm that channel address setup occurs independently of conversion initiation, enabling tight interleaved sampling sequences.

What power-saving modes does the AD7825BRUZ-REEL7 support?

The AD7825BRUZ-REEL7 supports two distinct power-saving modes: automatic power-down triggered by CONVST logic level sampling at EOC assertion, and explicit power-down via the dedicated PD pin. In automatic mode, the device draws ≤5 µA after conversion completes if CONVST is held low - ideal for burst-mode acquisition. In explicit mode, asserting PD low forces immediate shutdown regardless of CONVST state, enabling precise control in synchronized multi-device systems. Both modes reduce current from 12 mA (active) to <0.2 µA typical, and recovery time is ≤25 µs using the on-chip reference - verified in the datasheet's timing characteristics table.

Is the AD7825BRUZ-REEL7 pin-compatible with other members of the AD7822/AD7825/AD7829 family?

The AD7825BRUZ-REEL7 is pin-compatible with the AD7822BRUZ-REEL7 in the 24-lead TSSOP package, sharing identical pinouts for VDD, GND, CONVST, EOC, CS, RD, DB0–DB7, VREF, VMID, and PD - though AD7822 lacks A0, A1, and VIN2–VIN4. It is not pin-compatible with the 28-lead AD7829BRUZ-REEL7 due to added A2 and VIN5–VIN8 pins. This partial compatibility allows scalable design reuse: firmware and PCB layout for AD7825BRUZ-REEL7 can be adapted to AD7822BRUZ-REEL7 by removing unused traces, while upgrading to AD7829BRUZ-REEL7 requires mechanical redesign.