Analog Devices Inc. AD7887ARM

Overview

AD7887ARM from Analog Devices is a micropower, 12-bit successive approximation register (SAR) ADC with dual/single-channel operation, 125 kSPS throughput, 2.7 V to 5.25 V single-supply operation, and internal 2.5 V reference - used in battery-powered medical instruments and portable instrumentation where low power and compact size are critical.

For engineers reviewing the AD7887ARM datasheet, AD7887ARM pinout, AD7887ARM application, or AD7887ARM equivalent, key selection criteria include its 8-lead MSOP package, SPI/QSPI/MICROWIRE-compatible serial interface, flexible power-down modes (1 μA shutdown), dual-channel isolation (−80 dB), and straight binary output coding with 0–VREF or 0–VDD input range configurability.

Technical Context

The AD7887ARM implements a charge-redistribution DAC-based SAR architecture with integrated track-and-hold acquiring signals in 500 ns. Its control logic supports on-the-fly configuration via an 8-bit write-only register, enabling dynamic switching between single-channel (AIN0 only, AIN1/VREF as VREF) and dual-channel (AIN0 + AIN1, VDD as reference) modes.

Power management is implemented through four programmable modes (PM1/PM0 bits), including automatic shutdown after conversion (Mode 3) and standby with reference active (Mode 4). The serial interface operates at up to 2 MHz SCLK, delivering 16-bit frames (4 leading zeros + 12-bit result) MSB-first on DOUT synchronized to falling SCLK edges.

Key Specifications

Pinout & Package

AD7887ARM is housed in an 8-lead MSOP (Mini Small Outline Package), 3 mm × 3 mm, 0.65 mm pitch, thermally enhanced for low θ_JA = 205.9°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with ADS7822ID and MAX11131AUT+, the AD7887ARM uniquely balances 12-bit precision, dual-channel flexibility, internal reference, and micropower shutdown - making it optimal for battery-critical, multi-sensor applications where board space and supply versatility matter.

Availability

AD7887ARM is available at Aetrix Electronics and suitable for portable medical instrumentation, battery-powered data loggers, and industrial process monitoring requiring stable component supply, long-term lifecycle support, and automotive-qualified variants.

Supply support for AD7887ARM 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.

The AD7887ARM belongs to Analog Devices' precision SAR ADC product line, engineered for low-power, high-accuracy data acquisition in portable and embedded systems where supply headroom and PCB area are constrained.

FAQ

What is the maximum sampling rate supported by the AD7887ARM?

The AD7887ARM supports a maximum throughput rate of 125 kSPS when operated with a 2 MHz SCLK. This is achieved with a total conversion time of 14.5 SCLK cycles plus 1.5 SCLK cycles for track-and-hold acquisition, totaling 16 SCLK cycles per sample. At 2 MHz, this yields exactly 125,000 samples per second - confirmed in Table 1 and General Description section of Rev. E datasheet.

Does the AD7887ARM require an external reference voltage?

No, the AD7887ARM includes an internal 2.5 V reference (2.45–2.55 V) accessible at the AIN1/VREF pin in single-channel mode. When configured for dual-channel operation, the part uses VDD as reference, and the internal reference is disabled. External reference override is supported from 1.2 V to VDD, but is not required - the AD7887ARM functions fully with its internal reference enabled.

How does the AD7887ARM handle dual-channel versus single-channel operation?

The AD7887ARM switches between dual- and single-channel modes via Bit 4 (SIN/DUAL) in its 8-bit control register. In single-channel mode (SIN/DUAL = 0), AIN1/VREF becomes the reference terminal and only AIN0 is active. In dual-channel mode (SIN/DUAL = 1), AIN1/VREF becomes the second analog input and VDD supplies the reference - both AIN0 and AIN1 accept 0–VDD inputs. Channel selection in dual mode is controlled by Bit 3 (CH).

What power management modes are available on the AD7887ARM?

The AD7887ARM offers four programmable power modes via PM1/PM0 bits: Mode 1 (hardware shutdown via CS), Mode 2 (always-on), Mode 3 (auto-shutdown after each conversion), and Mode 4 (standby with reference active). Shutdown current is 1 μA max (VDD = 2.7–3.6 V), and standby current is 210 μA max - all specified in Table 1 under POWER REQUIREMENTS.

Is the AD7887ARM pin-compatible with other packages of the same device?

Yes, the AD7887ARM (MSOP) shares identical pinout and electrical functionality with the AD7887AR (SOIC_N) variant - both use the same 8-pin configuration shown in Figures 3 and 4 of the datasheet. Pin numbering, signal names, and terminal functions (CS, VDD, GND, AIN1/VREF, etc.) are fully identical; only the package dimensions and thermal characteristics differ.