Analog Devices Inc. AD7888ARZ

Overview

AD7888ARZ from Analog Devices is a micropower, 12-bit, 8-channel successive-approximation ADC operating from a single 2.7 V to 5.25 V supply, delivering 125 kSPS throughput with 500 ns track/hold acquisition time and on-chip 2.5 V reference. It features SPI/QSPI/MICROWIRE/DSP-compatible serial interface and supports battery-powered medical instruments and portable instrumentation.

For engineers reviewing the AD7888ARZ datasheet, AD7888ARZ pinout, AD7888ARZ application, or AD7888ARZ equivalent, key selection considerations include its 12-bit resolution with ±1 LSB DNL (B-grade), 71 dB SNR at 10 kHz, flexible power management (down to 1 µA in shutdown), 16-lead TSSOP package, and 0–V_REF single-ended input range.

Technical Context

The AD7888ARZ employs a charge redistribution SAR architecture with integrated track-and-hold, enabling full-power signal conversion up to 2.5 MHz. Its multiplexed eight single-ended analog inputs (AIN1–AIN8) are selected via a programmable 3-bit address in an 8-bit control register.

Serial communication uses a 16-clock cycle frame: first 8 rising edges load the control register (ADD2–ADD0, REF, PM1/PM0), while the next 8 falling edges output 4 leading zeros followed by 12-bit MSB-first conversion data. Power modes-Normal, Full Shutdown, Autoshutdown (5 µs wake-up), and Autostandby-are controlled exclusively through the PM bits.

Key Specifications

Pinout & Package

AD7888ARZ is housed in a 16-lead, 4.4 mm × 5.0 mm thin shrink small outline package (TSSOP) with exposed pad (RoHS-compliant, lead-free).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX11131ETE+, the AD7888ARZ uniquely balances 12-bit accuracy, ultra-low shutdown current (1 µA), wide 2.7–5.25 V operation, and integrated 2.5 V reference in a standard TSSOP - making it optimal for battery longevity and design simplicity in portable instrumentation.

Availability

AD7888ARZ is available at Aetrix Electronics and suitable for battery-powered medical instruments, portable data loggers, industrial sensor interfaces, and high-speed modem analog front ends requiring stable component supply and long-lifecycle support.

Supply support for AD7888ARZ 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The AD7888ARZ belongs to Analog Devices' precision data acquisition product line, engineered specifically for low-power, multichannel, high-fidelity analog-to-digital conversion in space- and energy-constrained portable and embedded systems.

FAQ

What is the maximum sampling frequency supported by the AD7888ARZ?

The AD7888ARZ achieves a maximum throughput rate of 125 kSPS when operated with a 2 MHz SCLK across its full 2.7 V to 5.25 V supply range. This corresponds to a minimum conversion + acquisition time of 16 SCLK cycles (7.25 µs at 2 MHz). The device maintains full 12-bit performance up to a 2.5 MHz full-power input bandwidth, making it suitable for antialiasing-filtered signals well beyond its Nyquist limit.

Does the AD7888ARZ require an external reference, or does it have an internal one?

The AD7888ARZ includes a factory-trimmed 2.5 V internal reference with ±50 ppm/°C tempco, accessible at the REF IN/REF OUT pin. This reference can be used directly or overdriven by an external source (1.2 V to VDD). When an external reference is applied, best practice is to disable the internal reference via the REF bit in the control register to minimize noise and improve accuracy - a feature explicitly confirmed in the AD7888ARZ datasheet Section "On-Chip Reference".

How many analog input channels does the AD7888ARZ support, and what is their configuration?

The AD7888ARZ supports eight single-ended analog input channels (AIN1 through AIN8), each with a 0 V to V_REF input range. Channel selection is controlled by the ADD2–ADD0 bits in the 8-bit control register, allowing software-selectable routing to the internal track-and-hold amplifier. Unused channels must be tied to AGND to prevent noise coupling - a requirement specified in the AD7888ARZ Pin Function Descriptions and Typical Connection Diagram.

What power management modes are available on the AD7888ARZ, and how are they configured?

The AD7888ARZ offers four power modes controlled by the PM1 and PM0 bits in its control register: Normal Operation (full power), Full Shutdown (all circuitry off, 2 µA max), Autoshutdown (auto-enters shutdown after conversion, 5 µs wake-up), and Autostandby (reference remains active, faster wake-up). These modes are configured via serial write to DIN during CS low, as defined in Table III of the AD7888ARZ datasheet - enabling dynamic adaptation to system-level duty cycling requirements.

Is the AD7888ARZ pin-compatible with other members of the AD78xx family?

No, the AD7888ARZ is not pin-compatible with other AD78xx-series ADCs such as the AD7887 or AD7889. Its 16-lead TSSOP pinout - including dual AGND pins (4 & 13), dedicated REF IN/REF OUT (Pin 2), and specific DIN/DOUT/SCLK placement - is unique to the AD7888ARZ and AD7888BRZ variants. Substitution requires PCB layout revision, as confirmed by comparing Pin Configurations pages across respective datasheets.