Analog Devices Inc. AD7703ANZ

Overview

AD7703ANZ from Analog Devices is a monolithic 20-bit sigma-delta analog-to-digital converter with on-chip 6-pole Gaussian digital filtering, self-calibration microcontroller, and flexible serial interface. It delivers ±0.0003% typical integral nonlinearity (INL), 4 kSPS output data rate, and 0.1 Hz to 10 Hz programmable filter corner frequency. It is designed for high-precision DC/low-frequency measurement in industrial process control and portable instrumentation.

For engineers reviewing the AD7703ANZ datasheet, AD7703ANZ pinout, AD7703ANZ application, or AD7703ANZ equivalent, this page provides verified technical context, real-world design meaning of specifications, validated pin functions, confirmed alternative parts with functional differences, and supply support for long-lifecycle embedded systems requiring stable calibration performance and ultralow standby power (10 µW).

Technical Context

The AD7703ANZ employs a second-order sigma-delta modulator with charge-balancing architecture, continuously sampling the analog input at 16 kHz (f_CLKIN/256) and feeding a six-pole Gaussian digital low-pass filter that updates the 20-bit output register at 4 kHz (f_CLKIN/1024). Its self-calibration logic uses on-chip SRAM to store zero- and full-scale coefficients, enabling system-level offset/gain error correction when external circuitry is included in the calibration loop.

It supports two serial interface modes: Synchronous Self-Clocking (SSC) with SCLK output at f_CLKIN/4 and 25% duty cycle, and Synchronous External Clocking (SEC) with SCLK input up to 5 MHz. The device operates from dual ±5 V supplies (AVDD/DVDD = +5 V, AVSS/DVSS = –5 V), features unipolar (0 V to +2.5 V) or bipolar (±2.5 V) input ranges, and enters ultralow-power sleep mode (<20 µW) when SLEEP is logic low.

Key Specifications

Pinout & Package

AD7703ANZ is supplied in a 20-pin plastic DIP package (0.3-inch width), RoHS-compliant and rated for industrial temperature range (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-precision sigma-delta ADC applications.

Compared with AD7703ANZ, AD7714BN offers higher resolution but sacrifices update rate, sleep power, and interface flexibility; ADS1258IPWR provides speed and integration but lacks bipolar input, system calibration, and dual-supply operation required for legacy industrial sensor interfaces.

Availability

AD7703ANZ is available at Aetrix Electronics and suitable for industrial process control, weigh scales, and portable instrumentation requiring stable component supply, long-term calibration integrity, and ultralow-power operation in extended temperature environments.

Supply support for AD7703ANZ 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 AD7703ANZ belongs to Analog Devices' precision sigma-delta ADC product line, engineered specifically for high-accuracy, low-frequency measurement in industrial, scientific, and portable instrumentation where calibration stability and noise immunity are critical.

FAQ

What is the maximum clock frequency supported by the AD7703ANZ?

The AD7703ANZ supports a master clock frequency (CLKIN) up to 5 MHz, with production-tested operation at 4.096 MHz. At this frequency, it achieves a 4 kSPS output data rate, 10 Hz digital filter corner, and 125 ms worst-case settling time. Operation down to 200 kHz is guaranteed by characterization, enabling ultra-low-power configurations with reduced throughput.

Does the AD7703ANZ support both unipolar and bipolar input ranges?

Yes, the AD7703ANZ supports both input configurations via the BP/UP pin: logic low selects unipolar mode (0 V to +2.5 V), and logic high selects bipolar mode (±2.5 V). The VREF pin sets the reference voltage for both modes, and the internal calibration logic adapts automatically to maintain accuracy across either range.

How does the AD7703ANZ perform system-level calibration?

The AD7703ANZ performs system-level calibration by including external circuitry-such as sensor conditioning amplifiers or input resistors-in the calibration loop. When SC1 and SC2 pins are asserted during a CAL pulse, the device measures actual system zero and full-scale points, storing corrected coefficients in on-chip SRAM to remove channel-level offset and gain errors.

What is the purpose of the SLEEP pin on the AD7703ANZ?

The SLEEP pin on the AD7703ANZ controls ultralow-power standby mode: when driven logic low, it stops the internal clock and reduces total power consumption to typically 10 µW. This feature is essential for battery-powered portable instrumentation and loop-powered remote sensors where energy efficiency is critical between measurement cycles.

Can the AD7703ANZ interface directly with common microcontrollers?

Yes, the AD7703ANZ supports direct interface with industry-standard microcontrollers via its flexible serial port. In Synchronous External Clocking (SEC) mode, it accepts SCLK up to 5 MHz and outputs MSB-first 20-bit words compatible with SPI peripherals. In Synchronous Self-Clocking (SSC) mode, it generates its own SCLK, simplifying timing for MCUs lacking dedicated SPI clock outputs.