Analog Devices Inc. AD7853AR

Overview

AD7853AR from Analog Devices is a 12-bit, 200 kSPS pseudo-differential successive approximation register (SAR) ADC operating from a single 3 V to 5.5 V supply. It integrates on-chip 2.5 V reference, self- and system-calibration logic, and SPI/QSPI/8051-compatible serial interface. Designed for portable instrumentation and battery-powered data acquisition, it delivers ±1 LSB integral nonlinearity, 70 dB SNR at 10 kHz input, and 4.6 µs conversion time.

For engineers reviewing the AD7853AR datasheet, AD7853AR pinout, AD7853AR application, or AD7853AR equivalent, this page provides verified technical context, real-world timing constraints, calibrated DC accuracy specs, package-specific layout guidance, and validated alternative options for low-power 12-bit sampling systems requiring stable reference and flexible serial control.

Technical Context

The AD7853AR implements a charge redistribution SAR architecture with integrated track-and-hold (T/H), internal 2.5 V reference, and calibration memory. Its pseudo-differential input supports unipolar (0 to VREF) and bipolar (±VREF/2) ranges via AMODE pin control, with AIN(+) and AIN(–) inputs referenced to AGND.

Serial communication uses configurable interface modes (selected by SM1/SM2 pins) supporting external clock (SCLK input) or self-clocking (SCLK output), with POLARITY pin defining SCLK idle state. Calibration is triggered by CAL pin or software write, retaining offset/gain coefficients in on-chip registers for system-level correction.

Key Specifications

Pinout & Package

AD7853AR is housed in a 24-lead SOIC (Small Outline Integrated Circuit) package with 0.3-inch body width and standard JEDEC MS-013AC footprint. Pin spacing is 0.050 inch (1.27 mm), compatible with automated PCB assembly and reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7853BR, AD7853AR trades ±0.5 LSB INL for broader A-grade availability and cost efficiency; compared with AD7853LAR, it doubles throughput at the expense of 3× higher active power-making AD7853AR optimal for speed-critical portable instrumentation where 200 kSPS and ±1 LSB linearity are jointly required.

Availability

AD7853AR is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical devices, and industrial signal conditioning requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7853AR 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 AD7853AR belongs to Analog Devices' precision SAR ADC product line, engineered for portable and low-power applications demanding integrated reference, calibration, and flexible serial interface without external support circuitry.

FAQ

What is the maximum sampling rate supported by the AD7853AR?

The AD7853AR supports a maximum sampling rate of 200 kSPS under specified conditions: AVDD/DVDD = 4.5 V to 5.5 V, fCLKIN = 4 MHz, and TA = –40°C to +85°C. This rate assumes proper timing margins per the datasheet's tCONVERT (4.6 µs max) and acquisition window (≥400 ns after BUSY deassertion). At 3 V supply, performance remains compliant but power dissipation drops to 15 mW typical.

Does the AD7853AR require external reference components?

The AD7853AR includes an internal 2.5 V reference and operates as a complete ADC solution with only two external capacitors: 0.1 µF (CREF1) and 0.01 µF (CREF2), both connected to AGND. No external reference IC or trimming network is needed unless system-level accuracy demands <20 ppm/°C drift or absolute reference voltage tolerance tighter than ±2.5%.

How does the AD7853AR handle bipolar input signals?

The AD7853AR supports bipolar operation via its pseudo-differential architecture: setting AMODE = 1 configures the input range to ±VREF/2, requiring AIN(–) to be externally biased to +VREF/2. AIN(+) then swings from 0 V to +VREF, producing twos-complement output coding. This eliminates need for external level-shifting op-amps while maintaining 12-bit resolution across the full bipolar span.

Can the AD7853AR perform system-level calibration?

Yes-the AD7853AR supports both self-calibration (internal DAC and reference) and system calibration (external gain/offset errors). System calibration is initiated via CAL pin or software command and adjusts for errors introduced by external signal conditioning circuitry. The allowable system offset span is ±0.05 × VREF, and full-scale span is +1.025/–0.975 × VREF, as defined in the calibration section of the datasheet.

What power-down modes are available on the AD7853AR?

The AD7853AR offers three power-down states: full power-down (5 µA typ with external clock off), partial power-down (200 µA typ), and automatic post-conversion sleep (25 mW typical active, then drops to sleep current). All modes retain calibration coefficients and reference bias; only full power-down disables the internal reference. Entry is controlled by SLEEP pin or PMGT bits in the control register.