Analog Devices Inc. AD7853BR

Overview

AD7853BR from Analog Devices is a 12-bit, 200 kSPS pseudo-differential successive-approximation ADC operating from a single 3 V to 5.5 V supply, featuring on-chip 2.5 V reference, self- and system-calibration, and SPI/QSPI/8051-compatible serial interface. It delivers ±1 LSB integral nonlinearity, 71 dB SNR at 10 kHz input, and 4.6 µs conversion time - optimized for portable instrumentation and battery-powered data acquisition.

For engineers reviewing the AD7853BR datasheet, AD7853BR pinout, AD7853BR application, or AD7853BR equivalent, this page provides verified technical context, real-world timing behavior, 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 AD7853BR implements a charge redistribution SAR architecture with integrated track-and-hold (500 ns acquisition), internal 2.5 V reference buffer, and programmable analog input range (0 to VREF or ±VREF/2) controlled by AMODE. Its calibration memory retains offset/gain coefficients across power cycles.

Serial communication supports five interface modes via SM1/SM2 pins, including external-clock (SCLK input) and self-clocking (SCLK output) configurations, with POLARITY pin selecting SCLK idle state. CONVST edge-triggered conversion and BUSY status signaling enable precise timing coordination in embedded microcontroller systems.

Key Specifications

Pinout & Package

AD7853BR is supplied in a 24-lead SOIC (R-24) package with 0.3-inch body width and standard JEDEC MS-013 footprint. Thermal impedance θ_JA = 75°C/W enables operation up to +85°C ambient without forced airflow.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7853AR and ADS7822U, the AD7853BR uniquely combines ±0.5 LSB INL grade, internal 2.5 V reference, autocal on power-up, and true 3 V–5.5 V operation - making it optimal for portable, precision, low-maintenance data acquisition where calibration stability and supply flexibility are critical.

Availability

AD7853BR is available at Aetrix Electronics and suitable for battery-powered medical instrumentation, portable data acquisition systems, and industrial process monitoring requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7853BR 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 precision instrumentation, industrial automation, and communications markets since 1965.

The AD7853BR belongs to Analog Devices' legacy SAR ADC product line designed for portable, low-power, high-accuracy data acquisition - emphasizing integrated calibration, flexible serial interfaces, and robust performance across extended temperature ranges.

FAQ

What is the maximum master clock frequency supported by AD7853BR?

The AD7853BR supports a master clock (CLKIN) frequency of up to 4 MHz under standard operating conditions. This 4 MHz clock directly determines conversion time (4.6 µs max) and calibration duration. The device also operates down to 500 kHz, enabling reduced power consumption in low-throughput applications while maintaining full 12-bit accuracy and timing specification compliance.

Does AD7853BR require external reference components?

Yes, the AD7853BR requires two external capacitors: a 0.1 µF multilayer ceramic capacitor (CREF1) and a 0.01 µF ceramic disc capacitor (CREF2), both connected between their respective pins (CREF1, CREF2) and AGND. These stabilize the internal reference and DAC charge redistribution network. No external voltage reference IC is needed - the internal 2.5 V reference is fully functional with these capacitors.

How does the AMODE pin affect analog input configuration on AD7853BR?

The AMODE pin selects between two analog input ranges: Logic-0 configures unipolar mode (0 to VREF), where AIN(+) must remain ≥ AIN(–); Logic-1 configures bipolar mode (±VREF/2), requiring AIN(–) to be biased at +VREF/2 so AIN(+) can swing from 0 V to +VREF. This selection directly determines coding format (straight binary vs. twos complement) and input signal conditioning requirements.

Can AD7853BR perform system calibration with an external reference?

Yes, the AD7853BR supports system calibration using an external reference applied to the REFIN/REFOUT pin. During system calibration, the device measures actual full-scale and offset errors introduced by external circuitry (e.g., gain stages, filters) and stores correction coefficients in on-chip calibration registers. This compensates for end-to-end errors beyond the ADC's intrinsic performance, ensuring accuracy across the complete signal chain.

What power-down modes are available on AD7853BR and how are they controlled?

The AD7853BR offers three power-down states: (1) Full power-down (10 µA typ, clock-on) via SLEEP = 0 with PMGT1=1, PMGT0=0; (2) Partial power-down (400 µA typ, clock-on) via SLEEP = 0 with PMGT1=1, PMGT0=1; and (3) Deep sleep (5 µA max, clock-off) when CLKIN is disabled. All retain calibration data and resume operation within microseconds upon wake-up.