Analog Devices Inc. AD7949BCPZ

Overview

AD7949BCPZ from Analog Devices is a 14-bit, 8-channel successive approximation register (SAR) ADC with no missing codes, 250 kSPS throughput, ±0.5 LSB INL, and SPI-compatible serial interface. It integrates an internal 2.5 V/4.096 V reference, temperature sensor, channel sequencer, and selectable one-pole filter-enabling compact multichannel data acquisition in battery-powered medical ECG and power line monitoring systems.

For engineers reviewing the AD7949BCPZ datasheet, AD7949BCPZ pinout, AD7949BCPZ application, or AD7949BCPZ equivalent, this page delivers verified electrical parameters, real-world use cases, validated alternatives, and supply-chain support for industrial embedded and portable instrumentation designs.

Technical Context

The AD7949BCPZ employs a charge redistribution SAR architecture with zero pipeline delay, enabling deterministic timing for time-critical sampling. Its 8-channel multiplexer supports unipolar single-ended, differential (GND-sense), and pseudobipolar configurations-all referenced to either internal or external voltage references up to VDD.

Conversion is initiated by a rising edge on CNV, with results available on SDO synchronized to SCK. The device uses separate VDD (2.3–5.5 V) and VIO (1.8–VDD) supplies, allowing direct interfacing with 1.8 V, 2.5 V, 3.3 V, or 5 V logic without level shifters.

Key Specifications

Pinout & Package

AD7949BCPZ is housed in a 20-lead, 4 mm × 4 mm LFCSP package with exposed pad (EPAD) recommended for soldering to system ground. Pin 1 is top-left corner (VDD), and the EPAD is electrically unconnected but thermally critical.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel SAR ADC applications.

Compared with AD7689BCPZ and ADS8688IPWR, the AD7949BCPZ offers optimal balance of 14-bit precision, integrated reference/temperature/sequencer, and ultra-low power-making it ideal for space-constrained, battery-operated, or thermally aware multichannel systems where 16-bit resolution is unnecessary.

Availability

AD7949BCPZ is available at Aetrix Electronics and suitable for medical instrumentation, industrial power monitoring, and seismic data acquisition requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for AD7949BCPZ 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 AD7949BCPZ belongs to Analog Devices' PulSAR® family of precision SAR ADCs-designed specifically for multichannel, low-power, high-accuracy data acquisition in portable and industrial systems.

FAQ

What is the maximum sample rate of the AD7949BCPZ and under what conditions?

The AD7949BCPZ achieves 250 kSPS maximum throughput when VDD is 4.5 V to 5.5 V. At lower VDD (2.3–4.5 V), the maximum rate drops to 200 kSPS. This is specified across the full −40°C to +85°C operating range and confirmed in Table 2 of the Rev. F datasheet. The AD7949BCPZ maintains 85 dB SINAD at 20 kHz even at full rate, making it suitable for demanding signal acquisition tasks.

Does the AD7949BCPZ support differential input configurations, and how is it implemented?

Yes, the AD7949BCPZ supports true differential input via its 8-channel multiplexer with GND-sense capability. By configuring COM as VREF/2 and selecting paired channels (e.g., IN0/IN1), the device performs differential sampling with −125 dB crosstalk rejection at 100 kHz. This mode is set via the CFG register and does not require external op-amps-enabling compact, low-noise differential acquisition directly from transducers or current transformers.

How does the internal temperature sensor in the AD7949BCPZ function, and what is its accuracy?

The AD7949BCPZ includes an on-chip temperature sensor that outputs a voltage of 283 mV at 25°C with a linear sensitivity of 1 mV/°C. It is accessed as a dedicated multiplexer channel (TEMP), digitized with the same 14-bit SAR core, and calibrated across temperature. While absolute accuracy depends on system-level calibration, the sensor enables board-level thermal compensation and health monitoring without adding discrete components-directly enhancing reliability in the AD7949BCPZ design.

Can the AD7949BCPZ operate with a 1.8 V digital interface while using a 5 V analog supply?

Yes-the AD7949BCPZ features independent VDD (2.3–5.5 V) and VIO (1.8–VDD) supplies. With VDD = 5 V and VIO = 1.8 V, the digital interface remains fully compatible with low-voltage MCUs, while the analog core maintains full performance (250 kSPS, 85 dB SINAD). Timing parameters such as tDSDO and tEN are explicitly characterized down to 1.8 V VIO in Tables 3 and 4, confirming robust operation across mixed-supply systems using the AD7949BCPZ.

What decoupling is required for the REF pin of the AD7949BCPZ to ensure stable reference performance?

The REF pin requires a 10 µF ceramic capacitor placed as close as possible to the pin, with low-ESR characteristics-per Figure 2 and the Reference Decoupling section of the datasheet. For internal reference operation, REFIN also needs a 0.1 µF capacitor. These values are mandatory to suppress noise and ensure <±10 ppm/°C drift and <±0.5 LSB gain error. Omitting or undersizing these capacitors degrades INL, SINAD, and reference stability-critical for repeatable performance in the AD7949BCPZ.