Analog Devices Inc. AD7946BCPZRL

Overview

AD7946BCPZRL from Analog Devices is a 14-bit, 500 kSPS pseudo-differential successive approximation ADC with no missing codes, ±1 LSB INL max, and 85 dB SINAD at 20 kHz - designed for high-precision data acquisition in battery-powered instrumentation and medical instruments using single 5 V supply and flexible 1.8–5 V logic interface.

For engineers reviewing the AD7946BCPZRL datasheet, AD7946BCPZRL pinout, AD7946BCPZRL application, or AD7946BCPZRL equivalent, this page delivers verified specifications, validated pin functions, confirmed LFCSP-10 package mapping, real-world timing behavior (1.6 µs conversion time), and two rigorously cross-checked alternative parts for precision analog signal chain design.

Technical Context

The AD7946BCPZRL implements a charge redistribution SAR architecture with on-chip track-and-hold, zero pipeline delay, and internal conversion clock - enabling immediate result availability after CNV rising edge. Its differential input structure supports 0 V to REF range with IN− as ground sense, and CMRR reaches 65 dB at 200 kHz.

It features a proprietary SPI-compatible serial interface supporting CS mode (3-/4-wire) and chain mode daisy-chaining, with BUSY indicator option and VIO-supplied logic level independence (1.8 V to 5 V). Power scales linearly: 3.3 µW at 100 SPS, 19 mW at 500 kSPS.

Key Specifications

Pinout & Package

AD7946BCPZRL is housed in a 3 mm × 3 mm, 10-lead LFCSP (lead-frame chip-scale package) with exposed pad requiring connection to GND for thermal and EMI performance. Pin numbering follows standard top-view orientation with Pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed, high-precision SAR ADC applications.

Compared with AD7946BCPZRL, AD7686BRMZ offers higher resolution at lower speed in identical packaging, while AD7980BRMZ delivers greater throughput but requires layout changes and sacrifices daisy-chain capability - making AD7946BCPZRL optimal for balanced speed, power, and interface flexibility in portable and modular systems.

Availability

AD7946BCPZRL is available at Aetrix Electronics and suitable for battery-powered equipment, medical instruments, industrial process control, and portable test & measurement applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD7946BCPZRL 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, with design centers worldwide and over 50 years of precision converter innovation.

The AD7946BCPZRL belongs to Analog Devices' PulSAR® family of precision SAR ADCs - engineered specifically for applications demanding high resolution, low power, and flexible digital interfacing in space-constrained, battery-sensitive systems.

FAQ

What is the maximum reference voltage supported by the AD7946BCPZRL?

The AD7946BCPZRL supports an external reference voltage (REF) from 0.5 V up to VDD, with VDD specified from 4.5 V to 5.5 V. Therefore, the maximum REF is 5.5 V. Operation at REF = VDD = 5 V yields optimal AC performance including 85 dB SINAD and −100 dB THD at 20 kHz, as confirmed in the datasheet's Table 2 and Figure 12.

Does the AD7946BCPZRL require an external clock for conversion?

No, the AD7946BCPZRL does not require an external clock for conversion. It contains an internal conversion clock, so the SCK signal is used solely for serial data readout - not for core ADC timing. Conversion is triggered by the CNV rising edge, and results appear on SDO synchronized to SCK, as detailed in the "Converter Operation" section and timing Table 4.

Can the AD7946BCPZRL operate with a 1.8 V digital interface while using a 5 V analog supply?

Yes, the AD7946BCPZRL supports independent digital and analog supplies: VDD = 5 V powers the analog core, while VIO = 1.8 V powers the digital interface (SDI, SCK, SDO, CNV). This is explicitly specified in Table 3 (VIO range: 1.8 V to VDD + 0.3 V) and enables seamless interfacing with low-voltage microcontrollers without level-shifting circuitry.

What is the significance of the exposed pad on the AD7946BCPZRL LFCSP package?

The exposed pad on the AD7946BCPZRL LFCSP package must be connected to GND per datasheet Figure 5 and Table 6. While not required for basic electrical functionality, this connection is essential for achieving specified thermal performance (θJC = 2.96°C/W) and minimizing noise coupling - particularly critical in high-resolution, low-noise applications like medical instrumentation.

Is the AD7946BCPZRL pin-compatible with any other Analog Devices ADCs?

Yes, the AD7946BCPZRL is pin-for-pin compatible with the 16-bit AD7686, as stated in the General Description and Table 1. Both share identical 10-lead MSOP and LFCSP footprints, matching pin functions (REF, VDD, IN+, IN−, GND, CNV, SDO, SCK, SDI, VIO), enabling drop-in resolution upgrades or downgrades without PCB modification.