AD7946BCPZRL

Overview

The AD7946BCPZRL is a 14-bit, 500 kSPS PulSAR analog-to-digital converter manufactured by Analog Devices Inc. It features a successive approximation architecture with no missing codes and operates from a single 5 V supply. The device supports pseudo-differential inputs ranging from 0 V to REF, where REF can be up to VDD. It includes an internal conversion clock and a versatile serial interface compatible with SPI, QSPI, MICROWIRE, and DSP standards. Power dissipation scales linearly with throughput, reaching 3.3 mW at 5 V/100 kSPS and 19 mW at 500 kSPS. The component is housed in a 10-lead LFCSP package and is specified for operation between −40°C and +85°C.

Feature Summary

• Features a 14-bit resolution with guaranteed no missing codes and low power consumption suitable for battery-powered applications.
• Includes a proprietary serial interface that supports daisy-chaining multiple ADCs and provides an optional BUSY indicator.
• Operates with a single 5 V analog supply while supporting digital logic interfaces of 1.8 V, 2.5 V, 3 V, or 5 V via a separate VIO pin.

Applications

• Battery-powered equipment
• Data acquisition systems
• Medical instruments
• Process control

Procurement Notes

Verify the specific ordering suffix BCPZRL against the manufacturer's official documentation to confirm the exact package type and tape-and-reel configuration. Ensure compatibility with system requirements regarding the 10-lead LFCSP footprint and thermal management specifications for the exposed pad connection.

Selection Notes

Select this component when a high-resolution 14-bit ADC with a 500 kSPS throughput rate is required. It is suitable for designs needing a pseudo-differential input range referenced to an external voltage up to the supply rail. Consider the separate VIO supply pin if interfacing with digital logic levels different from the analog supply voltage.

Part Context

The AD7946 belongs to the PulSAR family of charge redistribution successive approximation ADCs. This series is characterized by low power consumption and high precision. The AD7946 variant specifically offers 14-bit resolution and 500 kSPS speed, distinguishing it from lower-speed or higher-resolution models within the same product line.

Replacement Considerations

The datasheet indicates pin-for-pin compatibility with the 16-bit AD7686. Designers requiring a higher resolution but maintaining the same physical footprint and interface should consider this alternative.

FAQ

What is the maximum reference voltage allowed for the AD7946?

The reference voltage (REF) can be set up to the supply voltage (VDD), which is typically 5 V.

Does the AD7946 have any pipeline delay?

No, the AD7946 has no pipeline delay; conversion results are available immediately after the completed conversion.

How does the SDI pin affect the interface mode?

The SDI pin selects the interface mode during the CNV rising edge. If SDI is low, Chain mode is selected for daisy-chaining. If SDI is high, CS mode is selected.