Analog Devices Inc. AD7381BCPZ-RL

Overview

AD7381BCPZ-RL from Analog Devices is a dual, simultaneous-sampling, 14-bit, 4 MSPS SAR analog-to-digital converter with fully differential inputs, 2.5 V internal reference, and on-chip oversampling. It operates from 3.0 V to 3.6 V supply, supports −40°C to +125°C, and targets high-precision motor current sensing and power quality monitoring where channel matching and low latency are critical.

For engineers reviewing the AD7381BCPZ-RL datasheet, AD7381BCPZ-RL pinout, AD7381BCPZ-RL application, or AD7381BCPZ-RL equivalent, this page delivers verified specifications, validated pin functions, confirmed dual-channel timing behavior, real-world SNR/INL performance at 4 MSPS, and two rigorously cross-checked alternative parts for 14-bit dual SAR ADC selection.

Technical Context

The AD7381BCPZ-RL implements two independent SAR ADC cores sharing a common clock and control interface, enabling true simultaneous sampling of two differential analog signals (AINA± and AINB±) with aperture delay match ≤100 ps. Its integrated oversampling block supports OSR up to 16, delivering up to 94.5 dB SNR and resolution boost functionality that enhances effective resolution without external processing.

It uses a buffered 2.5 V internal reference (±10 ppm/°C TC) or accepts external references up to 3.3 V, features a 1.65 V–3.6 V logic supply (VLOGIC) for flexible I/O interfacing, and employs a high-speed serial interface with CS-controlled frame synchronization and dual SDO outputs for concurrent readback of both channels.

Key Specifications

Pinout & Package

AD7381BCPZ-RL is housed in a 16-lead LFCSP package (3 mm × 3 mm), with exposed pad requiring connection to GND for thermal and electrical integrity. Pin functions are validated per Analog Devices' official pin configuration diagram (Rev. A, Figure 8).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7380BCPZ-RL, AD7381BCPZ-RL trades 2 bits of resolution for tighter INL (1.0 vs. 2.0 LSB) and lower system cost, while maintaining identical timing, oversampling, and thermal specs; ADS8900BRGER offers no functional equivalence for simultaneous dual-channel use cases.

Availability

AD7381BCPZ-RL is available at Aetrix Electronics and suitable for motor control position feedback, power quality monitoring, and sonar signal acquisition requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7381BCPZ-RL 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 AD7380/AD7381 family was designed specifically for high-fidelity, dual-channel data acquisition in demanding industrial and automotive systems where simultaneous sampling, low latency, and robust thermal performance are essential.

FAQ

What is the maximum supported oversampling ratio (OSR) for AD7381BCPZ-RL?

The AD7381BCPZ-RL supports oversampling ratios up to 16, delivering up to 94.5 dB SNR and enabling resolution boost functionality. This OSR is implemented entirely in hardware within the on-chip oversampling block, requiring no external processing. The AD7381BCPZ-RL achieves this at its full 4 MSPS throughput rate, with timing parameters like tCONVERTx explicitly defined for OSR configurations in the datasheet.

Does AD7381BCPZ-RL support external reference voltages, and what is the valid range?

Yes, AD7381BCPZ-RL supports external reference voltages applied to the REFIO pin within 2.49 V to 3.4 V. When using an external reference, the device disables its internal 2.5 V reference and uses the external source for conversion scaling. The datasheet specifies VREF input current as 0.47–0.51 mA and mandates 1 μF decoupling capacitance on REFIO for stability-critical for maintaining SNR and INL performance.

How does the ALERT function operate on AD7381BCPZ-RL?

The ALERT function on AD7381BCPZ-RL is implemented on Pin 14 (SDOB/ALERT). When enabled via the ALERT register, it asserts low when either ADC A or ADC B conversion result exceeds user-programmed high or low threshold values stored in ALERT_HIGH_THRESHOLD and ALERT_LOW_THRESHOLD registers. The assertion occurs within 200 ns of CS activation (tALERTS), providing deterministic real-time fault signaling without host processor intervention.

What is the aperture delay match specification for AD7381BCPZ-RL, and why does it matter?

The AD7381BCPZ-RL specifies aperture delay match of ≤100 ps between its two ADC channels (Table 3). This parameter quantifies the maximum timing skew between sampling instants of AINA± and AINB±. In applications like I/Q demodulation or three-phase current reconstruction, sub-100 ps matching ensures phase errors remain below 0.1° at 10 kHz-directly enabling accurate vector calculations and minimizing torque ripple in motor control loops.

Can AD7381BCPZ-RL interface directly with a 1.8 V microcontroller?

Yes, AD7381BCPZ-RL supports direct 1.8 V interface via its separate VLOGIC supply pin (Pin 2), which accepts 1.65 V to 3.6 V. When VLOGIC = 1.8 V, digital inputs (CS, SDI, SCLK) recognize VIH ≥ 1.44 V and VIL ≤ 0.36 V, while outputs (SDOA, SDOB/ALERT) drive VOH ≥ 1.5 V and VOL ≤ 0.4 V-fully compliant with standard 1.8 V CMOS logic levels. No level-shifting circuitry is required.