Analog Devices Inc. AD7664ASTZ

Overview

AD7664ASTZ from Analog Devices is a 16-bit, 570 kSPS charge redistribution SAR analog-to-digital converter operating from a single 5 V supply. It delivers ±2.5 LSB INL, 90 dB SNR at 45 kHz, and no missing codes across its 0 V to 2.5 V unipolar input range. It serves as a high-accuracy, low-latency ADC in precision data acquisition systems requiring synchronous sampling and dual-mode digital interfacing.

For engineers reviewing the AD7664ASTZ datasheet, AD7664ASTZ pinout, AD7664ASTZ application, or AD7664ASTZ equivalent, key selection criteria include Warp/Normal/Impulse mode throughput trade-offs, parallel-or-serial 3 V/5 V interface flexibility, internal error correction for guaranteed monotonicity, and LQFP-48 package compatibility with AD7660-based designs.

Technical Context

The AD7664ASTZ implements a capacitor-based charge redistribution SAR architecture with factory-calibrated error correction circuitry, eliminating pipeline delay and ensuring immediate availability of conversion results. Its three operational modes-Warp (570 kSPS), Normal (500 kSPS), and Impulse (444 kSPS)-dynamically scale power consumption while maintaining full DC and AC specifications over –40°C to +85°C.

It supports both straight binary and two's complement output coding via OB/2C control, and integrates a track-and-hold with 2 ns aperture delay and 5 ps rms jitter. The device accepts external 2.3–2.5 V references and features independent analog (AVDD/AGND), digital (DVDD/DGND), and I/O (OVDD/OGND) supply domains for noise isolation.

Key Specifications

Pinout & Package

AD7664ASTZ is housed in a 48-lead LQFP (ST-48 package option, CP-48-4 footprint) with exposed pad grounded per datasheet recommendation. Pin functions are validated per Rev. F datasheet Figures 1–20 and Pin Function Descriptions (pp. 5–7).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit SAR ADC applications.

Compared with AD7660ASTZ, AD7664ASTZ adds Warp Mode for 14% higher peak throughput and tighter INL; compared with AD7666ASTZ, it trades 230 kSPS and 1 LSB INL for 25 mW lower power and broader legacy compatibility - making AD7664ASTZ optimal for balanced speed/accuracy/power in industrial DAQ.

Availability

AD7664ASTZ is available at Aetrix Electronics and suitable for data acquisition, medical instrumentation, and battery-powered sensor systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AD7664ASTZ 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 AD7664ASTZ belongs to the PulSAR® family of precision SAR ADCs, designed specifically for applications demanding high resolution, fast throughput, and low power in single-supply, space-constrained environments.

FAQ

What are the supported operating modes of the AD7664ASTZ and how do they affect throughput?

The AD7664ASTZ supports three modes: Warp (570 kSPS), Normal (500 kSPS), and Impulse (444 kSPS). Warp Mode requires conversion intervals ≤1 ms to guarantee full accuracy; Normal Mode imposes no minimum rate constraint; Impulse Mode scales power linearly with throughput - e.g., 21 µW at 100 SPS. All modes retain the same 16-bit resolution and ±2.5 LSB INL specification. Selection is determined by real-time processing demands and thermal/power budgets in the target AD7664ASTZ application.

Does the AD7664ASTZ require an external reference, and what are the voltage and current requirements?

Yes, the AD7664ASTZ requires an external precision reference applied to the REF pin, with a valid range of 2.3 V to 2.5 V. At 570 kSPS throughput, it draws 115 µA from the reference source. The REFGND pin must be connected directly to the reference's ground return, and the reference must exhibit low noise (<10 µV rms) and high PSRR to maintain the specified 90 dB SNR and ±2.5 LSB INL. The AD7664ASTZ does not include an internal reference.

How does the AD7664ASTZ handle digital interface voltage levels, and can it connect directly to 3 V logic?

The AD7664ASTZ uses separate OVDD (I/O supply) and DVDD (core digital supply) rails. OVDD accepts 2.7 V to 5.25 V, allowing direct interfacing to 3 V or 5 V logic families without level shifters. Digital inputs (e.g., CNVST, RD, CS) tolerate –0.3 V to OVDD + 0.3 V, and outputs (e.g., D[15:0], BUSY) drive to 0.4 V low and OVDD – 0.6 V high under load. This dual-supply I/O architecture ensures robust operation in mixed-voltage systems using the AD7664ASTZ.

What is the significance of the OB/2C pin on the AD7664ASTZ, and how does it affect data interpretation?

The OB/2C pin selects between straight binary (OB/2C = HIGH) and two's complement (OB/2C = LOW) output coding. In straight binary mode, 0x0000 = 0 V and 0xFFFF = VREF – 1.5 LSB; in two's complement mode, 0x0000 = mid-scale (VREF/2) and 0x7FFF = positive full-scale. This choice impacts firmware sign-extension, scaling math, and compatibility with downstream DSP blocks. The AD7664ASTZ maintains identical AC/DC performance regardless of OB/2C state - the selection is purely a data formatting option.

Is the AD7664ASTZ pin-compatible with other devices in the PulSAR family, and what are the implications for board reuse?

Yes, the AD7664ASTZ is pin-to-pin compatible with the AD7660ASTZ in the same LQFP-48 package (ST-48), enabling drop-in upgrades to gain Warp Mode speed and improved INL. However, it is not compatible with AD7666ASTZ or AD7667ASTZ due to differing pin functions and timing - those require layout changes. For existing AD7660ASTZ designs, migrating to AD7664ASTZ requires only firmware updates to leverage enhanced modes; no PCB revision is needed.