Analog Devices Inc. AD7688BRMZRL7

Overview

AD7688BRMZRL7 from Analog Devices is a 16-bit, charge redistribution successive approximation ADC with true differential input, ±V_REF analog range, ±1.5 LSB max INL, 95.5 dB SNR at 20 kHz, and 500 kSPS throughput. It operates from a single 5 V supply with 1.8 V–5 V logic interface (VIO), features no pipeline delay, and targets high-precision data acquisition in battery-powered instrumentation and medical devices.

For engineers reviewing the AD7688BRMZRL7 datasheet, AD7688BRMZRL7 pinout, AD7688BRMZRL7 application, or AD7688BRMZRL7 equivalent, this page delivers verified specifications, validated MSOP/LFCSP pin mapping, real-world use cases in process control and portable diagnostics, and two confirmed alternative parts with documented functional and packaging differences.

Technical Context

The AD7688BRMZRL7 implements a proprietary charge redistribution DAC architecture with dual 16-bit capacitor arrays for true differential sampling, delivering zero pipeline latency and immediate result availability post-conversion. Its on-chip track-and-hold has 2.5 ns aperture delay and 9 MHz −3 dB input bandwidth, enabling accurate capture of fast transients without external hold circuitry.

It supports SPI/QSPI/MICROWIRE/DSP-compatible serial interfaces across three modes: CS-based 3-/4-wire and daisy-chain mode with BUSY indicator. The separate VIO rail (1.8 V–5 V) isolates digital I/O from analog supply (VDD = 4.5–5.5 V), while standby current is 1 nA - critical for ultra-low-power wake-up systems.

Key Specifications

Pinout & Package

AD7688BRMZRL7 is available in two RoHS-compliant packages: 10-lead MSOP (3.0 mm × 3.0 mm × 1.1 mm) and 10-lead LFCSP (3.0 mm × 3.0 mm × 0.8 mm). Both share identical pinout and thermal pad grounding requirement (LFCSP EPAD must be connected to GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7687BRMZ, AD7688BRMZRL7 delivers double throughput and identical integration; versus ADS8860IDRCT, it offers superior flexibility in multi-ADC synchronization and mixed-voltage interfacing but trades off peak speed.

Availability

AD7688BRMZRL7 is available at Aetrix Electronics and suitable for battery-powered instrumentation, portable medical diagnostics, and industrial process monitoring requiring stable component supply, long-term lifecycle assurance, and consistent parametric performance across production batches.

Supply support for AD7688BRMZRL7 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 ISO 9001-certified manufacturing.

The AD7688BRMZRL7 belongs to Analog Devices' PulSAR™ family of precision SAR ADCs, engineered for applications demanding high resolution, low power, and zero-latency conversion - especially where battery life, signal fidelity, and board space are constrained.

FAQ

What is the maximum recommended reference voltage for AD7688BRMZRL7?

The AD7688BRMZRL7 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. However, optimal SNR (95.5 dB) and THD (−118 dB) are achieved at VREF = VDD = 5 V per the datasheet's AC performance characterization. Using REF > VDD risks violating absolute maximum ratings and may cause latch-up.

Does AD1688BRMZRL7 require an external clock source for conversion?

No, the AD7688BRMZRL7 does not require an external clock for conversion. It contains an internal conversion clock, so the serial clock (SCK) is used solely for data readout - not for the ADC core operation. This eliminates timing jitter sensitivity and simplifies system clock tree design compared to externally clocked ADCs.

Can AD7688BRMZRL7 operate with a 3.3 V digital interface while using a 5 V analog supply?

Yes, AD7688BRMZRL7 supports independent analog and digital supplies: VDD = 4.5–5.5 V powers the ADC core, while VIO = 1.8–5 V sets the logic levels for CNV, SDI, SCK, and SDO. With VIO = 3.3 V and VDD = 5 V, the part maintains full 500 kSPS throughput and all specified AC performance, enabling seamless interfacing to 3.3 V microcontrollers without level shifters.

What is the significance of the "BRMZRL7" suffix in AD7688BRMZRL7?

The "BRMZRL7" suffix denotes a specific ordering option: "B" = grade (industrial −40°C to +85°C), "RMZ" = 10-lead MSOP package, "R" = tape-and-reel packaging, "L7" = 7-inch reel quantity. This matches Analog Devices' standard part numbering convention and confirms the device is the industrial-grade MSOP variant supplied in reel format - not the LFCSP or cut-tape version.

How does the daisy-chain mode function on AD7688BRMZRL7?

In daisy-chain mode, triggered by pulling SDI low at the CNV rising edge, the AD7688BRMZRL7 shifts its 16-bit conversion result onto SDO after 16 SCK cycles, while simultaneously passing the previous device's data through SDI → SDO. This allows N devices to share one SDO line and one SCK line, reducing interconnect count in multi-channel systems - with total latency equal to N × 16 SCK cycles.