Analog Devices Inc. AD7490BRU

Overview

AD7490BRU from Analog Devices is a 12-bit, 1 MSPS, 16-channel successive approximation ADC with integrated sequencer and track-and-hold amplifier. It operates from a single 2.7 V to 5.25 V supply, delivers 69.5 dB SNR at 50 kHz input, supports 0 V to REFIN or 0 V to 2 × REFIN input ranges, and features SPI/QSPI/MICROWIRE/DSP-compatible serial interface. It is used in multichannel system monitoring and power line monitoring applications.

For engineers reviewing the AD7490BRU datasheet, AD7490BRU pinout, AD7490BRU application, or AD7490BRU equivalent, key selection criteria include guaranteed 12-bit no-missed-codes performance, channel sequencing capability, VDRIVE-independent 3 V/5 V logic interface, full shutdown current ≤0.5 µA, and AEC-Q100 qualification for automotive use.

Technical Context

The AD7490BRU implements a standard successive approximation architecture with precise sampling controlled by the CS falling edge-no pipeline delay. Conversion timing is fully synchronized to the SCLK frequency (up to 20 MHz), enabling deterministic throughput from 250 kSPS to 1 MSPS.

It integrates a 16-channel analog multiplexer, programmable sequencer, and flexible reference handling: REFIN accepts 2.5 V ±1% external reference, and the RANGE bit selects between 0 V–REFIN (straight binary) or −REFIN to +REFIN (twos complement) input ranges. VDRIVE decouples logic I/O voltage (2.7 V–5.25 V) from VDD, enabling direct interfacing with mixed-voltage microcontrollers.

Key Specifications

Pinout & Package

AD7490BRU is packaged in a 28-lead TSSOP (JEDEC MO-153, 4.4 mm × 9.7 mm). All NC pins must be connected directly to AGND. Exposed pad is not present in TSSOP variant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit, multichannel SAR ADC applications.

Compared with ADS8688IPWR and AD7949BCPZ-RL7, the AD7490BRU uniquely combines 16-channel count, hardware sequencer, AEC-Q100 qualification, and VDRIVE voltage independence-making it optimal for automotive and industrial systems requiring autonomous, mixed-voltage, high-channel-count acquisition without added controller overhead.

Availability

AD7490BRU is available at Aetrix Electronics and suitable for multichannel system monitoring, battery-powered equipment, and power line monitoring requiring stable component supply, long-term lifecycle support, and automotive-grade reliability.

Supply support for AD7490BRU 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 semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The AD7490BRU belongs to Analog Devices' precision SAR ADC product line, designed for high-speed, low-power, multichannel data acquisition in automotive, industrial, and instrumentation systems where channel density and deterministic timing are critical.

FAQ

What is the maximum sample rate supported by the AD7490BRU?

The AD7490BRU achieves a maximum throughput rate of 1 MSPS when operated with a 20 MHz SCLK and VDD = 4.75 V to 5.25 V. At 3 V supplies, the maximum SCLK is 16 MHz, yielding 870 kSPS. Conversion time remains fixed at 16 SCLK cycles-800 ns at 20 MHz-ensuring deterministic timing for real-time control loops. The AD7490BRU datasheet specifies these limits in Table 1 and the Timing Specifications section.

Does the AD7490BRU require an external reference, and what voltage is specified?

Yes, the AD7490BRU requires an external reference applied to the REFIN pin. For specified performance-including full 12-bit linearity and 69.5 dB SNR-the reference voltage must be 2.5 V ±1%. REFIN input impedance is 36 kΩ at 1 MSPS, and the pin accepts voltages from −0.3 V to VDD + 0.3 V. The AD7490BRU does not include an internal reference; all accuracy specifications assume proper external reference sourcing and decoupling (1 µF recommended).

How does the channel sequencer function in the AD7490BRU?

The AD7490BRU's hardware sequencer uses the SEQ and SHADOW bits in its 16-bit control register to define a preprogrammed sequence of up to 16 channels (VIN0–VIN15). Once enabled, the sequencer automatically cycles through the selected channels without host intervention-ideal for continuous monitoring. Channel selection is encoded in the ADD3–ADD0 bits, and the sequencer advances on each CS assertion. This eliminates software overhead and ensures jitter-free timing between conversions, a key advantage over non-sequencing SAR ADCs like the AD7949BCPZ-RL7.

What package options are available for the AD7490BRU, and which one does this part number denote?

The AD7490BRU is the 28-lead TSSOP (Thin Shrink Small Outline Package) variant, with dimensions 4.4 mm × 9.7 mm and standard JEDEC MO-153 footprint. It differs from the 32-lead LFCSP (AD7490BCPZ) in pin count, layout, thermal resistance (θJA = 97.9°C/W vs. 108.2°C/W), and absence of an exposed pad. The "BRU" suffix explicitly denotes the TSSOP package; the LFCSP version uses "BCPZ". Both share identical electrical specifications and AEC-Q100 qualification (W grade), but PCB layout and thermal management differ.

Is the AD7490BRU suitable for automotive applications, and what qualification does it hold?

Yes, the AD7490BRU is qualified to AEC-Q100 Grade 1 (−40°C to +125°C) when ordered as the AD7490W variant. While "AD7490BRU" denotes the TSSOP package, the "W" temperature grade is indicated separately in ordering codes (e.g., AD7490WBRUZ). The device meets automotive reliability requirements including HTOL, TC, and ESD testing per AEC-Q100 Rev H. Its wide supply range (2.7 V–5.25 V), robust channel isolation (−82 dB), and low-noise performance make it suitable for battery monitoring, motor control feedback, and ADAS sensor interfaces in vehicles.