Analog Devices Inc. AD7790BRMZ-REEL

Overview

AD7790BRMZ-REEL from Analog Devices is a low-power, 16-bit buffered sigma-delta ADC with integrated PGA (gains 1/2/4/8), rail-to-rail input buffer, internal clock oscillator, and simultaneous 50 Hz/60 Hz rejection - designed for precision sensor front ends in battery-powered instrumentation and industrial transmitters.

For engineers reviewing the AD7790BRMZ-REEL datasheet, AD7790BRMZ-REEL pinout, AD7790BRMZ-REEL application, or AD7790BRMZ-REEL equivalent, key selection criteria include its 1.1 µV rms noise at 9.5 Hz, 75 µA max normal current, 10-lead MSOP package, SPI-compatible 3-wire interface, and VDD monitor channel for system-level power integrity monitoring.

Technical Context

The AD7790BRMZ-REEL implements a single-channel, fully differential sigma-delta modulator with on-chip digital filtering and programmable output update rates from 9.5 Hz to 120 Hz. Its internal clock eliminates external timing components, and clock division (×2/×4/×8) enables scalable power reduction without external reconfiguration.

It supports both buffered and unbuffered analog input modes, with rail-to-rail buffer enabling high-impedance sensor interfacing while maintaining 3.5 ppm typical INL and ±15 ppm max integral nonlinearity. The VDD monitor channel uses an internal 5:1 voltage divider and 1.17 V reference to provide supply telemetry without external components.

Key Specifications

Pinout & Package

AD7790BRMZ-REEL is housed in a 10-lead MSOP (3 mm × 3 mm, 0.5 mm pitch) package with exposed pad for thermal performance. Pin functions are validated per Analog Devices AD7790 Rev. A datasheet Figure 5 and Table 4.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar sigma-delta ADC applications.

Compared with AD7790BRMZ-REEL, AD7791BRMZ offers channel expansion at no cost to noise or power, while ADS124S08IPW trades ultra-low power and integrated clocking for higher resolution and configurability - making AD7790BRMZ-REEL optimal for cost-sensitive, battery-limited, single-sensor systems demanding proven line-frequency immunity.

Availability

AD7790BRMZ-REEL is available at Aetrix Electronics and suitable for smart transmitters, portable instrumentation, and industrial sensor measurement applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for AD7790BRMZ-REEL 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 Wilmington, MA.

The AD7790BRMZ-REEL belongs to Analog Devices' precision sigma-delta ADC product line, engineered specifically for low-power, high-accuracy measurement of low-frequency industrial and scientific sensors.

FAQ

What is the maximum RMS noise specification for AD7790BRMZ-REEL, and under what conditions is it measured?

The AD7790BRMZ-REEL achieves 1.1 µV rms noise at its lowest update rate of 9.5 Hz, measured with REFIN = 2.5 V, buffered input mode, and CDIV1/CDIV0 = 0. This value is typical and confirmed in Table 1 of the AD7790 Rev. A datasheet. Higher update rates increase noise - e.g., 1.5 µV at 16.6 Hz - due to reduced digital filter settling time.

Does AD7790BRMZ-REEL require an external clock source, and how is timing controlled?

No, AD7790BRMZ-REEL does not require an external clock source. It contains a fully integrated internal oscillator that drives the sigma-delta modulator and digital filter. Output update rate is software-programmable via the filter register's FS[2:0] bits, and internal clock division (×2/×4/×8) is controlled by CDIV1/CDIV0 bits to reduce current consumption without external components.

Can AD7790BRMZ-REEL measure its own supply voltage, and how is this implemented?

Yes, AD7790BRMZ-REEL includes a dedicated VDD monitor channel. When CH1/CH0 = 11 (per Table 7), the internal 5:1 resistor divider scales VDD and applies it to the modulator using the on-chip 1.17 V reference. This provides ratiometric supply telemetry without external components, and the result appears in the 16-bit data register like any other conversion.

What are the absolute voltage limits for the analog inputs of AD7790BRMZ-REEL in buffered mode?

In buffered mode, the AD7790BRMZ-REEL analog input pins AIN(+) and AIN(–) must remain within GND + 100 mV to VDD – 100 mV, as specified in Table 1. Exceeding these limits risks damaging the input ESD structure or causing inaccurate readings due to buffer saturation. Unbuffered mode allows wider range (GND – 30 mV to VDD + 30 mV) but with higher input current sensitivity.

How does AD7790BRMZ-REEL achieve simultaneous 50 Hz and 60 Hz rejection, and which configuration enables it?

AD7790BRMZ-REEL achieves simultaneous 50 Hz and 60 Hz rejection through its digital sinc³ filter architecture and selectable output word rates. The default FS[2:0] = 100 setting (16.6 Hz update rate) provides ≥65 dB rejection at both frequencies. This is enabled by configuring the filter register to set fADC such that the filter's notch frequencies align with both line frequencies - no external hardware or firmware averaging is required.