Analog Devices Inc. AD7440BRMZ

Overview

AD7440BRMZ from Analog Devices is a 10-bit, 1 MSPS successive approximation register (SAR) analog-to-digital converter with fully differential analog inputs, operating from single 3 V or 5 V supply, delivering 61 dB SINAD at 100 kHz input and 4 mW max power dissipation at 3 V/1 MSPS - used in high-accuracy transducer interface and portable instrumentation signal chains.

For engineers reviewing the AD7440BRMZ datasheet, AD7440BRMZ pinout, AD7440BRMZ application, or AD7440BRMZ equivalent, this page delivers verified specifications, package mapping to 8-lead SOT-23, functional pin roles, real-world use cases, and two confirmed alternative parts for differential-input, low-power, 1 MSPS ADC selection.

Technical Context

The AD7440BRMZ employs a SAR architecture with no pipeline delay, enabling deterministic conversion timing controlled by CS and SCLK edges. Its differential track-and-hold amplifier supports up to 3.5 MHz input bandwidth and accepts externally applied reference voltage (100 mV–2.2 V at 3 V supply, up to 3.5 V at 5 V), defining full-scale span as 2 × VREF.

Conversion is initiated on the falling edge of CS, with data output via SPI/QSPI/MICROWIRE/DSP-compatible serial interface (MSB-first, twos complement). Power-down mode draws ≤1 μA, and dynamic performance includes 61 dB SINAD, ±0.5 LSB INL, and guaranteed no missing codes over temperature (–40°C to +85°C).

Key Specifications

Pinout & Package

AD7440BRMZ is housed in an 8-lead SOT-23 package (JEDEC MO-178AA), with exposed pad not electrically connected. The package supports reflow soldering per JEDEC J-STD-020 and offers thermal impedance θJA = 211.5°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed, low-power, differential-input SAR ADC applications.

Compared with AD7440BRMZ, AD7450ABRMZ provides 2 extra bits and +9 dB SINAD at identical speed and footprint, while ADS8325IDR trades 10× lower throughput for 6-bit resolution gain and different packaging - making AD7440BRMZ optimal for cost-sensitive, battery-operated 1 MSPS systems needing 10-bit fidelity.

Availability

AD7440BRMZ is available at Aetrix Electronics and suitable for transducer interface, battery-powered systems, and motor control applications requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.

Supply support for AD7440BRMZ 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, founded in 1965 and headquartered in Wilmington, MA.

The AD7440BRMZ belongs to Analog Devices' precision SAR ADC product line, designed specifically for low-power, high-throughput, differential-input data acquisition in space- and energy-constrained embedded systems.

FAQ

What is the maximum sampling rate supported by the AD7440BRMZ?

The AD7440BRMZ supports a maximum throughput rate of 1 MSPS, achieved with an 18 MHz serial clock and 16 SCLK cycles per conversion. This rate is guaranteed across the full operating temperature range (–40°C to +85°C) and supply voltages (2.7–3.6 V or 4.75–5.25 V). At lower clock speeds, throughput scales linearly - e.g., 10 MHz SCLK yields ~555 kSPS. The AD7440BRMZ achieves this without pipeline delay due to its SAR architecture.

Does the AD7440BRMZ require an external reference voltage?

Yes, the AD7440BRMZ requires an external reference voltage applied to the VREF pin. It does not include an internal reference. For specified performance at 3 V supply, VREF should be 2.0 V (±1%); at 5 V supply, 2.5 V (±1%). The reference can be scaled from 100 mV to 2.2 V (3 V supply) or up to 3.5 V (5 V supply), directly setting the full-scale differential input range as 2 × VREF. A minimum 0.1 µF decoupling capacitor is mandatory at VREF.

What serial interface protocols is the AD7440BRMZ compatible with?

The AD7440BRMZ supports SPI, QSPI, MICROWIRE, and DSP-compatible serial interfaces. It uses a 4-wire interface (CS, SCLK, SDATA, GND) with CS-active-low framing and data output on the falling edge of SCLK. The AD7440BRMZ outputs 10-bit twos-complement data MSB-first, prefixed with four leading zeros. No configuration registers or setup commands are required - communication is inherently synchronous and hardware-controlled.

Can the AD7440BRMZ operate from a 3.3 V supply?

Yes, the AD7440BRMZ is fully specified for operation from 2.7 V to 3.6 V supplies, making 3.3 V a standard and recommended VDD voltage. At 3.3 V and 1 MSPS, it consumes ≤4 mW maximum and maintains all key specifications including 61 dB SINAD at 100 kHz, ±0.5 LSB INL, and 1 μA shutdown current. The reference voltage should be set to 2.0 V (±1%) for guaranteed performance, and decoupling requires both 0.1 µF ceramic and 10 µF tantalum capacitors on VDD.

What is the input bandwidth and common-mode rejection of the AD7440BRMZ?

The AD7440BRMZ features a fully differential track-and-hold amplifier with 3.5 MHz small-signal input bandwidth and 70 dB typical common-mode rejection ratio (CMRR) at 100 kHz. CMRR remains >60 dB up to 1 MHz, enabling robust operation in noisy environments such as motor drives or industrial PLCs. The differential input structure inherently rejects power supply ripple and electromagnetic interference coupled equally to VIN+ and VIN−, preserving signal integrity without external instrumentation amplifiers.