Analog Devices Inc. AD7440BRTZ-REEL7

Overview

AD7440BRTZ-REEL7 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 supplies. It delivers 61 dB SINAD at 100 kHz input frequency, ±0.5 LSB INL, and 4 mW max power dissipation at 3 V/1 MSPS, targeting precision data acquisition in space-constrained transducer interfaces.

For engineers reviewing the AD7440BRTZ-REEL7 datasheet, AD7440BRTZ-REEL7 pinout, AD7440BRTZ-REEL7 application, or AD7440BRTZ-REEL7 equivalent, key selection considerations include its 8-lead SOT-23 package, SPI/QSPI/MICROWIRE-compatible serial interface, differential track-and-hold architecture with 200 ns acquisition time, and support for externally adjustable reference voltages from 100 mV to 2.2 V (3 V supply) or 3.5 V (5 V supply).

Technical Context

The AD7440BRTZ-REEL7 implements a true SAR architecture with no pipeline delay, enabling deterministic conversion timing controlled by CS and SCLK edges. Its differential track-and-hold amplifier supports input frequencies up to 3.5 MHz and provides 70 dB SINAD at 100 kHz with 3 V supply.

Conversion is initiated on the falling edge of CS, with data output as 10-bit twos-complement words preceded by four leading zeros and followed by two trailing zeros. The device features flexible power management via serial clock speed scaling and a full power-down mode drawing ≤1 µA.

Key Specifications

Pinout & Package

AD7440BRTZ-REEL7 is housed in an 8-lead SOT-23 package (JEDEC MO-178AA), with 0.65 mm lead pitch and exposed pad for thermal enhancement. Pin 1 is marked with a dot; pin numbering follows standard SOT-23 top-view orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with AD7440BRTZ-REEL7, AD7450ABRTZ-REEL7 offers higher resolution at the expense of slightly relaxed DC accuracy, while ADS8325IDBVT delivers 16-bit fidelity but requires redesign of reference and power delivery-making AD7440BRTZ-REEL7 optimal for cost-sensitive, battery-aware 10-bit applications.

Availability

AD7440BRTZ-REEL7 is available at Aetrix Electronics and suitable for transducer interface, battery-powered systems, and data acquisition systems requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for AD7440BRTZ-REEL7 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, headquartered in Norwood, MA.

The AD7440BRTZ-REEL7 belongs to Analog Devices' precision SAR ADC product line, engineered for low-power, high-speed digitization in space-constrained industrial and portable measurement systems.

FAQ

What is the maximum sampling rate supported by the AD7440BRTZ-REEL7?

The AD7440BRTZ-REEL7 supports a maximum throughput rate of 1 MSPS, achieved with an 18 MHz serial clock and 16 SCLK cycles per conversion. At lower clock frequencies, the throughput scales linearly-for example, 500 kSPS at 9 MHz SCLK-enabling dynamic power reduction in duty-cycled applications.

Does the AD7440BRTZ-REEL7 require an external reference voltage?

Yes, the AD7440BRTZ-REEL7 requires an external reference applied to the VREF pin. For specified performance, VREF must be 2.0 V ±1% with a 3 V supply or 2.5 V ±1% with a 5 V supply, though it remains functional across 100 mV to 2.2 V (3 V) or 3.5 V (5 V). Decoupling with ≥0.1 µF to GND is mandatory.

What serial interface protocols is the AD7440BRTZ-REEL7 compatible with?

The AD7440BRTZ-REEL7 supports SPI, QSPI, MICROWIRE, and generic DSP serial interfaces. Its SDATA output is three-state, CS initiates conversion on the falling edge, and data is clocked out MSB-first on SCLK falling edges-matching standard SPI Mode 3 (CPOL = 1, CPHA = 1) timing.

Can the AD7440BRTZ-REEL7 operate with a single 3.3 V supply?

Yes, the AD7440BRTZ-REEL7 operates with VDD from 2.7 V to 3.6 V, making 3.3 V fully compliant. At 3.3 V, typical IDD is 1.45 mA in operational mode, and power dissipation remains ≤4 mW at 1 MSPS. VREF should be set to ~2.0 V for optimal performance.

What is the purpose of the four leading zeros and two trailing zeros in the AD7440BRTZ-REEL7 serial output format?

The AD7440BRTZ-REEL7 outputs 16-bit frames: four leading zeros, ten data bits (MSB first, twos-complement), and two trailing zeros. This structure ensures consistent 16-bit word alignment across SPI buses, simplifies firmware bit-shifting, and maintains compatibility with microcontrollers expecting fixed-width transfers-even though only 10 bits carry valid data.