Analog Devices Inc. AD7707BR

Overview

AD7707BR from Analog Devices is a 3-channel, 16-bit sigma-delta ADC optimized for low-frequency precision measurement. It integrates programmable-gain amplification (gain 1–128), on-chip digital filtering, and dual-input-range support (±10 mV to ±2.5 V low-level; ±10 V high-level) - enabling direct transducer interfacing in industrial sensor systems without external signal conditioning.

For engineers reviewing the AD7707BR datasheet, AD7707BR pinout, AD7707BR application, or AD7707BR equivalent, key selection criteria include its ±0.003% integral nonlinearity, 1 mW power dissipation at 3 V, true bipolar ±100 mV capability on low-level inputs, 3-wire SPI-compatible serial interface, and 20-lead SOIC/TSSOP package compatibility.

Technical Context

The AD7707BR employs a charge-balancing sigma-delta architecture with an on-chip analog modulator and configurable digital filter whose first notch is software-programmable to adjust cutoff frequency and output update rate. Its analog front end includes a proprietary programmable gain amplifier (PGA) supporting unipolar and bipolar input modes per channel.

It features two pseudo-differential low-level input channels (AIN1/AIN2) referenced to LCOM and one high-level single-ended channel (AIN3) referenced to HICOM, each with independent input range configuration. Calibration registers support both self-calibration and system calibration to eliminate zero-scale and full-scale errors across temperature.

Key Specifications

Pinout & Package

The AD7707BR is available in a 20-lead wide-body SOIC (0.3 inch) and TSSOP package. Pin functions are defined per the Analog Devices AD7707 Rev. B datasheet, Figure 1 and Page 10.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7714BRU and ADS1258IPWR, the AD7707BR uniquely combines ±10 V direct-input capability, true bipolar low-level operation, and sub-1.1 mW power in a 20-pin SOIC - making it optimal for compact, low-power, multi-range industrial sensor nodes where integration reduces design risk and bill-of-materials cost.

Availability

AD7707BR is available at Aetrix Electronics and suitable for pressure transmitters, thermocouple interfaces, RTD measurement modules, and smart actuator controllers requiring stable component supply across extended temperature and long production lifecycles.

Supply support for AD7707BR 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.

The AD7707BR belongs to Analog Devices' precision sigma-delta ADC product line, designed specifically for low-frequency industrial measurement applications requiring integrated signal conditioning, multi-range input flexibility, and robust noise rejection in harsh environments.

FAQ

What is the maximum input voltage range supported by the AD7707BR on its high-level channel?

The AD7707BR supports a ±10 V input voltage range on its high-level analog input channel (AIN3), referenced to HICOM. This is achieved using on-chip thin-film resistors that eliminate the need for external attenuators or split supplies - enabling direct connection of industrial-level signals while maintaining specified accuracy and linearity.

Does the AD7707BR require external calibration components to achieve its ±0.003% INL specification?

No, the AD7707BR does not require external calibration components. Its ±0.003% integral nonlinearity specification is guaranteed after on-chip self-calibration or system calibration, both of which are executed via the serial interface. The AD7707BR includes dedicated zero-scale and full-scale calibration registers that correct gain and offset errors internally without external hardware.

Can the AD7707BR simultaneously sample all three input channels?

No, the AD7707BR does not perform simultaneous sampling. It uses an internal multiplexer to sequentially route AIN1, AIN2, or AIN3 to the sigma-delta modulator. Channel selection is controlled via the setup register, and conversion results are output serially. However, its fast settling and programmable update rates support effective time-multiplexed acquisition across all three channels in real-time control loops.

What is the minimum master clock frequency required for guaranteed operation of the AD7707BR?

The AD7707BR requires a minimum master clock frequency of 400 kHz for guaranteed operation across its full temperature range (−40°C to +85°C), as specified in the Rev. B datasheet Table 4. Operation below this frequency may result in increased power consumption, loss of calibration integrity, or undefined timing behavior - particularly during filter notch configuration or calibration sequences.

Is the AD7707BR pin-compatible with other members of the AD77xx family, such as the AD7705 or AD7706?

No, the AD7707BR is not pin-compatible with the AD7705 or AD7706. While functionally similar as 16-bit sigma-delta ADCs, the AD7707BR has a distinct 20-pin SOIC/TSSOP pinout supporting three analog inputs (AIN1, AIN2, AIN3), dual common-mode references (LOCOM/HICOM), and additional digital control lines. The AD7705/AD7706 use 16-pin packages with only two analog inputs and no dedicated high-level input structure.