Texas Instruments ADS7827IDRBR

Overview

ADS7827IDRBR from Texas Instruments is an 8-bit, 250 kSPS successive approximation register (SAR) analog-to-digital converter with pseudo-differential rail-to-rail input, SPI-compatible serial interface, and micropower operation at 2.7 V to 5.25 V supply. It features ±1 LSB integral linearity error, 3 µA max power-down current, and operates in an ultra-small 3 × 3 mm SON-8 package for space-constrained battery-powered data acquisition.

For engineers reviewing the ADS7827IDRBR datasheet, ADS7827IDRBR pinout, ADS7827IDRBR application, or ADS7827IDRBR equivalent, key selection considerations include its 8-bit resolution at 250 kSPS throughput, 250 mV to V_CC reference range compatibility, low 260 µA quiescent current at full speed, and SON-8 package thermal performance in industrial temperature range (–40°C to +85°C).

Technical Context

The ADS7827IDRBR implements a capacitive redistribution SAR architecture with integrated sample-and-hold, enabling single-cycle acquisition in 1.5 DCLOCK cycles. Its pseudo-differential input accepts –In between –0.2 V and +1.0 V while +In spans –0.2 V to V_CC + 0.2 V, supporting remote ground sensing and common-mode rejection of small offsets.

It uses a synchronous 3-wire serial interface (CS/SHDN, DCLOCK, DOUT) with data valid on the falling edge of DCLOCK and outputs straight binary MSB-first format. Conversion is initiated by CS falling edge, and the device enters auto power-down mode when CS is high, reducing current to ≤3 µA.

Key Specifications

Pinout & Package

ADS7827IDRBR is housed in an 8-pin SON (PDSO) package measuring 3 mm × 3 mm × 0.9 mm, with wettable flank leads for automated optical inspection. The exposed pad is electrically connected to GND for thermal and noise performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit SAR ADC applications.

Compared with ADS7826IDRBR, the ADS7827IDRBR trades 2 bits of resolution for 25% higher throughput and identical power-down current-ideal for bandwidth-limited but latency-sensitive systems. Against ADS8320IDRBT, it offers triple the speed and half the supply voltage range at the cost of 8-bit fidelity, making it better suited for compact, battery-operated edge nodes rather than lab-grade instruments.

Availability

ADS7827IDRBR is available at Aetrix Electronics and suitable for battery-powered sensor nodes, remote data acquisition modules, simultaneous multichannel sampling systems, and isolated data acquisition front-ends requiring stable component supply across production lifecycles.

Supply support for ADS7827IDRBR 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

Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in precision data converters, power management, and signal chain solutions.

The ADS7826/27/29 family was designed for ultra-low-power, space-constrained data acquisition in portable and distributed sensing applications-emphasizing micropower operation, small-footprint packaging, and flexible reference architecture without sacrificing speed or linearity.

FAQ

What is the maximum DCLOCK frequency supported by the ADS7827IDRBR?

The ADS7827IDRBR supports a maximum DCLOCK frequency of 3 MHz, enabling its full 250 kSPS throughput. At this rate, the 12-clock-cycle conversion cycle (including acquisition and SAR logic) completes in 4 µs. Operation above 3 MHz is not characterized and may result in increased INL error or data corruption due to insufficient internal settling time.

Does the ADS7827IDRBR require an external reference voltage?

Yes, the ADS7827IDRBR requires an external reference voltage applied to the V_REF pin. It does not include an internal reference. The reference must be stable, low-noise, and fall within 50 mV to V_CC; typical implementations use a precision 2.5 V or 1.024 V reference IC with 0.1 µF ceramic bypassing directly at the V_REF pin.

Can the ADS7827IDRBR operate from a 2.0 V supply?

Yes, the ADS7827IDRBR can operate down to 2.0 V, but with reduced performance: maximum throughput drops to 100 kSPS, and reference voltage range narrows to 1.024 V–1.25 V. Full specifications-including ±1 LSB INL and 250 kSPS-are guaranteed only at V_CC ≥ 2.7 V, as stated in the SLAS388 datasheet.

How does the pseudo-differential input of the ADS7827IDRBR differ from a true differential input?

The ADS7827IDRBR's pseudo-differential input uses –IN solely as a common-mode reference point (e.g., remote ground), not as a fully active complementary input. The –IN pin is limited to –0.2 V to +1.0 V and is not resampled during conversion, unlike true differential SAR ADCs. This architecture rejects small common-mode shifts but does not support bipolar or fully differential signal sources.

What is the purpose of the null bit transmitted before data on the DOUT line of the ADS7827IDRBR?

The null bit preceding the 8-bit data stream on DOUT serves as a framing indicator that signals the start of valid conversion data. It ensures synchronization between the ADC and host controller-especially important when multiple devices share the same DCLOCK line-by providing a known transition edge before the first MSB, preventing misalignment due to clock domain crossing or startup glitches.