Texas Instruments ADS7816EC/250

Overview

ADS7816EC/250 from Burr-Brown (now Texas Instruments) is a 12-bit, 200kHz sampling SAR analog-to-digital converter with differential input, synchronous serial interface, and programmable reference voltage (100mV–5V). It delivers 1.9mW power at full rate, 3µA shutdown current, and ±0.75 LSB differential linearity - optimized for remote, isolated, or battery-powered data acquisition systems.

For engineers reviewing the ADS7816EC/250 datasheet, ADS7816EC/250 pinout, ADS7816EC/250 application, or ADS7816EC/250 equivalent, key selection considerations include its micro-power operation at variable sample rates (12.5kHz–200kHz), true differential input architecture with ±200mV common-mode range on –In, MSOP-8 package footprint, and CMOS-compatible serial timing with no pipeline delay.

Technical Context

The ADS7816EC/250 implements a capacitive redistribution successive approximation register (SAR) architecture fabricated in 0.6µm CMOS, integrating sample-and-hold functionality. Conversion is initiated by CS falling edge, with analog sampling occurring over 1.5–2.0 clock cycles before 12-cycle conversion completes.

Digital output appears serially on DOUT, most-significant-bit first, synchronized to DCLOCK falling edges - with no latency between conversion start and first bit output. The device draws reference current dependent on code value and sample rate (e.g., 2.4–20µA at 12.5kHz), and supports short-cycling termination after any bit for adaptive power control.

Key Specifications

Pinout & Package

ADS7816EC/250 is housed in an 8-lead MSOP package (JEDEC MO-187AA, 3mm × 3mm body, 0.65mm pitch), compatible with space-constrained PCB layouts and reflow assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with ADS7816U/2K5, ADS7816EC/250 offers tighter linearity in a smaller footprint; compared with ADS7822U, it provides differential input and reference flexibility at the cost of external reference design effort - making ADS7816EC/250 optimal for precision, isolated, or low-voltage sensor interfaces.

Availability

ADS7816EC/250 is available at Aetrix Electronics and suitable for battery-powered instrumentation, isolated industrial sensor nodes, remote data loggers, and multi-channel DAQ systems requiring stable component supply across extended production lifecycles.

Supply support for ADS7816EC/250 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

Burr-Brown Corporation, acquired by Texas Instruments in 2000, specialized in high-precision analog ICs including data converters, amplifiers, and references - known for low-noise, low-drift, and micro-power architectures.

The ADS7816EC/250 belongs to Burr-Brown's micro-power SAR ADC product line, designed specifically for portable, remote, and isolated measurement applications where accuracy, size, and energy efficiency are co-optimized.

FAQ

What is the minimum reference voltage supported by the ADS7816EC/250?

The ADS7816EC/250 supports a reference voltage range from 100mV to 5V. At 100mV, the LSB size is 24µV, enabling high-resolution measurement of low-level signals such as thermocouples. Operation below 100mV is not specified and may compromise linearity, offset, and noise performance as documented in the "Effective Number of Bits vs Reference Voltage" curve.

Does the ADS7816EC/250 require an external clock source?

Yes, the ADS7816EC/250 requires an external DCLOCK signal. Its serial interface is synchronous and relies on DCLOCK to control conversion timing and data output. Clock frequency must be 10kHz–3.2MHz, with minimum high/low times of 150ns. The device does not contain an internal oscillator and cannot operate without this externally supplied clock.

How does the differential input of the ADS7816EC/250 differ from conventional differential ADCs?

The ADS7816EC/250 uses a true differential input where +In and –In are sampled simultaneously onto the internal capacitor array - unlike some ADCs that resample –In later. However, –In is limited to ±200mV relative to GND, so it functions primarily as a remote ground sense point rather than a full differential signal input. This architecture rejects small common-mode shifts but does not support high common-mode voltage rejection.

Can the ADS7816EC/250 be powered from a 3.3V supply?

No, the ADS7816EC/250 requires a +VCC supply of 4.5V to 5.25V for specified performance. While absolute maximum rating allows +6V, operation below 4.5V is not characterized and may result in degraded linearity, increased noise, or failure to meet timing specifications - particularly for the CMOS logic interface and internal analog biasing.

What is the purpose of the CS/SHDN pin on the ADS7816EC/250?

The CS/SHDN pin serves dual functions: when pulled LOW, it initiates conversion and enables serial data output on DOUT; when driven HIGH, it places the ADS7816EC/250 into full shutdown mode, reducing supply current to ≤3µA. This pin is essential for power management - allowing precise control over active conversion windows and deep sleep states in battery-operated systems.