Texas Instruments ADS7816E/250

Overview

ADS7816E/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 range (100mV–5V). It delivers 1.9mW power at full rate, 3µA shutdown current, and ±2 LSB integral linearity - optimized for remote, isolated, or battery-powered data acquisition systems.

For engineers reviewing the ADS7816E/250 datasheet, ADS7816E/250 pinout, ADS7816E/250 application, or ADS7816E/250 equivalent, key selection criteria include its micro-power operation at variable sample rates (12.5kHz–200kHz), differential input architecture rejecting common-mode ground shifts, MSOP-8 package footprint, and straight-binary serial output timing synchronized to DCLOCK and CS/SHDN.

Technical Context

The ADS7816E/250 implements a capacitive redistribution successive approximation register (SAR) architecture on 0.6µm CMOS, integrating sample-and-hold functionality. Conversion is initiated by falling CS/SHDN, with analog sampling occurring over 1.5 clock cycles before 12-cycle conversion completes.

Digital output is serial, most-significant-bit-first, enabled after the second falling edge of DCLOCK; DOUT remains valid for 12 edges then enters tri-state. Reference current scales with sample rate and code value (e.g., 38–100µA at 200kHz), while internal noise contributes ≤33µVrms at VREF = 5V.

Key Specifications

Pinout & Package

ADS7816E/250 is housed in an 8-lead MSOP package (Package Drawing 337), measuring 3.0mm × 3.0mm × 1.0mm with 0.65mm lead pitch. Thermal pad optional; RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7816U/2K5, ADS7816E/250 offers 30% smaller PCB area and improved thermal performance in high-density layouts; versus ADS7822U, ADS7816E/250 provides native differential input capability critical for ground-referenced sensor interfaces without added components.

Availability

ADS7816E/250 is available at Aetrix Electronics and suitable for battery-operated systems, remote data acquisition nodes, and isolated industrial sensor interfaces requiring stable component supply across extended product lifecycles.

Supply support for ADS7816E/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 precision analog ICs including data converters, amplifiers, and references for industrial and instrumentation markets.

The ADS7816E/250 belongs to Burr-Brown's micro-power SAR ADC family designed specifically for portable, remote, and isolated data acquisition where low standby current and differential input integrity are essential.

FAQ

What is the minimum reference voltage supported by the ADS7816E/250?

The ADS7816E/250 supports a reference voltage range from 100mV to 5V. At 100mV, the LSB size is 24µV, enabling high-resolution digitization of low-output sensors like thermocouples. Operation below 100mV is not specified and may degrade linearity or cause missing codes. The device maintains full 12-bit performance across this range when layout and reference sourcing follow datasheet guidelines.

How does the ADS7816E/250 achieve power savings during idle periods?

The ADS7816E/250 achieves ultra-low power consumption via dual-stage power management: it automatically enters analog-only power-down after conversion completion, and full analog+digital shutdown when CS/SHDN is driven HIGH. In shutdown mode, supply current drops to ≤3µA. This behavior is intrinsic to the ADS7816E/250 design and requires no external control logic beyond proper CS/SHDN assertion.

Can the ADS7816E/250 interface directly with a 3.3V microcontroller?

Yes - the ADS7816E/250 digital interface (CS/SHDN, DCLOCK, DOUT) is CMOS-compatible with VIH ≥3V and VIL ≤0.8V at VCC = 5V, making it interoperable with 3.3V logic when driven through level-shifting or open-drain pull-up configurations. However, DOUT output swing is referenced to +VCC (5V), so direct connection to 3.3V MCU inputs requires series resistance or clamping to avoid overstress; verified operation documented in TI application note SBAA142.

What is the purpose of the –In pin on the ADS7816E/250, and how should it be connected?

The –In pin on the ADS7816E/250 serves as the inverting input for true differential measurement and as a remote ground sense point. It must be held within ±200mV of local GND. For single-ended use, tie –In to system GND; for remote sensing, connect –In directly to the sensor's ground reference point using a trace adjacent to +In - minimizing loop area to reject EMI. This configuration is explicitly validated in the ADS7816E/250 datasheet Figure 6.

Does the ADS7816E/250 require an external clock generator, or can it operate with a microcontroller's GPIO-timed clock?

The ADS7816E/250 requires an external clock signal applied to the DCLOCK pin but imposes no strict duty-cycle requirements - only minimum high/low times of 150ns. This allows reliable operation with microcontroller GPIO-driven clocks at frequencies from 10kHz to 3.2MHz. Timing margins are validated per Table I in the ADS7816E/250 datasheet, confirming robustness against jitter typical of software-generated clocks.