Texas Instruments ADS7806U/1K

Overview

ADS7806U/1K from Texas Instruments is a low-power, 12-bit sampling CMOS analog-to-digital converter (ADC) featuring a capacitor-based successive approximation register (SAR), integrated sample-and-hold, internal +2.5V reference, and dual parallel/serial digital interface. It achieves full 12-bit accuracy in ≤25 µs while consuming only 35 mW max at 40 kHz throughput, supporting ±10V, 0V to +5V, and 0V to +4V input ranges - ideal for industrial data acquisition systems requiring single-supply operation and high DC precision.

For engineers reviewing the ADS7806U/1K datasheet, ADS7806U/1K pinout, ADS7806U/1K application, or ADS7806U/1K equivalent, key selection criteria include its 72 dB min SINAD at 1 kHz, ±0.9 LSB max INL/DNL, power-down mode (50 µW), SO-28 package compatibility, and support for both internal and external reference configurations in industrial temperature range (–40°C to +85°C).

Technical Context

The ADS7806U/1K implements a fully integrated SAR architecture with on-chip capacitor DAC, comparator, control logic, and clock generation. Its analog front-end includes laser-trimmed scaling resistors enabling three factory-configured input ranges without external gain/offset components.

Digital interfacing is flexible: parallel output delivers 12-bit data in two 8-bit bytes (MSB/LSB selectable via BYTE pin), while serial output supports MSB-first BTC or SB format synchronized to either internal 900 kHz clock (EXT/INT = LOW) or external clock up to 10 MHz (EXT/INT = HIGH), with BUSY pin indicating conversion status and data validity.

Key Specifications

Pinout & Package

ADS7806U/1K is housed in a 28-pin SOIC (SO-28) package with 0.3-inch width, JEDEC MS-012AC compliant, and rated for industrial temperature operation. Pin layout matches ADS7806P (DIP-28) pin-for-pin, enabling drop-in replacement across package types.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7806U/1K, ADS7805U offers smaller footprint but sacrifices serial interface and power-down capability, while MAX195BCPP+ delivers superior resolution and speed at the cost of higher power and loss of parallel access - making ADS7806U/1K optimal for balanced industrial DAQ where interface flexibility and low idle power are critical.

Availability

ADS7806U/1K is available at Aetrix Electronics and suitable for industrial data acquisition, test equipment, medical instrumentation, and automotive diagnostic tools requiring stable component supply, long-lifecycle support, and guaranteed SO-28 packaging consistency.

Supply support for ADS7806U/1K 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 leader specializing in analog, embedded processing, and high-reliability components for industrial, automotive, and communications markets.

The ADS7806U/1K belongs to TI's precision data converter portfolio, designed specifically for medium-speed, high-accuracy industrial measurement systems where DC precision, low power, and dual-interface flexibility outweigh raw speed requirements.

FAQ

What is the maximum sampling rate supported by the ADS7806U/1K?

The ADS7806U/1K supports a maximum throughput rate of 40 kHz, corresponding to a complete acquire-and-convert cycle of ≤25 µs. This is achievable with internal reference, +5 V supplies, and industrial temperature conditions. At this rate, the device maintains 72 dB SINAD and ±0.9 LSB INL, making it suitable for sub-130 kHz signal bandwidth applications where precision outweighs ultra-high speed.

Does the ADS7806U/1K require external passive components for basic operation?

Yes - the ADS7806U/1K requires two 2.2 µF tantalum capacitors: one between CAP and AGND2, and another between REF and AGND2, as specified in the datasheet. Additionally, 0.1 µF ceramic and 10 µF tantalum decoupling capacitors are mandatory on VANA and VDIG. These components stabilize the internal reference and suppress supply noise to maintain ±0.9 LSB linearity and 72 dB SINAD performance.

Can the ADS7806U/1K operate with an external reference, and what voltage range is supported?

Yes, the ADS7806U/1K supports external reference voltages from 2.3 V to 2.7 V for specified linearity. When using an external 2.5000 V reference, full-scale error drift improves to ±0.5 ppm/°C versus ±7 ppm/°C with internal reference. The REFD pin must be driven HIGH to disable the internal reference, and external reference current drain is 100 µA - requiring a low-output-impedance buffer for optimal performance.

How does the BYTE pin affect parallel data output timing on the ADS7806U/1K?

The BYTE pin on the ADS7806U/1K selects between two parallel output modes: when LOW, D7–D0 present the eight most significant bits (MSBs) of the 12-bit result; when HIGH, they present the four least significant bits (LSBs). BUSY going HIGH indicates data validity for the selected byte. To read the full 12-bit word, toggle BYTE after latching the first byte - no additional conversion is needed, and timing remains within the 25 µs total cycle window.

Is the ADS7806U/1K pin-compatible with other members of the ADS78xx family?

Yes - the ADS7806U/1K is explicitly pin-compatible with the 16-bit ADS7807 in both SO-28 and DIP-28 packages, sharing identical pin functions and electrical characteristics for shared control signals (R/C, CS, BUSY, PWRD, REFD). This allows direct hardware upgrade paths from 12-bit to 16-bit resolution without PCB redesign, provided system firmware accommodates the wider data word.