Texas Instruments ADS7824UB

Overview

ADS7824UB from Burr-Brown is a 12-bit, 4-channel sampling analog-to-digital converter with ±10V input range, successive approximation architecture, and dual parallel/serial interface. It achieves 25µs max complete conversion cycle, ±0.5 LSB max INL/DNL, and operates from a single +5V supply. It is used in industrial data acquisition systems requiring multiplexed analog monitoring of ±10V sensor signals.

For engineers reviewing the ADS7824UB datasheet, ADS7824UB pinout, ADS7824UB application, or ADS7824UB equivalent, key selection considerations include its SOIC-28 package, continuous conversion mode, internal +2.5V reference, power-down capability (50µW), and compatibility with microprocessor buses via BYTE-selectable parallel output or synchronous serial interface.

Technical Context

The ADS7824UB integrates a 4-channel analog multiplexer, track-and-hold amplifier, 12-bit SAR ADC core, internal trimmed ±10V scaling resistors, and a +2.5V reference buffer. Its control logic supports both triggered and continuous conversion modes, with channel sequencing managed by CONTC and address pins A0/A1.

Digital interface flexibility is implemented through PAR/SER and BYTE inputs: parallel output delivers 12-bit data as two bytes (MSB on D7–D0, LSB on D4–D0), while serial mode uses SDATA/DATACLK with optional external clock (0.1–10 MHz) or internal clock (~900 kHz). BUSY provides conversion status for precise timing synchronization.

Key Specifications

Pinout & Package

ADS7824UB is housed in a 28-pin SOIC package (package code 217), 0.3" wide, with standard JEDEC MS-012AC dimensions and thermal resistance θ_JA = 75°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7825UB and AD7892BRZ-1, the ADS7824UB uniquely balances 4-channel multiplexing, ±10 V input range, internal reference, and parallel/serial interface in a single SOIC-28 package-making it optimal for industrial DAQ where channel count, ease of integration, and power efficiency are jointly prioritized.

Availability

ADS7824UB is available at Aetrix Electronics and suitable for industrial process monitoring, test equipment design, motor drive feedback systems, and energy metering front-ends requiring stable component supply and long-term obsolescence management.

Supply support for ADS7824UB 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 was a U.S.-based analog semiconductor company specializing in high-precision data converters, amplifiers, and interface ICs before its acquisition by Texas Instruments in 2000.

The ADS7824UB belongs to Burr-Brown's legacy industrial-grade SAR ADC product line, designed specifically for rugged, multi-channel data acquisition in factory automation, instrumentation, and control systems operating across –40°C to +85°C.

FAQ

What is the maximum sampling rate supported by the ADS7824UB?

The ADS7824UB achieves a maximum throughput rate of 40 kHz, corresponding to a complete acquire-and-convert cycle of 25 µs. This is measured under standard conditions: TA = –40°C to +85°C, VS = +5 V ±5%, and using the internal reference. In continuous conversion mode, this rate applies per channel, enabling up to 10 kHz per channel when cycling through all four inputs.

Does the ADS7824UB require an external reference voltage?

No, the ADS7824UB includes an internal +2.5 V reference with ±0.25% full-scale error and ±7 ppm/°C drift, sufficient for most industrial applications. The REF pin outputs this voltage and must be bypassed with a 2.2 µF tantalum capacitor to AGND2. An external reference can be applied to REF if higher accuracy or different voltage levels are required, but the internal reference eliminates the need for external components in standard ±10 V designs.

How does the continuous conversion mode work on the ADS7824UB?

When CONTC is driven HIGH and CS/R/C remain LOW, the ADS7824UB automatically cycles through AIN0 → AIN1 → AIN2 → AIN3 repeatedly, performing conversions without host intervention. Channel address pins A0/A1 output the current channel index. BUSY pulses low for each conversion, and data is updated in the output register. This mode reduces software overhead in cyclic scan systems such as PLC analog input modules.

Can the ADS7824UB interface directly with an 8-bit microcontroller bus?

Yes, the ADS7824UB supports direct connection to 8-bit microcontrollers via its parallel interface. With PAR/SER HIGH, data appears on D7–D0. BYTE selects either the 8 MSBs (BYTE = LOW) or the 4 LSBs (BYTE = HIGH), allowing full 12-bit reads in two consecutive bus cycles. BUSY's rising edge serves as a ready signal for latching, and CS/R/C provide standard memory-mapped or I/O-mapped control timing compatible with common 8051, Z80, or PIC architectures.

What is the purpose of the TAG pin on the ADS7824UB?

The TAG pin (D0 in serial mode) accepts serial input data synchronized to the DATACLK signal-either internal or external. Each rising/falling edge clocks one bit into the device. This feature allows bidirectional serial communication: SDATA outputs conversion results, while TAG inputs auxiliary data (e.g., channel ID, timestamp flags, or configuration bits) alongside the main data stream, enabling richer system-level protocol integration without additional control lines.