Texas Instruments ADS7804UB

Overview

ADS7804UB from Texas Instruments is a 12-bit successive approximation register (SAR) analog-to-digital converter with full parallel output, ±10V input range, 100kHz sampling rate, ±0.45 LSB integral linearity error, and single +5V supply operation. It integrates sample/hold, internal 2.5V reference, clock, and three-state drivers for microprocessor interfacing in industrial data acquisition systems.

For engineers reviewing the ADS7804UB datasheet, ADS7804UB pinout, ADS7804UB application, or ADS7804UB equivalent, this page delivers verified specifications, SO-28 package layout, real-world timing behavior, hardware calibration guidance, and validated alternative options for precision ±10V signal digitization at 100kSPS.

Technical Context

The ADS7804UB implements a capacitor-based SAR architecture with on-chip sample/hold, internal reference buffer, and digital control logic that initiates conversion on CS/R/C falling edges and asserts BUSY until output registers are updated. Its binary two's complement output format supports full 12-bit parallel reads or byte-mode access via BYTE pin.

It operates over –40°C to +85°C using a single +5V supply (VDIG = VANA), draws 16mA analog current and 0.3mA digital current, and achieves 72dB SINAD at 45kHz input while maintaining no missing codes across its full transfer function.

Key Specifications

Pinout & Package

ADS7804UB is housed in a 28-pin SOIC (DW) package with 0.3" body width, gull-wing leads, and moisture sensitivity level 3 (260°C peak reflow). Pin spacing is 0.050", and thermal resistance θ_JA is 75°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7804U and ADS8320EB, the ADS7804UB uniquely delivers guaranteed ±0.45 LSB linearity, full parallel output, and integrated reference in a drop-in SO-28 package-enabling faster system integration and lower total solution cost for ±10V, 100kSPS applications.

Availability

ADS7804UB is available at Aetrix Electronics and suitable for industrial process monitoring, test equipment, motor drive feedback, and medical instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADS7804UB 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 solutions for industrial, automotive, and communications markets.

The ADS7804UB belongs to TI's precision data converter product line, designed specifically for high-accuracy, single-supply, ±10V industrial signal digitization with minimal external components.

FAQ

What is the maximum sampling rate of the ADS7804UB?

The ADS7804UB is specified for a minimum sampling rate of 100kHz across its full operating temperature range (–40°C to +85°C). This corresponds to a 10µs complete acquisition-and-conversion cycle. The device achieves this performance using an internal clock and does not require external timing components. At 100kHz, ADS7804UB maintains 72dB SINAD and ±0.45 LSB INL, making it suitable for real-time control and data logging applications where consistent throughput is critical.

Does the ADS7804UB require an external reference voltage?

No, the ADS7804UB includes an internal 2.5V reference with ±0.02V initial accuracy and ≤8 ppm/°C drift, eliminating the need for an external reference in most applications. Pin 3 (REF) serves as the reference output, and pin 4 (CAP) provides the buffered reference output-both require a 2.2µF tantalum capacitor to ground. An external reference between 2.3V and 2.7V can be applied to REF to override the internal source, enabling custom full-scale ranges or improved stability in high-precision systems.

How is the ADS7804UB calibrated for offset and gain errors?

The ADS7804UB supports both hardware and software calibration. Hardware calibration uses external resistors and potentiometers (per Figure 6a in the datasheet) to trim offset (±15mV range) and gain (±60mV range). Software calibration skips external components and corrects offset/gain digitally using known reference points-ideal for systems with processor resources. The ADS7804UB's typical uncalibrated bipolar zero error is ±10mV and full-scale error is ±0.5%, both reducible to <±0.1% with either method.

What are the power supply requirements for the ADS7804UB?

The ADS7804UB operates from a single +5V supply applied to both VANA (pin 27) and VDIG (pin 28), with specified voltage range +4.75V to +5.25V. VDIG must not exceed VANA. Typical analog supply current is 16mA, digital supply current is 0.3mA, and total power dissipation remains ≤100mW at 100kHz sampling. Decoupling requires a 0.1µF ceramic capacitor and 10µF tantalum capacitor per supply pin, placed as close as possible to the device.

Is the ADS7804UB pin-compatible with other devices in the ADS78xx family?

Yes, the ADS7804UB is pin-compatible with the ADS7805 (16-bit version) in the same SO-28 package, allowing direct upgrade paths in existing designs. It shares identical pin assignments for power, grounds, reference, control signals (CS, R/C, BYTE, BUSY), and parallel data outputs (D0–D11). However, the ADS7805 has higher resolution (16-bit), tighter INL (±1.5 LSB), and lower sampling rate (50kHz), so system firmware and timing constraints must be reviewed before substitution.