Texas Instruments ADS774KE

Overview

ADS774KE from Burr-Brown Corporation is a 12-bit CMOS successive-approximation analog-to-digital converter with integrated sampling, internal 2.5V reference, microprocessor interface, and three-state parallel outputs. It operates from a single +5V supply, achieves ≤8.5µs max conversion time over temperature, supports ±10V/±5V/0–10V/0–20V input ranges, and replaces ADC574/ADC674/ADC774 in legacy industrial data acquisition systems.

For engineers reviewing the ADS774KE datasheet, ADS774KE pinout, ADS774KE application, or ADS774KE equivalent, this page delivers verified technical context, exact package mapping (28-pin 0.3" plastic DIP), confirmed DC/AC performance specs, real-world timing behavior in Control and Emulation Modes, and validated drop-in alternatives for legacy ADC774-based designs.

Technical Context

The ADS774KE implements charge-redistribution successive approximation using a laser-trimmed capacitor array (CDAC) and precision scaling resistors. It integrates an internal 2.5V reference (±0.1V tolerance), clock generator, and TTL/CMOS-compatible control logic for 8- or 12-bit conversions via CE/CS/R/C/AO/12/8 inputs.

It operates in two distinct modes: S/H Control Mode (VEE = +5V) enables full internal sample-and-hold with 1.4µs settling and 300ps aperture jitter; ADC774 Emulation Mode (VEE = –15V) provides 1.6µs aperture delay and drop-in compatibility with existing ADC774 layouts and firmware.

Key Specifications

Pinout & Package

ADS774KE is supplied in a 28-pin 0.3" wide plastic DIP (Package Drawing #246), with separate analog and digital commons (pins 9 and 15), dual-range analog input select pins (10V Range on pin 13, 20V Range on pin 14), and TTL/CMOS-compatible control interface.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS774KE, ADS774KP offers identical functionality in a mechanically larger DIP package for legacy socket fit, while ADS774KU delivers the same precision and timing in a compact SOIC for modern high-density PCBs-both retain full Control and Emulation Mode operation without firmware or timing changes.

Availability

ADS774KE is available at Aetrix Electronics and suitable for industrial data acquisition, legacy system upgrades, and embedded instrumentation requiring stable component supply, long-term lifecycle support, and verified drop-in replacement capability for ADC774-based designs.

Supply support for ADS774KE 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 manufacturer specializing in precision data converters, amplifiers, and interface ICs before its acquisition by Texas Instruments in 2000.

The ADS774KE belongs to Burr-Brown's mid-1990s generation of microprocessor-compatible sampling ADCs, designed specifically to replace industry-standard 12-bit converters like the ADC774 while integrating internal reference, clock, and S/H to simplify system-level design.

FAQ

What is the maximum sampling rate achievable with the ADS774KE?

The ADS774KE achieves a maximum sustained sampling rate of 117kHz over its full operating temperature range (0°C to +70°C), based on its guaranteed ≤8.5µs total conversion time including acquisition. At +25°C, it reaches 125kHz. This rate assumes proper decoupling, correct VEE configuration (–15V for Emulation Mode or +5V for Control Mode), and adherence to timing specifications for CE/CS/R/C control signals. The ADS774KE maintains this throughput without external sample/hold in Control Mode.

Does the ADS774KE require external reference or clock components?

No, the ADS774KE does not require external reference or clock components. It integrates a laser-trimmed 2.5V internal reference (2.4V to 2.6V) capable of sourcing up to 0.5mA, and a fully self-contained clock generator. These features eliminate the need for external precision references, crystal oscillators, or timing circuitry-reducing BOM cost and board space. External reference override (REF IN) is supported but optional.

How does the ADS774KE differ from the ADS774JE in terms of performance?

The ADS774KE offers superior DC accuracy versus the ADS774JE: ±0.5 LSB linearity error (vs ±1 LSB), ±4 LSB unipolar offset (vs ±2 LSB), and 70 dB SINAD (vs 68 dB). Both share identical package (28-pin 0.3" DIP), pinout, control interface, and operational modes. The ADS774KE's tighter specifications make it suitable for higher-precision applications where JE-grade drift or error margins are unacceptable-such as calibrated test equipment or closed-loop control feedback paths.

Can the ADS774KE operate without a negative supply voltage?

Yes, the ADS774KE operates fully from a single +5V supply (VDD = +5V). The VEE pin is optional and serves only as a logic-level mode selector: connecting VEE to –15V enables ADC774 Emulation Mode, while VEE = +5V enables S/H Control Mode. No negative supply is required for functionality, power delivery, or biasing-unlike earlier-generation converters such as the ADC774, which mandated ±15V rails. This simplifies power architecture and reduces system cost.

What are the key layout recommendations for optimal ADS774KE performance?

Optimal ADS774KE layout requires strict separation of analog and digital grounds: connect pins 9 (Analog Common) and 15 (Digital Common) together externally near the device and tie both to a unified analog ground plane. Route VDD with 10µF bulk + 0.1µF ceramic decoupling directly at pin 1. Keep unused range-select pins (e.g., pin 14 for 10V mode) floating-no capacitive loading. Cross analog and digital traces at right angles; avoid parallel runs. Place external offset/full-scale pots adjacent to pins 12 and 10 to minimize noise pickup.