Analog Devices Inc. LTC1272-8CCN#PBF

Overview

LTC1272-8CCN#PBF from Analog Devices (formerly Linear Technology) is a 12-bit, 8 µs conversion time, successive approximation analog-to-digital converter with on-chip sample-and-hold and internal 2.42 V reference. It operates from a single 5 V supply, delivers up to 111 kHz sampling rate, and maintains ±1 LSB integral linearity over 0°C to 70°C. It serves as a drop-in replacement for AD7572 in unipolar data acquisition systems requiring fast, single-supply ADC performance.

For engineers reviewing the LTC1272-8CCN#PBF datasheet, LTC1272-8CCN#PBF pinout, LTC1272-8CCN#PBF application, or LTC1272-8CCN#PBF equivalent, key selection criteria include its 8 µs conversion time, 25 ppm/°C reference tempco, 24-pin narrow DIP package compatibility with legacy AD7572 layouts, and support for both parallel 12-bit and two-byte 8-bit microprocessor interfaces.

Technical Context

The LTC1272-8CCN#PBF implements a switched-capacitor SAR architecture using LTBiCMOS technology, integrating a precision bandgap reference, sample-and-hold amplifier, and 12-bit capacitive DAC. Its internal clock supports 1.6 MHz operation for the -8 speed grade, enabling 111 kHz sustained sampling.

Control logic uses asynchronous CS/RD/HBEN gating to initiate conversion and manage three-state data output multiplexing-HBEN selects between full 12-bit parallel output (D11–D0/8) or high-byte-only mode (D11–D8 active, D7–D0/8 low), allowing flexible interfacing with 8-bit and 16-bit processors without external latches.

Key Specifications

Pinout & Package

Package: 24-lead plastic dual in-line package (PDIP), 0.3″ wide, JEDEC MS-001 compliant. Pin pitch: 0.1″, body width: 0.3″, operating temperature range: 0°C to 70°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7572KNZ, LTC1272-8CCN#PBF eliminates negative supply dependency and adds integrated S&H, while matching pinout. Against LTC1278CN, it trades 3 µs speed for lower dynamic power and relaxed clock timing margins-making it preferable for thermally constrained or cost-sensitive 111 kHz systems.

Availability

LTC1272-8CCN#PBF is available at Aetrix Electronics and suitable for industrial process monitoring, DSP-based signal analysis, and multiplexed sensor acquisition requiring stable component supply, long-term obsolescence mitigation, and RoHS-compliant lead-free packaging.

Supply support for LTC1272-8CCN#PBF 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

Analog Devices, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC1272 product line was developed by Linear Technology (acquired by ADI in 2017) to deliver pin-compatible, enhanced-performance replacements for legacy industry-standard ADCs-specifically targeting upgrade paths from AD7572 in single-supply, high-speed data acquisition systems.

FAQ

What is the maximum sampling rate supported by the LTC1272-8CCN#PBF?

The LTC1272-8CCN#PBF supports a maximum sampling rate of 111 kHz, derived from its 8 µs conversion time. This is achieved using a 1.6 MHz clock input and is validated under typical conditions (VDD = 5 V, TA = 25°C). The device maintains 72 dB S/(N+D) and 11.5 ENOB at this rate for input frequencies up to 20 kHz, making it suitable for FFT-based spectral analysis and real-time control loop sampling.

Can the LTC1272-8CCN#PBF replace the AD7572 in an existing design without PCB changes?

Yes-the LTC1272-8CCN#PBF uses the identical 24-pin narrow DIP footprint and pinout as the AD7572. To implement the replacement, reverse the polarity of the reference bypass capacitor (since LTC1272-8CCN#PBF outputs +2.42 V vs. AD7572's –5.25 V) and leave Pin 23 (NC) unconnected. No PCB layout changes or trace modifications are required, and the 1 µs minimum inter-conversion delay satisfies timing compatibility.

How does the HBEN pin affect data readout on the LTC1272-8CCN#PBF?

The HBEN (High Byte Enable) pin on the LTC1272-8CCN#PBF controls data bus multiplexing: when HBEN = LOW, all 12 bits (DB11–DB0) appear on D11–D0/8 for parallel read; when HBEN = HIGH, only the upper 4 bits (DB11–DB8) drive D11–D8, while D7–D0/8 output LOW-enabling two-byte reads on 8-bit buses. HBEN = HIGH also disables new conversion starts, providing hardware-level conversion gating.

What is the purpose of the NC pin (Pin 23) on the LTC1272-8CCN#PBF?

Pin 23 on the LTC1272-8CCN#PBF is Not Connected internally and replaces the AD7572's –15 V supply pin. It is electrically isolated and may be left floating or tied to ground per layout best practices. Its presence ensures mechanical compatibility with AD7572 sockets while eliminating negative supply requirements-simplifying power design and enhancing reliability in single-supply systems.

Does the LTC1272-8CCN#PBF require an external clock source, or can it operate with a crystal?

The LTC1272-8CCN#PBF supports both configurations: an external 1.6 MHz TTL/CMOS clock may be applied to CLK IN (Pin 17), or a 1.6 MHz crystal/ceramic resonator can be connected between CLK IN and CLK OUT (Pins 17 and 18) to use the internal oscillator. The datasheet specifies minimal capacitance on CLK OUT for optimal analog performance, and duty cycle is not critical for external clocks.