Analog Devices Inc. LTC1605IG#PBF

Overview

LTC1605IG#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, 100ksps sampling analog-to-digital converter with ±10V bipolar input range, internal 2.5V reference, and parallel 16-bit two's-complement output. It operates from a single 5V supply, draws 11–16mA, and delivers ±2.0LSB integral nonlinearity and 87.5dB SINAD at 1kHz - used in industrial data acquisition systems requiring high DC accuracy and moderate-speed digitization.

For engineers reviewing the LTC1605IG#PBF datasheet, LTC1605IG#PBF pinout, LTC1605IG#PBF application, or LTC1605IG#PBF equivalent, key selection criteria include guaranteed no missing codes over temperature, ±40°C to +85°C industrial operating range, microprocessor-compatible BUSY/CS/R/C control interface, and SSOP-28 package compatibility with layout-sensitive analog/digital ground separation.

Technical Context

The LTC1605IG#PBF implements a switched-capacitor successive approximation architecture with integrated sample-and-hold, precision bandgap reference, and trimmed internal clock - eliminating external timing components. Its 16-bit DAC core uses binary-weighted capacitive array switching synchronized to internal timing logic.

Control is managed via dual-signal interface: R/C initiates conversion and holds sample when CS is low; BUSY signals active conversion state, while BYTE selects 16-bit word or byte-mode output on D15–D0 pins. All digital I/O meets TTL/CMOS voltage thresholds with Hi-Z tri-state capability under CS or R/C control.

Key Specifications

Pinout & Package

Package: 28-lead plastic SSOP (G package), exposed pad soldered to PCB ground for thermal and noise performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit SAR ADC applications.

Compared with ADS7805UB and AD976ARZ, the LTC1605IG#PBF offers integrated reference, clock, and sample-and-hold in a single SSOP-28 package - reducing component count and design validation effort for parallel-interface industrial DAQ systems.

Availability

LTC1605IG#PBF is available at Aetrix Electronics and suitable for industrial process control, multiplexed data acquisition systems, and high-speed PC-based data acquisition requiring stable component supply and long-term lifecycle support.

Supply support for LTC1605IG#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 LTC1605IG#PBF belongs to ADI's legacy Linear Technology precision data conversion product line, designed specifically for industrial-grade, medium-speed, high-resolution digitization where DC accuracy, noise immunity, and ease of microprocessor interfacing are critical.

FAQ

What is the operating temperature range of the LTC1605IG#PBF?

The LTC1605IG#PBF is rated for industrial operation from –40°C to +85°C ambient temperature. This specification is guaranteed across all electrical parameters including INL, offset, full-scale error, and timing characteristics - making it suitable for deployment in factory floors, outdoor instrumentation, and uncontrolled environmental enclosures where thermal stability is essential. The "I" grade designation explicitly confirms this extended temperature qualification.

Does the LTC1605IG#PBF require an external clock source?

No, the LTC1605IG#PBF does not require an external clock source. It integrates a factory-trimmed internal clock that delivers a typical conversion time of 8µs and guarantees 100ksps sampling rate. This eliminates the need for external oscillators, crystals, or clock distribution circuitry - reducing bill-of-materials cost and layout sensitivity. The internal clock is fully synchronized with the sample-and-hold and SAR logic.

How is the analog input protected on the LTC1605IG#PBF?

The LTC1605IG#PBF analog input (VIN) is protected to ±25V absolute maximum rating, exceeding its ±10V full-scale range. Internal clamping diodes conduct when VIN falls below AGND2 or rises above VANA, allowing survival of transient overvoltages up to ±25V without latch-up. The device tolerates >100mA fault current under such conditions, providing robustness against wiring errors, ESD events, and sensor disconnect surges in industrial environments.

Can the LTC1605IG#PBF operate with an external reference?

Yes, the LTC1605IG#PBF supports external reference operation. The REF pin accepts an external 2.30V to 2.70V reference voltage, overriding the internal 2.500V bandgap source. When using an external reference, full-scale range becomes ±4 × VREF, preserving linearity and no-missing-codes guarantee. This option is used when superior temperature coefficient (e.g., <1ppm/°C) or long-term drift performance is required beyond the internal reference's ±5ppm/°C spec.

What is the purpose of the CAP pin on the LTC1605IG#PBF?

The CAP pin on the LTC1605IG#PBF is the output of the internal unity-gain reference buffer, delivering a low-impedance 2.5V source for the internal DAC array. It must be decoupled with a 2.2µF tantalum capacitor to suppress high-frequency noise. CAP is not intended for driving AC loads or external circuitry - doing so degrades AC performance. Its sole design role is to stabilize the internal reference path, ensuring consistent DAC switching and minimal code transition noise.