Analog Devices Inc. LTC1286IS8#TRPBF

Overview

LTC1286IS8#TRPBF from Analog Devices is a micropower, 12-bit successive approximation ADC with differential analog inputs, on-chip sample-and-hold, and SPI/Microwire-compatible serial interface. It operates from 4.5V to 9V, draws 250µA typical supply current at 12.5 ksps, auto-shuts down to 1nA, and is housed in an 8-pin SOIC package. It is used in battery-operated remote data acquisition systems requiring high-impedance analog sensing and ratiometric operation.

For engineers reviewing the LTC1286IS8#TRPBF datasheet, LTC1286IS8#TRPBF pinout, LTC1286IS8#TRPBF application, or LTC1286IS8#TRPBF equivalent, key selection criteria include guaranteed ±3/4 LSB DNL, 60µs conversion time, single-supply 4.5–9V operation, differential input architecture, and shutdown current specification under 1nA at T_A = 25°C.

Technical Context

The LTC1286IS8#TRPBF implements a switched-capacitor SAR architecture with integrated sample-and-hold, enabling accurate DC-coupled measurements of floating signals. Its differential input supports common-mode rejection and direct sensor interfacing without external gain stages.

It uses a 3-wire synchronous serial interface (CS/SHDN, CLK, DOUT) with MSB-first output format and no DIN pin. Conversion is initiated by CS falling edge; DOUT becomes active after two clock cycles, delivering 12-bit data plus one null bit, with automatic power-down between transfers.

Key Specifications

Pinout & Package

Package: 8-lead plastic SOIC (S8), 150°C maximum junction temperature, θ_JA = 175°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS7822U and MAX1113EUA+, the LTC1286IS8#TRPBF uniquely combines wide 4.5–9 V operation, true differential input, and sub-nA shutdown-making it the sole option for battery-powered, floating-sensor, and mixed-voltage industrial applications demanding both precision and ultra-low quiescent power.

Availability

LTC1286IS8#TRPBF is available at Aetrix Electronics and suitable for battery monitoring, remote data acquisition, and isolated medical instrumentation requiring stable component supply over extended production lifecycles.

Supply support for LTC1286IS8#TRPBF 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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The LTC1286 product line delivers micropower, precision ADCs optimized for battery-operated and energy-constrained systems where low supply current, guaranteed linearity, and robust analog input architecture are critical.

FAQ

What is the maximum clock frequency supported by the LTC1286IS8#TRPBF?

The LTC1286IS8#TRPBF supports up to 200 kHz clock frequency at V_CC = 5 V. At higher supply voltages (e.g., 9 V), the maximum clock rate increases slightly per the typical curve in the datasheet. Operation above 200 kHz at 5 V risks timing violations and degraded DNL performance. The LTC1286IS8#TRPBF must be operated within its specified f_CLK limits to guarantee 12-bit accuracy and ±3/4 LSB DNL.

Does the LTC1286IS8#TRPBF require an external reference voltage?

No-the LTC1286IS8#TRPBF can operate with either an external reference applied to the VREF pin or with VREF tied to VCC. When using VCC as reference, full-scale range equals VCC; when using an external reference, full-scale equals VREF. The LTC1286IS8#TRPBF's high-impedance VREF input (5 MΩ) allows direct connection to precision references or resistor dividers without loading error.

How does the LTC1286IS8#TRPBF achieve 1 nA shutdown current?

The LTC1286IS8#TRPBF achieves 1 nA shutdown current by fully gating internal bias circuits, comparator, and reference buffer when CS/SHDN is driven high to VCC. This state disables all active circuitry except leakage paths, resulting in sub-nanoampere total supply current. The LTC1286IS8#TRPBF maintains this spec across temperature and process variation, verified per the Typical Performance Characteristics graph "Shutdown Supply Current vs Clock Rate".

Can the LTC1286IS8#TRPBF interface directly with a 3.3 V microcontroller?

Yes-with level-shifting precautions. While the LTC1286IS8#TRPBF operates from 4.5–9 V, its digital outputs (DOUT) swing rail-to-rail (0 V to VCC). To interface safely with a 3.3 V MCU, a resistive divider or level translator is required on DOUT. CS and CLK inputs tolerate 0–12 V, so 3.3 V logic levels are acceptable for control signals. The LTC1286IS8#TRPBF's input thresholds scale with VCC, ensuring reliable recognition of 3.3 V logic highs.

What is the analog input impedance of the LTC1286IS8#TRPBF?

The LTC1286IS8#TRPBF exhibits high analog input impedance: 20 pF capacitance on-channel and ±1 µA leakage current across the full temperature range. Its switched-capacitor SAR architecture samples charge onto an internal capacitor; effective DC impedance exceeds 1 GΩ during hold phase. For optimal accuracy, source impedance should remain below 1 kΩ to limit settling error within the 1.5-clock sample time.