Analog Devices Inc. LTC1860CS8#TRPBF

Overview

LTC1860CS8#TRPBF from Analog Devices (formerly Linear Technology) is a 12-bit, single-channel, successive-approximation analog-to-digital converter (SAR ADC) in an 8-lead SOIC package, operating on a single 5V supply. It delivers 250ksps sampling rate with only 850µA typical supply current, features true differential analog inputs (IN+, IN–), SPI/MICROWIRE-compatible 3-wire serial interface, and auto-shutdown to 1nA between conversions. It is used in compact, battery-powered instrumentation requiring high-speed, low-power signal digitization.

For engineers reviewing the LTC1860CS8#TRPBF datasheet, LTC1860CS8#TRPBF pinout, LTC1860CS8#TRPBF application, or LTC1860CS8#TRPBF equivalent, key selection criteria include its 12-bit resolution at 250ksps, differential input architecture with adjustable reference, SO-8 thermal performance (θ_JA = 175°C/W), and guaranteed operation from 0°C to 70°C - critical for portable data acquisition and isolated sensor interfaces.

Technical Context

The LTC1860CS8#TRPBF implements a switched-capacitor SAR architecture with integrated sample-and-hold. Its conversion cycle is initiated by a rising edge on CONV, completes in ≤3.3µs, and supports rail-to-rail input spans when VREF = VCC and IN– is grounded. The SO-8 variant ties VREF internally to VCC, eliminating external reference routing.

It uses a 3-wire serial interface (SCK, SDO, CONV) with data output on SDO's falling SCK edge and capture on the rising edge. No SDI pin is present - unlike the LTC1861 - confirming its fixed 1-channel, non-multiplexed configuration. Timing is specified up to 20MHz SCK for H-grade, but the CS8 variant supports ≥16.7MHz at full temperature range.

Key Specifications

Pinout & Package

Package: 8-lead plastic SOIC (narrow, 0.150-inch width), JEDEC MS-012, θ_JA = 175°C/W, RoHS-compliant, tape-and-reel (#TRPBF).

Key Features

Applications

Equivalent & Alternatives

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

Compared with LTC1864CS8#PBF and ADS7822U, the LTC1860CS8#TRPBF uniquely balances 250ksps speed, sub-µA sleep, and SO-8 simplicity - making it optimal for battery-constrained, medium-accuracy data acquisition where 12-bit fidelity suffices and layout space is premium.

Availability

LTC1860CS8#TRPBF is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor interfaces, and isolated power supply feedback requiring stable component supply, commercial-temperature reliability, and SOIC manufacturability.

Supply support for LTC1860CS8#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 acquired Linear Technology in 2017 and maintains full product support, documentation, and manufacturing continuity for legacy Linear parts including the LTC1860 series.

The LTC1860 belongs to Linear's µPower SAR ADC family, designed specifically for space- and energy-constrained systems requiring high-speed, low-voltage, single-supply digitization without sacrificing DC accuracy or noise performance.

FAQ

What is the maximum sampling frequency of the LTC1860CS8#TRPBF?

The LTC1860CS8#TRPBF achieves a maximum sampling frequency of 250ksps across its full 0°C to 70°C operating temperature range. This is supported by a minimum conversion time of 2.75µs and timing specifications validated for SO-8 packaging. At this rate, the device maintains 12-bit no-missing-codes performance and 72dB SNR, making it suitable for real-time signal capture in compact instrumentation.

Does the LTC1860CS8#TRPBF require an external reference voltage?

No, the LTC1860CS8#TRPBF does not require an external reference voltage. In the SO-8 package variant, the VREF pin is tied internally to VCC, establishing a ratiometric full-scale span equal to the supply voltage (4.75V–5.25V). This eliminates external reference components, reduces layout sensitivity, and ensures inherent immunity to VREF drift - a key advantage over MSOP variants that require external VREF routing.

What is the supply current of the LTC1860CS8#TRPBF during active conversion and sleep modes?

The LTC1860CS8#TRPBF draws 850µA typical supply current during continuous 250ksps conversion, and automatically powers down to just 1nA typical between conversions when CONV is held high. This ultra-low sleep current is confirmed in the datasheet's "Sleep Current vs Temperature" plot (Figure G03) and enables multi-year battery life in intermittently sampled applications such as remote environmental sensors.

Is the LTC1860CS8#TRPBF pin-compatible with the LTC1861 series?

No, the LTC1860CS8#TRPBF is not pin-compatible with the LTC1861 series. While both share the SO-8 package outline, the LTC1861CS8#TRPBF includes an SDI pin (Pin 5) and repurposes GND to Pin 4, whereas the LTC1860CS8#TRPBF uses Pin 4 as GND and Pin 5 as CONV. Their pin functions, register maps, and multiplexing capabilities differ fundamentally - substitution requires PCB redesign and firmware changes.

What are the absolute maximum ratings for the analog input pins of the LTC1860CS8#TRPBF?

The absolute maximum rating for the analog input pins (IN+, IN–) of the LTC1860CS8#TRPBF is (GND – 0.3V) to (VCC + 0.3V). Exceeding this range risks permanent damage. Under normal operation, the differential input voltage must remain within 0V to VREF (i.e., 0V to VCC), and the absolute voltage on each input must stay within the specified common-mode range - e.g., IN+ from –0.05V to VCC + 0.05V, IN– from –0.05V to VCC/2 - per the Absolute Maximum Ratings table.