Analog Devices Inc. LTC1864AHMS8#PBF

Overview

LTC1864AHMS8#PBF from Analog Devices (formerly Linear Technology) is a 16-bit, 250ksps single-channel differential successive approximation ADC in an 8-lead MSOP package, operating on a single 5V supply with 850μA typical supply current at full speed and auto-shutdown to 2μA at 1ksps. It features true differential analog inputs (IN+, IN–), adjustable external reference (VREF), SPI/MICROWIRE-compatible 3-wire serial interface, and guaranteed operation from –40°C to +125°C - ideal for high-precision, low-power industrial sensor interfaces.

For engineers reviewing the LTC1864AHMS8#PBF datasheet, LTC1864AHMS8#PBF pinout, LTC1864AHMS8#PBF application, or LTC1864AHMS8#PBF equivalent, key selection criteria include its 16-bit resolution with ±8 LSB INL (H-grade), 87 dB SNR, 2.75 μs conversion time, rail-to-rail input capability down to 1V full-scale, and MSOP-8 thermal performance (θ_JA = 210°C/W) for compact embedded data acquisition.

Technical Context

The LTC1864AHMS8#PBF implements a switched-capacitor SAR architecture with integrated sample-and-hold, supporting unipolar differential input measurement where output code = (IN+ − IN−) × 65535 / VREF. Its auto-power-down logic triggers between conversions when CONV remains high, reducing current draw proportionally to sampling frequency.

It uses a 3-wire serial interface (SCK, SDO, CONV) with data shifted out on SDO falling edges synchronized to SCK, requiring capture on rising SCK edges. The device accepts external references from 1V to VCC and supports ratiometric operation, with high-impedance analog inputs enabling direct connection to low-output-impedance sensors without gain stages.

Key Specifications

Pinout & Package

Package: 8-lead plastic MSOP (MS8), 3mm × 3mm body, 0.65mm pitch, θ_JA = 210°C/W, TJ_MAX = 150°C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADS8860IDRCT and AD7682BRMZ, the LTC1864AHMS8#PBF uniquely combines guaranteed 125°C operation, true differential input, auto-shutdown, and 5V single-supply compatibility - making it the only choice for ruggedized industrial and automotive subsystems requiring all four attributes.

Availability

LTC1864AHMS8#PBF is available at Aetrix Electronics and suitable for industrial sensor interfaces, portable instrumentation, isolated data acquisition, and motor drive current sensing requiring stable component supply across extended temperature ranges.

Supply support for LTC1864AHMS8#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 LTC1864AHMS8#PBF belongs to ADI's legacy Linear Technology precision data acquisition product line, designed specifically for high-resolution, low-power, wide-temperature industrial and instrumentation applications where reliability and parametric consistency are critical.

FAQ

What is the maximum clock frequency supported by the LTC1864AHMS8#PBF for reliable serial communication?

The LTC1864AHMS8#PBF supports a maximum SCK frequency of 20 MHz for H-grade devices across the full –40°C to +125°C operating range. This timing is validated per the datasheet's recommended operating conditions and ensures correct setup/hold margins for CONV and SDO transitions. Exceeding 20 MHz may cause data corruption or missed conversions, especially at temperature extremes.

Does the LTC1864AHMS8#PBF require an external reference, or can it operate with VCC as reference?

The LTC1864AHMS8#PBF requires an external reference applied to the VREF pin and does not internally tie VREF to VCC. Unlike the SO-8 version of the LTC1865, the LTC1864AHMS8#PBF has no internal reference connection - VREF must be supplied externally from 1V to VCC to define the full-scale range. Using VCC directly as reference is possible only if routed externally to VREF.

How does the auto-shutdown feature of the LTC1864AHMS8#PBF reduce power consumption during low-duty-cycle operation?

The LTC1864AHMS8#PBF automatically powers down between conversions when the CONV pin remains high after conversion completion. At 1ksps, this reduces supply current from 850μA to 2μA - a 425× reduction. This behavior is inherent to the internal bias and clock-gating logic and requires no configuration register writes, making it ideal for burst-mode sensing in energy-constrained applications.

Can the LTC1864AHMS8#PBF interface directly with a microcontroller's standard SPI peripheral without additional level-shifting?

Yes - the LTC1864AHMS8#PBF is SPI/MICROWIRE™ compatible with 3-wire operation (SCK, SDO, CONV). Its digital inputs meet 5V-tolerant thresholds (VIH = 2.4V min, VIL = 0.8V max at VCC = 5V), and SDO output swings rail-to-rail. When interfaced with 5V microcontrollers, no level-shifting is needed; for 3.3V MCUs, verify VIL/VIH margins using the actual VCC and MCU IO specs.

What is the guaranteed integral nonlinearity (INL) specification for the LTC1864AHMS8#PBF over its full operating temperature range?

The LTC1864AHMS8#PBF guarantees ±8 LSB INL over its full –40°C to +125°C operating temperature range (H-grade). This specification is explicitly stated in the "Converter and Multiplexer Characteristics" table of the datasheet and applies to all production units meeting the H-grade screening, ensuring consistent linearity without recalibration across extreme ambient conditions.