Analog Devices Inc. LTC4151CS-2#PBF

Overview

LTC4151CS-2#PBF from Analog Devices (formerly Linear Technology) is a high-side power monitor IC designed for 7V–80V systems, integrating a 12-bit ΔΣ ADC to concurrently measure differential sense voltage (81.92 mV FS, 20 µV LSB), input supply voltage (102.4 V FS, 25 mV LSB), and external analog voltage (2.048 V FS, 0.5 mV LSB) via I²C interface. It supports continuous scan mode (7.5 Hz update rate) and on-demand snapshot mode, with dedicated SDAI/SDAO pins for opto-isolated bus interfacing in telecom and industrial power monitoring.

For engineers reviewing the LTC4151CS-2#PBF datasheet, LTC4151CS-2#PBF pinout, LTC4151CS-2#PBF application, or LTC4151CS-2#PBF equivalent, key selection criteria include its 16-pin SO package, non-inverted SDAO output, 0°C to 70°C operating range, and support for SMBus Read/Write Word/Page commands - critical for isolated high-voltage telemetry in battery management and DC distribution systems.

Technical Context

The LTC4151CS-2#PBF implements a ΔΣ ADC architecture that inherently averages noise during conversion, enabling stable current sensing across wide common-mode voltages. Its internal 2.048 V reference ensures consistent scaling for all three measured channels: SENSE+–SENSE–, VIN, and ADIN.

Unlike the base LTC4151 or LTC4151-1, the LTC4151CS-2#PBF uses physically separated SDAI (input) and SDAO (non-inverted open-drain output) pins to simplify bidirectional opto-isolation without signal inversion - a requirement for galvanically isolated microcontroller interfaces in 48 V telecom infrastructure and automotive auxiliary power supplies.

Key Specifications

Pinout & Package

Package: 16-Lead Plastic SO (Small Outline). Exposed pad not present. Pin 1 marked by dot; pin numbering follows standard SOIC convention (counterclockwise from top-left corner).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side current and voltage monitoring applications.

Compared with INA226AIDGST and LTC4151CMS-2#PBF, the LTC4151CS-2#PBF uniquely supports 80 V operation and native opto-isolation via non-inverted SDAO - making it the only choice for 48 V telecom rectifiers and isolated industrial power supplies requiring direct VIN monitoring above 36 V.

Availability

LTC4151CS-2#PBF is available at Aetrix Electronics and suitable for telecom infrastructure, automotive auxiliary power, and industrial DC power supplies requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for LTC4151CS-2#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.

The LTC4151 product line was designed specifically for high-side power telemetry in harsh, high-voltage environments - emphasizing galvanic isolation readiness, wide input range, and minimal external components for rapid system integration.

FAQ

What is the maximum input voltage rating for the LTC4151CS-2#PBF?

The LTC4151CS-2#PBF has an absolute maximum VIN rating of 90 V, with guaranteed operation from 7 V to 80 V. This allows direct monitoring of 48 V telecom systems and 24 V/12 V automotive rails without external attenuation. The internal voltage divider scales VIN to 102.4 V full-scale for the ADC, ensuring ±0.5% accuracy across the rated range. Exceeding 80 V during normal operation may degrade long-term reliability.

Does the LTC4151CS-2#PBF support opto-isolation natively, and how does it differ from the LTC4151-1?

Yes, the LTC4151CS-2#PBF supports native opto-isolation via separate SDAI (input) and SDAO (non-inverted open-drain output) pins. Unlike the LTC4151-1, which inverts SDAO for legacy optocoupler compatibility, the LTC4151CS-2#PBF provides a true non-inverted output - simplifying interface design with modern high-speed optocouplers like the Si87xx family. Both variants eliminate the need for external inverters in isolated bus architectures.

What are the full-scale ranges and LSB values for each measurement channel on the LTC4151CS-2#PBF?

The LTC4151CS-2#PBF measures three channels: (1) SENSE+–SENSE– with 81.92 mV full-scale and 20 µV LSB; (2) VIN with 102.4 V full-scale and 25 mV LSB; (3) ADIN with 2.048 V full-scale and 0.5 mV LSB. These fixed scalings derive from the internal 2.048 V reference and precision resistor dividers/amplifiers - no calibration or external components are required to achieve specified accuracy.

Can the LTC4151CS-2#PBF operate in snapshot mode, and how is it configured?

Yes, the LTC4151CS-2#PBF supports snapshot mode via the CONTROL register (address 06h). Setting bit G7 enables snapshot mode, while bits G6/G5 select the channel (00 = SENSE, 01 = VIN, 10 = ADIN). After writing the command, the ADC performs a single conversion and sets the corresponding Busy bit (B3/D3/F3) until complete. This mode is ideal for event-triggered measurements without disrupting continuous telemetry.

What is the I²C timing compliance of the LTC4151CS-2#PBF, and does it support SMBus protocols?

The LTC4151CS-2#PBF complies with standard I²C Fast Mode (400 kHz max SCL frequency) and supports all SMBus 2.0 commands: Read Byte, Write Byte, Read Word, Write Word, Read Page, and Write Page. Its tLOW (0.65 µs min), tHIGH (50 ns min), and tBUF (0.12 µs min) meet SMBus timing requirements. Stuck-bus recovery (33 ms timeout) further enhances robustness in noisy industrial environments.