Texas Instruments LMP91300YZRT

Overview

LMP91300YZRT from Texas Instruments is an industrial-grade analog front end (AFE) IC designed specifically for inductive proximity sensors. It directly converts the resistance-to-inductance ratio (RP) of an external LC tank into a 16-bit digital value, supports programmable detection thresholds (16-bit resolution), operates from 6.5V to 40V loop supply, and integrates digital temperature compensation using an external NTC sensor - enabling precise metal object detection in factory automation systems.

For engineers reviewing the LMP91300YZRT datasheet, LMP91300YZRT pinout, LMP91300YZRT application, or LMP91300YZRT equivalent, key selection considerations include its 20-terminal DSBGA package (2.05mm × 2.67mm), support for both NPN and PNP 3-wire configurations, integrated LED driver with 2.5/5 mA sink current options, SWIF single-wire interface (1–10 kbps), and programmable oscillator frequency range (5 kHz to 5 MHz).

Technical Context

The LMP91300YZRT implements a direct RP-to-digital conversion architecture with on-chip oscillator, digital comparator, and Look-Up Table (LUT)-based temperature compensation (registers 0x00–0x5D). Its functional block includes a 5–5 MHz programmable LC oscillator, 16-bit threshold decision engine, and SWIF serial interface for post-production calibration.

It supports dual-output modes: SWDRV drives external NPN/PNP transistors with four selectable current levels (2–11 mA), while LED provides visual status indication. Overload protection uses an external SENSE resistor to detect >310 mV drop and enforce short-circuit duty cycling (0.1% or 0.8%) with 30 µs on-time.

Key Specifications

Pinout & Package

Package: 20-terminal DSBGA (2.05 mm × 2.67 mm), rated for −40°C to +125°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar inductive proximity sensor AFE applications.

Compared with MAX22000 and AD8233, the LMP91300YZRT delivers purpose-built functionality for inductive proximity sensing - including integrated LC oscillator, RP-to-digital converter, programmable thresholds, and SWIF-based calibration - without requiring external MCU or complex signal processing.

Availability

LMP91300YZRT is available at Aetrix Electronics and suitable for industrial automation, factory production lines, and material handling equipment requiring stable component supply and long-term lifecycle support.

Supply support for LMP91300YZRT 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with over 50 years of innovation in industrial and automotive electronics.

The LMP91300YZRT belongs to TI's Industrial Interface & Signal Chain AFE product line, engineered specifically to simplify design of robust, programmable inductive proximity sensors for harsh factory environments.

FAQ

What is the primary function of the LMP91300YZRT in an inductive proximity sensor system?

The LMP91300YZRT serves as a complete analog front end that directly converts the resistance-to-inductance ratio (RP) of an external LC tank into a digital value. It performs digital temperature compensation using an external NTC sensor, applies programmable detection thresholds and hysteresis, and drives an external transistor via SWDRV - all within a single 20-pin DSBGA package. This eliminates the need for external microcontrollers or discrete signal conditioning in standard 3-wire proximity sensors.

Does the LMP91300YZRT support both NPN and PNP output configurations?

Yes, the LMP91300YZRT supports both NPN and PNP 3-wire configurations. Its SWDRV pin drives the external transistor base (EXT B) and emitter (V+/EXT E) terminals, allowing flexible implementation of either topology. The device includes distinct overload protection thresholds for each mode (248–376 mV for PNP, 279–341 mV for NPN), and configuration is handled entirely through register settings - no hardware changes are needed to switch between modes.

How does the LMP91300YZRT implement temperature compensation?

The LMP91300YZRT uses a digital Look-Up Table (LUT) stored in registers 0x00–0x5D to compensate for temperature-induced drift in the external LC tank's RP value. It reads temperature from an external NTC sensor connected to TEMP+ and TEMP−, then applies gain correction factors derived from factory calibration. The LUT supports 4°C increments from −48°C to +136°C with linear interpolation for 1°C resolution, achieving ±2.5°C accuracy when used with the Murata NCP03WF104F05RL NTC.

What communication interface does the LMP91300YZRT use for configuration and calibration?

The LMP91300YZRT uses a Single-Wire Interface (SWIF) for post-production configuration and calibration. Operating at 1–10 kbps, SWIF shares the SENSE2+/SWIF RX pin with the analog sense path, enabling bidirectional communication over a single wire. This allows full programming of detection thresholds, hysteresis, oscillator parameters, LED behavior, and temperature compensation LUT - all without requiring additional pins or external UART peripherals.

What are the key overload protection features of the LMP91300YZRT?

The LMP91300YZRT implements hardware-based overload protection using an external SENSE resistor. When voltage across RSENSE exceeds ~310 mV, it triggers short-circuit detection and forces SWDRV into a pulsed output mode with user-selectable 0.1% or 0.8% duty cycle (30 µs on-time). During overload, load current is limited to I = 480 mV / RSENSE. Recovery occurs automatically once the SENSE voltage drops below the threshold, ensuring robust operation in industrial environments with frequent cable faults or connector shorts.