Texas Instruments LP877451A1RXVR

Overview

LP877451A1RXVR from Texas Instruments is a highly integrated power management IC designed specifically for IWR-series millimeter-wave radar sensors. It integrates three 3-A buck converters (0.8–1.9 V output), a 5-V/350-mA boost converter, and a programmable 1.8-V/3.3-V 150-mA LDO-all operating from a 3.0–4.0-V input and rated for –40°C to +125°C ambient. Its 4.4/8.8/17.6-MHz programmable switching frequencies enable low-noise, LDO-free RF rail generation in factory automation radar modules.

For engineers reviewing the LP877451A1RXVR datasheet, LP877451A1RXVR pinout, LP877451A1RXVR application, or LP877451A1RXVR equivalent, key selection criteria include multi-rail sequencing control via SPI, remote voltage sensing for POL accuracy, PWM-mode forcing for optimal RF performance, and thermal/overvoltage/short-circuit protection across all rails.

Technical Context

The LP877451A1RXVR implements three independent synchronous buck regulators with selectable 4.4 MHz, 8.8 MHz, or 17.6 MHz switching frequencies-each delivering up to 3 A with programmable output voltages from 0.8 V to 1.9 V. The 5-V boost converter supplies up to 350 mA and powers the integrated 1.8-V/3.3-V LDO, which is dedicated to xWR sensor I/O supply.

Control is implemented via a 4-wire SPI interface (CS_SPI/SDI/SCK/SDO) supporting register configuration, fault reporting (nINT, nERR/GPO2), and synchronized startup/shutdown sequences. Remote sensing on FB_B1/FB_B2/FB_B3 compensates for IR drop, while SYNCCLKIN enables external clock synchronization for EMI reduction and timing coherence across multiple devices.

Key Specifications

Pinout & Package

VQFN-HR (RXV) package, 28-pin, 4.5 mm × 5.0 mm body size, 1.0 mm max height, exposed thermal pad. RoHS-compliant, green (Pb-free, no Sb/Br), MSL Level-2-260°C-1 year.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-rail radar power management applications.

Compared with LP877451A1RXVR, the A3 variant trades RF-performance-optimized switching speed for broader EMI headroom, while the TPS653221AQRVCRQ1 adds automotive safety infrastructure at the cost of radar-specific features like remote sensing and flexible frequency selection.

Availability

LP877451A1RXVR is available at Aetrix Electronics and suitable for factory automation radar modules, industrial transport obstacle detection, and low-ripple radar-based level sensing requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for LP877451A1RXVR 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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management technologies with over 50 years of innovation in industrial and automotive electronics.

The LP8774x family was developed to address the stringent power integrity, sequencing, and thermal demands of TI's IWR millimeter-wave radar sensors-enabling compact, high-performance radar solutions for industrial sensing and automation.

FAQ

What is the maximum output current capability of each buck converter in the LP877451A1RXVR?

Each of the three buck converters in the LP877451A1RXVR delivers up to 3 A continuously. This rating is verified across the full –40°C to +125°C ambient temperature range and supports simultaneous full-load operation when thermally managed per the RXV package layout guidelines in the datasheet. The LP877451A1RXVR maintains regulation within specification under these conditions without derating.

Does the LP877451A1RXVR support external clock synchronization, and how is it implemented?

Yes, the LP877451A1RXVR supports external clock synchronization via the SYNCCLKIN pin (Pin 23). When enabled, this feature locks the internal buck switching clocks to an external reference, eliminating beat frequencies and enabling deterministic EMI behavior across multiple synchronized LP877451A1RXVR devices in multi-sensor radar arrays.

How does the LP877451A1RXVR handle voltage regulation accuracy at the point-of-load?

The LP877451A1RXVR achieves high point-of-load accuracy through dedicated remote sense inputs (FB_B1, FB_B2, FB_B3) for each buck converter. These pins connect directly to the load side of PCB traces, allowing the device to compensate for IR drop up to ~100 mΩ-maintaining ±1% output voltage regulation at the actual load terminal under dynamic current conditions.

Can the LP877451A1RXVR's LDO output be configured for both 1.8 V and 3.3 V, and what controls the selection?

Yes, the integrated LDO in the LP877451A1RXVR is factory-programmed via OTP to output either 1.8 V or 3.3 V. The LP877451A1RXVR variant uses OTP code "A1", which configures the LDO for 1.8 V operation-matching the I/O voltage requirement of IWR6843 and IWR6443 radar sensors. Selection is fixed at manufacture and not runtime-configurable.

What protection features are integrated into the LP877451A1RXVR, and how are faults reported?

The LP877451A1RXVR integrates input overvoltage protection (OVP), undervoltage lockout (UVLO), output short-circuit and overload protection, and overtemperature warning/shutdown. Faults are reported via dedicated open-drain outputs (nINT, nERR/GPO2) and readable status registers accessible through the SPI interface-enabling both hardware interrupt handling and software-based diagnostics in the host processor.