Texas Instruments LP87521ERNFRQ1

Overview

LP87521ERNFRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive buck converter IC with four integrated high-efficiency DC/DC cores configured as a single 4-phase output delivering up to 10 A at 0.6–3.36 V, operating from 2.8–5.5 V input, and switching at 2 MHz for infotainment and ADAS power rails.

For engineers reviewing the LP87521ERNFRQ1 datasheet, LP87521ERNFRQ1 pinout, LP87521ERNFRQ1 application, or LP87521ERNFRQ1 equivalent, key selection criteria include its 4-phase fixed topology, I²C programmability (up to 3.4 MHz), spread-spectrum and phase-interleaving for EMI reduction, remote differential sensing, and integrated current measurement without external sense resistors.

Technical Context

The LP87521ERNFRQ1 implements a fixed 4-phase synchronous buck architecture with automatic PWM-to-PFM mode transition, phase shedding (down to 1-phase) at ≤2.4 A load, and phase adding at ≥3 A. It uses internal high-side (29–65 mΩ) and low-side (17–35 mΩ) FETs per phase, supports external clock synchronization (1–24 MHz), and delivers <±2% DC output accuracy across –40°C to +125°C ambient.

Its digital control loop enables programmable soft-start slew rates (0.47–10 mV/µs), configurable PGOOD thresholds (±8–20 mV), and real-time load-current monitoring (20 mA LSB, <10% error above 1 A). Protection includes overtemperature warning (115–135°C), shutdown (140–160°C), OVP/UVLO on VANA, and per-phase forward/negative current limiting.

Key Specifications

Pinout & Package

VQFN-HR (26-pin) package, 4.50 mm × 4.00 mm body size with thermal pad; RoHS-compliant, automotive-grade molding compound.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multi-phase buck converter applications.

Compared with LP87522ERNFRQ1 and LP87525ERNFRQ1, the LP87521ERNFRQ1 uniquely provides a single 4-phase output capable of 10 A continuous current - making it the only option among the LP8752x-Q1 family for high-current, low-ripple core supplies where rail consolidation simplifies layout and reduces component count.

Availability

LP87521ERNFRQ1 is available at Aetrix Electronics and suitable for automotive infotainment, digital cluster, and radar power applications requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for LP87521ERNFRQ1 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 specializing in analog, embedded processing, and automotive ICs, with decades of leadership in power management innovation.

The LP8752x-Q1 product line was designed specifically for automotive ADAS and infotainment platforms, integrating multi-phase buck conversion, advanced sequencing, and diagnostic telemetry into a single AEC-Q100-qualified package.

FAQ

What is the maximum output current capability of the LP87521ERNFRQ1?

The LP87521ERNFRQ1 delivers up to 10 A total output current as a single 4-phase rail. This rating holds for VIN ≥3 V; at 2.8 V ≤VIN < 3 V, max output is 7.2 A. The device enforces per-phase current limits (programmable 1.5–5 A forward, 1.6–2.4 A reverse) and thermal protection to sustain this output safely across –40°C to +125°C ambient.

Does the LP87521ERNFRQ1 support external clock synchronization?

Yes, the LP87521ERNFRQ1 accepts an external clock input on the CLKIN pin (Pin 3), supporting frequencies from 1 MHz to 24 MHz with ±30% tolerance. When enabled, the internal PLL locks to the external reference, allowing precise switching frequency alignment to reduce beat frequencies in multi-regulator systems - critical for radar and camera EMI compliance.

How does the LP87521ERNFRQ1 handle load transients?

The LP87521ERNFRQ1 achieves ±40 mV load-step response for 0.1–2 A steps with 1 µs edge rate in 1-phase mode, tightening to ±3% (±30 mV at 1 V) in 4-phase mode. Its adaptive phase shedding (down to 1-phase at 0.7 A) and fast PWM control loop ensure stable regulation during rapid processor DVFS events without external compensation.

Can the LP87521ERNFRQ1 measure output current without external sense resistors?

Yes, the LP87521ERNFRQ1 integrates per-phase current sensing with 20 mA LSB resolution and <10% accuracy above 1 A. Current data is accessible via I²C register reads, enabling real-time power monitoring, thermal derating, and fault logging - eliminating the need for external sense resistors and associated PCB area and power loss.

What protection features are built into the LP87521ERNFRQ1?

The LP87521ERNFRQ1 includes overvoltage (OVP) and undervoltage lockout (UVLO) on VANA, per-phase short-circuit and overload protection, thermal warning (115–135°C) and shutdown (140–160°C), and programmable PGOOD monitoring with ±8–20 mV thresholds. All protections trigger interrupt reporting via nINT and status registers for system-level fault handling.