Texas Instruments LP87561IRNFRQ1

Overview

LP87561IRNFRQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive buck converter IC with four integrated high-side/low-side FETs, configured exclusively as a single 4-phase 16-A output (4 A per phase), supporting 0.6 V to 3.36 V programmable output voltage, 2 MHz fixed switching frequency, and I²C-controlled slew-rate (0.5–10 mV/µs). It delivers power to high-current processor cores in automotive infotainment and ADAS domain controllers.

For engineers reviewing the LP87561IRNFRQ1 datasheet, LP87561IRNFRQ1 pinout, LP87561IRNFRQ1 application, or LP87561IRNFRQ1 equivalent, key selection criteria include its 4-phase-only topology, remote differential sensing capability, automotive-grade thermal warning/shutdown thresholds (125 °C warn / 150 °C shutdown), and support for spread-spectrum and external clock synchronization to meet EMI requirements in safety-critical vehicle systems.

Technical Context

The LP87561IRNFRQ1 implements a fully integrated 4-phase synchronous buck architecture with automatic phase shedding (down to 1-phase) and PWM-to-PFM mode transition at ≤200 mA load, optimizing efficiency across 1 mA to 16 A output current range. Its dual-loop control supports remote differential voltage sensing via dedicated FB_Bx pins to compensate IR drop between regulator and point-of-load.

Configuration and monitoring are handled via a 3.4 MHz I²C interface with hardware interrupt (nINT), programmable PGOOD timing, and three configurable GPIOs (EN1/EN2/EN3) usable for sequencing external regulators or processor reset. Internal protection includes overtemperature warning (125 °C), thermal shutdown (150 °C), OVP/UVOV on VANA, and per-phase forward/negative current limiting (1.5–5 A / 1.6–2.4 A).

Key Specifications

Pinout & Package

VQFN-HR (RNF) package, 26-pin, 4.50 mm × 4.00 mm body size with exposed thermal pad. Pin count and layout optimized for 4-phase multiphase routing and thermal dissipation in automotive PCB stacks.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP87562IRNFRQ1 and TPS65917B1ZWSR, the LP87561IRNFRQ1 uniquely delivers 16-A single-rail output with phase-interleaved ripple cancellation and automotive-grade thermal management - making it irreplaceable for high-performance ADAS and infotainment SoC core supplies where current density and transient response are critical.

Availability

LP87561IRNFRQ1 is available at Aetrix Electronics and suitable for automotive infotainment, ADAS radar, and digital instrument cluster applications requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for LP87561IRNFRQ1 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 deep expertise in automotive power management and functional safety design.

The LP8756x-Q1 product line was developed specifically for next-generation automotive processors, emphasizing high-current density, EMI robustness, and ASIL-B ready diagnostics - targeting infotainment, cluster, radar, and camera power subsystems.

FAQ

What is the maximum output current capability of the LP87561IRNFRQ1?

The LP87561IRNFRQ1 delivers up to 16 A total output current in its fixed 4-phase configuration, with 4 A per phase. This rating assumes input voltage ≥3 V and proper thermal management - at 2.8 V–3 V input, max output drops to 12 A. The device uses per-phase current limiting (1.5–5 A forward, 1.6–2.4 A negative) and thermal shutdown (150 °C) to protect against overload conditions. LP87561IRNFRQ1 maintains this rating across –40 °C to +125 °C ambient temperature per AEC-Q100 Grade 1.

Does the LP87561IRNFRQ1 support multiphase reconfiguration like other LP8756x-Q1 variants?

No, the LP87561IRNFRQ1 is factory-configured exclusively for a single 4-phase output and cannot be reprogrammed to operate as 3+1, 2+2, or four independent 1-phase rails. This fixed topology differs from LP87562IRNFRQ1 (3+1), LP87563IRNFRQ1 (2+2), and others in the family. The LP87561IRNFRQ1 achieves optimal current sharing and ripple cancellation only in 4-phase mode, with phase-add/shed thresholds set at 1 A, 2 A, and 3 A for seamless light-load efficiency.

How does the LP87561IRNFRQ1 handle voltage transient response during load steps?

The LP87561IRNFRQ1 achieves ±3% output deviation for 0–8 A load steps (10 µs edge) and ±40 mV for 0.1–8 A steps (1 µs edge) in 4-phase PWM mode with 22 µF/phase output capacitance. This performance relies on adaptive phase shedding, fast current-mode control, and programmable slew-rate limiting to suppress overshoot. LP87561IRNFRQ1 also supports remote differential sensing via FB_Bx pins to maintain accuracy at the point-of-load despite PCB IR drop - critical for SoC core regulation.

What I²C speeds and timing modes does the LP87561IRNFRQ1 support?

The LP87561IRNFRQ1 supports Standard (100 kHz), Fast (400 kHz), Fast+ (1 MHz), and High-Speed (3.4 MHz) I²C modes with full timing compliance per JEDEC standards. Its SDA/SCL pins tolerate 1.65–1.95 V or 3.1–3.6 V logic levels depending on mode, and internal pull-downs ensure robust bus recovery. The LP87561IRNFRQ1 uses these speeds for real-time DVFS updates, fault logging, and dynamic PGOOD threshold adjustment - all without CPU intervention via interrupt-driven nINT signaling.

Can the LP87561IRNFRQ1 synchronize its switching frequency to an external clock source?

Yes, the LP87561IRNFRQ1 accepts an external clock signal on the CLKIN pin (1–24 MHz nominal) to synchronize its 2 MHz internal oscillator, reducing beat frequencies and EMI peaks in sensitive RF domains like radar and camera modules. Clock detection includes 1.8 µs missing-clock timeout and 20 µs debounce, with 600 µs delay before switching to external reference. This feature is essential for CISPR-25 Class 5 compliance in automotive EMC testing - and LP87561IRNFRQ1 retains full regulation during clock loss via seamless fallback to internal RC oscillator.