Texas Instruments LP875650RNFTQ1

Overview

LP875650RNFTQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive buck converter IC with two independent 2-phase DC/DC outputs, delivering up to 8 A per output (16 A total), 0.6 V–3.36 V programmable output voltage, 2 MHz switching frequency, and I²C interface supporting up to 3.4 MHz. It serves as a multi-rail power management solution for radar and camera domain controllers requiring precise slew-rate control and phase interleaving.

For engineers reviewing the LP875650RNFTQ1 datasheet, LP875650RNFTQ1 pinout, LP875650RNFTQ1 application, or LP875650RNFTQ1 equivalent, key selection criteria include its dual 2-phase configuration, remote differential sensing capability, programmable current limits (1.5–5 A/phase), thermal warning/shutdown thresholds, and support for spread-spectrum and external clock synchronization in safety-critical automotive systems.

Technical Context

The LP875650RNFTQ1 implements four synchronous buck converter cores configured exclusively as two independent 2-phase outputs - distinct from LP87561-Q1 (4-phase), LP87562-Q1 (3+1), LP87563-Q1 (2+1+1), and LP87564-Q1 (four 1-phase). Each 2-phase rail supports automatic phase shedding (down to 1-phase) at ≤0.7 A and phase adding at ≥1 A, with current mismatch <10% between phases under load.

Its digital control loop uses an internal RC oscillator or external CLKIN (1–24 MHz) with PLL-based clock generation, enabling synchronized PWM operation across both rails. The device supports PFM-to-PWM transition at 200 mA and PWM-to-PFM at 600 mA per rail, with programmable slew rates (0.47–10 mV/µs) tied to total output capacitance constraints per configuration.

Key Specifications

Pinout & Package

VQFN-HR (RNF) 26-pin package, 4.50 mm × 4.00 mm body size, with exposed thermal pad. Pin functions validated per TI SNVSB22 datasheet Rev. March 2018.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LP875620RNFTQ1 and TPS6594131RGERQ1, the LP875650RNFTQ1 uniquely provides matched dual 2-phase regulation with remote sensing, programmable slew control, and integrated current monitoring - making it the only option qualified for simultaneous high-current, low-noise, and thermally adaptive radar + camera power delivery in ASIL-B systems.

Availability

LP875650RNFTQ1 is available at Aetrix Electronics and suitable for automotive radar, camera, domain controller, and instrument cluster applications requiring stable component supply, AEC-Q100 Grade 1 qualification, and long-term production continuity.

Supply support for LP875650RNFTQ1 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 and embedded processing technologies, with deep expertise in automotive power management and functional safety design.

The LP8756x-Q1 product line was developed specifically for automotive ADAS and infotainment systems, delivering high-efficiency, multi-phase DC/DC conversion with integrated diagnostics, thermal management, and ASIL-ready features.

FAQ

What is the exact output configuration of the LP875650RNFTQ1?

The LP875650RNFTQ1 is factory-configured as two independent 2-phase buck converters - not a 4-phase, 3+1, or 2+1+1 arrangement. This means SW_B0/SW_B1 and FB_B0/FB_B1 form the first 2-phase rail, while SW_B2/SW_B3 and FB_B2/FB_B3 form the second. Each rail delivers up to 8 A with interleaved switching to reduce input/output ripple. This configuration is fixed and cannot be reprogrammed to other topologies.

Does the LP875650RNFTQ1 support remote differential voltage sensing?

Yes, the LP875650RNFTQ1 supports true remote differential sensing on both rails: FB_B0/FB_B1 for rail 1 and FB_B2/FB_B3 for rail 2. Each pair measures voltage directly at the load point, compensating for PCB trace resistance and ensuring ±2% output accuracy at the SoC or sensor die. This eliminates the need for Kelvin routing and maintains regulation stability under dynamic load conditions.

What are the programmable output voltage and slew-rate ranges for the LP875650RNFTQ1?

The LP875650RNFTQ1 supports programmable output voltage from 0.6 V to 3.36 V in 5–20 mV steps depending on range, and slew rate from 0.47 mV/µs to 10 mV/µs. Slew-rate selection is linked to total output capacitance: e.g., 10 mV/µs requires ≤80 µF/phase, while 0.47 mV/µs supports up to 500 µF/phase. These settings are configured via I²C registers and directly impact in-rush current and overshoot during startup.

How does the LP875650RNFTQ1 handle thermal protection and current limiting?

The LP875650RNFTQ1 includes configurable thermal warning (115–147°C) and hard shutdown (140–160°C) with 20°C hysteresis, plus per-phase forward current limits (1.5–5 A, ±5–20% accuracy) and negative current limits (1.6–2.4 A). These protections are hardware-enforced and operate independently per rail, enabling safe operation in sealed radar enclosures where ambient temperatures exceed 105°C.

Can the LP875650RNFTQ1 be synchronized to an external clock source?

Yes, the LP875650RNFTQ1 accepts an external clock on the CLKIN pin (1–24 MHz nominal) and uses an internal PLL to synchronize switching across both 2-phase rails. This minimizes beat frequencies and EMI peaks in multi-IC systems. Clock loss detection occurs within 1.8 µs, and the device automatically reverts to its internal RC oscillator - ensuring uninterrupted regulation during clock glitches.