Monolithic Power Systems Inc. MP1921HR-A-LF-P

Overview

MP1921HR-A-LF-P from Monolithic Power Systems is a high-frequency, 100V half-bridge gate driver IC for N-channel MOSFETs, featuring independently controlled high-side and low-side outputs with <5ns propagation matching, integrated bootstrap diode, and dual UVLO protection on VDD and BST-SW rails. It delivers 2.5A peak sink/source current and drives 1nF loads with 12ns/9ns rise/fall times at 12V VDD in telecom power supplies.

For engineers reviewing the MP1921HR-A-LF-P datasheet, MP1921HR-A-LF-P pinout, MP1921HR-A-LF-P application, or MP1921HR-A-LF-P equivalent, key selection criteria include bootstrap voltage range (120V), propagation delay (16ns typ), gate drive matching (<5ns), thermal resistance (θJA = 47°C/W), and QFN10 (4×4mm) package compatibility with high-density DC-DC converter layouts.

Technical Context

The MP1921HR-A-LF-P implements a level-shifted floating driver architecture to enable high-side operation up to 100V SW node voltage, with independent TTL-compatible INH/INL inputs controlling DRVH and DRVL outputs. Its internal bootstrap diode eliminates external diode requirement while supporting 120V BST voltage range.

UVLO thresholds are set at 8.1V (VDD) and 7.1V (BST–SW) with 0.5V/0.55V hysteresis, forcing both outputs low during undervoltage conditions. Propagation delays (TDLRR/TDHRR = 16ns typ) and matching (TMON/TMOFF ≤5ns) are guaranteed across temperature for precise dead-time control in hard-switched topologies.

Key Specifications

Pinout & Package

MP1921HR-A-LF-P is housed in a thermally enhanced QFN10 (4×4mm, 0.75mm height) package with exposed thermal pad on underside. Pin 1 is marked by index area; pins 5 and 9 are NC (no connection). The exposed pad must be soldered to PCB ground plane for optimal thermal dissipation and EMI suppression.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-frequency half-bridge gate driver applications.

Compared with MP1921HQ-A and MP1921HS-A, MP1921HR-A-LF-P offers the lowest thermal resistance (47°C/W) and largest footprint (QFN10), making it optimal for production-grade telecom and avionics converters where power density and reliability outweigh package size constraints.

Availability

MP1921HR-A-LF-P is available at Aetrix Electronics and suitable for telecom half-bridge power supplies, avionics DC-DC converters, and two-switch forward converters requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle assurance.

Supply support for MP1921HR-A-LF-P 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers in the US, China, and Taiwan.

The MP1921 series targets high-frequency, high-voltage gate driving in isolated DC-DC conversion, emphasizing precision timing, integrated bootstrap functionality, and robust UVLO for mission-critical power systems.

FAQ

What is the maximum allowable SW node voltage for MP1921HR-A-LF-P?

The absolute maximum SW voltage is +105V for transient events <100ns, with recommended continuous operation up to +100V. This rating enables direct use in 48V and 54V telecom rectifier primaries and 100V industrial bus interfaces without external level-shifting circuitry.

Does MP1921HR-A-LF-P require an external bootstrap diode?

No. The device integrates a low-forward-voltage bootstrap diode (VF = 0.5V @ 100µA, 0.9V @ 100mA) with dynamic resistance of 2.5Ω, eliminating the need for an external diode and reducing PCB area and component count in half-bridge designs.

How is shoot-through prevented in MP1921HR-A-LF-P designs?

Shoot-through is avoided by enforcing minimum dead time (>50ns) between INH and INL transitions, leveraging the device's <5ns propagation matching. The internal UVLO also forces both outputs low during supply faults, adding hardware-level protection beyond PWM controller dead-time settings.

What is the purpose of the NC pins (5 and 9) in the QFN10 package?

Pins 5 and 9 are internally unconnected and serve no electrical function. They may be left floating or tied to VSS for mechanical stability and improved thermal conduction-MPS recommends grounding them to the exposed pad via short traces to enhance heat transfer and reduce EMI susceptibility.

Can MP1921HR-A-LF-P drive GaN FETs?

Yes, its 16ns propagation delay, 12ns/9ns rise/fall times, and 2.5A peak current support fast-switching GaN HEMTs with gate charges ≤20nC. However, layout must minimize parasitic inductance on DRVH/DRVL paths, and BST capacitor selection must account for GaN's higher dV/dt-induced bootstrap discharge.

What is the recommended BST capacitor value for 500kHz operation?

A 100nF X7R ceramic capacitor rated ≥25V is recommended between BST and SW pins. At 500kHz with 50% duty cycle, this provides sufficient charge hold-off to maintain >7.1V BST–SW during high-side conduction, verified by MPS reference design testing and bootstrap diode leakage (≤1µA).

Is MP1921HR-A-LF-P pin-compatible with other MP1921 variants?

No. MP1921HR-A-LF-P (QFN10) has distinct pinout versus MP1921HQ-A (QFN8) and MP1921HS-A (SOIC-8); pin counts and terminal assignments differ. Layouts must be redesigned per package-refer to MPS Package Reference diagrams for exact mapping of VDD, BST, DRVH, SW, INH, INL, VSS, and DRVL positions.