Monolithic Power Systems Inc. MP18021HQ-A-LF-Z

Overview

MP18021HQ-A-LF-Z from Monolithic Power Systems is a high-frequency, 100V half-bridge N-channel MOSFET gate driver in QFN8 (3×3mm) package, delivering matched 16ns propagation delay and <5ns high-side/low-side timing skew. It integrates a bootstrap diode, supports 9–18V VDD, and drives 1nF loads with 12ns/9ns rise/fall times-used in telecom DC-DC half-bridge power supplies.

For engineers reviewing the MP18021HQ-A-LF-Z datasheet, MP18021HQ-A-LF-Z pinout, MP18021HQ-A-LF-Z application, or MP18021HQ-A-LF-Z equivalent, key selection criteria include bootstrap diode integration, 100V BST voltage range, UVLO on both supplies, SOIC8E/QFN8 dual-package availability, and independent INH/INL control for shoot-through prevention.

Technical Context

The MP18021HQ-A-LF-Z implements a level-shifted floating driver architecture with dedicated high-side and low-side channels, each featuring independent TTL-compatible inputs (INH, INL) and under-voltage lockout (UVLO) thresholds of 7.7–8.5V (VDD) and 6.7–7.5V (VBST–SW). Its internal bootstrap diode eliminates external diode requirement.

Timing precision is achieved via matched propagation delays (16ns typ. for both DRVH and DRVL), <5ns inter-channel skew, and 50ns minimum input pulse width. The device operates across –40°C to +125°C junction temperature with thermal shutdown at 160°C and 20°C hysteresis.

Key Specifications

Pinout & Package

MP18021HQ-A-LF-Z uses a thermally enhanced QFN8 (3×3mm) package with exposed pad (Pin 7 = VSS), optimized for high-power density layouts and efficient heat dissipation in compact DC-DC converters.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRS21844SPbF and LM5109BMAX/NOPB, MP18021HQ-A-LF-Z uniquely combines integrated bootstrap diode, matched 16ns timing, dual-domain UVLO, and QFN8 thermal performance-making it optimal for compact, high-frequency, 100V half-bridge designs requiring minimal external components and robust fault protection.

Availability

MP18021HQ-A-LF-Z is available at Aetrix Electronics and suitable for telecom power supplies, avionics DC-DC converters, and two-switch forward converters requiring stable component supply, RoHS-compliant packaging, and QFN8 thermal performance.

Supply support for MP18021HQ-A-LF-Z 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, headquartered in Kirkland, WA, with global design and support operations.

The MP18021 product line delivers high-frequency, high-voltage gate drivers for isolated and non-isolated DC-DC topologies-designed specifically for telecom, aerospace, and industrial power conversion where timing precision, integration, and reliability are critical.

FAQ

What is the maximum allowable SW node voltage swing for MP18021HQ-A-LF-Z?

The absolute maximum SW voltage is –5.0V to +105V, with recommended operating range of –1.0V to +100V. This 100V rating enables use in 48V and 54V telecom systems with sufficient safety margin for transients and ringing.

Does MP18021HQ-A-LF-Z require an external bootstrap diode?

No. The device integrates a bootstrap diode with VF = 0.5V at 100µA and 0.9V at 100mA. This eliminates the need for an external diode, reducing board area and component count while maintaining reliable high-side bias generation.

How does the UVLO function protect the MP18021HQ-A-LF-Z during startup?

UVLO monitors both VDD (7.7–8.5V threshold) and BST–SW (6.7–7.5V threshold). If either supply falls below its threshold, the corresponding driver output (DRVH or DRVL) is forced low, preventing partial MOSFET turn-on and potential shoot-through or thermal runaway.

Can INH and INL be driven by the same PWM signal?

Yes, but only in topologies like two-switch forward where both MOSFETs switch simultaneously. For half-bridge or active-clamp forward, independent INH/INL control is required to insert dead time and prevent shoot-through-timing must be managed externally by the controller.

What is the thermal resistance (θJA) of the QFN8 package?

The QFN8 (3×3mm) package has θJA = 50°C/W and θJC = 12°C/W when mounted on a 4-layer JEDEC-standard PCB. The exposed pad (Pin 7/VSS) must be soldered to a thermal pad connected to internal ground planes for optimal heat transfer.

Is MP18021HQ-A-LF-Z pin-compatible with MP18021HN-A-LF-Z?

No. MP18021HQ-A-LF-Z uses QFN8 (3×3mm) with exposed pad; MP18021HN-A-LF-Z uses SOIC8E. Pin functions match (VDD, BST, DRVH, SW, INH, INL, VSS, DRVL), but physical layout, thermal path, and land pattern differ significantly-requiring separate PCB designs.

What is the minimum input pulse width supported by MP18021HQ-A-LF-Z?

The minimum input pulse width that reliably changes the output is 50ns, verified through bench characterization. This enables operation at switching frequencies up to ~10MHz in edge-triggered configurations, though practical limits are set by gate charge and layout parasitics.