Monolithic Power Systems Inc. MP1925HR-LF-Z

Overview

MP1925HR-LF-Z from Monolithic Power Systems is a high-frequency, half-bridge N-channel MOSFET gate driver with independent high-side and low-side control channels, 100V SW voltage rating, <5ns channel matching, and integrated bootstrap diode. It delivers 4A sink/source capability at 12V VDD and drives 2.2nF loads with 15ns rise/10ns fall times-used in telecom DC/DC converters requiring precise timing and shoot-through prevention.

For engineers reviewing the MP1925HR-LF-Z datasheet, MP1925HR-LF-Z pinout, MP1925HR-LF-Z application, or MP1925HR-LF-Z equivalent, key selection criteria include bootstrap voltage range (115V), UVLO thresholds (6.8V VDD / 6.5V BST-SW), propagation delay (20ns), thermal shutdown (150°C), and QFN-8 package thermal resistance (θJA = 47°C/W).

Technical Context

The MP1925HR-LF-Z implements dual-channel, independently controlled gate drivers with matched propagation delays (<5ns) and separate under-voltage lockout on both VDD and BST-SW rails. Its floating high-side driver uses bootstrap biasing with an on-chip diode, eliminating external diode requirements while supporting up to 115V BST voltage.

It operates across -40°C to +125°C junction temperature, accepts TTL-compatible inputs (INH/INL), and enforces dead-time–sensitive switching via independent input control-critical for half-bridge topologies like two-switch forward and active clamp forward converters where shoot-through must be avoided.

Key Specifications

Pinout & Package

MP1925HR-LF-Z is housed in a thermally enhanced QFN-8 (4mm × 4mm) package with exposed thermal pad (Pin 7, VSS). The package supports ≤2.66W continuous power dissipation at 25°C ambient and requires PCB copper area under the exposed pad for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRS2004STRPBF and LM5109BMAX/NOPB, MP1925HR-LF-Z offers superior timing precision (20ns vs ≥60ns), integrated bootstrap diode (reducing BOM by one part), and robust dual-rail UVLO-making it optimal for compact, high-frequency, high-reliability half-bridge designs where layout area and thermal safety are constrained.

Availability

MP1925HR-LF-Z is available at Aetrix Electronics and suitable for telecom DC/DC converters, avionics power modules, and industrial motor drivers requiring stable component supply, RoHS-compliant packaging, and QFN-8 thermal performance.

Supply support for MP1925HR-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 power management ICs, including DC/DC converters, LED drivers, and gate drivers, with global manufacturing and quality certifications.

The MP1925 belongs to MPS's high-frequency gate driver product line, engineered for efficiency-critical, space-constrained half-bridge power stages in telecom, industrial, and aerospace DC/DC conversion.

FAQ

What is the maximum allowable bootstrap capacitor value for MP1925HR-LF-Z?

The MP1925HR-LF-Z does not specify a maximum bootstrap capacitor value. However, practical design limits arise from charging time: with typical BST quiescent current of 90µA and 115V BST rating, a 100nF capacitor charges fully within ~1ms after startup. Larger values (e.g., 220nF) are used in high-duty-cycle applications to maintain voltage during long ON periods, provided PCB layout minimizes BST–SW loop inductance.

Can MP1925HR-LF-Z drive P-channel high-side MOSFETs?

No. MP1925HR-LF-Z is designed exclusively for N-channel MOSFET half-bridges. Its high-side driver is a floating bootstrap-based source-follower configuration that requires the high-side MOSFET source to connect to SW and its gate to be driven positive relative to SW-only compatible with N-channel devices. Driving P-channel MOSFETs would require inverted logic and different bias architecture.

Is the exposed thermal pad (Pin 7) electrically connected to VSS internally?

Yes. Pin 7 is labeled "VSS, exposed pad" in the datasheet and is internally bonded to the silicon substrate ground. It must be soldered to a PCB copper pour tied directly to the system ground plane to ensure both thermal dissipation (θJC = 7°C/W) and low-impedance return path for high-frequency gate currents.

Does MP1925HR-LF-Z support 3.3V logic inputs?

No. MP1925HR-LF-Z inputs (INH/INL) are TTL-compatible: VIH(min) = 2.0V, VIL(max) = 1.4V. While a 3.3V CMOS signal exceeds VIH, it remains within absolute max rating (VDD + 0.3V = 15.3V). However, the internal 185kΩ pull-down ensures reliable low-state detection only when driven actively-passive 3.3V pull-ups are insufficient for guaranteed logic low.

What happens during simultaneous INH and INL high assertion?

Both DRVH and DRVL go high, causing shoot-through if the external MOSFETs are connected in half-bridge configuration. The device does not include built-in shoot-through protection. Designers must enforce dead time externally-via controller-level delay or RC networks-since the MP1925HR-LF-Z provides only independent, uncoordinated gate drive outputs.

How is thermal performance affected if the exposed pad is not soldered?

Omitting solder connection to the exposed pad increases θJA from 47°C/W to >100°C/W, reducing maximum allowable power dissipation by >50%. At 1W dissipation, junction temperature could exceed 150°C within seconds, triggering thermal shutdown. Full thermal pad soldering is mandatory for rated performance and reliability.

Is there a recommended minimum dead time when using MP1925HR-LF-Z?

The datasheet does not specify a fixed minimum dead time, but recommends ensuring INH and INL transitions are separated by ≥50ns (minimum input pulse width t_PW). Given <5ns channel matching and 20ns propagation delay, a 100ns dead time is typical in practice to accommodate controller jitter and layout skew-verified via oscilloscope measurement of actual SW node transitions.