Monolithic Power Systems Inc. MP18021HN-LF-Z

Overview

MP18021HN-LF-Z from Monolithic Power Systems is a 100V high-frequency half-bridge N-channel MOSFET gate driver in SOIC8 EPAD package, featuring independently controlled high-side and low-side channels with ≤5ns propagation delay matching, 16ns typical propagation delay, integrated bootstrap diode, and dual UVLO protection on VDD and BST-SW rails. It drives 1nF loads with 12ns/9ns rise/fall times at 12V VDD and supports telecom half-bridge power supplies.

For engineers reviewing the MP18021HN-LF-Z datasheet, MP18021HN-LF-Z pinout, MP18021HN-LF-Z application, or MP18021HN-LF-Z equivalent, key selection criteria include 100V BST voltage range, TTL-compatible inputs, <150µA quiescent current, SOIC8 EPAD thermal performance (θJA = 48°C/W), and bootstrap diode integration reducing external component count.

Technical Context

The MP18021 employs independent level-shifted drivers for high-side and low-side N-MOSFET control, with matched propagation delays (≤5ns skew) enabling precise timing in high-frequency switching topologies. Its internal bootstrap diode eliminates need for external discrete diode, simplifying layout and improving reliability in isolated half-bridge configurations.

UVLO thresholds are set at 7.7–8.5V for VDD and 6.7–7.5V for BST-SW, each with 0.5V/0.55V hysteresis to prevent erratic operation during supply ramp-up or brownout. The device operates across –40°C to +125°C junction temperature with thermal shutdown at 160°C and recovery at 140°C.

Key Specifications

Pinout & Package

MP18021HN-LF-Z uses SOIC8 with exposed thermal pad (JEDEC MS-012 BA). The exposed pad must be soldered to PCB ground plane for optimal thermal performance and EMI suppression.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IRS21844SPbF and LM5109BMM/NOPB, MP18021HN-LF-Z uniquely combines 100V BST rating, ≤5ns channel matching, integrated bootstrap diode, and independent TTL inputs in thermally enhanced SOIC8 EPAD - making it optimal for compact, high-frequency telecom and avionics half-bridge designs requiring precise timing and low BOM count.

Availability

MP18021HN-LF-Z 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 extended temperature support (–40°C to +125°C).

Supply support for MP18021HN-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, with focus on DC-DC conversion, LED drivers, and motor control solutions.

The MP18021 belongs to MPS's high-voltage gate driver product line, engineered specifically for high-frequency, high-reliability half-bridge topologies in telecom infrastructure and aerospace power systems.

FAQ

What is the maximum allowable V_SW voltage for MP18021HN-LF-Z?

The absolute maximum V_SW rating is –5.0V to +100V relative to VSS. This allows safe operation in 48V telecom and 28V avionics systems with transient margins up to 100V, provided V_DD and V_BST remain within their respective limits (–0.3V to +18V and –0.3V to +100V).

Does MP18021HN-LF-Z require an external bootstrap diode?

No. MP18021HN-LF-Z integrates a bootstrap diode with forward voltage of 0.9V at 100mA and dynamic resistance of 2.5Ω. This eliminates the need for an external Schottky diode, reducing PCB area and component count while maintaining efficient bootstrapping up to 500kHz.

How does the dual UVLO function protect the system?

MP18021HN-LF-Z implements separate UVLO circuits on VDD (7.7–8.5V threshold) and BST–SW (6.7–7.5V threshold), each with hysteresis. If either supply drops below its threshold, the corresponding driver output is forced low - preventing partial turn-on of MOSFETs and eliminating shoot-through risk during startup or fault conditions.

Can MP18021HN-LF-Z drive 1nF gate capacitance at 500kHz?

Yes. At 12V VDD, MP18021HN-LF-Z delivers 12ns rise and 9ns fall times into a 1nF load, supporting >500kHz PWM operation. Its 2.5A peak source/sink capability ensures adequate gate charge delivery, and measured IBSTO is 2.1–3mA at 500kHz, confirming stable high-frequency performance.

What is the role of the exposed thermal pad in SOIC8 EPAD package?

The exposed pad on MP18021HN-LF-Z serves as both thermal conduction path and electrical ground connection. When soldered to a PCB copper pour tied to VSS, it reduces θ_JA to 48°C/W - lowering junction temperature by ~15°C versus standard SOIC8 - and improves EMI immunity by providing low-inductance ground return.

Is MP18021HN-LF-Z compatible with 3.3V logic controllers?

Yes. Its INH and INL inputs are TTL-compatible with guaranteed recognition of logic high at ≥2.0V and logic low at ≤1.4V. A 3.3V microcontroller GPIO can directly drive these inputs without level shifting, as the internal 185kΩ pull-down ensures defined state during reset or high-impedance output.

What is the minimum input pulse width supported by MP18021HN-LF-Z?

The minimum input pulse width that reliably changes the output is 50ns, as characterized in bench testing. This enables use in high-duty-cycle, high-frequency applications such as active clamp forward converters operating above 300kHz with narrow dead-time requirements.