Monolithic Power Systems Inc. MP62181DH-LF-Z

Overview

MP62181DH-LF-Z from Monolithic Power Systems is a single-channel, active-high enable, current-limited power distribution switch with 2A continuous load capability, 2.8A typical current limit, and integrated thermal shutdown and under-voltage lockout. It uses an internal 75mΩ MOSFET and operates across 2.7V–5.5V input, serving as a protected USB VBUS or peripheral power rail switch in portable electronics.

For engineers reviewing the MP62181DH-LF-Z datasheet, MP62181DH-LF-Z pinout, MP62181DH-LF-Z application, or MP62181DH-LF-Z equivalent, key selection criteria include its active-high EN logic, 8ms FLAG deglitch time, reverse current blocking, and MSOP8E package thermal performance (θJA = 55°C/W) for compact hot-swap designs.

Technical Context

The MP62181DH-LF-Z implements a precision current-limit architecture that enters constant-current mode at ~2.8A (typical), with trip current rising to 4A under fast-ramp short-circuit conditions. Its internal charge pump ensures stable gate drive across the full 2.7V–5.5V VIN range.

Thermal protection activates at 140°C junction temperature with 20°C hysteresis, enabling automatic recovery at ~120°C. The open-drain FLAG pin reports over-current only after 8ms deglitching-eliminating false triggers during startup or transient overload-while remaining un-deglitched during UVLO or thermal shutdown events.

Key Specifications

Pinout & Package

MP62181DH-LF-Z is housed in an MSOP8E (3mm × 3mm) package with exposed thermal pad soldered to PCB ground plane for enhanced thermal dissipation (θJC = 12°C/W). Pin 1 is marked with a half-circle indicator.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar current-limited power distribution switch applications.

Compared with TPS22965DSGR and NCP45561MUTBG, MP62181DH-LF-Z uniquely combines active-high EN, reverse current blocking, 8ms deglitched FLAG, and auto-recovering thermal shutdown-making it optimal for USB-compliant, battery-powered hot-swap systems requiring high fault fidelity.

Availability

MP62181DH-LF-Z is available at Aetrix Electronics and suitable for USB power distribution, smartphone peripheral rail management, notebook PC card slot control, and portable GPS power sequencing requiring stable component supply and RoHS-compliant packaging.

Supply support for MP62181DH-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP6218x series belongs to MPS's protected power distribution switch product line, engineered specifically for space-constrained, high-reliability portable electronics requiring integrated current limiting, thermal safety, and hot-swap readiness.

FAQ

What is the logic polarity of the EN pin on MP62181DH-LF-Z?

The EN pin on MP62181DH-LF-Z is active-high: the device enables when EN voltage exceeds 2V (min), and disables when EN falls below 0.8V (max). This distinguishes it from the MP62180 variant, which uses active-low EN logic.

Does MP62181DH-LF-Z block reverse current flow from OUT to IN?

Yes-MP62181DH-LF-Z provides reverse current blocking with only 0.2μA leakage when OUT is biased to 5.5V and IN is grounded. This prevents backfeed into upstream supplies during fault or standby conditions.

How does the FLAG pin behave during thermal shutdown?

During thermal shutdown, the FLAG pin asserts low immediately-without deglitching-providing real-time over-temperature indication. Unlike over-current events, thermal faults bypass the 8ms deglitch circuit to ensure fastest possible system response.

What is the recommended input capacitance for MP62181DH-LF-Z?

A minimum 10μF ceramic or tantalum capacitor between IN and GND is recommended to suppress input transients and improve immunity to short-circuit-induced ringing. Larger values (e.g., 22μF) further enhance stability under dynamic load steps.

Can multiple MP62181DH-LF-Z devices be paralleled for higher current?

No-MP62181DH-LF-Z is not designed for current sharing. Its internal current-limit circuitry is calibrated per unit, and paralleling would cause uneven load distribution and potential thermal runaway due to R_DS(on) mismatch.

Is the exposed thermal pad on the MSOP8E package required to be connected to GND?

Yes-the exposed pad must be soldered to a PCB copper pour tied to GND. It serves as both thermal conduction path (reducing θJA from 90°C/W to 55°C/W) and electrical ground reference for internal circuitry; floating the pad violates absolute maximum ratings.

What happens if the input voltage drops below UVLO threshold during operation?

If VIN falls below 1.95V (UVLO falling threshold), MP62181DH-LF-Z disables the output and holds FLAG high. Output re-enables only after VIN rises above 2.65V (rising threshold) and EN remains asserted-preventing oscillation near dropout.