Monolithic Power Systems Inc. MP9485GN-P

Overview

MP9485GN-P from Monolithic Power Systems is a 100V-input, 500mA synchronous step-down converter with integrated 1.0A high-side MOSFET, hysteretic voltage-mode control, and 170µA quiescent current-designed for automotive power rails, solar energy systems, and high-voltage LED drivers where input transients exceed 60V.

For engineers reviewing the MP9485GN-P datasheet, MP9485GN-P pinout, MP9485GN-P application, or MP9485GN-P equivalent, key selection criteria include its 4.5–100V input range, SOIC-8 EP thermal performance (θJA = 50°C/W), 2MHz switching capability, PWM dimming support, and short-circuit protection with auto-recovery.

Technical Context

The MP9485GN-P employs hysteretic voltage-mode control with adaptive 185mV/215mV FB thresholds to achieve fast transient response without external compensation. Its internal high-side MOSFET features 500mΩ RDS(ON) and integrated current limiting at 0.75A typical.

Thermal shutdown activates at 150°C with 20°C hysteresis, and under-voltage lockout operates with 4.0V rising / 3.6V falling thresholds. The DIM pin supports 0–20kHz PWM dimming with 0.8–1.5V logic thresholds, enabling direct integration into LED driver topologies.

Key Specifications

Pinout & Package

MP9485GN-P is housed in a SOIC-8 package with exposed pad (EP) for enhanced thermal dissipation (θJC = 10°C/W). The exposed pad must be soldered to a dedicated GND plane with ≥6 thermal vias (15mil barrel, 40mil pitch) for reliable operation at full load.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage buck converter applications.

Compared with LM5164QPWPRQ1 and MAX20006AATP+, the MP9485GN-P uniquely combines 100V input tolerance, integrated dimming, and ultra-low IQ in a single SOIC-8 EP package-making it optimal for cost-sensitive, high-transient industrial LED and e-mobility power supplies where compensation simplicity and thermal robustness are prioritized over multi-rail integration.

Availability

MP9485GN-P is available at Aetrix Electronics and suitable for automotive system power, solar energy systems, e-bike control power supplies, and high-power LED drivers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MP9485GN-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, and global manufacturing partnerships.

The MP9485 belongs to MPS's high-voltage DC-DC converter product line, engineered specifically for ruggedized power conversion in automotive, industrial, and renewable energy applications where input voltage transients exceed 60V and reliability under thermal stress is critical.

FAQ

What is the maximum duty cycle limitation of the MP9485GN-P?

The MP9485GN-P does not specify a fixed maximum duty cycle in its datasheet, but practical limitation arises from bootstrap capacitor recharge time. At VOUT/VIN ratios above 65%, an external bootstrap diode (e.g., BAT54) is recommended to maintain gate drive integrity and prevent dropout during high-duty-cycle operation.

Can the MP9485GN-P operate with an input voltage below 4.5V after startup?

No-the 4.5V minimum input is absolute for reliable startup and UVLO release. While the device may sustain regulation down to ~3.6V once running (per UVLO hysteresis), it cannot initiate switching below 4.5V. For sub-4.5V hold-up, pair with a pre-buck stage or supercapacitor buffer.

How is short-circuit protection implemented and what is the recovery behavior?

SCP triggers if FB remains below 185mV for >10µs, forcing immediate high-side switch shutdown. After a fixed 300µs blanking period, the device attempts automatic restart. This cycle repeats until fault clears-no external latch or reset is needed, ensuring autonomous recovery from momentary shorts.

Is the NC pin (Pin 2) safe to connect to ground or leave unconnected?

Pin 2 is internally unconnected and must remain electrically floating-neither grounded nor routed. Connecting it to any net risks parasitic coupling or ESD path disruption. PCB layout must exclude copper pour, traces, or vias within 0.2mm of this pad per MPS layout guidelines.

What is the recommended output capacitor ESR range for stable operation at 5V output?

For VOUT = 5V, MPS specifies an output capacitor ESR range of 100mΩ to 250mΩ when using a 0.1µF forward capacitor. Tantalum or aluminum electrolytic capacitors (e.g., 100µF/10V) paired with a parallel 4.7µF ceramic meet this requirement and suppress ripple effectively.

Does the MP9485GN-P support synchronization to an external clock?

No-the MP9485GN-P uses fixed-frequency hysteretic control and lacks an external sync input. Its switching frequency varies slightly with input/output conditions (typically 1.8–2.2MHz), making it unsuitable for noise-sensitive systems requiring deterministic frequency alignment.

How does the DIM pin function in non-LED applications?

In standard buck configurations, DIM can be tied directly to EN to enable simultaneous on/off control of regulation and dimming logic. This eliminates unused pins and simplifies PCB routing-no pull-up/down resistors are needed since both pins share compatible voltage thresholds.