Monolithic Power Systems Inc. MP9486AGN-Z

Overview

MP9486AGN-Z from Monolithic Power Systems is a high-voltage, hysteretic-mode step-down DC/DC converter integrating a 100V-rated high-side MOSFET with 3.5A typical peak current limit, delivering up to 1A continuous output current at up to 1MHz switching frequency. It features 170µA quiescent current, PWM dimming input (DIM), and built-in short-circuit and thermal shutdown protection. It is used in automotive system power rails and high-power LED drivers requiring wide-input operation.

For engineers reviewing the MP9486AGN-Z datasheet, MP9486AGN-Z pinout, MP9486AGN-Z application, or MP9486AGN-Z equivalent, this page delivers verified technical context, SOIC-8 EP package mapping, functional pin definitions, real-world application constraints, and validated alternative options for 4.5–95V input buck conversion with integrated high-side switch.

Technical Context

The MP9486AGN-Z employs hysteretic voltage-mode control with adaptive 185mV/215mV FB thresholds-no external compensation required. Its internal high-side MOSFET has 500mΩ typical R_DS(ON) and operates across 4.5V–95V input range, enabling direct connection to unregulated battery or bus rails.

It integrates dedicated bootstrap regulation (BST node), EN enable logic with 1.55V rising threshold and 320mV hysteresis, and DIM input supporting up to 20kHz PWM dimming. Short-circuit protection triggers within 10µs and recovers after ~300µs, while thermal shutdown activates at 150°C with 20°C hysteresis.

Key Specifications

Pinout & Package

MP9486AGN-Z is housed in an SOIC-8 package with exposed pad (EP) for enhanced thermal dissipation. The exposed pad must be soldered to a GND plane using ≥9 thermal vias (15mil barrel, 40mil pitch) per MPS layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP9486AGN-Z, MPQ4420AGL-A-Z trades input voltage range for higher output current and tighter regulation, while LM5164QPWPRQ1 offers automotive qualification and EMI features at the cost of added external components and reduced integration.

Availability

MP9486AGN-Z is available at Aetrix Electronics and suitable for automotive system power, solar energy systems, high-power LED drivers, and industrial power supplies requiring stable component supply across extended temperature and voltage ranges.

Supply support for MP9486AGN-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 core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MP9486A belongs to MPS's high-voltage buck converter product line, designed specifically for rugged, wide-input applications in automotive, industrial, and renewable energy systems where simplicity, reliability, and thermal efficiency are critical.

FAQ

What is the maximum recommended input voltage for continuous operation?

The MP9486AGN-Z is rated for continuous operation up to 95V input, as specified in Recommended Operating Conditions. Absolute maximum VIN is +100V, but sustained operation above 95V risks exceeding junction temperature limits under load and is not guaranteed for reliability or lifetime.

Can the DIM pin be left unconnected in non-LED applications?

No - the DIM pin must not be left floating. If PWM dimming is unused, MPS recommends connecting DIM directly to EN to ensure predictable enable behavior and avoid noise-induced switching instability. Pulling DIM to GND or VIN is not advised due to undefined threshold margins.

How does the hysteretic control affect output voltage accuracy?

Output voltage accuracy depends on FB resistor divider tolerance and the 185mV/215mV hysteretic band. With 1% resistors, typical output error is ±1.5% over line/load/temperature. The 200mV nominal FB voltage minimizes divider current and improves light-load regulation versus higher-reference alternatives.

Is an external bootstrap diode required for reliable operation?

An external bootstrap diode (e.g., BAT54) is optional but recommended when VIN ≤ 5V, VOUT/VIN > 65%, or switching near 1MHz. It improves BST capacitor charging efficiency and prevents UVLO on the floating driver, especially in high-duty-cycle LED boost-buck configurations.

What thermal vias configuration meets MPS's SOIC-8 EP requirements?

MPS specifies ≥9 thermal vias under the exposed pad, each with 15mil drill diameter and 40mil center-to-center pitch, connecting the pad directly to an internal or bottom-layer solid GND plane. This achieves θ_JA = 34°C/W on a 2-layer 63mm×63mm board per EV9486-N-00A reference design.

Does the MP9486AGN-Z support synchronous rectification?

No - the MP9486AGN-Z uses an external Schottky diode for output rectification. It does not integrate a synchronous MOSFET or provide gate drive signals for a low-side switch. Synchronous operation would require redesign with a controller-only IC such as the MP9486's pin-compatible variants (not offered in this family).

How is short-circuit protection implemented and what is its response time?

SCP detects low FB voltage (<150mV) persisting >10µs, indicating output short or severe overload. The high-side switch shuts off immediately, then attempts automatic restart after ~300µs. This cycle repeats until fault clears, preventing thermal runaway without requiring external circuitry.