Monolithic Power Systems Inc. MP9486AGN

Overview

MP9486AGN 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 switching current limit, 4.5–95V input range, 170µA quiescent current, and PWM dimming control-designed for automotive power rails, solar charge controllers, and high-power LED drivers requiring robust over-current and thermal protection.

For engineers reviewing the MP9486AGN datasheet, MP9486AGN pinout, MP9486AGN application, or MP9486AGN equivalent, this device supports fast transient response in battery-backed industrial systems, enables compact 1MHz designs with minimal external components, and delivers regulated output down to 200mV FB reference with adaptive hysteretic thresholds (185mV/215mV).

Technical Context

The MP9486AGN employs fixed-frequency hysteretic voltage-mode control with adaptive feedback thresholds (185mV low / 215mV high) to maintain 200mV average FB voltage-eliminating loop compensation while ensuring stable regulation across line, load, and temperature. Its integrated high-side MOSFET features 500mΩ R_DS(ON) and internal current sensing for accurate 3.5A peak limit triggering.

Operation includes dedicated EN pin with 1.55V rising threshold and 320mV hysteresis, DIM pin supporting 20kHz PWM dimming for LED applications, and bootstrap-driven gate drive with internal 5V BST regulator. Thermal shutdown activates at 150°C with 20°C hysteresis, and short-circuit protection responds within 10µs.

Key Specifications

Pinout & Package

MP9486AGN is housed in an SOIC-8 package with exposed pad for enhanced thermal dissipation (θ_JA = 34°C/W on 2-layer board). The exposed pad must be soldered to a GND plane using ≥9 thermal vias (15mil barrel, 40mil pitch) for optimal junction temperature control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP9486AGN, MPQ4420AGL-A trades input voltage headroom for lower cost and smaller footprint, while LM5164QPWPRQ1 adds automotive qualification at the expense of component count and dimming capability-making MP9486AGN optimal for cost-constrained, high-voltage, LED-integrated designs.

Availability

MP9486AGN is available at Aetrix Electronics and suitable for automotive system power, solar charge controllers, e-mobility control units, and high-power LED lighting requiring stable component supply across extended temperature and voltage ranges.

Supply support for MP9486AGN 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 MP9486A belongs to MPS's high-voltage DC/DC converter product line, engineered specifically for ruggedized power conversion in automotive, industrial, and renewable energy systems where wide input range and integrated protection are critical.

FAQ

What is the maximum recommended output current for continuous operation?

The MP9486AGN delivers up to 1A continuous output current under typical thermal conditions (TA = +25°C, SOIC-8 EP on 2-layer board with thermal vias). At higher ambient temperatures or reduced airflow, derating is required-e.g., 0.7A at +85°C ambient per thermal simulation data in the datasheet.

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

No-DIM must be either pulled high (>1.5V) to enable full output or tied to EN to synchronize dimming and enable functions. Leaving DIM floating may cause unpredictable switching behavior due to noise coupling; the datasheet explicitly recommends connecting DIM to EN for standard buck operation.

Is an external bootstrap diode required for reliable operation?

An external bootstrap diode (e.g., BAT54) is recommended-not required-when VIN ≤ 5V, VOUT is 3.3–5V, duty cycle exceeds 65%, or switching frequency approaches 1MHz. It improves BST capacitor charging efficiency and reduces gate drive losses but is optional in most 12–60V applications.

How does the hysteretic control affect output voltage accuracy?

Hysteretic control maintains output voltage by regulating FB at 200mV average, with ±15mV tolerance (185–215mV thresholds). This yields ±1.5% output error for a 5V rail-tighter than many current-mode converters without trimming, and unaffected by component aging or temperature drift in the feedback divider.

What is the minimum recommended output capacitance for stable operation?

The datasheet specifies ≥100µF total output capacitance with 100–250mΩ ESR for 5V output. Using a 100µF/10V aluminum electrolytic plus 0.1µF ceramic meets both requirements-lower ESR risks subharmonic oscillation, while insufficient capacitance increases output ripple beyond 50mVpp.

Does the MP9486AGN support synchronous rectification?

No-the MP9486AGN uses an external Schottky diode for asynchronous rectification. It lacks a second gate driver or control logic for synchronous FETs. For synchronous operation, consider MPS's MP9488 (pin-compatible upgrade with integrated low-side FET).

What PCB layout practices prevent thermal shutdown during full-load operation?

To avoid thermal shutdown, solder the exposed pad to a ≥1cm² GND copper area using ≥9 thermal vias (15mil barrel, 40mil pitch), place input/output capacitors within 5mm of respective pins, and avoid routing noisy signals (SW, BST) near FB or DIM traces-verified to keep T_J < 125°C at 1A/5V output.