Monolithic Power Systems Inc. MP4470AGL-P

Overview

MP4470AGL-P from Monolithic Power Systems is a synchronous step-down DC/DC converter delivering 5A continuous output current with 4.5V–36V input range, integrated 40mΩ high-side and 20mΩ low-side MOSFETs, 1% reference voltage accuracy, and programmable soft-start. It enables compact, high-efficiency power conversion in automotive infotainment systems requiring fast transient response and robust protection.

For engineers reviewing the MP4470AGL-P datasheet, MP4470AGL-P pinout, MP4470AGL-P application, or MP4470AGL-P equivalent, key selection criteria include its absence of OVP latch (vs. MP4470), 200kHz–1MHz adjustable switching frequency, thermal shutdown at 175°C with 45°C hysteresis, and QFN20 (3×4mm) package with exposed thermal pads for PCB-level thermal management.

Technical Context

The MP4470AGL-P implements a current-mode PWM controller with proprietary switching-loss-reduction technology and internal dead-time control to prevent shoot-through between its integrated high- and low-side MOSFETs. Its feedback loop uses a 0.815V reference with ±1% tolerance and supports output regulation from 0.8V to 0.9×VIN via external resistor divider.

It operates in continuous conduction mode (CCM) under heavy load and automatically transitions to skip mode at light loads to maintain efficiency. The device features an internal 8.5μA soft-start current source, open-drain PGOOD with 700μs delay, and cycle-by-cycle over-current protection with 100μs hiccup timer - but omits OVP latch functionality present in the MP4470 variant.

Key Specifications

Pinout & Package

MP4470AGL-P is housed in a thermally enhanced 3mm × 4mm, 20-pin QFN package with five exposed thermal pads (pins 8, 19, 21–23) connected to IN and six exposed ground pads (pins 9, 10, 17, 18, 24, 25) tied to SW and PGND respectively - enabling efficient heat dissipation in space-constrained layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with MP4470AGL-P, MP4470GL-P adds fail-safe OVP latching at the cost of reduced flexibility in recovery behavior, while TPS54560BQPWPRQ1 trades integration for wider input range and automotive certification - making MP4470AGL-P optimal for cost-sensitive, space-constrained 36V-max applications requiring fast transient response and minimal external components.

Availability

MP4470AGL-P is available at Aetrix Electronics and suitable for automotive infotainment, notebook I/O power, and industrial networking applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP4470AGL-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 MP4470/4470A product line targets compact, high-efficiency DC/DC conversion in automotive, computing, and industrial systems - emphasizing integration, thermal robustness, and ease of use through minimal external component count.

FAQ

What is the key functional difference between MP4470AGL-P and MP4470GL-P?

The MP4470AGL-P omits the output over-voltage protection (OVP) latch function present in the MP4470GL-P. When V_FB exceeds 1.25×V_REF (≈1.02V), MP4470GL-P enters latched shutdown requiring power cycle recovery, whereas MP4470AGL-P continues normal operation. All other electrical characteristics, pinout, package, and protection features (SCP, OCP, UVP, thermal shutdown) are identical.

Can MP4470AGL-P operate with ceramic output capacitors without external compensation?

No - ceramic capacitors lack sufficient ESR to provide natural loop stabilization. An external ramp network (R4/C4) must be connected to the FB pin to ensure stability in PWM mode. The datasheet specifies R4/C4 values for common output voltages and frequencies (e.g., 953kΩ/390pF at 300kHz, 3.3V_OUT). POSCAP or aluminum polymer capacitors with ≥12mΩ ESR do not require external ramp.

How is switching frequency set, and what is the impact of input voltage variation?

Switching frequency is set by connecting a resistor (R_FREQ) from FREQ pin to GND. The formula is f_SW(kHz) = 10⁶ / [96 × R_FREQ(kΩ) + t_DELAY(ns) × V_IN(V)], where t_DELAY ≈ 20ns. Because V_IN feeds forward into the one-shot timer, f_SW remains stable across input voltage changes - e.g., variation is <±3% from 4.5V to 36V with fixed R_FREQ.

What thermal derating applies at elevated ambient temperatures?

With θ_JA = 48°C/W on a 4-layer PCB, maximum continuous output current derates linearly above 25°C ambient. At 70°C ambient, maximum safe output current is ~3.8A (calculated as I_OUT = (125°C − T_A) / (θ_JA × P_LOSS)). Derating curves are provided in Figure 12 of the datasheet; PCB copper area and airflow significantly affect actual performance.

Does MP4470AGL-P support forced PWM mode, or is skip mode mandatory at light loads?

MP4470AGL-P does not support forced PWM mode - it automatically enters skip mode below the critical output current (~0.5A at 12V_IN/3.3V_OUT). This is inherent to its current-mode architecture and light-load optimization. Skip mode reduces switching losses and improves efficiency at <10% load, but introduces low-frequency output ripple that may require additional filtering in noise-sensitive analog circuits.

What is the minimum recommended input capacitance for 5A operation?

For 5A continuous output, the input capacitor must handle RMS ripple current ≥2.5A (half the load current). A 22μF X5R/X7R ceramic capacitor rated for ≥3A RMS and ≥35V DC, placed within 3mm of the IN and PGND pins, meets typical requirements. Parallel placement of two 10μF capacitors further reduces ESL and improves high-frequency decoupling.

How does the bootstrap circuit maintain gate drive under high-duty-cycle conditions?

The MP4470AGL-P includes an active bootstrap refresh circuit: when V_BST−V_SW drops below 2.3V, the low-side MOSFET is briefly turned on to recharge the BST capacitor via the VIN→BST→SW path. This allows stable operation up to 95% duty cycle (e.g., 36V_IN→3.3V_OUT) without external charge pumps or complex timing control.