Monolithic Power Systems Inc. MP5461GC-P

Overview

MP5461GC-P from Monolithic Power Systems is a dual-input, 4-switch integrated buck-boost converter with auto-ORing and power-path selection. It regulates a fixed 3.3V/500mA output from either VIN1 (4.2–5.5V, 22V stress-rated) or VIN2 (2.5–5.5V), supports 1.8MHz PWM/CCM + PFM light-load operation, and integrates MOSFETs in a CSP-12 (1.4mm × 1.8mm) package for USB-C VCONN and dual-source portable power applications.

For engineers reviewing the MP5461GC-P datasheet, MP5461GC-P pinout, MP5461GC-P application, or MP5461GC-P equivalent, key selection criteria include dual-input ORing timing (<2μs reverse block), buck-boost regulation across input/output crossover, hiccup-mode OCP, 5.75V VIN1 OVP shutdown, and STATUS pin logic for real-time path monitoring.

Technical Context

The MP5461GC-P implements a current-mode controlled 4-switch buck-boost topology with independent dual-input ORing using integrated NMOS/PMOS pairs. Its control architecture combines two synchronized PWM loops - one for buck leg (SWA/SWB) and one for boost leg (SWC/SWD) - with shared current-sense ramp and dynamic mode transition between buck, buck-boost, and boost regions based on VIN-to-VOUT ratio.

Power-path selection is managed via SEL pin logic (active-high for VIN2, pull-down default for VIN1) and monitored by open-drain STATUS (high-Z when VIN1 selected, low when VIN2 selected). Internal VCC generation uses an IN1 LDO or OR_OUT sourcing, while EN enables/disables the entire system with 300μs startup delay to OR_OUT.

Key Specifications

Pinout & Package

The MP5461GC-P is housed in a wafer-level chip-scale package (CSP-12) measuring 1.4mm × 1.8mm with 0.4mm pitch, optimized for ultra-compact USB-C and wearable designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-input buck-boost converter applications.

Compared with MP5461GC-P, MP5471GC-P offers configurability at the cost of added complexity, while TPS63802DRLR reduces integration but forces external ORing design - making MP5461GC-P optimal for space-constrained dual-rail USB-C and portable applications where simplicity and reliability are prioritized.

Availability

MP5461GC-P is available at Aetrix Electronics and suitable for USB-C cable assemblies, VCONN-powered peripherals, and dual-source industrial sensor nodes requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MP5461GC-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 core expertise in DC/DC conversion, motor drivers, and LED lighting solutions.

The MP5461GC-P belongs to MPS's integrated power management product line, designed specifically for compact, dual-input power architectures in USB-C, portable electronics, and battery-assisted embedded systems.

FAQ

What is the maximum allowable voltage on IN1, and what happens above that threshold?

The MP5461GC-P supports up to 22V voltage stress on IN1 without damage, but functional operation is limited to 4.2–5.5V. When IN1 exceeds 5.75V, the device triggers input over-voltage protection (OVP) and shuts down. Recovery occurs only after IN1 falls below 5.5V, per the hysteresis specification. This behavior ensures robustness against USB PD negotiation spikes and hot-plug transients.

How does the STATUS pin indicate which input is active, and is external pull-up required?

STATUS is an open-drain output: it remains high-impedance (floating) when VIN1 is selected or no valid input is present, and pulls low when VIN2 is selected. An external pull-up resistor (typically 10kΩ to 3.3V or 5V) is required to generate a defined logic-high level. The truth table in the datasheet defines all combinations, including cases where one input is absent or out-of-range.

Can the MP5461GC-P operate with only one input connected, and how is path selection handled?

Yes - the MP5461GC-P automatically selects the available input when only VIN1 or VIN2 is present. If both are valid, selection defaults to VIN1 unless SEL is driven high. The auto-selection logic is implemented in hardware and requires no firmware intervention. This makes it ideal for applications where source availability is unpredictable, such as USB-C cables plugged into varying hosts or accessories.

What is the purpose of the EN-to-OR_OUT startup delay, and how does it affect system sequencing?

The 300μs EN-to-OR_OUT delay ensures that internal biasing, UVLO validation, and ORing MOSFET soft-start complete before the buck-boost stage activates. This prevents inrush current surges and stabilizes the OR_OUT rail prior to downstream regulation. In systems with strict power-on reset timing, this delay must be accounted for in host controller sequencing - especially when STATUS or VOUT monitoring is used for firmware initialization.

Does the MP5461GC-P support forced PWM mode, or is PFM automatic only?

The MP5461GC-P operates exclusively in automatic PFM/PWM mode - there is no pin or register to force continuous PWM. At light loads (<10mA), it enters PFM to maintain high efficiency; above ~50mA, it transitions seamlessly to 1.8MHz PWM for optimal transient response. This hybrid mode is fully internal and requires no external configuration, simplifying design for variable-load applications like USB-C accessories with intermittent communication bursts.

What thermal considerations apply to the CSP-12 package in continuous 500mA operation?

In the CSP-12 (1.4mm × 1.8mm) package, continuous 500mA output at full load requires careful PCB layout: AGND and GND must be connected with ≥4 thermal vias to an inner-layer copper pour, and the exposed die pad (if applicable) must be soldered to a dedicated thermal pad. With proper layout on a 4-layer board, junction temperature stays within -40°C to +125°C operating range up to 500mA at TA = +85°C, per θJA = 110°C/W and PD(MAX) = 1.14W.

Is the 3.3V output internally trimmed, and can it be adjusted externally?

Yes - the 3.3V output is factory-trimmed to ±1.5% accuracy using internal resistive feedback; no external resistors are supported or required. The MP5461GC-P does not provide an FB pin or external feedback option. For adjustable outputs, designers should consider the pin-compatible MP5471GC-P, which features I2C-programmable VOUT from 2.5V to 5.0V in 50mV steps.