Monolithic Power Systems Inc. MP5505GL-Z

Overview

MP5505GL-Z from Monolithic Power Systems is a 7V-input, 4A-lossless energy storage and management unit in a 20-pin QFN (3mm×4mm) package. It integrates input-current limiting with dv/dt control, programmable bus voltage slew rate, Power-On-Reset, and bidirectional Buck/Boost energy transfer for solid-state and hard-disk drive power-backup applications. It pumps VIN to up to 30V storage voltage and releases energy at up to 4.5A during input outage.

For engineers reviewing the MP5505GL-Z datasheet, MP5505GL-Z pinout, MP5505GL-Z application, or MP5505GL-Z equivalent, this device supports precise hold-up timing via programmable VSTORAGE/VRELEASE feedback dividers, thermal shutdown at 150°C, reverse-current protection, and dual enable control (EN/ENCH) for safe charge-release sequencing.

Technical Context

The MP5505GL-Z implements a patented bidirectional Buck/Boost architecture: during normal operation, its boost converter charges an external capacitor to a user-set storage voltage (VIN to 30V); upon input loss, it switches to buck mode to discharge stored energy into the bus at up to 4.5A. The internal 60mΩ input FET limits inrush current, while dv/dt control on the DVDT pin programs bus voltage ramp time.

It features two independent feedback loops - FBS sets storage voltage (0.79V reference), FBB sets release threshold (0.79V reference) - enabling independent configuration of charge and hold-up profiles. The device uses constant-on-time (COT) control in buck release mode for fast transient response and supports 100% duty cycle operation to fully deplete stored energy.

Key Specifications

Pinout & Package

MP5505GL-Z is housed in a thermally enhanced 20-pin QFN package (3mm × 4mm, 0.5mm pitch) with exposed thermal pad. Pin mapping is validated per MPS Rev. 1.01 datasheet and functional block diagram.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar energy storage and management applications.

Compared with TPS43060 and LTC4425, MP5505GL-Z uniquely integrates bidirectional power conversion, programmable storage/release voltages, and 4.5A release capability in one QFN20 package - reducing BOM count by ≥5 components and eliminating inter-stage timing coordination.

Availability

MP5505GL-Z is available at Aetrix Electronics and suitable for solid-state drive power hold-up, hard-disk drive crash protection, and industrial PLC I/O module backup requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP5505GL-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 energy management solutions.

The MP5505 product line targets compact, high-efficiency power-backup systems for storage-class devices - designed to replace bulky capacitor banks and discrete supervisory circuits with a single integrated energy storage and release unit.

FAQ

What is the maximum storage voltage supported by MP5505GL-Z?

The MP5505GL-Z supports storage voltages from VIN up to 30V, as confirmed in the Recommended Operating Conditions table (Rev. 1.01, p.3). This range enables efficient energy density scaling - e.g., storing energy at 12V instead of 5V reduces required capacitance by ~5.7× for the same hold-up energy.

How does the MP5505GL-Z prevent reverse current flow during energy release?

It uses integrated reverse-current protection via the input hot-swap MOSFET, which turns off when VIN falls below VB during release. This blocks energy backfeed from STRG/VB to VIN, as specified in the Operation section (p.10) and Absolute Maximum Ratings (VSTRG to -0.3V).

Can MP5505GL-Z operate with a 3.3V input supply?

Yes - its 2.7V–7V input range includes 3.3V operation. However, minimum storage voltage becomes 3.3V, limiting hold-up energy; for optimal performance, use VIN ≥ 5V to enable higher VSTORAGE (e.g., 12V) and maximize capacitor utilization per the Application Information section (p.11).

What is the purpose of the ENCH pin, and why is sequencing with EN critical?

ENCH enables only the charge/release circuitry, while EN controls the entire IC. Sequencing ENCH after VB settles (per Figure 3) prevents false release triggering caused by VB droop during boost-mode charging - a documented design requirement in the Operation section (p.9) to avoid premature hold-up activation.

Does MP5505GL-Z require an external diode in the boost path?

Yes - an external diode (D1 in Typical Application schematic, p.1) is strongly recommended across the boost inductor to prevent reverse conduction and ensure reliable pre-charge mode operation, as stated in the Application Information section (p.12).

How is thermal performance affected by PCB layout?

θJA is specified at 48°C/W on a 4-layer JEDEC board (p.2). Layout directly impacts this: the exposed thermal pad must be soldered to a ≥250mm² copper pour with ≥4 thermal vias (0.3mm diameter) to inner ground planes - failure to do so risks thermal shutdown above 2.5W dissipation.

What happens if the ILIM pin is left unconnected?

The ILIM pin must not be left floating - it requires a resistor to GND to set the input current limit. An open ILIM pin results in undefined current-limit behavior and potential overcurrent damage, as explicitly warned in the PIN FUNCTIONS table (p.7).