Monolithic Power Systems Inc. MP2172GJ-Z

Overview

MP2172GJ-Z from Monolithic Power Systems is a synchronous step-down DC/DC converter with integrated 80mΩ high-side and 45mΩ low-side MOSFETs, delivering up to 2A continuous output current from a 2.5V–5.5V input, regulating output down to 0.6V using constant-on-time (COT) control, and featuring power-good (PG) and enable (EN) pins for sequencing in automotive infotainment and telematics systems.

For engineers reviewing the MP2172GJ-Z datasheet, MP2172GJ-Z pinout, MP2172GJ-Z application, or MP2172GJ-Z equivalent, key selection criteria include its 2.6MHz nominal switching frequency, ±10% PG threshold window, 1.3ms soft-start time, thermal shutdown at 170°C, and TSOT23-8 package compatibility with space-constrained PCB layouts.

Technical Context

The MP2172GJ-Z employs constant-on-time (COT) control with input voltage feed-forward to maintain stable switching frequency across input (2.5V–5.5V) and output (0.6V–VIN−0.5V) ranges, enabling fast transient response without external compensation. Its internal power stage integrates complementary MOSFETs with 80mΩ/45mΩ R_DS(ON), supporting 100% duty cycle operation in dropout.

It implements cycle-by-cycle over-current protection with 4.5A typical high-side current limit, hiccup-mode short-circuit recovery, and open-drain PG output referenced to VIN with 500kΩ internal pull-up - all coordinated via separate analog (AGND) and power (PGND) ground pins to minimize noise coupling in sensitive feedback paths.

Key Specifications

Pinout & Package

MP2172GJ-Z is housed in a thermally enhanced TSOT23-8 package (2.9mm × 1.6mm × 0.85mm), with exposed pad for improved heat dissipation and optimized high-frequency layout. Pin 4 (PGND) and Pin 6 (AGND) are separately routed to isolate power-switching noise from analog reference paths.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2172GJ-Z, TPS62864DRLR offers higher current and precision but demands more complex layout for EMI; RT7295BGJ8F reduces radiated noise via spread spectrum but sacrifices PG signaling and controlled discharge - making MP2172GJ-Z optimal for automotive sequencing-critical, thermally constrained, and cost-sensitive 2A POL applications.

Availability

MP2172GJ-Z is available at Aetrix Electronics and suitable for automotive infotainment, portable instrumentation, and low-voltage I/O system power applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MP2172GJ-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP2172 belongs to MPS's high-frequency synchronous buck converter product line, engineered for space-constrained, thermally demanding applications in automotive, industrial, and portable electronics where fast transient response and minimal external components are essential.

FAQ

What is the recommended input capacitor for MP2172GJ-Z?

A 10µF X5R/X7R ceramic capacitor placed directly between VIN and PGND is recommended for most applications. For higher output voltages or noisy input sources, a 47µF unit improves stability. The capacitor must handle ≥1A RMS ripple current - approximately half the maximum load current - and be located within 2mm of the VIN and PGND pins to minimize high-frequency loop inductance.

Does MP2172GJ-Z require an external compensation network?

No. MP2172GJ-Z uses constant-on-time (COT) control architecture, which eliminates the need for external compensation components like type-II or type-III networks. Stability is inherently achieved through input voltage feed-forward and fixed on-time modulation, simplifying design and reducing bill-of-materials cost.

How does the power-good (PG) pin behave during startup and fault conditions?

PG asserts high (pulled to VIN via internal 500kΩ resistor) only when FB voltage remains within ±10% of 0.6V for ≥110µs. During startup, PG delays activation until output settles; during overvoltage, undervoltage, or short-circuit events, PG pulls low immediately. PG remains low for ≥200µs after fault clearance before re-asserting.

Can MP2172GJ-Z operate with a 2.5V input and 1.8V output?

Yes. With 2.5V input and 1.8V output, MP2172GJ-Z operates in continuous conduction mode with ~2.2MHz switching frequency and maintains >88% efficiency at 2A. The 100% duty-cycle capability ensures regulation even as input drops near V_OUT + 0.5V, making it suitable for single-cell Li-ion (2.7–4.2V) applications.

What is the thermal performance of MP2172GJ-Z in a standard 4-layer PCB layout?

On a JEDEC-standard 4-layer board (2oz copper, 1in² thermal pad connected via 9×0.3mm vias), MP2172GJ-Z exhibits θ_JA = 100°C/W. At 2A load and 5V input, junction temperature rise is ~12°C above ambient - well below the 125°C max operating limit. Thermal shutdown activates only under sustained overload or inadequate PCB copper area.

Is the TSOT23-8 package of MP2172GJ-Z lead-free and RoHS compliant?

Yes. MP2172GJ-Z is fully lead-free, halogen-free, and compliant with the EU RoHS Directive 2011/65/EU. The TSOT23-8 package uses matte-tin plating over copper leadframe and meets IPC/JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), allowing unlimited floor life at ≤30°C/60% RH.