Monolithic Power Systems Inc. MP2161GJ-P

Overview

MP2161GJ-P from Monolithic Power Systems is a synchronous step-down DC/DC converter IC with integrated 100mΩ high-side and 60mΩ low-side MOSFETs, delivering up to 2A continuous output current from a 2.5V–6V input while regulating output down to 0.6V. It employs Constant-On-Time (COT) control for fast transient response, features 17μA quiescent current, 1.5MHz switching frequency, and power-good signaling - optimized for space-constrained portable and battery-powered systems.

For engineers reviewing the MP2161GJ-P datasheet, MP2161GJ-P pinout, MP2161GJ-P application, or MP2161GJ-P equivalent, key selection criteria include its TSOT23-8 footprint, COT-based light-load efficiency, EN-controlled sequencing capability, and ±10% PGOOD window referenced to 0.6V feedback threshold.

Technical Context

The MP2161GJ-P implements a constant-on-time control architecture with input-voltage feedforward to maintain stable ~1.5MHz switching across input (2.5V–6V) and output (0.6V–VIN) ranges. Its internal PFET/NFET power stage enables 100% duty-cycle operation in dropout, while cycle-by-cycle current limiting and hiccup-mode short-circuit protection ensure robust fault handling.

It integrates soft-start (1.5ms), under-voltage lockout (2.3V rising threshold with 260mV hysteresis), and an open-drain PG pin with 550kΩ internal pull-up to VIN. The FB pin senses output via resistor divider with ±3% typical VFB accuracy and only 10–50nA bias current, enabling high-impedance feedback networks.

Key Specifications

Pinout & Package

MP2161GJ-P is housed in a thermally enhanced 8-pin TSOT23 package (2.9mm × 1.6mm × 0.85mm), optimized for high-density PCB layouts and efficient heat dissipation via exposed PGND pad.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62864DRLR and RT7297CGJ8F, MP2161GJ-P uniquely combines PG signaling, OUT sense, 100% duty-cycle operation, and ultra-low 17μA IQ in TSOT23-8 - making it optimal for battery-critical, space-constrained, and multi-rail sequenced systems.

Availability

MP2161GJ-P is available at Aetrix Electronics and suitable for wireless networking cards, portable medical instruments, and battery-powered industrial sensors requiring stable component supply with long-term lifecycle support.

Supply support for MP2161GJ-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.

The MP2161 belongs to MPS's high-efficiency, low-IQ DC/DC converter product line, engineered specifically for portable, battery-operated, and space-constrained applications demanding minimal quiescent power and fast transient response.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP2161GJ-P is stable with low-ESR ceramic capacitors ≥10μF. For 1.2V/2A operation, a 22μF X7R 0805 capacitor achieves <10mV peak-to-peak ripple and maintains phase margin >45°. Larger values improve transient response but require verification of ESR impact on COT loop stability.

Does MP2161GJ-P support forced PWM mode at light loads?

No - MP2161GJ-P automatically enters discontinuous conduction mode (DCM) under light loads to minimize switching losses. It does not offer a pin-selectable forced PWM mode; DCM operation is inherent to its proprietary light-load control scheme and contributes directly to the 17μA quiescent current specification.

How is the soft-start time determined, and can it be adjusted?

The soft-start time is fixed at 1.5ms (typical) by internal current source charging an internal capacitor. It cannot be externally adjusted. This controlled ramp prevents output overshoot and limits inrush current to <3A during startup into a 22μF output capacitor.

What is the maximum allowable voltage on the SW pin during startup or fault conditions?

The SW pin withstands -0.3V (DC) or -1.5V for <20ns pulses and -4V for <8ns pulses, with absolute max of 10V for <10ns transients. These ratings ensure safe operation during inductive kickback and short-circuit recovery events without external clamping diodes.

Can MP2161GJ-P regulate output voltages below 0.6V using external circuitry?

No - the internal 0.6V reference is trimmed and unadjustable. Output voltage is set only by the resistor divider ratio applied to the FB pin. Attempting sub-0.6V regulation violates the feedback architecture and results in loss of regulation; the lowest valid output is 0.6V (at VFB = 0.6V).

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

Yes - MP2161GJ-P is fully RoHS-compliant and lead-free per EU Directive 2011/65/EU. All solderable surfaces meet JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), and the device is qualified for reflow per IPC/JEDEC J-STD-020D.3.