Monolithic Power Systems Inc. MP3217DJ-LF-P

Overview

MP3217DJ-LF-P from Monolithic Power Systems is a monolithic 36V step-up DC-DC converter with integrated 0.5A/0.6Ω MOSFET switch, fixed 670kHz current-mode control, and 1.24V feedback reference. It delivers regulated high-voltage bias (e.g., 33V @ 10mA) for APD circuits and portable imaging systems, featuring cycle-by-cycle overcurrent protection, 42V overvoltage shutdown, and thermal shutdown.

For engineers reviewing the MP3217DJ-LF-P datasheet, MP3217DJ-LF-P pinout, MP3217DJ-LF-P application, or MP3217DJ-LF-P equivalent, key selection criteria include input voltage range (2.5–6V), output capability up to 36V, TSOT23-6 footprint constraints, and enable threshold compatibility (2V ON / 0.8V OFF) in battery-powered designs.

Technical Context

The MP3217DJ-LF-P implements a constant-frequency peak-current-mode boost architecture with internal ramp compensation to suppress subharmonic oscillation above 50% duty cycle. Its error amplifier compares FB voltage against a 1.24V reference to modulate switch conduction time via PWM comparator.

Protection logic includes under-voltage lockout (UVLO rising at 2.45V with 92mV hysteresis), 42V output overvoltage shutdown that latches until power recycle, and thermal shutdown at 150°C. The dual ground pins (PGND and GND) separate high-current power return from signal reference to minimize noise coupling.

Key Specifications

Pinout & Package

MP3217DJ-LF-P is housed in a thermally enhanced 6-pin TSOT23 package (2.9mm × 1.6mm × 0.85mm), with exposed pad for improved heat dissipation. Pin 1 (PGND) and Pin 2 (GND) are physically separate grounds to isolate high di/dt power return from sensitive analog reference paths.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61088RHLR and MAX17222ELT+, MP3217DJ-LF-P uniquely balances 36V output capability, 42V latching OVP, and TSOT23-6 size-making it optimal for APD bias where safety, precision, and footprint are jointly constrained.

Availability

MP3217DJ-LF-P is available at Aetrix Electronics and suitable for APD bias generation, portable digital cameras, handheld medical scanners, and industrial handheld terminals requiring stable component supply across automotive-grade temperature ranges and long production lifecycles.

Supply support for MP3217DJ-LF-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 MP3217 belongs to MPS's high-voltage boost converter product line, engineered specifically for compact, high-reliability bias supply applications in optical sensing, imaging, and portable instrumentation.

FAQ

What is the maximum recommended output voltage for MP3217DJ-LF-P?

The MP3217DJ-LF-P is rated for up to 36V output under normal operation. Its overvoltage protection triggers at 42V and latches off until power is cycled, making 36V the practical maximum for continuous, reliable operation with margin.

Can MP3217DJ-LF-P operate with a 3.3V input to generate 33V output?

Yes - the MP3217DJ-LF-P supports input voltages from 2.5V to 6V. With a 3.3V input, it achieves 33V output using a 133kΩ/5.1kΩ resistor divider, maintaining >80% efficiency at 10mA load per typical performance curves.

Why does MP3217DJ-LF-P have two ground pins (PGND and GND)?

PGND carries high di/dt switch return current, while GND serves as the quiet reference for FB, EN, and internal regulators. Separating them minimizes noise coupling into the feedback path, preserving regulation accuracy and loop stability in noisy layouts.

Is an external Schottky diode required, and what specifications are critical?

Yes - an external Schottky diode (e.g., B0540) is mandatory. It must withstand ≥36V reverse voltage, handle ≥10mA average current, and support ≥0.5A peak inductor current. Low forward voltage (<0.45V) and fast recovery (<10ns) minimize conduction and switching losses.

Does MP3217DJ-LF-P support automatic startup without an external enable signal?

Yes - leaving the EN pin unconnected (floating) ties it internally to VIN through a weak pull-up, enabling automatic startup when input voltage exceeds UVLO threshold (2.45V). This simplifies designs where sequenced enable control is unnecessary.

What is the thermal performance limitation in TSOT23-6 package?

In free-air conditions, the TSOT23-6 package has θ_JA = 220°C/W. At 25°C ambient, maximum continuous power dissipation is ~0.56W before thermal shutdown activates at 150°C junction temperature - limiting sustained output power to ~150mW at full 36V/0.5A theoretical capability.

How does the 1.24V feedback reference improve output accuracy compared to 1.20V or 1.25V references?

The 1.24V ±0.04V reference provides tighter absolute accuracy than typical 1.20V or 1.25V references, reducing output error to ±0.3% for a 33V design (vs. ±0.6–1.0% with looser references), critical for APD gain linearity and sensor calibration stability.