Monolithic Power Systems Inc. MP1567DQ-LF-P

Overview

MP1567DQ-LF-P from Monolithic Power Systems is a 1.2A, 800kHz synchronous step-down DC/DC converter in a 3mm × 3mm QFN-10 package, designed for space-constrained low-voltage systems. It operates from 2.6V–6V input, delivers regulated output down to 0.9V (e.g., 1.8V @ 1.2A), achieves >90% efficiency via integrated 180mΩ high-side and 220mΩ low-side MOSFETs, and includes cycle-by-cycle current limiting, thermal shutdown, and soft-start-enabling reliable power delivery in handheld and portable electronics.

For engineers reviewing the MP1567DQ-LF-P datasheet, MP1567DQ-LF-P pinout, MP1567DQ-LF-P application, or MP1567DQ-LF-P equivalent, key selection criteria include its 800kHz fixed-frequency operation, internal power switches eliminating external FETs, 0.9V feedback reference enabling precise output setting, and QFN thermal performance (θJA = 50°C/W) critical for thermally dense PCB layouts.

Technical Context

The MP1567DQ-LF-P implements current-mode control with an internal 0.9V reference and transconductance error amplifier (G_EA = 300 µA/V, A_VEA = 400 V/V), enabling fast transient response and stable loop compensation via the COMP pin. Its bootstrap gate drive architecture requires a 10nF capacitor between BS and SW to sustain high-side N-MOSFET conduction during duty cycles up to 85%.

Protection features are hardware-integrated: undervoltage lockout triggers at 2.2V with 100mV hysteresis, thermal shutdown activates at 160°C, and current limiting is implemented separately for source (1.5–2.0A) and sink (350mA) paths-ensuring robust operation under overload and short-circuit conditions without external circuitry.

Key Specifications

Pinout & Package

MP1567DQ-LF-P uses a lead-free, exposed-pad 3mm × 3mm QFN-10 package (JEDEC MO-220 variant) with thermal pad on underside for enhanced heat transfer to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP1567DQ-LF-P, MP2101DJ-LF-Z trades output capability for smaller size and simpler BST implementation, while TPS62231DRYR prioritizes miniaturization over efficiency and ease of design-making MP1567DQ-LF-P optimal for balanced 1.2A, thermally constrained, production-ready buck designs.

Availability

MP1567DQ-LF-P is available at Aetrix Electronics and suitable for handheld computing, cellular handsets, digital video cameras, and small LCD displays requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP1567DQ-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP1567 belongs to MPS's high-efficiency DC/DC converter product line, engineered specifically for portable and battery-powered devices demanding minimal board area, low quiescent current, and robust protection in thermally limited environments.

FAQ

What is the minimum recommended input voltage for reliable operation?

The MP1567DQ-LF-P has a guaranteed operating range from 2.6V to 6V. Input voltage must remain above 2.6V to maintain regulation; below 2.2V, undervoltage lockout disables the device. For stable 1.2A output at 1.8V, VIN ≥ 2.8V is recommended to ensure sufficient headroom for dropout and ripple.

Can the MP1567DQ-LF-P be used without an external bootstrap capacitor?

No. The BS pin requires a minimum 10nF capacitor connected to SW to generate gate drive voltage for the high-side MOSFET. Omitting this capacitor causes immediate failure to regulate-SW remains stuck low, and the device cannot initiate switching.

How is output voltage accuracy affected by resistor tolerance in the feedback divider?

With a 0.905V nominal feedback reference and 1% resistors, output voltage error is dominated by resistor ratio tolerance. For a 1.8V output using 10kΩ (R1) and 10kΩ (R2), total error is ±2% (±1% from each resistor). Using 0.1% resistors reduces total error to ±0.2%.

Does the MP1567DQ-LF-P support forced PWM mode or only PFM at light loads?

The MP1567DQ-LF-P operates exclusively in forced PWM mode at all load levels-no pulse-frequency modulation or discontinuous conduction mode. This ensures constant 800kHz switching, predictable EMI spectrum, and stable loop behavior across 0–1.2A.

What is the maximum allowable output capacitance for stable operation?

No upper limit is specified, but stability depends on ESR and compensation. Ceramic outputs up to 47µF are stable with standard R3/C3 values; tantalum outputs >47µF require C4 addition per Table 1. Excessive capacitance (>100µF) without recompensation risks overshoot and ringing during load transients.

Is the exposed thermal pad electrically connected internally?

Yes-the exposed pad on the MP1567DQ-LF-P QFN package is internally connected to PGND. It must be soldered to a dedicated PCB thermal pad tied to the main PGND plane using ≥4 thermal vias (0.3mm diameter) for optimal thermal performance and electrical integrity.

How does the soft-start capacitor value affect startup time?

Soft-start time t_SS (ms) ≈ 0.45 × C_SS (nF). A 10nF capacitor yields ~4.5ms ramp; 22nF yields ~10ms. Values outside 10–22nF risk excessive inrush (too short) or unacceptable boot delay (too long), especially in battery-powered systems.