Monolithic Power Systems Inc. MP1567DK-LF-Z

Overview

MP1567DK-LF-Z from Monolithic Power Systems is a 1.2A, 800kHz synchronous step-down DC/DC converter in a 10-pin MSOP 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/220mΩ MOSFETs, and includes cycle-by-cycle current limiting, soft-start, UVLO, and thermal shutdown - enabling compact power rails in handheld and portable electronics.

For engineers reviewing the MP1567DK-LF-Z datasheet, MP1567DK-LF-Z pinout, MP1567DK-LF-Z application, or MP1567DK-LF-Z equivalent, key selection criteria include its 800kHz fixed-frequency operation, internal power switches, 0.9V feedback reference, zero-current shutdown mode, and compatibility with ceramic input/output capacitors in miniaturized SOHO and mobile designs.

Technical Context

The MP1567DK-LF-Z implements current-mode control with an internal 0.9V reference and transconductance error amplifier (G_EA = 300 µA/V, A_VEA = 400 V/V). Its PWM comparator compares COMP voltage against sensed inductor current to regulate duty cycle, delivering fast transient response and stable loop behavior across load and line variations.

It integrates dual N-channel MOSFETs (180mΩ high-side, 220mΩ low-side), a 2.4V internal LDO regulator (bypassed at BP), and bootstrap circuitry requiring a ≥10nF capacitor between BS and SW. The device supports automatic startup when EN is tied to IN and enters zero-current shutdown with <1.0 µA quiescent current when disabled.

Key Specifications

Pinout & Package

MP1567DK-LF-Z uses a lead-free, RoHS-compliant 10-pin MSOP package (3mm × 3mm × 1.1mm height) with exposed thermal pad on underside for enhanced heat dissipation in high-density layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP1567DK-LF-Z, MP1582EN-LF-Z trades compactness and low-VIN optimization for higher power and input flexibility, while TPS62231DRYR sacrifices protection and drive strength for extreme low-power operation - making MP1567DK-LF-Z the balanced choice for 1.2A, 2.6–6V portable applications requiring full fault coverage and minimal board area.

Availability

MP1567DK-LF-Z is available at Aetrix Electronics and suitable for SOHO routers, handheld computers, and digital video cameras requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for MP1567DK-LF-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 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 space- and thermally constrained portable electronics requiring integrated power switches, low quiescent current, and robust protection in miniature packages.

FAQ

What is the minimum recommended input voltage for reliable operation?

The MP1567DK-LF-Z has a guaranteed operating input range of 2.6V to 6V. Below 2.6V, undervoltage lockout activates at 2.2V (with 100mV hysteresis), disabling the device. Sustained operation below 2.6V risks regulation loss, especially under load, and is outside datasheet specifications.

Can the MP1567DK-LF-Z be used with a 10µF ceramic output capacitor?

Yes - a 10µF X5R/X7R ceramic capacitor is explicitly recommended in the datasheet for most applications. Its low ESR ensures minimal output ripple (<5mVpp typical at 1.8V/1A) and contributes to loop stability without requiring additional ESR-based compensation.

Is an external bootstrap diode required for normal operation?

No - the internal bootstrap circuit functions reliably with only a ≥10nF capacitor between BS and SW. An external diode (e.g., IN4148) is optional and only recommended for high-duty-cycle conditions (V_OUT/V_IN > 65%) at 3.3V or 5V outputs to marginally improve efficiency.

How is the soft-start duration calculated and adjusted?

Soft-start time t_SS (ms) = 0.45 × C_SS (nF). For example, a 10nF capacitor yields ~4.5ms ramp time. To adjust, replace C_SS (pin 6 to SGND) with standard values from 10nF to 22nF, covering 4–10ms durations - no resistor or other components are needed.

What is the maximum allowable output voltage and how is it set?

The MP1567DK-LF-Z supports output voltages from 0.9V to 4.5V, set by a resistive divider from V_OUT to FB. With V_FB = 0.905V, use R1 = 10kΩ (to SGND) and R2 = 11.1kΩ × (V_OUT − 0.9V); e.g., for 3.3V output, R2 = 26.7kΩ (standard 27kΩ yields 3.31V).

Does the MP1567DK-LF-Z require external compensation components?

Yes - stability depends on a series RC network from COMP to SGND. Recommended values depend on V_OUT and output capacitor type; for 1.8V/10µF ceramic, use 7.5kΩ + 1nF. Omitting or mis-sizing these components causes oscillation or poor transient response.

What thermal performance can be expected in a standard 2-layer PCB layout?

With the MSOP-10 package mounted on a 1"² 1oz copper pad, θ_JA = 150°C/W. At 1.2A/1.8V output (1.1W dissipation), junction temperature rise is ~165°C above ambient - thus derating or adding thermal vias to inner layers is essential to stay below the 160°C shutdown threshold.