MT3608 DC Voltage Regulator Module

Обновлено: 05 февраля 2026 г. 08:24

The MT3608 is a 6‑pin SOT‑23, constant‑frequency step‑up regulator designed for compact, low‑power applications. It switches at 1.2 MHz, which permits the use of tiny, inexpensive inductors and capacitors (≤ 2 mm tall). An internal soft‑start limits inrush current, extending battery life.

Automatic shift to PWM mode at light loads for higher efficiency
Under‑voltage lockout, current limiting, and thermal overload protection to guard against overloads
Peak‑current mode, fixed‑frequency architecture that regulates voltage via the feedback (FB) pin

Operating Principle

During each oscillator cycle the control circuit turns the power MOSFET on. A stabilizing ramp added to the current‑sense amplifier output prevents sub‑harmonic oscillations when the duty cycle exceeds 50 %. When this ramp‑adjusted voltage equals the error‑amplifier output (which amplifies the difference between the 0.6 V band‑gap reference and the FB voltage), the MOSFET turns off, maintaining regulation.

If the output voltage falls, the error‑amplifier output rises, increasing MOSFET current and restoring the output level. The soft‑start also curbs startup surge and output overshoot.

Component Selection Guidelines

Component	Recommended Specs	Reason
Inductor	4.7 µH – 22 µH, low DCR, low core loss at 1.2 MHz	Small size, high efficiency; choose a current rating above the peak inductor current to avoid saturation
Capacitors	22 µF ceramic (X5R or X7R), low ESR	Provides good filtering and wide voltage/temperature range
Diode	Schottky, low forward drop, fast reverse recovery, reverse voltage > VOUT	Improves efficiency at high switching frequency; RMS current rating must satisfy `I_PEAK ≈ 1.8 × I_OUT,RMS`
Feedback Divider	Resistors R1 and R2 set VOUT via `V_OUT = V_REF × (1 + R1/R2)`	Allows precise voltage adjustment; many modules include a 25‑turn trimpot for fine tuning

Typical Performance

Input range: 2 V – 24 V
Adjustable output: 0.6 V – 28 V (set with the feedback divider)
Maximum output current: up to 2 A (depends on input voltage and inductor choice)
Efficiency: often > 90 % thanks to the high switching frequency and Schottky diode

The MT3608’s compact size, built‑in protections, and ability to operate with very small passive components make it ideal for portable devices, LED drivers, and other battery‑powered systems where space and efficiency are critical.

Download PDF
Похожие статьи:

Ничего не найдено