Overview

The MP2307 (commonly packaged as MP2307DN in SOIC-8 with exposed thermal pad) is a monolithic 3.0 A3.0\text{ A} synchronous step-down (buck) switching regulator manufactured by Monolithic Power Systems (MPS). Famous for driving ultra-tiny buck converter modules such as the Mini360 and KIS-3R33S, it integrates both high-side (100 mΩ100\text{ m}\Omega) and low-side (20 mΩ20\text{ m}\Omega) power MOSFET switches on-chip.

By replacing the external freewheeling Schottky diode with an integrated low-side synchronous MOSFET switch, the MP2307 achieves efficiency levels up to 95%95\%, drastically reducing thermal dissipation and component count.

Quick reference

Regulator TypeSynchronous Step-Down (Buck) Converter
PackageSOIC-8 EP / Mini360 Breakout Module (17×11 mm17\times11\text{ mm})
Input Voltage Range (VINV_{IN})4.75 V4.75\text{ V} to 23.0 V23.0\text{ V} DC
Output Voltage Range (VOUTV_{OUT})0.925 V0.925\text{ V} to 20.0 V20.0\text{ V} DC (Adjustable)
Continuous Output Current (IOUTI_{OUT})Up to 3.0 A3.0\text{ A} (4.0 A4.0\text{ A} peak)
Switching Frequency340 kHz340\text{ kHz} fixed internal oscillator
Conversion Efficiency90%…95%90\% \dots 95\%
Control FeaturesProgrammable soft-start (SS), logic enable (EN)

Pinout (SOIC-8 EP Package)

text
        ┌─────────────┐
    BS ─│ 1         8 │─ SS
    IN ─│ 2         7 │─ EN
    SW ─│ 3    EP   6 │─ COMP
   GND ─│ 4         5 │─ FB
        └─────────────┘
PinNameDescription
1BS / BSTHigh-side gate drive bootstrap pin (10nF cap between BS and SW)
2IN / VINPower supply input (+4.75V to +23V DC)
3SWSwitch node output connecting internal high-side and low-side MOSFETs to inductor
4GNDGround reference (connected to exposed pad underneath)
5FBFeedback input pin (0.925V0.925\text{V} reference voltage)
6COMPError amplifier compensation node for loop stability
7ENEnable input pin (High = ON, Low = OFF)
8SSSoft-start pin (capacitor to GND sets soft-start timing)

Specifications

ParameterSymbolMinTypMaxUnitConditions
Input Supply VoltageVINV_{IN}4.751223VOperating range
Feedback Reference VoltsVFBV_{FB}0.9000.9250.950VTA=25∘CT_A = 25^\circ\text{C}
Continuous Output CurrentIOUTI_{OUT}—3.0—AVIN=12V,VOUT=5VV_{IN} = 12\text{V}, V_{OUT} = 5\text{V}
Peak Current LimitICLI_{CL}4.05.8—AHigh-side switch current limit
High-Side Switch RDS(ON)R_{DS(ON)}RDS(ON)HR_{DS(ON)H}—100—mΩ\text{m}\OmegaVBS−VSW=5VV_{BS} - V_{SW} = 5\text{V}
Low-Side Switch RDS(ON)R_{DS(ON)}RDS(ON)LR_{DS(ON)L}—20—mΩ\text{m}\OmegaVIN=12VV_{IN} = 12\text{V}
Switching FrequencyfSWf_{SW}300340380kHzFixed internal clock
Shutdown CurrentISDI_{SD}—110μA\mu\text{A}VEN=0VV_{EN} = 0\text{V}

Typical Application Circuit (Synchronous Buck)

text
       +V_IN (4.75V - 23V Input)
          │
       [Pin 2: IN]
        MP2307DN ──── [Pin 3: SW] ──── [ 10µH Inductor ] ───┬─── +V_OUT Regulated Output
          │                                                  │
       [Pin 4: GND]                                       [ R1 ]
          │                                                  │
         GND ────────────────────────────────────────────────┼─── [Pin 5: FB]
                                                             │
                                                           [ R2 ]
                                                             │
                                                            GND

VOUT=0.925V×(1+R1R2)V_{OUT} = 0.925\text{V} \times \left( 1 + \frac{R_1}{R_2} \right)

Common mistakes

  • Exceeding the 23V input limit: The MP2307 absolute maximum input voltage is 26 V26\text{ V} (23 V23\text{ V} recommended operational). Using it on 24 V24\text{ V} industrial or solar rails will cause destructive overvoltage breakdown.
  • Floating the EN pin: Leaving the enable pin unconnected can result in erratic startup. Tie EN directly to IN for automatic power-on operation.

Notes

  • Synchronous vs Non-Synchronous Buck: The MP2307 contains an integrated low-side MOSFET switch so no external diode is required, yielding higher efficiency than non-synchronous regulators like LM2596.

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