Overview

The MP1584 (specifically MP1584EN in an 8-pin SOIC package with exposed thermal pad) is a high-frequency 3.0 A3.0\text{ A} step-down (buck) switching voltage regulator manufactured by Monolithic Power Systems (MPS). Featuring an integrated 100 mΩ100\text{ m}\Omega high-side N-channel MOSFET, it accepts input voltages from 4.5 V4.5\text{ V} to 28 V28\text{ V} and delivers output voltages adjustable down to 0.8 V0.8\text{ V}.

Capable of operating at switching frequencies up to 1.5 MHz1.5\text{ MHz}, the MP1584 allows the use of very small ceramic capacitors and low-profile 4.7 μH4.7\ \mu\text{H} or 10 μH10\ \mu\text{H} inductors. As a result, MP1584 modules are significantly smaller and lighter than legacy LM2596 modules while delivering superior efficiency.

Quick reference

Regulator TypeHigh-Frequency Monolithic Step-Down (Buck) Converter
PackageSOIC-8 EP (Exposed Pad) / Mini Buck Module (22×17 mm22\times17\text{ mm})
Input Voltage Range (VINV_{IN})4.5 V4.5\text{ V} to 28.0 V28.0\text{ V} DC
Output Voltage Range (VOUTV_{OUT})0.8 V0.8\text{ V} to 25.0 V25.0\text{ V} DC (Adjustable)
Continuous Output Current (IOUTI_{OUT})Up to 3.0 A3.0\text{ A}
Switching FrequencyProgrammable up to 1.5 MHz1.5\text{ MHz} (Typically 100 kHz…1.5 MHz100\text{ kHz} \dots 1.5\text{ MHz})
Conversion Efficiency88%…95%88\% \dots 95\%
FeaturesInternal soft-start, thermal shutdown, pulse-skipping light-load mode

Pinout (SOIC-8 EP Package)

text
        ┌─────────────┐
    SW ─│ 1         8 │─ BST
    EN ─│ 2         7 │─ VIN
  COMP ─│ 3    EP   6 │─ FREQ
    FB ─│ 4         5 │─ GND
        └─────────────┘
PinNameDescription
1SWSwitch node output connecting internal MOSFET to catch diode and inductor
2ENEnable input (>1.35V enables, <1.15V disables; internal pull-up)
3COMPError amplifier output / loop compensation network
4FBFeedback sense pin (0.8V0.8\text{V} reference voltage)
5GNDGround reference (connected to exposed pad underneath)
6FREQ / FSETSwitching frequency configuration pin (resistor connected to GND sets fSWf_{SW})
7VINPower supply input (+4.5V to +28V DC)
8BSTBootstrap pin for internal N-channel high-side gate drive (10nF cap to SW)

Specifications

ParameterSymbolMinTypMaxUnitConditions
Input Supply VoltageVINV_{IN}4.51228VDC input
Feedback Reference VoltageVFBV_{FB}0.7760.8000.824VTA=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}
High-Side On-ResistanceRDS(ON)R_{DS(ON)}—100—mΩ\text{m}\OmegaVBST−VSW=5VV_{BST} - V_{SW} = 5\text{V}
Switching FrequencyfSWf_{SW}10010001500kHzSet by resistor on FREQ pin
Quiescent CurrentIQI_Q—360450μA\mu\text{A}Unswitched state (VFB=1.0VV_{FB} = 1.0\text{V})
Shutdown CurrentISDI_{SD}—110μA\mu\text{A}VEN=0VV_{EN} = 0\text{V}

Typical Application Circuit

text
       +V_IN (4.5V - 28V DC Input)
          │
       [Pin 7: VIN]
        MP1584EN ──── [Pin 1: SW] ──── [ 4.7µH - 10µH Inductor ] ──┬─── +V_OUT Regulated Output
          │                                  │                     │
       [Pin 5: GND]               [B340A Schottky Diode]        [ R1 ]
          │                                  │                     │
         GND ────────────────────────────────┴─────────────────────┼─── [Pin 4: FB]
                                                                   │
                                                                 [ R2 ]
                                                                   │
                                                                  GND

VOUT=0.8V×(1+R1R2)V_{OUT} = 0.8\text{V} \times \left( 1 + \frac{R_1}{R_2} \right)

Common mistakes

  • Overheating under high continuous current without thermal dissipation: While rated for 3A peak, running continuously at 3A on miniature breakout boards without heatsinking or thermal vias will trigger internal thermal protection.
  • Operating above 28V input: Unlike the LM2596 (40V rating), the MP1584 max input rating is strictly 28 V28\text{ V}. Connecting a fully charged 24 V24\text{ V} lead-acid battery or spikes over 28 V28\text{ V} will destroy the chip.

Notes

  • MP1584 vs LM2596: The MP1584 runs 10x faster (1.5 MHz1.5\text{ MHz} vs 150 kHz150\text{ kHz}), allowing modules to be 1/31/3 the size of LM2596 boards.

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