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SOP-8 · MP1584EN
Active3A Buck Converter
MP1584EN
Monolithic Power Systems · SOP-8 · 3A Buck Converter
Price on Request
Get a competitive quote within 24 hours. Volume discounts available. Shenzhen stock ships in 1-2 business days.
Overview
The MP1584EN is Monolithic Power Systems' 3 A, 1.5 MHz, 28 V step-down converter, and it is the silicon behind the ubiquitous mini buck modules sold for single-board computers, camera rigs and automotive accessories. Architecture is peak current-mode control with an integrated high-side power MOSFET and an external Schottky catch diode, which gives fast loop response, simple type-II compensation on the COMP pin and inherent cycle-by-cycle current limiting. Input range is 4.5 V to 28 V with a 30 V absolute maximum, output is programmable from 0.8 V to 25 V against a 0.8 V feedback reference held to ±3%, and the internal current limit is set at 4.0 A minimum with no sense resistor required.
The headline feature for modern designs is frequency programmability: a single resistor from the FREQ pin to ground sets the oscillator anywhere between 100 kHz and 1.5 MHz (100 kΩ gives 900 kHz typical). Running at 1.5 MHz shrinks the inductor to 2.2 µH to 4.7 µH and the output capacitors to a few tens of microfarads of ceramic, and pushes the fundamental above the AM radio and ADSL bands that plague 150 kHz converters. Light-load pulse skipping and frequency foldback keep quiescent current at 100 µA typical and 125 µA maximum, and the EN pin pulls supply current down to 12 µA to 20 µA in shutdown, so the part can live permanently on a battery-backed rail. Efficiency peaks in the low 90% region for a 12 V to 5 V conversion and stays high across the load range because switching and gate-drive losses scale down at light load.
Thermal and layout behaviour deserve attention. The SOIC8E package has an exposed pad, with 50 °C/W junction-to-ambient and 10 °C/W junction-to-case on a JESD51-7 four-layer board and a 2.5 W dissipation limit at 25 °C; connect the pad to a solid ground plane with several vias. The high-side switch is 150 mΩ typical, so conduction loss is modest, but at 1.5 MHz the switching-node loop (VIN capacitor, IC, Schottky) must be laid out in a few square millimetres or EMI will dominate. Soft-start is internal at 1.5 ms, minimum on and off times are 100 ns each, and thermal shutdown trips at 150 °C with 15 °C hysteresis. Free-air temperature rating for MP1584EN is -20 °C to +85 °C — note this is narrower than the -40 °C industrial rating of the LM2596 or XL4015, which matters for outdoor and automotive-adjacent products.
For sourcing, order the full code MP1584EN-LF-Z (lead-free, tape-and-reel) so you receive the RoHS-compliant SOIC8E on reel; the thermally enhanced SOIC8E is the only package MPS lists for this order code, so never accept a bare MP1584EN description on a purchase order. Shenzhen stock is deep because module makers buy it in volume, but the market is heavily remarked: genuine MPS parts carry a clean laser-etched MP1584EN top mark and produce a stable 1.5 MHz (or your programmed) switching frequency, while clones oscillate erratically, fold back current early and often lack real thermal shutdown. MOQ from our warehouse is 100 pcs loose or 2,500 pcs on reel, shipping in one to two business days; authorised MPS channel replenishment runs ten to sixteen weeks.
Key Features
- 3 A output from a 4.5 V to 28 V input with 0.8 V to 25 V adjustable output
- Programmable 100 kHz to 1.5 MHz switching for tiny magnetics and low EMI
- 100 µA operating quiescent current, 12 µA to 20 µA in EN shutdown
- 150 mΩ internal high-side MOSFET with 4 A minimum internal current limit
- SOIC8E with exposed pad: 50 °C/W junction-to-ambient, 2.5 W dissipation limit
Typical Applications
- 12 V and 24 V automotive or industrial rails down to 5 V and 3.3 V logic
- Compact buck modules for Raspberry Pi, camera and single-board-computer kits
- Battery-powered instruments where light-load efficiency dominates runtime
- Pre-regulation for LDOs feeding noise-sensitive analogue and RF circuits
- Distributed point-of-load conversion on networking and control boards
Specifications
- Topology
- Step-Down Buck (Current Mode)
- Input Voltage
- 4.5 to 28 V
- Output Voltage
- 0.8 to 25 V
- Output Current (Max)
- 3 A
- Switching Frequency (Programmable)
- 0.1 to 1.5 MHz
- Peak Efficiency (Typ, 12 V to 5 V)
- 92 %
- High-Side Switch RDS(on)
- 150 mΩ
- Quiescent Current (No Load, Typ)
- 100 µA
- Pins
- 8
- RoHS
- Compliant
Procurement Tips
Always write the full order code MP1584EN-LF-Z on the purchase order — a bare MP1584EN description lets the assembler substitute tube packing, a non-lead-free build or an outright remarked clone, and insist on the FREQ programming resistor being fitted even if you want the maximum 1.5 MHz rate.
Frequently Asked Questions
MP1584EN versus LM2596 — which fits my board?
The MP1584EN wins on size, light-load efficiency and EMI: 1.5 MHz operation means a 2.2 µH to 4.7 µH inductor and small ceramics, 100 µA quiescent current keeps battery runtime up, and it fits in an 8-pin SOIC. The LM2596 wins on input voltage (40 V versus 28 V), temperature range (-40 °C to +125 °C junction versus -20 °C to +85 °C free air for MP1584EN) and ruggedness in a TO-220 with a heatsink. For a 12 V automotive rail with load dumps, keep the LM2596 or add input protection; for a dense 5 V/3 A board, use the MP1584EN.
How do I set the switching frequency, and does it matter?
Connect a resistor from FREQ to ground: the datasheet specifies 900 kHz with 100 kΩ, and the full range is 100 kHz to 1.5 MHz. Leaving the pin floating is not a defined 1.5 MHz condition, so always fit a resistor. Higher frequency shrinks the inductor and output capacitors and moves noise above the AM band, but increases switching loss in the 150 mΩ MOSFET and gate-drive loss, lowering peak efficiency by a few percent. For a 12 V to 5 V/3 A conversion, 500 kHz is usually the sweet spot between size and efficiency.
Why does my MP1584 module only deliver 2 A before it shuts down?
Usually heat, not silicon. The module versions use a thin 2-layer PCB with little copper under the exposed pad, so at 12 V to 5 V and 2 A the junction climbs past 150 °C and thermal shutdown cycles the output. Fixes: add airflow, solder a small heatsink or copper shim to the IC, reduce switching frequency to cut switching loss, or move to a 5 A part such as the XL4015. Also check that the catch diode is a real Schottky and not a slow rectifier, which adds several hundred millivolts of loss.
Can the MP1584EN run from a 24 V truck battery or a 28 V supply?
The absolute maximum input is 30 V and the operating range is 4.5 V to 28 V, so a nominal 24 V rail is acceptable if transients are clamped. Automotive load dump and cold-crank conditions will exceed 30 V, so add a TVS (SMBJ28A class) and reverse-polarity protection, and prefer an AEC-Q100 part such as the LM2596 or a 40 V-rated synchronous buck for certified automotive designs. The MP1584EN free-air rating is -20 °C to +85 °C, which excludes under-bonnet mounting.
What output capacitor and inductor should I use at 1.5 MHz?
A 2.2 µH to 4.7 µH low-DCR shielded inductor rated for 4 A or more, and 22 µF to 44 µF of X5R or X7R ceramic on the output (two 22 µF 0805 or 1206 parts in parallel), plus 100 nF close to the feedback divider. The device is specified as ceramic-capacitor stable, so no tantalum ESR trick is needed. Remember that X5R ceramics lose half their capacitance at rated DC bias, so derate: a 22 µF 0805 at 5 V behaves like 12 µF to 15 µF.
How do I spot a counterfeit MP1584EN?
Check the top mark for laser-etched MP1584EN with the MPS logo and a traceable date code, examine the exposed pad for uniform plating rather than re-tinning, and measure on the bench: a genuine part shows a clean, stable programmed frequency, starts up in about 1.5 ms with no overshoot above the 0.8 V reference tolerance, holds regulation to 3 A and shuts down cleanly when you pull EN low. Clones typically show frequency drift, poor line regulation above 20 V and no thermal shutdown. We sample-test every reel on a 3 A load bank.
What is the MOQ and lead time?
MOQ is 100 pcs loose for prototyping or 2,500 pcs on tape-and-reel for MP1584EN-LF-Z. Shenzhen stock ships in one to two business days; authorised MPS replenishment is ten to sixteen weeks.
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