Answer: The MP1584EN is a 4.5–28 V input, 3 A step-down converter in SOIC8E with an internal high-side MOSFET and an external Schottky catch diode. Frequency is set from 100 kHz to 1.5 MHz with one resistor; feedback is 0.8 V (0.776–0.824 V). Status: NRFND. MPS keeps it in production for existing customers and names the MP2338GTL for new designs, which is not pin-compatible. Order code: MP1584EN-LF-Z (RoHS, tape and reel). (MPS MP1584 Rev. 1.0, pp.1–3; MPS product page, checked 2026-10-26.)
Key specifications
| Parameter | Value | Condition | Source |
|---|---|---|---|
| Input voltage (recommended) | 4.5 to 28 V | Absolute maximum −0.3 to +30 V | p.2 Recommended Operating Conditions / Absolute Maximum Ratings |
| Output voltage range | 0.8 to 25 V | — | p.2 Recommended Operating Conditions |
| Feedback voltage VFB | 0.776 / 0.8 / 0.824 V | 4.5 V < VIN < 28 V, TA = 25 °C | p.3 Electrical Characteristics |
| Current limit | 4.0 min / 4.7 typ A | TA = 25 °C | p.3 Electrical Characteristics |
| High-side switch RDS(ON) | 150 mΩ typ | VBST − VSW = 5 V | p.3 Electrical Characteristics |
| Oscillator frequency | 900 kHz typ at RFREQ = 100 kΩ; programmable 100 kHz – 1.5 MHz | — | p.3 Electrical Characteristics; p.1 Features |
| VIN UVLO threshold / hysteresis | 2.7 / 3.0 / 3.3 V; 0.35 V | Rising | p.3 Electrical Characteristics |
| EN up threshold / hysteresis | 1.35 / 1.5 / 1.65 V; 300 mV | Floating EN pulled up to ≈3.0 V by 1 µA | p.3 Electrical Characteristics; p.8 Enable Control |
| Quiescent / shutdown supply current | 100 typ, 125 max µA; 12 typ, 20 max µA | No load VFB = 0.9 V; VEN = 0 V | p.3 Electrical Characteristics |
| Minimum on / off time | 100 ns / 100 ns typ | Guaranteed by design | p.3 Electrical Characteristics (note 5) |
| Soft-start time | 1.5 ms typ | 0 V < VFB < 0.8 V, guaranteed by design | p.3 Electrical Characteristics |
| Thermal shutdown / hysteresis | 150 °C / 15 °C typ | — | p.3 Electrical Characteristics |
| Thermal resistance θJA / θJC | 50 / 10 °C/W | SOIC8E, JESD51-7 4-layer PCB | p.2 Thermal Resistance, note 4 |
| Operating temperature | TA −20 to +85 °C; TJ −20 to +125 °C | — | p.2 Ordering Information / Recommended Operating Conditions |
Status: not recommended for new designs
MPS lists the MP1584 as NRFND. The product page says it “continues to be in production for existing customers” and names the MP2338GTL as the alternative. Every page of the current datasheet carries a “Not recommended for new designs, refer to MP2338” watermark. The MP2338GTL uses a different package (SOT583) and pinout, so moving to it means a new layout. Use this page to maintain, repair or second-source an existing MP1584 board.
Pinout (SOIC8E, top view)
| Pin | Name | Function (p.4) |
|---|---|---|
| 1 | SW | Switch node. Needs a low-drop Schottky diode to ground, placed close to the pin |
| 2 | EN | Enable. Floating or high = on; below threshold = shutdown |
| 3 | COMP | Error-amplifier output; series RC compensation to GND |
| 4 | FB | Feedback, regulates to 0.8 V |
| 5 | GND / exposed pad | Ground; solder the pad to the GND plane |
| 6 | FREQ | Resistor to GND sets switching frequency |
| 7 | VIN | Supply; decouple close to the pin |
| 8 | BST | Bootstrap capacitor to SW |
Design values from the datasheet
Frequency resistor (p.9): RFREQ (kΩ) = 180000 / fS(kHz)^1.1. That gives 193 kΩ for 500 kHz, 101 kΩ for 900 kHz (matching the 100 kΩ / 900 kHz typical on p.3), and 58 kΩ for 1.5 MHz.
Output divider (p.10): VOUT = 0.8 V × (R1 + R2) / R2. About 20 µA from the bootstrap circuit flows into the output at no load, so MPS asks for R2 under 40 kΩ, then uses 40.2 kΩ in its own example. With R2 = 40.2 kΩ, R1 = 50.25 × (VOUT − 0.8) kΩ: 127 kΩ for 3.3 V (MPS’s example), 211 kΩ for 5 V.
Inductor (p.10): MPS aims for ripple of about 30 % of the switch current limit: L = VOUT / (fS × ΔIL) × (1 − VOUT/VIN). Worked example, 12 V to 5 V at 500 kHz with ΔIL = 1.2 A (30 % of the 4.0 A minimum limit): L ≈ 4.9 µH. With a 4.7 µH part, ripple is 1.24 A and peak current at a 2 A load is about 2.6 A, below the 4.0 A minimum limit.
Catch diode and capacitors (p.11): use a Schottky diode rated above the maximum VIN and the maximum load current; the examples are 40 V / 3 A parts. Size the input capacitor for an RMS current above half the maximum load current. With electrolytic or tantalum input capacitors, add a 0.1 µF ceramic right at the IC.
Minimum on-time. The 100 ns minimum on-time (p.3) limits how far you can step down at high frequency. At 1.5 MHz, 24 V to 3.3 V needs an on-time of about 92 ns, below the minimum. At 500 kHz the same conversion needs about 275 ns.
Light load and bootstrap (p.14): at no or light load the part skips pulses, and the bootstrap needs VIN − VOUT > 3 V. For a 3.3 V output, VIN must be above 6.3 V; MPS suggests using EN to set the input UVLO to VOUT + 3 V. An external bootstrap diode (1N4148 or BAT54 class) from a 5 V rail is recommended when VIN ≤ 5 V, when a 5 V rail exists, or when VOUT/VIN > 65 %.
Enable as UVLO (p.8): EN rises at 1.5 V and falls at a precision 1.2 V, so a divider from VIN to EN works as an adjustable under-voltage lockout. Any pull-down only has to sink 1 µA.
Layout (pp.14, 16)
- Keep the loop through the input capacitor, high-side switch and catch diode short.
- Place the feedback resistors and compensation parts close to the chip, away from SW.
- For heat, use small thermal vias (15 mil barrel, 40 mil pitch) under the exposed pad, plus large copper on IN, SW and especially GND.
Heat check: with θJA = 50 °C/W (4-layer JESD51-7 board), the 150 °C absolute-maximum junction leaves about 1.3 W at 85 °C ambient. Taking the 125 °C operating junction limit instead, it is 0.8 W.
Pitfalls specific to MP1584EN
- Leaving out the catch diode. It is a non-synchronous buck with only a high-side switch, so SW needs an external Schottky to ground (p.4).
- Using an R2 above 40 kΩ at no load. The 20 µA bootstrap leakage pushes the output up if the divider current is too small (p.10).
- Asking for a big step-down at 1.5 MHz. The 100 ns minimum on-time stops you (p.3).
- Running VIN within 3 V of VOUT at light load. The bootstrap starves (p.14).
- Pulling EN low through a weak pull-down. Anything that cannot sink 1 µA leaves the chip enabled (p.8).
- Treating MP2338GTL as a drop-in. It is a different package and pinout.
Part numbers (information only)
| Code | Meaning | Source |
|---|---|---|
| MP1584EN | Base part, SOIC8E, top marking MP1584EN, TA −20 to +85 °C | p.2 Ordering Information |
| MP1584EN-Z | Tape and reel | p.2 footnote |
| MP1584EN-LF-Z | RoHS-compliant packaging, tape and reel | p.2 footnote |
The datasheet does not give reel quantities.
Related pages
- Buck converters
- TI LM2596S-ADJ part page: an asynchronous buck with a 150 kHz fixed frequency, for comparison
- Power calculator for loss and heat sums
FAQ
- Is the MP1584 discontinued? No. MPS lists it as NRFND: still in production for existing customers, not recommended for new designs.
- What replaces the MP1584? MPS names the MP2338GTL. It is not pin-compatible (different package and pinout), so it needs a new layout.
- What is the MP1584 pinout? 1 SW, 2 EN, 3 COMP, 4 FB, 5 GND (exposed pad), 6 FREQ, 7 VIN, 8 BST.
- How do I set the MP1584 switching frequency? RFREQ (kΩ) = 180000 / fS(kHz)^1.1, for example about 193 kΩ for 500 kHz.
- What resistors give 3.3 V on an MP1584? R2 = 40.2 kΩ and R1 = 127 kΩ, the datasheet example.
- Does the MP1584 need an external diode? Yes. A Schottky from SW to ground, rated above the maximum input voltage and load current.
Related (internal links)
Sources (retrieved 2026-10-26)
- Monolithic Power Systems, MP1584 3A, 1.5MHz, 28V Step-Down Converter, datasheet Rev. 1.0 (NRFND version): https://www.monolithicpower.com/en/documentview/productdocument/index/version/2/document_type/Datasheet/lang/en/sku/MP1584EN-LF-Z/document_id/204/
- Monolithic Power Systems, MP1584 product page (status NRFND, alternative MP2338GTL), checked 2026-10-26: https://www.monolithicpower.com/en/products/mp1584.html
Disclaimer
Values are copied from MPS MP1584 datasheet Rev. 1.0 (NRFND version) and the MPS product page, both read on 26 Oct 2026. Electrical Characteristics are at TA = 25 °C only; the datasheet gives no over-temperature limits. Many low-cost “MP1584” modules do not say which silicon they carry. NRFND status can change; check the MPS product page before ordering.
Reviewed by: Jasper · Updated: 2026-10-26