Real View
MP1584Step-down switching converter
Follow the switching path from input energy to a regulated output.
MP1584 is a non-synchronous buck converter with an internal high-side MOSFET. An external inductor, Schottky catch diode and capacitors turn its switching waveform into a lower DC voltage; a resistor divider sets the output around a 0.8 V feedback reference. The eight-lead SOIC-8E package has an exposed ground pad underneath. Its current class is 3 A, subject to component selection, board cooling and operating conditions. This reference is for the IC, rather than a particular adjustable module sold around it. The example uses a regulated 12 V input and a nominal 5 V output, with explicit bootstrap, frequency and compensation connections. MPS marks MP1584 as not recommended for new designs and points to MP2338 as an alternative; this page supports understanding and maintaining existing MP1584 designs.
8Physical pins
MP1584EN-LF-ZSOIC-8E
Manufacturer-referencedMonolithic Power Systems
Pin diagram
Select a pin to explore its connection
Highlight
MP1584SOIC-8ETop view · 8 leads; underside exposed pad = GND5
Click a lead or use the arrow keys. Top view · 8 leads; underside exposed pad = GND5
PIN 1 · Switching power stage
Switching power nodeSW
Function
The internal high-side MOSFET drives this node. The inductor and external catch diode complete the buck power stage.
How to connect
Connect the inductor to the output and the Schottky cathode to SW; its anode returns to ground.
Electrical note
SW is a noisy switching node, not the regulated DC output.
PIN 2 · Enable and loop control
Enable inputEN
Function
A high level enables operation; a low level disables it. An open pin also enables the device.
How to connect
Leave open for the fixed 12 V example, or drive within the specified pin limits.
Electrical note
Typical rising threshold 1.5 V. Do not tie EN directly to a 12 V input; its absolute maximum is 6 V.
PIN 3 · Enable and loop control
Loop compensationCOMP
Function
Error-amplifier output used to shape the converter feedback loop.
How to connect
Fit the reviewed series RC network from COMP to ground.
Electrical note
Compensation depends on the inductor, output capacitance, ESR and operating conditions.
PIN 4 · Voltage feedback
Output-voltage feedbackFB
Function
The control loop compares the divided output to a nominal 0.8 V reference.
How to connect
Connect the midpoint of the output-to-ground divider.
Electrical note
Route away from SW and the high-current loop.
PIN 5 · Ground
Ground and exposed padGND
Function
Return for control and power circuitry. The exposed underside pad also connects to ground.
How to connect
Join pin 5 and the exposed pad to a suitable ground plane.
Electrical note
The footprint repeats electrical pad number 5 on the exposed pad; it does not invent a separate signal pin.
PIN 6 · Enable and loop control
Frequency programmingFREQ
Function
A resistor from FREQ to ground sets the switching frequency.
How to connect
Use 200 kΩ in the approximately 500 kHz example.
Electrical note
The frequency setting is nominal; light-load pulse skipping changes the observed switching activity.
PIN 7 · Supply
Input supplyVIN
Function
Supplies the internal control and high-side switching stage.
How to connect
Place a low-ESR input bypass close to VIN and the power return.
Electrical note
Operating input is 4.5–28 V; 30 V is an absolute stress limit, not a working target.
PIN 8 · Supply
Floating bootstrap supplyBST
Function
Provides gate-drive supply above the SW node.
How to connect
Connect 100 nF between BST and SW, with short traces.
Electrical note
Observe the 6 V absolute BST-to-SW limit; this capacitor does not connect to ground.
Key specifications
When the high-side switch turns off, the external Schottky diode provides a path for the inductor current. The output capacitor smooths the voltage while feedback adjusts the switching action.
Operating input4.5–28 V
Output range0.8–25 V · requires input headroom
Output-current class3 A · thermal limits apply
Operating junction−20–125 °C
Package details
MP1584EN-LF-Z · SOIC-8E
| Property | Details |
|---|---|
| Manufacturer | Monolithic Power Systems |
| Part number | MP1584EN-LF-Z |
| Package | SOIC-8E |
| Connections | 8 pins |
| Mounting | SMD |
| Lead pitch | 1.27 mm |
| Package code | SOIC-8E |
| Thermal reference | −20–85°C ambient; −20–125°C operating junction |
Operating envelope
MP1584EN · limits and test conditions
Manufacturer specifications 7 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Input supply | 4.5–28 V | Recommended operating range |
| Output adjustment | 0.8–25 V | Must remain below input with adequate headroom |
| Output-current class | 3 A | Limited by power components, temperature and layout |
| Operating junction | −20 to +125°C | Do not use shutdown temperature as an operating target |
| Ambient ordering range | −20 to +85°C | MP1584EN package reference |
| Package | SOIC-8E | Eight leads plus a grounded exposed pad |
| Lifecycle note | Not recommended for new designs | MPS identifies MP2338 as an alternative; it is not pin-compatible by assumption |
No specifications match. Try a parameter name or a unit.
Electrical table baseline is VIN = 12 V, VEN = 2.5 V, VCOMP = 1.4 V and TA = 25°C unless stated.
Electrical reference
Separate nominal behavior from guaranteed limits
Manufacturer specifications 9 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Feedback voltage | 0.776 / 0.800 / 0.824 V | Minimum / typical / maximum; 4.5 V < VIN < 28 V |
| High-side on resistance | 150 mΩ typical | BST − SW = 5 V |
| Current-limit threshold | 4.0 A minimum; 4.7 A typical | No maximum is stated here; not a 3 A output guarantee |
| UVLO rising threshold | 2.7 / 3.0 / 3.3 V | Internal threshold; operation still requires the specified input range |
| UVLO hysteresis | 0.35 V typical | Input undervoltage control |
| EN rising threshold | 1.35 / 1.50 / 1.65 V | EN hysteresis 0.30 V typical |
| No-load quiescent current | 100 µA typical; 125 µA maximum | FB = 0.9 V |
| Shutdown current | 12 µA typical; 20 µA maximum | EN = 0 V |
| Soft start | 1.5 ms | Design-guaranteed source value; FB from 0 to 0.8 V |
No specifications match. Try a parameter name or a unit.
Typical values do not establish worst-case performance.
Frequency and compensation
The example follows the 5 V compensation row
Manufacturer specifications 7 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Programmable frequency | 100 kHz–1.5 MHz | External resistor at FREQ |
| RFREQ relationship | RFREQ[kΩ] = 180000 / f[kHz]^1.1 | Approximate design equation |
| Example RFREQ | 200 kΩ | Approximately 485 kHz by the equation; nominal 500 kHz class |
| Example output inductor | 15 µH | Source table lists 15–22 µH for 5 V / 22 µF output |
| Example output capacitor | 22 µF low-ESR ceramic | Account for capacitance loss under DC bias |
| COMP series network | 100 kΩ and 150 pF to ground | Source 5 V compensation row |
| Extra COMP capacitor | Not fitted in this example | Evaluate separately for high-ESR output capacitors |
No specifications match. Try a parameter name or a unit.
Changing power-stage components can require a new loop-stability review.
12 V to nominal 5 V
Illustrative 1 A load · regulated bench input
Manufacturer specifications 10 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Input / output | 12 V / 4.984 V nominal | Before reference, resistor and regulation errors |
| Feedback divider | 52.3 kΩ upper; 10 kΩ lower | Use 1% resistors; nominal divider current 80 µA |
| Bootstrap capacitor | 100 nF | Between BST8 and SW1 |
| Input bypass | 10 µF, 50 V ceramic | Place close to VIN7 and the power return |
| Catch diode | 40 V Schottky, at least 3 A class | Cathode at SW; anode at GND; check losses and surge ratings |
| Output inductor | 15 µH, ≥4 A saturation rating for normal operation | Check RMS current and fault behavior separately |
| Output capacitor | 22 µF, 10 V ceramic | Effective capacitance and ESR matter |
| Example load | 5 Ω, at least 10 W | About 1 A and 5 W; resistor will dissipate heat |
| EN connection | Open | Fixed 12 V input example; do not tie EN to VIN |
| Ideal inductor ripple | About 0.39 A peak-to-peak at 500 kHz | 12 V input, 5 V output, 15 µH; continuous-conduction approximation |
No specifications match. Try a parameter name or a unit.
This is an engineering starting circuit, not a claim of tested converter hardware.
Layout and startup
Short power paths; quiet feedback
Manufacturer specifications 7 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Hot loop | Input bypass → VIN / switch → catch diode → return | Keep the switching-current loop compact |
| SW copper | Short connection to inductor and diode | Keep clear of FB and compensation traces |
| Exposed pad | Connect to ground copper | Thermal vias and solder stencil need assembly-specific review |
| Bootstrap loop | BST capacitor close to BST and SW | Do not connect this capacitor to ground |
| Light-load headroom | VIN − VOUT greater than 3 V | Source guidance for refreshing the floating bootstrap supply |
| High duty ratio / low input | Review external bootstrap diode guidance | Source recommends it when VOUT/VIN >65% or VIN <5 V |
| Feedback pickup | Sense the regulated output after the inductor | Keep the divider and COMP components close to the IC |
No specifications match. Try a parameter name or a unit.
The fixed 12 V-to-5 V example provides generous bootstrap headroom.
Heat and stress limits
Stress ratings are not normal operating conditions
Manufacturer specifications 7 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Junction-to-ambient reference | 50°C/W | JESD51-7 four-layer test board |
| Junction-to-case reference | 10°C/W | Source package metric |
| Thermal shutdown | 150°C typical | 15°C typical hysteresis |
| Input absolute maximum | 30 V | Normal operation limited to 28 V |
| BST relative to SW | −0.3 to +6 V | Absolute stress limits |
| Other control pins | −0.3 to +6 V | Includes EN; do not connect directly to a high input rail |
| Absolute junction / storage | 150°C / −65 to +150°C | Stress / storage ratings |
No specifications match. Try a parameter name or a unit.
Actual temperature depends on switching losses, diode and inductor losses, copper and airflow.
Package and footprint
MP1584EN-LF-Z · top-view numbering
Manufacturer specifications 7 parameters
Scroll sideways to see all columns.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Nominal molded body | 3.9 × 4.9 mm | SOIC-8E; 1.27 mm lead pitch |
| Body height | 1.30–1.70 mm | Manufacturer mechanical drawing |
| Lead span | 5.80–6.20 mm | Across the two banks |
| Exposed pad | 2.26–2.56 × 3.15–3.45 mm | Underside metal; electrically GND |
| Outer lands | 1.60 × 0.61 mm | 5.40 mm row centers; 1.27 mm pitch |
| Exposed land | 2.62 × 3.51 mm | Same electrical pad number 5 as the GND lead |
| Surface mounting only | SOIC-8E | No through-hole version is presented |
No specifications match. Try a parameter name or a unit.
The original footprint is a starting land pattern; review mask, stencil, vias and assembly clearances.
Connections by function
Select a pin for its function, connection guidance and electrical notes.
Switching power stage1 pin
Enable and loop control3 pins
Voltage feedback1 pin
Ground1 pin
Supply2 pins
MP1584 at a glance
Follow the labeled connections and functional stages
How it works
3 stages · Explore one step at a time
Store energy
During the on interval, current flows from VIN through the MOSFET and inductor into the output.
Keep current flowing
During the off interval, the Schottky diode conducts from ground into SW, completing the inductor-current path.
Close the loop
FB senses the output divider. COMP and the FREQ resistor shape the response and nominal switching rate.
Step 1 of 3
MP1584 in a circuit
Physical SOIC-8E pin positions with the external power and control networks.
Connect it, step by step
Follow the component values and pin connections
Connect the power stage
VIN takes the bypassed 12 V input; SW feeds the inductor and diode cathode.
Add control networks
Connect the output divider, FREQ resistor and COMP series RC.
Complete the return
Ground pin 5 and the underside exposed pad; keep the physical switching loop short.
Inside MP1584
A compact functional cutaway of the current-mode buck controller.
Explore the circuit
Select a stage to see its role and connections
Compare and control
The 0.8 V reference and error amplifier process the FB voltage.
Switch the high side
A bootstrap-powered driver operates the integrated MOSFET.
Limit abnormal operation
Current limiting, UVLO, soft start and thermal control constrain the power stage.
Selected packageSOIC-8EMP1584EN-LF-Z
Physical connections8 pinsPackage-specific numbering
Reference collection8 tables54 parameters & pin functions
Pin reference
Signal names, electrical functions and connection guidance
Physical pin numbers8 pins
Scroll within the table to see all columns and rows.
| Pin | Signal | Type | Function & connection |
|---|---|---|---|
| SW | Switching power node | The internal high-side MOSFET drives this node. The inductor and external catch diode complete the buck power stage.Connection guidanceConnect the inductor to the output and the Schottky cathode to SW; its anode returns to ground. SW is a noisy switching node, not the regulated DC output. | |
| EN | Enable input | A high level enables operation; a low level disables it. An open pin also enables the device.Connection guidanceLeave open for the fixed 12 V example, or drive within the specified pin limits. Typical rising threshold 1.5 V. Do not tie EN directly to a 12 V input; its absolute maximum is 6 V. | |
| COMP | Loop compensation | Error-amplifier output used to shape the converter feedback loop.Connection guidanceFit the reviewed series RC network from COMP to ground. Compensation depends on the inductor, output capacitance, ESR and operating conditions. | |
| FB | Output-voltage feedback | The control loop compares the divided output to a nominal 0.8 V reference.Connection guidanceConnect the midpoint of the output-to-ground divider. Route away from SW and the high-current loop. | |
| GND | Ground and exposed pad | Return for control and power circuitry. The exposed underside pad also connects to ground.Connection guidanceJoin pin 5 and the exposed pad to a suitable ground plane. The footprint repeats electrical pad number 5 on the exposed pad; it does not invent a separate signal pin. | |
| FREQ | Frequency programming | A resistor from FREQ to ground sets the switching frequency.Connection guidanceUse 200 kΩ in the approximately 500 kHz example. The frequency setting is nominal; light-load pulse skipping changes the observed switching activity. | |
| VIN | Input supply | Supplies the internal control and high-side switching stage.Connection guidancePlace a low-ESR input bypass close to VIN and the power return. Operating input is 4.5–28 V; 30 V is an absolute stress limit, not a working target. | |
| BST | Floating bootstrap supply | Provides gate-drive supply above the SW node.Connection guidanceConnect 100 nF between BST and SW, with short traces. Observe the 6 V absolute BST-to-SW limit; this capacitor does not connect to ground. |
No pins match these filters. Try another signal name or reset the filters.
Operating envelope
MP1584EN · limits and test conditions
Manufacturer-referenced values7 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Input supply | 4.5–28 V | Recommended operating range |
| Output adjustment | 0.8–25 V | Must remain below input with adequate headroom |
| Output-current class | 3 A | Limited by power components, temperature and layout |
| Operating junction | −20 to +125°C | Do not use shutdown temperature as an operating target |
| Ambient ordering range | −20 to +85°C | MP1584EN package reference |
| Package | SOIC-8E | Eight leads plus a grounded exposed pad |
| Lifecycle note | Not recommended for new designs | MPS identifies MP2338 as an alternative; it is not pin-compatible by assumption |
No specifications match. Try a parameter name or a unit.
Electrical table baseline is VIN = 12 V, VEN = 2.5 V, VCOMP = 1.4 V and TA = 25°C unless stated.
Electrical reference
Separate nominal behavior from guaranteed limits
Manufacturer-referenced values9 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Feedback voltage | 0.776 / 0.800 / 0.824 V | Minimum / typical / maximum; 4.5 V < VIN < 28 V |
| High-side on resistance | 150 mΩ typical | BST − SW = 5 V |
| Current-limit threshold | 4.0 A minimum; 4.7 A typical | No maximum is stated here; not a 3 A output guarantee |
| UVLO rising threshold | 2.7 / 3.0 / 3.3 V | Internal threshold; operation still requires the specified input range |
| UVLO hysteresis | 0.35 V typical | Input undervoltage control |
| EN rising threshold | 1.35 / 1.50 / 1.65 V | EN hysteresis 0.30 V typical |
| No-load quiescent current | 100 µA typical; 125 µA maximum | FB = 0.9 V |
| Shutdown current | 12 µA typical; 20 µA maximum | EN = 0 V |
| Soft start | 1.5 ms | Design-guaranteed source value; FB from 0 to 0.8 V |
No specifications match. Try a parameter name or a unit.
Typical values do not establish worst-case performance.
Frequency and compensation
The example follows the 5 V compensation row
Manufacturer-referenced values7 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Programmable frequency | 100 kHz–1.5 MHz | External resistor at FREQ |
| RFREQ relationship | RFREQ[kΩ] = 180000 / f[kHz]^1.1 | Approximate design equation |
| Example RFREQ | 200 kΩ | Approximately 485 kHz by the equation; nominal 500 kHz class |
| Example output inductor | 15 µH | Source table lists 15–22 µH for 5 V / 22 µF output |
| Example output capacitor | 22 µF low-ESR ceramic | Account for capacitance loss under DC bias |
| COMP series network | 100 kΩ and 150 pF to ground | Source 5 V compensation row |
| Extra COMP capacitor | Not fitted in this example | Evaluate separately for high-ESR output capacitors |
No specifications match. Try a parameter name or a unit.
Changing power-stage components can require a new loop-stability review.
12 V to nominal 5 V
Illustrative 1 A load · regulated bench input
Manufacturer-referenced values10 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Input / output | 12 V / 4.984 V nominal | Before reference, resistor and regulation errors |
| Feedback divider | 52.3 kΩ upper; 10 kΩ lower | Use 1% resistors; nominal divider current 80 µA |
| Bootstrap capacitor | 100 nF | Between BST8 and SW1 |
| Input bypass | 10 µF, 50 V ceramic | Place close to VIN7 and the power return |
| Catch diode | 40 V Schottky, at least 3 A class | Cathode at SW; anode at GND; check losses and surge ratings |
| Output inductor | 15 µH, ≥4 A saturation rating for normal operation | Check RMS current and fault behavior separately |
| Output capacitor | 22 µF, 10 V ceramic | Effective capacitance and ESR matter |
| Example load | 5 Ω, at least 10 W | About 1 A and 5 W; resistor will dissipate heat |
| EN connection | Open | Fixed 12 V input example; do not tie EN to VIN |
| Ideal inductor ripple | About 0.39 A peak-to-peak at 500 kHz | 12 V input, 5 V output, 15 µH; continuous-conduction approximation |
No specifications match. Try a parameter name or a unit.
This is an engineering starting circuit, not a claim of tested converter hardware.
Layout and startup
Short power paths; quiet feedback
Manufacturer-referenced values7 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Hot loop | Input bypass → VIN / switch → catch diode → return | Keep the switching-current loop compact |
| SW copper | Short connection to inductor and diode | Keep clear of FB and compensation traces |
| Exposed pad | Connect to ground copper | Thermal vias and solder stencil need assembly-specific review |
| Bootstrap loop | BST capacitor close to BST and SW | Do not connect this capacitor to ground |
| Light-load headroom | VIN − VOUT greater than 3 V | Source guidance for refreshing the floating bootstrap supply |
| High duty ratio / low input | Review external bootstrap diode guidance | Source recommends it when VOUT/VIN >65% or VIN <5 V |
| Feedback pickup | Sense the regulated output after the inductor | Keep the divider and COMP components close to the IC |
No specifications match. Try a parameter name or a unit.
The fixed 12 V-to-5 V example provides generous bootstrap headroom.
Heat and stress limits
Stress ratings are not normal operating conditions
Manufacturer-referenced values7 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Junction-to-ambient reference | 50°C/W | JESD51-7 four-layer test board |
| Junction-to-case reference | 10°C/W | Source package metric |
| Thermal shutdown | 150°C typical | 15°C typical hysteresis |
| Input absolute maximum | 30 V | Normal operation limited to 28 V |
| BST relative to SW | −0.3 to +6 V | Absolute stress limits |
| Other control pins | −0.3 to +6 V | Includes EN; do not connect directly to a high input rail |
| Absolute junction / storage | 150°C / −65 to +150°C | Stress / storage ratings |
No specifications match. Try a parameter name or a unit.
Actual temperature depends on switching losses, diode and inductor losses, copper and airflow.
Package and footprint
MP1584EN-LF-Z · top-view numbering
Manufacturer-referenced values7 parameters
Scroll within the table to see all columns and rows.
| Parameter | Value | Conditions / notes |
|---|---|---|
| Nominal molded body | 3.9 × 4.9 mm | SOIC-8E; 1.27 mm lead pitch |
| Body height | 1.30–1.70 mm | Manufacturer mechanical drawing |
| Lead span | 5.80–6.20 mm | Across the two banks |
| Exposed pad | 2.26–2.56 × 3.15–3.45 mm | Underside metal; electrically GND |
| Outer lands | 1.60 × 0.61 mm | 5.40 mm row centers; 1.27 mm pitch |
| Exposed land | 2.62 × 3.51 mm | Same electrical pad number 5 as the GND lead |
| Surface mounting only | SOIC-8E | No through-hole version is presented |
No specifications match. Try a parameter name or a unit.
The original footprint is a starting land pattern; review mask, stencil, vias and assembly clearances.
No matching rowsTry a pin name, parameter, unit or test condition, or reset the filters.
Existing buck supplies
Understand compact MP1584-based supplies and their operating limits.
Manufacturer application guideSwitching-power education
Trace on/off current paths, feedback and the bootstrap supply.
Manufacturer application guideBoard review
Check ground-pad cooling, diode polarity and separation of SW from feedback.
Manufacturer application guideTake it into ProTech
Find MP1584 in the Components Library to place its schematic symbol and connect its pins.
Reference page · circuit simulation model not yet availableOpen ProTech