View source for MP1584

{{Module
| name = MP1584 / MP1584EN
| function = Step-Down DC-DC Converter (Buck Converter)
| type = Integrated Circuit / Breakout Module
| manufacturer = Monolithic Power Systems (MPS)
| voltage = Input: 4.5V – 28V / Output: 0.8V – 20V (adjustable)
| current = 3A maximum output
| package = SOIC-8 (IC) / Breakout Module
| interface = Analog (potentiometer adjustment)
| cost = $0.50 – $1.50 USD (module)
| datasheet = [https://www.monolithicpower.com/en/mp1584.html MP1584 Datasheet (MPS)]
}}

The '''MP1584''' (or '''MP1584EN''') is a high-efficiency {{Wikipedia|Buck_converter|step-down (buck) DC-DC converter}} IC commonly used to provide regulated voltage for microcontrollers and other electronics. It's widely available as a small breakout module with an adjustable output voltage.

== Overview ==

The MP1584 is a switching regulator that efficiently converts a higher input voltage to a lower output voltage. Unlike {{Wikipedia|Linear_regulator|linear regulators}}, which waste excess voltage as heat, buck converters use high-frequency switching and energy storage (inductors and capacitors) to achieve >90% efficiency.

For robotics applications, the MP1584 module is typically used to step down battery voltage (6V from 4× AA batteries) to the 3.3V or 5V required by microcontrollers and sensors.

== Key Features ==

* '''High Efficiency''': Up to 96% efficiency (typical 92% at moderate loads)
* '''Wide Input Range''': 4.5V to 28V input
* '''Adjustable Output''': 0.8V to 20V (must be lower than input)
* '''High Current''': 3A maximum output current
* '''Compact Size''': Module typically 22mm × 17mm × 4mm
* '''Over-Current Protection''': Built-in current limiting
* '''Thermal Shutdown''': Protects IC from overheating
* '''Fixed Switching Frequency''': 1.5 MHz (reduces inductor/capacitor size)

== Module Configuration ==

The typical MP1584 breakout module includes:

* '''MP1584EN IC''': The switching regulator chip
* '''Inductor''': Energy storage element (typically 22µH or 33µH)
* '''Input Capacitor''': Smooths input voltage
* '''Output Capacitor''': Smooths output voltage
* '''Potentiometer''': Adjusts output voltage
* '''Input/Output Terminals''': Screw terminals or solder pads

== Pin Configuration ==

Typical module pinout:
* '''IN+ / VIN''': Positive input voltage (4.5V – 28V)
* '''IN− / GND''': Ground input
* '''OUT+ / VOUT''': Positive output voltage (adjustable)
* '''OUT− / GND''': Ground output

== How Buck Converters Work ==

A {{Wikipedia|Buck_converter|buck converter}} uses:

# '''Switching Transistor''': Rapidly switches input voltage on/off (1.5 MHz in MP1584)
# '''Inductor''': Stores energy when switch is ON, releases when OFF
# '''Diode''' (or synchronous rectifier): Provides current path when switch is OFF
# '''Capacitor''': Smooths the output voltage

The output voltage is controlled by the duty cycle (percentage of time the switch is ON):

: <math>V_{out} = V_{in} \times D</math>

Where D is the duty cycle (0 to 1). The MP1584's feedback loop automatically adjusts the duty cycle to maintain the set output voltage.

== Adjustment Procedure ==

'''CRITICAL: Always adjust the buck converter BEFORE connecting it to your circuit!'''

# Do NOT connect your microcontroller or other electronics yet
# Connect a voltmeter to the output terminals
# Apply power to the input (e.g., connect battery)
# Use a small screwdriver to adjust the potentiometer
# Turn clockwise to increase voltage, counter-clockwise to decrease
# Set to desired voltage (e.g., 3.3V for Raspberry Pi Pico)
# Verify voltage is stable
# Disconnect power
# Now you can connect the buck converter to your circuit

'''WARNING''': If you connect electronics before adjusting, the output could be too high and damage your components. Always set the voltage first!

== Usage in BRS Projects ==

The MP1584 is used in [[SimpleBot]]'s [[BRS Differential Drive Robot Control Board]] to convert the 6V battery voltage (4× AA batteries) down to 3.3V for the [[Raspberry Pi Pico]].

=== Why Use a Buck Converter? ===

* '''Efficiency''': ~92% efficient vs. ~60% for linear regulators at this voltage drop
* '''Less Heat''': Wasted energy is minimized, so the converter stays cool
* '''Battery Life''': Higher efficiency means longer runtime on the same batteries
* '''Stable Voltage''': Output remains constant even as battery voltage drops

=== Design Considerations ===

* '''Input Voltage Range''': 4× fresh AA batteries = 6V, but drops to ~4.8V when depleted. The MP1584's 4.5V minimum input means the robot will function until batteries are nearly dead.
* '''Output Current''': The Pico and sensors draw <500mA, well within the 3A capability
* '''Capacitors''': The module's capacitors smooth out voltage ripple for clean microcontroller power

== Efficiency Comparison ==

For 6V → 3.3V conversion at 500mA load:

{| class="wikitable"
! Regulator Type !! Efficiency !! Power Loss !! Heat
|-
| MP1584 (Buck) || ~92% || 0.14W || Minimal
|-
| LM1117 (Linear) || ~55% || 1.35W || Significant
|-
| AMS1117 (Linear) || ~55% || 1.35W || Significant
|}

The buck converter wastes 90% less power as heat!

== Heat Dissipation ==

At moderate loads (<1.5A), the MP1584 module requires no heatsink. At higher currents, the IC and inductor will warm up:

* '''<1A''': No heatsinking needed
* '''1-2A''': Module may become warm (safe)
* '''2-3A''': Module will become hot; ensure good airflow or add heatsink

== Common Issues ==

* '''Output Voltage Too High''': Adjust potentiometer before connecting load
* '''Output Voltage Drops Under Load''': Input voltage too low or module current limit reached
* '''Excessive Ripple''': Bad capacitors or counterfeit module
* '''Module Gets Hot''': Normal at high currents, but check for short circuits
* '''No Output''': Input voltage below 4.5V or module damaged

== Alternatives ==

* '''LM2596''': Older buck converter, lower frequency (52 kHz), lower efficiency, but very common
* '''XL4015''': Higher current capability (5A) for more powerful applications
* '''MP2307''': Smaller package, lower current (3A max)
* '''Linear Regulators (LM1117, AMS1117)''': Simpler but much less efficient

== Buck vs. Linear Regulator ==

{| class="wikitable"
! Feature !! Buck Converter (MP1584) !! Linear Regulator (LM1117)
|-
| Efficiency || 85-96% || 50-70%
|-
| Heat Generation || Low || High
|-
| Output Ripple || Some (mV) || Very low
|-
| Component Count || More (L, C, diode) || Fewer (just capacitors)
|-
| Cost || $1-1.50 || $0.30-0.50
|-
| Complexity || Higher || Lower
|-
| Best For || Battery power || Clean, low-current supplies
|}

For battery-powered robots, buck converters are almost always the better choice.

== See Also ==

* [[BRS Differential Drive Robot Control Board]] - Uses MP1584 for power regulation
* [[SimpleBot]] - Powered by 4× AA batteries via MP1584
* {{Wikipedia|Buck_converter}} - More on step-down converters
* {{Wikipedia|Linear_regulator}} - Alternative voltage regulation method

[[Category:Component]]
[[Category:Power Supply]]
[[Category:DC-DC Converter]]