# SparkFun Buck Regulator Breakout - 1.8V (AP3429A)

**Type:** Product page · **SKU:** COM-21338 · **Brand:** [Sparkfun](https://core-electronics.com.au/brands/sparkfun-australia)
**Page:** https://core-electronics.com.au/sparkfun-buck-regulator-breakout-18v-ap3429a.html ([markdown](https://core-electronics.com.au/sparkfun-buck-regulator-breakout-18v-ap3429a.html.md))

The SparkFun 1.8V Buck Regulator Breakout features the AP3429A from Diodes Inc., a 2A step-down DC-DC converter with an input voltage range of 2.7V to 5.5V...

## Pricing

- **Price:** $12.25 (inc GST) — $11.14 AUD, exc GST
- **Quantity discounts:** 5+ $10.80 (exc GST) · 25+ $10.58 (exc GST) · 100+ $10.14 (exc GST)

## Availability & dispatch

- Available with a lead time — expect dispatch between Aug 21 and Aug 27.

## Description

The SparkFun 1.8V Buck Regulator Breakout features the AP3429A from Diodes Inc., a 2A step-down DC-DC converter with an input voltage range of 2.7V to 5.5V. This full-size, 1in. x 1in. version of our [buck regulator boards](https://www.sparkfun.com/categories/tags/buck-) is configured to provide a regulated 1.8V output, which is controlled by an `EN` *(enable)* pin. To dissipate excess heat, a 0.6in. x 0.5in. copper pad is provided to attach a heat sink to the bottom of the board.

As a full-size buck regulator breakout, additional options for connecting input and output power are available. There is a pre-assembled screw terminal for a non-permanent connection, the option to solder on a [barrel jack](https://core-electronics.com.au/search/?q=119) for an [external power supply](https://www.sparkfun.com/categories/308), and five PTH pins to create a more permanent installation. Our full-size buck regulators also come with a red, power indication LED that light up when the power output is enabled. This board has four mounting holes compatible with [4-40 hardware](https://core-electronics.com.au/search/?q=4-40).

 [Get Started with the SparkFun AP3429A Buck Regulator Guide](https://docs.sparkfun.com/SparkFun_Buck_Regulator_AP3429A)### Features

**Buck Board:**

- 1in. x 1in. PCB layout
- Three power input/output options:
    - Pre-assembled 4-pin screw terminal
    - Five 0.1in. spaced PTH pins
    - Four plated slots for a [DC barrel jack](https://core-electronics.com.au/search/?q=119) *(input only)*
- Power connections:
    - `VIN` - Power In (2.7V to 5.5V)
    - `GND` - Common Ground
    - `VOUT` - Power Out (Regulated 1.8V)
    - `EN` - Enable (Pull high to enable the power output)
- Red, power LED indicator
- 0.5in. x 0.6in. Plated copper pad *(for heat sinks)*

**AP3429A:**

- VIN: 2.7V to 5.5V
- VOUT: 0.6V to VIN
- 2A Continuous Output Current
- 90µA No-Load Quiescent Current
- 1MHz Switching Frequency
- Protection Circuitry
    - Undervoltage Lockout (UVLO)
    - Input Overvoltage Protection
    - Over Current Protection
        - Cycle-by-Cycle Peak Current Limit
    - Thermal Shutdown (160°C/320°F)

### Documents

- [Schematic](https://core-electronics.com.au/attachments/localcontent/schematic-Buck1V8_96348fc0f80.pdf)
- [Eagle Files](https://core-electronics.com.au/attachments/localcontent/eagle_files-Buck1V8_179036df555.zip)
- [Board Dimensions](https://core-electronics.com.au/attachments/localcontent/dimensions_11227aad0ba.pdf)
- [Hookup Guide](https://docs.sparkfun.com/SparkFun_Buck_Regulator_AP3429A/)
- [Datasheet](https://core-electronics.com.au/attachments/localcontent/AP3429A_644929ec47f.pdf) (AP3429A)
    - [AP3428 Application Note](https://core-electronics.com.au/attachments/localcontent/AN_AP3428_2832575ade8.pdf)
- [Manufacturer's Product Page](https://www.diodes.com/part/view/AP3429A/) (AP3429A)
    - [Technical Documentation](https://www.diodes.com/part/view/AP3429A/#tab-details)
    - [Diodes Technical Support Page](https://www.diodes.com/about/contact-us/technical-support/)
- [GitHub Hardware Repo](https://github.com/sparkfun/SparkFun_Buck_Regulator_AP3429A)

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/C/O/COM-21338-1.jpg)