> **Source:** Core Electronics is an Australian maker-electronics retailer and manufacturer based in Newcastle, NSW, run by a team of makers and educators. We design and manufacture our own product lines (PiicoDev, CE originals) and are official retailers for iconic maker and industrial brands including Raspberry Pi, Arduino, Adafruit, SparkFun and DFRobot. Orders ship Australia-wide from our Newcastle warehouse. Prices are in AUD and include GST. Pricing, stock and dispatch on this page are generated from the store's live catalog. Full machine-readable index: https://core-electronics.com.au/llms.txt # 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. ## How to buy - **Build a cart:** compose `https://core-electronics.com.au/cart/link?items=COM-21338:1` (comma-separated SKU:qty pairs) and share the link. Opening it shows a confirmation page with live pricing and stock before anything is added to the cart. - **Verify the cart first:** fetch `https://core-electronics.com.au/cart/link/COM-21338:1.md` for live line prices (inc & exc GST, quantity discounts applied), stock and dispatch estimates, and totals. Append `/to/{AU-postcode}` (or `/to/{country-code}:{postcode}`) before `.md` for delivery options and prices to that destination. Unknown, retired, or out-of-stock SKUs are flagged. (Query form `cart/link.md?items=...` also works but some robots parsers refuse query strings here.) - **Checkout** is completed on-site and includes a captcha at the payment step. Share the cart link; checkout takes it from there. - **Search the catalogue:** `https://core-electronics.com.au/search/{query}.md` (URL-encode the query; pages 2-3 at `search/{query}/{page}.md`; `search.md?q=` also works) - **Payment methods, purchase orders, policies and contact details:** https://core-electronics.com.au/llms.txt ## 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)