USB Power Delivery Trigger HAT

Overview

This tutorial walks through designing a USB Power Delivery (PD) Trigger HAT using tscircuit. A USB PD Trigger HAT negotiates higher voltages from a USB-C PD power source—unlocking 9V, 12V, 15V, or 20V instead of the default 5V. This is ideal for powering motors, high-brightness LEDs, audio amplifiers, or any project needing more than the standard 500mA at 5V.

What is USB Power Delivery?

USB Power Delivery (USB PD) is a fast-charging standard that allows USB-C devices to negotiate higher power levels. Standard USB provides 5V at up to 500mA (2.5W), but USB PD can deliver:

Voltage	Max Current	Max Power
5V	3A	15W
9V	3A	27W
12V	3A	36W
15V	3A	45W
20V	5A	100W

How PD Negotiation Works

When you plug a USB-C PD charger into a device, communication happens over the CC (Configuration Channel) pins. The process works like this:

Detection: The charger (source) detects a device (sink) on the CC line with a pull-down resistor
Capability Advertisement: The source sends its supported voltage/current profiles to the sink
Request: The sink requests a specific voltage from the available profiles
Acceptance: The source switches to the requested voltage and signals "power ready"
Delivery: Power flows at the negotiated voltage

PD Trigger ICs

A PD Trigger IC handles this negotiation automatically. Instead of implementing the complex USB PD protocol yourself, a tiny chip like the CH224K or IP2721 does it all:

CH224K: Configurable via a single resistor or pin. Supports 5V/9V/12V/15V/20V output. SOT-23-6 package, costs under $0.15.
IP2721: Similar functionality with additional protection features. Supports up to 100W.

The trigger IC connects to the CC pins of the USB-C port and handles the entire PD handshake, outputting the negotiated voltage on its VOUT pin.

Circuit Requirements

Our USB PD Trigger HAT needs to:

Accept USB-C input with PD negotiation
Output a configurable PD voltage (e.g., 12V or 20V)
Provide a regulated 3.3V rail for logic-level devices
Expose power rails via pin headers for downstream use

Building the Circuit Step by Step

Step 1: Add the USB-C Connector

The USB-C connector provides access to VBUS (power), CC (configuration), and GND pins. We use all four VBUS pins to handle the full current capacity.

Step 2: Add the PD Trigger IC (CH224K)

The CH224K is a 6-pin chip. The key pins are:

CC: Connects to both CC1 and CC2 of the USB-C port for PD negotiation
VOUT: Outputs the negotiated voltage (e.g., 12V)
SEL: Configuration pin — setting this pin high/low selects the desired output voltage
PG: Power Good indicator — goes high when negotiation is complete and power is stable

Step 3: Add a 3.3V Voltage Regulator

Most microcontrollers and logic circuits run at 3.3V. We add an AMS1117-3.3 regulator to derive 3.3V from the PD voltage. Input and output capacitors are essential for stability.

Step 4: Add Output Headers

Pin headers make it easy to tap into the PD voltage and 3.3V rail for downstream circuits.

Step 5: Wire Everything Together

Now we connect all components — USB-C VBUS to the PD trigger IC, CC pins for negotiation, the regulator, and the output headers.

export default () => (
<board width="65mm" height="30mm">
  <chip
    name="J1"
    manufacturerPartNumber="USB-C-16P"
    footprint="ssop16"
    pinLabels={{
      pin1: ["GND"],
      pin2: ["VBUS1"],
      pin3: ["CC1"],
      pin4: ["D-"],
      pin5: ["D+"],
      pin6: ["SBU1"],
      pin7: ["VBUS2"],
      pin8: ["GND"],
      pin9: ["GND"],
      pin10: ["VBUS3"],
      pin11: ["CC2"],
      pin12: ["D+"],
      pin13: ["D-"],
      pin14: ["SBU2"],
      pin15: ["VBUS4"],
      pin16: ["GND"],
    }}
    schPortArrangement={{
      leftSide: { pins: ["VBUS1", "D-", "D+", "SBU1", "VBUS2", "CC1", "CC2"], direction: "top-to-bottom" },
      rightSide: { pins: ["VBUS3", "D+", "D-", "SBU2", "VBUS4", "GND", "GND"], direction: "top-to-bottom" },
    }}
    pcbX={-22}
    pcbY={0}
  />
  <chip
    name="U1"
    manufacturerPartNumber="CH224K"
    footprint="sot23-6"
    pinLabels={{
      pin1: ["sel"],
      pin2: ["vout"],
      pin3: ["gnd"],
      pin4: ["cc"],
      pin5: ["nc"],
      pin6: ["pg"],
    }}
    schPortArrangement={{
      leftSide: { pins: ["sel", "cc", "nc"], direction: "top-to-bottom" },
      rightSide: { pins: ["vout", "gnd", "pg"], direction: "top-to-bottom" },
    }}
    pcbX={0}
    pcbY={0}
  />
  <chip
    name="U2"
    manufacturerPartNumber="AMS1117-3.3"
    footprint="sot223"
    pinLabels={{
      pin1: ["gnd"],
      pin2: ["vout"],
      pin3: ["vin"],
    }}
    schPortArrangement={{
      leftSide: { pins: ["gnd"], direction: "top-to-bottom" },
      rightSide: { pins: ["vin", "vout"], direction: "top-to-bottom" },
    }}
    pcbX={12}
    pcbY={0}
  />
  <capacitor name="C1" capacitance="10uF" footprint="0603" pcbX={12} pcbY={-5} />
  <capacitor name="C2" capacitance="10uF" footprint="0603" pcbX={12} pcbY={5} />
  <pinheader name="H1" pinCount={4} pcbX={22} pcbY={0} />

  <trace from=".J1 .VBUS1" to=".U1 .vout" />
  <trace from=".J1 .VBUS2" to=".U1 .vout" />
  <trace from=".J1 .VBUS3" to=".U1 .vout" />
  <trace from=".J1 .VBUS4" to=".U1 .vout" />
  <trace from=".J1 .GND" to="net.GND" />

  <trace from=".J1 .CC1" to=".U1 .cc" />
  <trace from=".J1 .CC2" to=".U1 .cc" />

  <trace from=".U1 .gnd" to="net.GND" />

  <trace from=".U1 .vout" to=".U2 .vin" />
  <trace from=".U1 .vout" to=".H1 .pin1" />

  <trace from=".U2 .gnd" to="net.GND" />
  <trace from=".U2 .vout" to=".C1 .pos" />
  <trace from=".U2 .vout" to=".H1 .pin3" />
  <trace from=".C1 .neg" to="net.GND" />

  <trace from=".C2 .pos" to=".U1 .vout" />
  <trace from=".C2 .neg" to="net.GND" />

  <trace from=".H1 .pin2" to="net.GND" />
  <trace from=".H1 .pin4" to="net.GND" />
</board>
)

Configuring the Output Voltage

The CH224K trigger IC detects the desired voltage based on the state of the SEL pin. The CH224K supports multiple configuration modes:

Resistor-Based Configuration (CH224K)

Connect a resistor between the SEL pin and GND to select the output voltage:

Resistance	Output Voltage
NC (float)	5V
10k	9V
5.1k	12V
3.3k	15V
2k	20V

In our circuit, you can replace the SEL pin connection with a specific resistor to set the desired voltage. For example, to select 12V output:

<resistor name="R_SEL" resistance="5.1k" footprint="0402" pcbX={-5} pcbY={-5} />
<trace from=".U1 .sel" to=".R_SEL .pos" />
<trace from=".R_SEL .neg" to="net.GND" />

Output Pin Header Reference

The 4-pin output header provides:

Pin	Signal	Description
1	VPD	Negotiated PD voltage (e.g., 12V)
2	GND	Ground
3	V3.3	Regulated 3.3V output
4	GND	Ground

Safety Considerations

Minimum Load: Some PD chargers require a minimum current draw to maintain the negotiated voltage. If the output drops unexpectedly, add a small load resistor
Heat Dissipation: At higher voltages, the AMS1117 may get hot if drawing significant current on the 3.3V rail. Consider a switching regulator for high-current 3.3V loads
Inrush Current: Add a bulk capacitor (10-100 F) on the PD output if powering inductive loads like motors
Reverse Current Protection: Add a Schottky diode if there's any risk of back-feeding voltage into the PD trigger IC

PCB Layout

Here is the full PCB layout with all components positioned:

export default () => (
<board width="65mm" height="30mm">
  <chip
    name="J1"
    manufacturerPartNumber="USB-C-16P"
    footprint="ssop16"
    pinLabels={{
      pin1: ["GND"],
      pin2: ["VBUS1"],
      pin3: ["CC1"],
      pin4: ["D-"],
      pin5: ["D+"],
      pin6: ["SBU1"],
      pin7: ["VBUS2"],
      pin8: ["GND"],
      pin9: ["GND"],
      pin10: ["VBUS3"],
      pin11: ["CC2"],
      pin12: ["D+"],
      pin13: ["D-"],
      pin14: ["SBU2"],
      pin15: ["VBUS4"],
      pin16: ["GND"],
    }}
    schPortArrangement={{
      leftSide: { pins: ["VBUS1", "D-", "D+", "SBU1", "VBUS2", "CC1", "CC2"], direction: "top-to-bottom" },
      rightSide: { pins: ["VBUS3", "D+", "D-", "SBU2", "VBUS4", "GND", "GND"], direction: "top-to-bottom" },
    }}
    pcbX={-22}
    pcbY={0}
  />
  <chip
    name="U1"
    manufacturerPartNumber="CH224K"
    footprint="sot23-6"
    pinLabels={{
      pin1: ["sel"],
      pin2: ["vout"],
      pin3: ["gnd"],
      pin4: ["cc"],
      pin5: ["nc"],
      pin6: ["pg"],
    }}
    schPortArrangement={{
      leftSide: { pins: ["sel", "cc", "nc"], direction: "top-to-bottom" },
      rightSide: { pins: ["vout", "gnd", "pg"], direction: "top-to-bottom" },
    }}
    pcbX={0}
    pcbY={0}
  />
  <chip
    name="U2"
    manufacturerPartNumber="AMS1117-3.3"
    footprint="sot223"
    pinLabels={{
      pin1: ["gnd"],
      pin2: ["vout"],
      pin3: ["vin"],
    }}
    schPortArrangement={{
      leftSide: { pins: ["gnd"], direction: "top-to-bottom" },
      rightSide: { pins: ["vin", "vout"], direction: "top-to-bottom" },
    }}
    pcbX={12}
    pcbY={0}
  />
  <capacitor name="C1" capacitance="10uF" footprint="0603" pcbX={12} pcbY={-5} />
  <capacitor name="C2" capacitance="10uF" footprint="0603" pcbX={12} pcbY={5} />
  <pinheader name="H1" pinCount={4} pcbX={22} pcbY={0} />

  <trace from=".J1 .VBUS1" to=".U1 .vout" />
  <trace from=".J1 .VBUS2" to=".U1 .vout" />
  <trace from=".J1 .VBUS3" to=".U1 .vout" />
  <trace from=".J1 .VBUS4" to=".U1 .vout" />
  <trace from=".J1 .GND" to="net.GND" />

  <trace from=".J1 .CC1" to=".U1 .cc" />
  <trace from=".J1 .CC2" to=".U1 .cc" />

  <trace from=".U1 .gnd" to="net.GND" />

  <trace from=".U1 .vout" to=".U2 .vin" />
  <trace from=".U1 .vout" to=".H1 .pin1" />

  <trace from=".U2 .gnd" to="net.GND" />
  <trace from=".U2 .vout" to=".C1 .pos" />
  <trace from=".U2 .vout" to=".H1 .pin3" />
  <trace from=".C1 .neg" to="net.GND" />

  <trace from=".C2 .pos" to=".U1 .vout" />
  <trace from=".C2 .neg" to="net.GND" />

  <trace from=".H1 .pin2" to="net.GND" />
  <trace from=".H1 .pin4" to="net.GND" />
</board>
)

Ordering the PCB

You can order this PCB by downloading the fabrication files (Gerbers) and uploading them to JLCPCB. Follow the instructions from Ordering Prototypes.

Next Steps

Add a toggle switch or jumper to select between multiple PD voltage levels
Integrate a microcontroller to monitor the PG (Power Good) signal
Add an INA219 current sensor to measure power consumption
Pair with a Class D audio amplifier HAT that needs a 12V supply
Design a custom enclosure using the 3D CAD model from tscircuit

Overview​

What is USB Power Delivery?​

How PD Negotiation Works​

PD Trigger ICs​

Circuit Requirements​

Building the Circuit Step by Step​

Step 1: Add the USB-C Connector​

Step 2: Add the PD Trigger IC (CH224K)​

Step 3: Add a 3.3V Voltage Regulator​

Step 4: Add Output Headers​

Step 5: Wire Everything Together​

Configuring the Output Voltage​

Resistor-Based Configuration (CH224K)​

Output Pin Header Reference​

Safety Considerations​

PCB Layout​

Ordering the PCB​

Next Steps​