12V Input to 65W USB-PD Source
- Daniel Puratich
- Ian Van Den Steen
Introduction
Who
Daniel Puratich arch
Ian Van den Steen EE designer, documentation
What
Take a 12V input DC and output 65W over USB-C PD
Each board should be less than 20 dollars
Why
CSA approval means we need to buy expensive USB-C PD sources for use in the bay
We have CSA approved 12V power supplies already
This will save us money
Resources
USB Charger (USB Power Delivery)
USB Power Delivery explained: What you need to know about ubiquitous charging
100W USB Type-C Power Delivery Source: Getting Started
A Primer on USB Type-C® and USB Power Delivery Applications and Requirements
Engineering
PD controller Selection
Main Options
There were a couple options available:
Decision Matrix
USB PD Controller | Option 1 | Option 2 | Option 3 | Option 4 |
|---|---|---|---|---|
Name | MPQ5031GRE-0001-AEC1-Z | TPS65988DJRSHR | STUSB4761QTR | TPS25751 |
Description | 100W USB PD controller | Dual channel 100W USB PD Controller | 100W USB PD controller |
|
Price | $3.16 CAD | $6.27 CAD | $2.58 CAD | $2.51/2.56 CAD |
Configuration | I2C | I2C interface | NVM config thru I2C or cc pin |
|
Misc. Pros | PPS, simple | Dual channel | Cheap, simple, PPS | PPS<br>Preconfigured firmware |
Misc. Cons | More expensive | Only for TBT3 designs, expensive, more complex | Odd datasheet | more complex |
Option 1 was chosen for its extensive datasheet, simplicity
Buck boost controller selection
Main Options
I found a very limited selection of buck/boost, and boost converter ICs that were within the scope of the product. Another alternative is to just use a buck converter IC and cap the voltage at 12V, and thus 60W.
Decision Matrix
PMIC | Option 1 | Option 2 | Option 3 |
|---|---|---|---|
Name | MP4245GVE-0000-Z | TPS54531DDAR | MP4247GQV-0000-Z |
Description | 36V 6A Buck/Boost converter | 28V 5A Buck converter | Switching Voltage Regulators 36V, 100W, Buck-Boost Converter with Integrated Low-Side MOSFETs and I2C Interface |
Price | $6.95 CAD | $2.70 CAD | $5.28 CAD |
Configuration | I2C | Resistor divider | I2C |
Misc. Pros | Good datasheet | Cheap, already used | Good datasheet, reasonable price, 100W |
Misc. Cons | Expensive<br><br>Unclear but seems to be only 60W | Can only buck down, so limits Vbus to 12V, thus 60W output<br><br>Unclear whether you can adjust output voltage without changing resistor divider | Mouser<br><br> |
Option 3 was chosen for its easy integration with USB PD IC and ability to reach 100W.
Inductor Selection
Requirements:
10A current rating
Cheap
SRP1038A-4R7M was chosen because it fit the requirements
MOSFET Selection
Requirements:
Handles over 20V
Handles over 10A of cont. current
Drive voltage of <6V
DMP3013SFV-7 was chosen because it fit the requirements
GPIO Pin Functions
GPIO No. | Function | Related Components | Notes |
|---|---|---|---|
1 | Interrupt input pin | Connected to Buck Boost converter's ALT pin |
|
2 | VBATT_SENSE/PWR_SHARE/POL output |
| POL output shows USB C Connector Orientation |
3 | EN/ATTACH |
|
|
4 | EN/NTC2/VBATT_SENSE |
|
|
5 | VBUS_UV_FIXPDO/ATTACH/IPWM |
| In VBUS voltage detection, connect a 1/5 resistor divider to VBUS |
6 | POL/EN/VSEL2 |
|
|
7 | DISCHG | Controls an N Channel MOSFET connected to GND and VBUS |
|