This project involves the schematic and PCB design of a compact power management module built around the Analog Devices ADP5360 PMIC. The design supports USB-C input, Changable output (3.3V / 1.8V), single-cell Li-ion battery charging, I2C programmability, and includes essential passive components for safe and efficient operation. It is specifically optimized for low-power wearable devices requiring 3.7 V, 100 mAh battery management.
- Power Management IC: ADP5360
- Input Power: USB-C (5 V nominal)
- Output Power: Can be selected between 3.3 V and 1.8 V using switch
- Battery: Single-cell Li-ion, 3.7 V, 100 mAh (eg: grepow)
- Charging Current: 250 mA max
- input Current: 300 mA max
- I2C Interface: Exposed for configuration
- Test Pins: Exposed via pin headers for key signals and voltage levels
- PCB Size: Compact layout suitable for wearable integration (59mm x 49.5mm)
- Layers: 2-layer PCB (Top: Signal, Bottom: Ground Plane)
| Test Pin | Signal | Description |
|---|---|---|
| TP1 | VBAT | Direct battery voltage for monitoring |
| TP2 | VBUS | Direct voltage from USB |
| TP3 | VOUT | Voltage output from buck regulator |
| TP4 | VDD | Voltage output for internal connections |
| TP5 | VSYS | System voltage output |
| TP6 | GND | For ground reference |
These are broken out via 1.27 mm pitch pin headers for easy access.
| Component | Value | Function |
|---|---|---|
| TH1 | 10 kΩ NTC | Battery temperature sensing |
| Lim_IP | 20 kΩ | Input current limit (~300 mA) |
| Lim_Chg | 15 kΩ | Charging current limit (~250 mA) |
| Rx | 10 kΩ | I2C pull-up resistors |
| R_Highx | 1 MΩ | Pull-up resistors |
| R_CCx | 5.1 kΩ | For power sink configuration in USB connector |
| R_th | 10 kΩ | For voltage divider configuration (THR pin) |
| R_3.3 | 100 kΩ | To select output voltage as 3.3V |
| R_1.8 | 27 kΩ | To select output voltage as 1.8V |
| Cx | 1 µF, 10 µF, 2.2 µF | bypass & decoupling capacitors |
| CR | Schottky diode | Reverse protection for USB connector |
| Lx | 4.7 µH | Inductors for internal regulators |
| SW1 | Push switch | For manual reset purpose |
| SW_1.8<->3.3 | SPDT switch | For switching output between 3.3V and 1.8V |
pmic_adp5360.kicad_sch→ Schematic filepmic_adp5360.kicad_pcb→ PCB layout filepmic_adp5360.kicad_pro→ Main project file containing paths, libraries etcmanufacturing/→ Contains manufacture regarding files like gerber, drill, component position, bom.
During development, the following resources were used for validation and design references:
- ADP5360 Datasheet and Hardware User Guide
- Analog Devices reference designs
- USB-C power delivery standards
- KiCad documentation for DRC and layer stackup
- Hardware design best practices for I2C and power rails
- JLCPCB for design aspects