TUYA DC Power Supply Board V2.0 User manual

DC Power Supply Board V2.0
Version: 20210909
Online Version

Contents
Contents
1 Background Information 2
2 Features 4
3 Key components 5
4 I/O port 6
5 Technical requirements of power supply 8
6 Schematic diagram and PCB 9
7 Things to note 11
8 Reference 12
I

Contents
This topic describes version 2.0 of the Tuya Sandwich DC power supply board.
1 / 12

1 Background Information
1 Background Information
The Tuya Sandwich DC power supply board is part of the Tuya Sandwich Develop-
ment Kit and is used to power other related components of Tuya Sandwich.
2 / 12

1 Background Information
The power development board has two input ports: DC 12V and DC 5V.
• When DC 12V is input, two SY8012B chips work at the same time, which can
provide DC 12V, DC 5V, and DC 3.3V power supply for other development board
components.
• When DC 5V is input, only one SY8012B chip works, which can provide DC 5V
and DC 3.3V power supply for other development board components.
• Support lithium battery power supply, which can output DC 5V and DC 3.3V
power supply.
3 / 12

2 Features
2 Features
The Tuya Sandwich DC power supply board adopts the standard Arduino dimensions.
You can directly stack the development boards on top for power supply.
• Flexible input: There are DC 005 DC 12V input, micro USB DC 5V input, and
rechargeable 3.7V 15400 packaged lithium battery input.
• Overvoltage protection: with 12V TVS tube and 5V TVS tube.
• Anti-reverse connection circuit: 12V input terminal has an anti-reverse connec-
tion protection circuit composed of fuse resistor and TVS tube.
• Anti-current back󰍔ow: SS14 prevents current back󰍔ow during 5V power supply.
• Buck circuit: Choose Silicon Lijie SY8012B chip, with 5V 1A, 3.3V 1A power
supply capability, and adopt SOT23-6 package.
• Indicator lights: 12V, 5V, and 3.3V power outputs have corresponding indica-
tors, as well as lithium battery charging indicators.
4 / 12

3 Key components
3 Key components
Tuya Sandwich DC power supply board hardware includes 12V to 5V DC-DC step-
down chip, 5V to 3.3V DC-DC step-down chip, micro USB port, 12V DC input port,
lithium battery charge and discharge chip, and USB 5V output port. As shown in the
following table:
Device Description
U1, U2 SY8121B, high e󰍕ciency, 1.2MHz, 2A
output synchronous step-down constant
voltage controller. Input voltage range:
4.5-18V. SOT23-6 package.
U4 ETA6095, maximum 2A charging
current, 1.5A output current lithium
battery management chip.
Input voltage range: 4.5-5.5V, output
voltage range: 5.0-5.2V, DFN2*3-8
package.
DC3 USB AF, rated current: 2A, contact
resistance: 30 mΩ.
DC2 Micro USB, rated load: 30V, 1.5A.
DC1 DC005, inner core: 2.0 mm, rated load:
30V, 1.5A.
5 / 12

4 I/O port
4 I/O port
The peripheral interface con󰍓guration of the development board is shown in the
󰍓gure below.
• 1: Micro USB input port, input voltage range: 4.5V to 5.5V.
• 2: DC005 input port, input voltage range: 7V to 12.5V.
• 3: USB AF output port, output voltage range: 4.5V to 5.5V.
• 4: Lithium battery access port. Only rechargeable 3.7V 15400 packaged
lithium battery can be used.
6 / 12

4 I/O port
The pin de󰍓nition is as follows: |I/O|Description| |:—-|:—-| |12V| The pin output volt-
age follows the DC005 input voltage. The default is 12V input and 12V output. |
|5V|5V DC output, output voltage range: 4.5V to 5.5V. | |3.3V|3.3 VDC DC output,
output voltage range: 3.2V to 3.4V. | |GND|DC power reference ground. | |NC|This
pin is left 󰍔oating. |
7 / 12

5 Technical requirements of power supply
5 Technical requirements of power supply
• Power input supply voltage is 12V or 5V, and 12V and 5V cannot be supplied
at the same time.
• The power board outputs a rated power of 5W.
• Refer to 12V power adapter for 12V power supply capacity.
• The maximum output current of 5V power supply is 1A.
• The maximum output current of 3.3V power supply is 1A.
• The maximum output current of USB AF is 1A.
Note: The power board cannot output 5V/1A and 3.3V/1A at the same
time.
8 / 12