Domestic synchronous buck verification board

Introduction: Synchronous buck, integrated MOS, AP2905, AP2965A, NDP1480QB verification board

has been physically verified

1. Product introduction: DCDC verification board using domestic chips, synchronous buck mode, integrated MOS, multi-power, multi-application range;


2. Application Scenario: AP2905 solution can be used for microcontroller power supply; NDP1480QB solution can be used for 3.3-12v voltage, 5A current applications;


3. Product Overview:

AP2905 is a mini synchronous step-down solution,

input voltage 2S-8S (7-34V), fixed 5v output (The other AP2903 is 3.3v), 700mA output current, measured 700mA, with short circuit protection

AP2965A is a synchronous step-down solution,

input voltage 2S-8S (7-34V), adjustable 3.3-12v output, 4A output current, measured 4A , with short circuit protection (size, power comparison, can be replaced by NDP1480QB)

NDP1480QB is an 8A synchronous buck solution,

input voltage 2S-8S (7-34V), adjustable 3.3-12v output, 7A output current, measured 12V/5.5A output When the current is over 5A, the room temperature rises from 28 degrees to 80 degrees. When the 12V/7A output is used, the room temperature rises from 28 degrees to 100 degrees. Therefore, be careful about fan heat when the current exceeds 5A.

This solution is a CC/CV mode step-down module with current control. Determined by the sampling resistor, only 5A constant current output has been measured. DCDC with CC mode can output multiple modules in parallel to increase power.


4. Product parameters:

Input voltage: 2S-8S (7-34V)

AP2905 output voltage: 5v (fixed)

NDP1480QB, AP2965A output voltage: 3.3-12v (adjustable)

Output current: 0.7A (AP2905), 4A (AP2965A) , 8A (NDP1480QB)

Maximum power: 3.5W (AP2905), 48W (AP2965A), 96W (NDP1480QB)

Ripple: ≥50mvp-p (not recommended for analog acquisition power supply)

Board structure: The board adopts a double-layer board design. Single-sided layout

working mode: CV (AP2905), CC/CV (AP2965A, NDP1480QB)

Special features: short circuit protection

Size: 7.1mm x 9mm


5. Instructions for use:

As shown in the "3D Introduction Picture" in the reference design download,

1) Connect the positive and negative poles of the adjustable power supply to the positive power input and input ground shown in the yellow box,

2) Connect the positive input pole of the load tester to ① (AP2905) ② (AP2905) ③ (AP2965) ⑤ (NDP1480QB) 3) Connect the

negative input of the load tester to the ④ contact

4) Adjust v1 rheostat to adjust the output voltage of AP2965, the output voltage range is 3.3-12V

5) Adjust v2 rheostat to adjust the output voltage of NDP1480QB, The output voltage range is 3.3-25V

6) The output voltage adjustment must not exceed the voltage range, otherwise it may cause the module to work unstable

7) The f1 rheostat can adjust the operating frequency of NDP1480QB, and the recommended operating frequency is 300KHZ


6. Remarks:

1) The attachment is Drawings drawn by Chuangeda Professional Edition can be directly downloaded and opened by Chuangeda Professional Edition (the program occupies very little memory), or you can open it with the web version of Chuangeda

2) This design is a pure hardware design, no need to download firmware, and can be powered on Direct use

3) Cost description: The total of some materials of AP2905 is about 3.5 yuan (excluding board making fee), the total of some materials of AP2965 is about 10 yuan (excluding board making fee), the total of some materials of NDP1480QB is about 6 yuan (Excluding board manufacturing fee)

4) BOM components do not include SW1, SW2, SW3. You can search the component number in Lichuang Mall: SW1-3: C2921732 (W503)

5) Test points U14, U17, U21, U22, U23, The purpose of U24 is to set aside holes for convenient testing. You can choose welding wires, welding test points or leave them empty according to personal habits. I chose to leave them empty here to facilitate multimeter testing.

6) For the data sheet, please see the attachment [Data Sheet]