DIODES DDB103R3 Ideal Diode Controller

Quick Start Guide

Table 1: DDB103R3 Pin Description

The DDB103R3 demo board has a simple layout and allows access to the appropriate signals through test points. To evaluate the performance of the DDB103R3, follow the procedure below:

1. Set jumpers to default positions. For more information about jumper configuration, please see page 2.
2. Connect a DC power supply between the VIN and GND terminals.
3. Connect the load to the VOUT and GND terminals.
4. Check all connections, then turn on the power supply.
5. The EVM board should now power up with a 5V output voltage.

Jumper Configuration

Note: A pale blue row indicates the default jumper position.

	J1/J2	Effect on DDB103R3
	Header on J1	Enables the AP66x00Q/AP64x03Q device
	Header on J2	Disables the AP66x00Q/AP64x03Q device
	Neither/Both Connected	Not recommended

	J3	Effect on DDB103R3
	Header on pin 1 and 2	Switching frequency of the AP66x00Q/AP64x03Q set to 500 kHz
	Header on pin 2 and 3	Switching frequency of the AP66x00Q/AP64x03Q to 2.5MHz
	Neither/Both Connected	Not recommended

	J5	Effect on DDB103R3
	Header on left 2 (horizontal) pins	Connect GND through capacitor for default external soft start
	Header on right 2 (horizontal) pins	Connect VCC for internal soft start of 1.7ms
	Neither/Both Connected	Not recommended

	J6	Effect on DDB103R3
	Header on top 2 (horizontal) pins	Connect BIAS pin to VOUT
	Header on middle 2 (horizontal) pins	Connect an external voltage source on BIAS pin (<15 V)
	Header on bottom 2 (horizontal) pins	Connect BIAS pin to PGND
	Neither/Both Connected	Not recommended

Description

The DDB103R3 Demo Board showcases the AP66x00Q/AP64x03Q 3A DC-DC buck converter, the AP74700Q ideal diode controller, and an EMI input filter. It demonstrates a system-level solution with reverse voltage protection, ISO 7637-2 transient pulse protection (using a suitable TVS), EMI filtering that passes CISPR 25 Class 5, and the DC-DC buck converter. The input filter (as shown in figure 3 within the red square) contains a common mode choke with capacitors on either side in a Pi configuration. This is connected in series with an LC low pass filter containing an inductor and a capacitor. This combination makes the board CISPR 25 class 5 compliant.

The TVS is highlighted in light blue; this provides the board with ISO7367-2 pulse protection (the SMF4L30CAQ, for example, is a suitable choice). The input RVP section of the board is highlighted in green and consist of the AP74700Q.

Description (continued)
The AP74700Q is a ±65V ideal diode MOSFET controller which provides a low-loss 20mV forward voltage drop rectifier in unidirectional power paths, as well as reverse voltage. The AP74700Q supports a wide input operation range from 3.2V to 65V, allowing control of many popular DC rail voltages such as 12V, 24V, or higher automotive battery systems. The 3.2V input voltage support fits for severe cold crank requirements in automotive systems. The AP74700Q can withstand and protect the loads from reverse voltages down to -65V.

The MOSFET design requirements of the AP74700Q are:

• 60V VDS(MAX) and ±20V VGS(MAX)
• RDS(ON) @ILoad(Nominal): (20 mV/ ILoad(Nominal)) ≤ RDS(ON)
• MOSFET gate threshold voltage VTH: 2V maximum

Due to the DDB103R3’s 3×3 footprint and the AP74700Q’s design requirements, the DMTH6016LFVWQ is the best choice of MOSFET (Q1). The AP66x00Q/AP64x03Q (highlighted in yellow) are adjustable switching frequency, internally compensated, synchronous DC-DC buck converter families. The AP66x00Q family has a VIN range of 3.8V-60V, and the AP64x03Q family has a VIN of 3.8V-40V. The  AP66x00Q/AP64x03Q device families fully integrate a high-side power MOSFET and low-side power MOSFET to provide high-efficiency step-down DC-DC conversion. The AP66x00Q/AP64x03Q enables continuous load currents of up to 2A/3A, with efficiency as high as 95%. It features current mode control operation, which enables easy loop stabilization supporting a wide range of capacitive loads. The AP66x00Q/AP64x03Q simplifies board layout with its high level of integration and minimal external components. The AP66x00Q/AP64x03Q is available in the U-QFN4040-16/SWP package.

Schematic Diagram

Board Layers (top view)

Board Layers (top view) (continued)

Mid Layer 2:

Bottom Layer:

BILL OF MATERIALS for DDB103R3 EVM

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• DDB103R3 EVB User Guide Rev. 1
• 08/02/2024 www.Diodes.com

Specifications

• Input Voltage: DC
• Output Voltage: 5V
• Switching Frequency: Configurable to 500 kHz or 2.5 MHz
• Soft Start: Internal or External

FAQ

Q: What should I do if the board does not power up with a 5V output voltage?
A: Check the jumper configurations and ensure all connections are correct. Verify the input voltage and load connections as well.

Q: Can I change the switching frequency of the device?
A: Yes, you can configure the switching frequency to either 500 kHz or 2.5 MHz using the appropriate jumpers on the board.

Documents / Resources

DIODES DDB103R3 Ideal Diode Controller [pdf] User Guide DDB103R3, AP74700Q, DDB103R3 Ideal Diode Controller, DDB103R3, Ideal Diode Controller, Diode Controller, Controller

References

• User Manual