BD9D321EFJ-EVK-101 ROHM

Datasheet 4.5V to 18V Input, 3.0A Integrated MOSFET 1ch Synchronous Buck DC/DC Converter BD9D321EFJ General Description Key Specifications BD9D321EFJ is a synchronous buck switching regulator Input Voltage Range: 4.5V to 18.0 V with built-in low on-resistance power MOSFETs. It is Output Voltage Setting Range: 0.765V to 7V TM capable of providing current of up to 3 A. The SLLM (V 0.07)V to (V 0.65)V IN IN control provides excellent efficiency characteristics in Output Current: 3 A (Max) light-load conditions which make the product appropriate Switching Frequency: 700 kHz (Typ) for equipment and devices that demand minimal standby High Side MOSFET On-Resistance:100 m (Typ) power consumption. External phase compensation circuit Low Side MOSFET On-Resistance: 70 m (Typ) is not necessary for it is a constant on-time control DC/DC Standby Current: 2 A (Typ) converter with high speed response. Package W (Typ) x D (Typ) x H (Max) Features HTSOP-J8 4.90mm x 6.00mm x 1.00mm Synchronous Single DC/DC Converter Constant On-time Control TM SLLM (Simple Light Load Mode) Control Over Current Protection Short Circuit Protection Thermal Shutdown Protection Under Voltage Lockout Protection Adjustable Soft Start HTSOP-J8 Package (Backside Heat Dissipation) Applications Step-down Power Supply for DSPs, FPGAs, Microprocessors, etc. Set-top Box LCD TVs HTSOP-J8 DVD / Blu-ray Player / Recorder Entertainment Devices Typical Application Circuit Figure 1. Typical Application Circuit Product structure: Silicon monolithic integrated circuit This product has no designed protection against radioactive rays. www.rohm.co.jp TSZ02201-0J3J0AC00490-1-2 2013 ROHM Co., Ltd. All rights reserved. 1/25 TSZ2211114001 29.Jan.2015 Rev.002DatasheetDatasheet BD9D321EFJ Pin Configuration (TOP VIEW) EN 1 8 VIN FB BOOT 2 7 SW VREG 3 6 4 5 GND SS Figure 2. Pin Assignment Pin Descriptions Terminal Symbol Function No. Turning this terminal signal low level (0.3 V or lower) forces the device to enter the shutdown 1 EN mode. Turning this terminal signal high level (2.2 V or higher) enables the device. This terminal must be terminated. An inverting input terminal of comparator which compares with reference voltage (V ). REF 2 FB Refer to page.17 for how to calculate the resistance of the output voltage setting. Power supply voltage terminal inside IC. 3 VREG Voltage of 5.25V (Typ) is outputted with more than 2.2V is impressed to EN terminal. Connect 1F ceramic capacitor to ground. Terminal for setting the soft start time. The rise time of the output voltage can be specified by 4 SS connecting a capacitor to this terminal. Refer to page.17 for how to calculate the capacitance. 5 GND Ground terminal for the output stage of the switching regulator and the control circuit Switch node. This terminal is connected to the source of the high-side MOSFET and drain of the low-side MOSFET. Connect a bootstrap capacitor of 0.1F between this terminal and 6 SW BOOT terminal. In addition, connect an inductor considering the direct current superimposition characteristic. Connect a bootstrap capacitor of 0.1F between this terminal and SW terminal. 7 BOOT The voltage of this capacitor is the gate drive voltage of the high-side MOSFET. Power supply terminal for the switching regulator. 8 VIN Connecting a 20F(10F2) and 0.1F ceramic capacitor to ground is recommended. A backside heat dissipation pad. Connecting to the internal PCB ground plane by using - FIN multiple via provides excellent heat dissipation characteristics. www.rohm.co.jp TSZ02201-0J3J0AC00490-1-2 2013 ROHM Co., Ltd. All rights reserved. 2/25 TSZ22111 15 001 29.Jan.2015 Rev.002