BD9B500MUV Datasheet, PDF (2/34 Pages) Rohm – Integrated MOSFET Single Synchronous Buck DC/DC Converter

BD9B500MUV
Pin Configuration(s)
(TOP VIEW)
16 15 14 13
PVIN 1
PVIN 2
PGND 3
PGND 4
E-Pad
12 SW
11 SW
10 SW
9 SS
5
6
7
8
Pin Description(s)
Pin No.
Pin Name
1, 2
PVIN
3, 4
PGND
5
AGND
6
FB
7
FREQ
8
MODE
9
SS
10, 11, 12
SW
13
BOOT
14
PGD
15
EN
16
AVIN
-
E-Pad
Figure 2. Pin Assignment
Function
Power supply terminals for the switching regulator.
These terminals supply power to the output stage of the switching regulator.
Connecting a 22µF ceramic capacitor is recommended.
Ground terminals for the output stage of the switching regulator.
Ground terminal for the control circuit.
An inverting input node for the error amplifier and main comparator.
See page 22 for how to calculate the resistance of the output voltage setting.
Terminal for setting switching frequency. Connecting this terminal to ground makes
switching to operate constant on-time corresponding to 2.0MHz. Connecting this
terminal to AVIN makes switching to operate constant on-time corresponding to
1.0MHz. Please fix this terminal to AVIN or ground in operation.
Terminal for setting switching control mode. Connecting this terminal to AVIN forces
the device to operate in the fixed frequency PWM mode. Connecting this terminal to
ground enables the Deep-SLLM control and the mode is automatically switched
between the Deep-SLLM control and fixed frequency PWM mode. Please fix this
terminal to AVIN or ground in operation.
Terminal for setting the soft start time. The rise time of the output voltage can be
specified by connecting a capacitor to this terminal. See page 23 for how to calculate
the capacitance.
Switch nodes. These terminals are connected to the source of the High-Side
MOSFET and drain of the Low-Side MOSFET. Connect a bootstrap capacitor of 0.1µF
between these terminals and BOOT terminal. In addition, connect an inductor of
0.47µH to 1.0µH (FREQ=L), 1.0μH to 1.5μH (FREQ=H) considering the direct current
superimposition characteristic.
Terminal for bootstrap. Connect a bootstrap capacitor of 0.1µF between this terminal
and SW terminals. The voltage of this terminal is the gate drive voltage of the
High-Side MOSFET.
A “Power Good” terminal, an open drain output. Use of pull up resistor is needed. See
page 17 for how to specify the resistance. When the FB terminal voltage reaches
more than 80% of 0.8 V, the internal Nch MOSFET turns off and the output turns High.
Enable terminal. Turning this terminal signal Low (0.8V or lower) forces the device to
enter the shutdown mode. Turning this terminal signal High (2.0V or higher) enables
the device. This terminal must be terminated.
Terminal for supplying power to the control circuit of the switching regulator.
Connecting a 0.1µF ceramic capacitor is recommended.
This terminal must be connected to PVIN.
A backside heat dissipation exposed pad. Connecting to the internal PCB ground
plane by using multiple vias provides excellent heat dissipation characteristics.
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TSZ02201-0J3J0AJ01280-1-2
25.May.2016 Rev.001