BD52xx series BD53xx series
Datasheet
3) Examples of the power supply with resistor dividers
In applications wherein the power supply voltage of an IC comes from a resistor divider circuit, an in-rush current will flow
into the circuit when the output level switches from “High” to “Low” or vice versa. In-rush current is a sudden surge of
current that flows from the power supply (VDD) to ground (GND) as the output logic changes its state. This current flow
may cause malfunction in the systems operation such as output oscillations, etc.
V1
Figure.21
IDD
R2
I1
VDD
Through
Current
R1
CIN
BD52xx
BD53xx
VOUT
CL
GND
0
VDET
VDD
When an in-rush current (I1) flows into the circuit (Refer to Fig. 21) at the time when output switches from “Low” to “High”,
a voltage drop of I1×R2 (input resistor) will occur in the circuit causing the VDD supply voltage to decrease. When the VDD
voltage drops below the detection voltage, the output will switch from “High” to “Low”. While the output voltage is at “Low”
condition, in-rush current will stop flowing and the voltage drop will be reduced. As a result, the output voltage will switches
again from “Low” to “High” which causes an in-rush current and a voltage drop. This operation repeats and will result to
oscillation.
VDD - IDD Peak Current Ta=25℃
10
BD52xx
BD53xx
1
0. 1
0. 01
0. 001
3 4 5 6 7 8 9 10
VDD[V]
Figure.22 IDD Peak Current vs. Power Supply Voltage
* This data is for reference only.
The figures will vary with the application, so please confirm actual operating conditions before use.
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TSZ02201-0R7R0G300040-1-2
22.May.2013 Rev.006