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BD52xx series BD53xx series
TSZ02201-0R7R0G300040-1-
© 2013 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
●Circuit Applications
1) Examples of a common power supply detection reset circuit
Application examples of BD52xx series (Open Drain
output type) and BD53xx series (CMOS output type) are
shown below.
CASE1: Power supply of the microcontroller (V
DD2
)
differs from the power supply of the reset detection
(V
DD1
).
Use an open drain output type (BD52xx) device with a
load resistance R
L
attached as shown Fig.18.
CASE2: Power supply of the microcontroller (V
DD1
) is the
same as the power supply of the reset detection (V
DD1
).
Use a CMOS output type (BD53xx) device or an open
drain output type (BD52xx) device with a pull up resistor
between the output and V
DD1
.
When a capacitance C
L
for noise filtering is connected to
the V
OUT
pin (the reset signal input terminal of the
microcontroller), please take into account the waveform
of the rise and fall of the output voltage (V
OUT
).
Please refer to Operational Notes for recommendations
on resistor and capacitor values.
2) The following is an example of a circuit application in which an OR connection between two types of detection voltage
resets the microcontroller.
To reset the microcontroller when many independent power supplies are used in the system, OR connect an open drain
output type (BD52xx series) to the microcontroller’s input with pull-up resistor to the supply voltage of the microcontroller
(V
DD3
) as shown in Fig. 20. By pulling-up to V
DD3
, output “High” voltage of micro-controller power supply is possible.
V
DD1
BD52xx
V
DD2
GND
C
L
(Noise-filtering
Capacitor)
C
T
L
ST
Micro
controller
Fig.18 Open Drain Output Type
C
L
(Noise-filtering
Capacitor)
V
DD1
BD53xx
C
T
GND
ST
Micro
controller
Fig.19 CMOS Output Type
VDD1 VDD3
GND
RST
microcontroller
CT
RL
VDD2
CT
BD52xx
NO.1
BD52xx
NO.2
Fig.20