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Circuit Applications 

1

  The following is an example of an application circuit using Reset IC for normal power supply detection. BD47

□□

G series requires a 

pull up resistor on the output terminal. The pull up resister value should be decided. As the application with enough confirmation of 
power supply level and output current capability. When a capacitor has been inserted into the output terminal to delay the output time 
or to remove noise, the output will be slower during starting or stopping. Please be careful to select the appropriate pull up resistors, 
output current and capacitor when inserting a bypass capacitor between input and GND. Please be aware that if an extremely large 
capacitor is used, the response time will become excessively slow. 

 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
2

  The following shows an example of adding delay time to a reset signal. It is possible to set the delay time using the capacitor CL and 

the resistor RL connected to the output terminal as shown below. At VCC start up, CL will be charged by RL. The CL and RL time 
constants and the threshold voltage of the Reset terminal determine the charge delay time. When VCC is decreased, CL is 
discharged through the Reset IC. The sum of the respective times plus the delay time of the IC itself becomes the reset signal delay 
time. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 

Fig.12 

Vref 

V

OUT

 

V

CC 

GND

5

4

3

BD47

□□

G

V

DD

 

Reset Pin

microcontroller

 

●●●●●●●●●●●●

 

●●●●●●●●●●●●

 




 

GND

BD47

□□

G

RESET 

GND 

V

OUT

V

DD

V

CC 

CPU 
Micro-controller 

C

L

R

 

V

CC 

V

S

+

Δ

V

S

V

S

0V

RESET 
(=V

OUT

)

 

T

PLH 

T

PLH 

V

OL

V

OH

V

CC

T

PHL 

Fig.13

 

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Summary of Contents for BD47 G Series

Page 1: ...et output 5 Compact SSOP5 package Applications All electronic devices that use microcontrollers and logic circuits Selection Guide Number Specifications Description Detection Voltage Example Voltage range over 1 9V 4 6V in 0 1V increments 2 9V is marked as 29 Lineup Marking Detection Voltage Part Number Marking Detection Voltage Part Number Marking Detection Voltage Part Number B2 4 6V BD4746 BR 3...

Page 2: ... H L H Transmission Delay Time 1 TPLH 20 50 µs CL 100pF RL 4 7kΩ L Transmission Delay Time 2 TPHL 60 120 µs CL 100pF RL 4 7kΩ L Output Voltage VOL 0 1 0 4 V VCC VSMin 0 05V RL 4 7kΩ Circuit Current at ON ICC1 1 5 3 0 µA VCC VSMin 0 05V RL Circuit Current at OFF ICC2 1 6 3 2 µA VCC VSTyp 0 85V RL Operating Voltage Range VOPL 0 65 0 85 V RL 4 7kΩ VOL 0 4V Low Output Current IOL 3 0 15 0 mA Vo 0 4V V...

Page 3: ...9G VOPL 0 675V Fig 5 Operating Limit Voltage Fig 7 Circuit Current when ON 0 0 0 5 1 0 1 5 2 0 2 5 20 10 0 10 20 30 40 50 60 70 80 TEMPERATURE Ta CIRCUIT CURRENT WHEN ON I CC1 mA BD4729G Fig 8 Circuit Current when OFF 0 0 0 5 1 0 1 5 2 0 2 5 20 10 0 10 20 30 40 50 60 70 80 TEMPERATURE Ta CIRCUIT CURRENT WHEN OFF I CC2 mA BD4729G Fig 9 Operating Limit Voltage 0 4 0 5 0 6 0 7 0 8 0 9 20 10 0 10 20 3...

Page 4: ...tage VOPL until TPHL There fore it is possible that the reset signal is not outputted when the rise time of VDD is faster than TPHL When VDD is greater than VOPL but less than the reset release voltage VS VS the output voltages will switch to Low If VDD exceeds the reset release voltage VS VS then VOUT switches from L to H If VDD drops below the detection voltage VS when the power supply is powere...

Page 5: ...that if an extremely large capacitor is used the response time will become excessively slow 2 The following shows an example of adding delay time to a reset signal It is possible to set the delay time using the capacitor CL and the resistor RL connected to the output terminal as shown below At VCC start up CL will be charged by RL The CL and RL time constants and the threshold voltage of the Reset...

Page 6: ...e output of the BD47 G series consists of a bipolar NPN transistor When the input voltage is at or below the detection voltage VS VOUT will be set to Low This configuration makes it easier to secure output current capacity even when the output voltage falls as well as when the pull up resistor RL at the output has to be made smaller or when many reset terminals have to be driven by a single reset ...

Page 7: ...pplication values in these conditions should be selected carefully If the leakage is assumed between the VOUT terminal and the GND terminal the pull up resistor should be less than 1 10 of the assumed leak resistance 7 External parameters The recommended parameter range for RL is 2kΩ 1MΩ There are many factors board layout etc that can affect characteristics Please verify and confirm using practic...

Page 8: ...xamples of standard use and operation Please pay careful attention to the peripheral conditions when designing circuits and deciding upon circuit constants in the set Any data including but not limited to application circuit diagrams and information described herein are intended only as illustrations of such devices and not as the specifications for such devices ROHM CO LTD disclaims any warranty ...

Page 9: ...tion design Appendix1 Rev2 0 Thank you for your accessing to ROHM product informations More detail product informations and catalogs are available please contact your nearest sales office ROHM Customer Support System THE AMERICAS EUPOPE ASIA JAPAN Contact us webmaster rohm co jp www rohm com Copyright 2007 ROHM CO LTD The products listed in this document are designed to be used with ordinary elect...

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