XC6129
Series
■NOTE ON USE
1) Please use this IC within the stated maximum ratings. For temporary, transitional voltage drop or voltage rising phenomenon, the IC is
liable to malfunction should the ratings be exceeded.
2) The power input pin voltage may fall due to the flow through current during IC operation and the resistance component
between the power supply and the power input pin.
In the case of CMOS output, a drop in the power input pin voltage may occur in the same way due to the output current. When
this happens, if the power input pin voltage drops below the minimum operating voltage, malfunctioning may occur.
In addition, when the power input pin voltage is below the detect voltage, the output pin voltage may oscillate. Exercise
caution in particular if a resistor is connected to the power input pin.
3) Note that large, sharp changes of the power input pin voltage may cause malfunctioning.
4) Power supply noise is sometimes a cause of malfunctioning. Sufficiently test using the actual device, such as inserting a
capacitor between VIN and GND.
5) If a capacitor is connected to the delay capacitance pin and the power input pin voltage drops suddenly during release operation (for
example, from 6.0V to 0V), there is a possibility that the delay capacitance pin voltage will exceed the absolute maximum rating. If
there is a possibility that the power input pin voltage will drop suddenly during release operation, connect a Schottky diode
between the power input pin and delay capacitance pin as shown in Fig. 5.
(not needed with CMOS output)
Fig. 5: Circuit example with a Schottky diode connected to the delay capacitance pin
6) When an N-ch open drain output is used, the VRESETB voltage at detection and release is determined by the pull-up resistance
connected to the output pin. Refer to the following when selecting the resistance value.
At detection:
V
RESETB=Vpull/(1+Rpull/RON
)
Vpull : Voltage after pull-up
RON(*1): ON resistance of N-ch driver M3 (calculated from VRESETB/IRBOUT1 based on electrical characteristics)
Example: When VIN=2.0V(*2), RON=0.5/5.2×10-3=96Ω (MAX.). If it is desired to make VRESETB at detection 0.1V or less when Vpull is 3.0V,
Rpull=(Vpull/VRESETB-1)×RON=(3/0.1-1)×96≒2.8kΩ
Therefore, to make the output voltage at detection 0.1V or less under the above conditions, the pull-up resistance must be 2.8kΩ or higher.
(*1) Note that RON becomes larger as VIN becomes smaller.
(*2) For VIN in the calculation, use the lowest value of the input voltage range you will use.
At release:
V
RESETB=Vpull/(1+Rpull/Roff)
pull: Voltage after pull-up
V
Roff: Resistance when N-ch driver M3 is OFF (calculated from VRESETB/ILEAK based on electrical characteristics)
Example: When Vpull is 6.0V, Roff=6/(0.1×10-6)=60MΩ (MIN.). If it is desired to make VRESETB 5.99V or higher,
R
pull=(Vpull/VRESETB-1)×Roff=(6/5.99-1)×60×106≒100kΩ
Therefore, to make the output voltage at release 5.99V or higher under the above conditions, the pull-up resistance must be
100kΩ or less.
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