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The information presented in this cross reference is based on TOSHIBA's selection criteria and should be treated as a suggestion only. Please carefully review the latest versions of all relevant information on the TOSHIBA products, including without limitation data sheets and validate all operating parameters of the TOSHIBA products to ensure that the suggested TOSHIBA products are truly compatible with your design and application.
Please note that this cross reference is based on TOSHIBA's estimate of compatibility with other manufacturers' products, based on other manufacturers' published data, at the time the data was collected.
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Is it OK to connect a capacitor to an output?

[Figure 1: Connecting a large capacitor to an output]
[Figure 1: Connecting a large capacitor to an output]

If a large capacitor is connected to a CMOS device, a large charge/discharge current may flow when switching to the output mode (“H”⇒“L”, “L”⇒“H”), causing malfunction. In the worst case, this large current may cause the internal wiring to melt and break. Also, if the power supply is turned off steeply, a current larger than the specified value may flow to the output parasitic diode due to the charge discharge of the capacity. It is recommended to keep the capacitive load on an output pin below 500 pF. If it is exceeded, insert a resistor to limit the charge and discharge currents as shown in Figure 1. In this case, note that a delay occurs in the output signal.

[Figure 2: Connecting a large capacitor to an input of the TCTC4000 and TC74HC/AC series]
[Figure 2: Connecting a large capacitor to an input of the TCTC4000 and TC74HC/AC series]

Devices without an input-tolerant function such as the TC4000 and TC74HC/AC series should not also drive a large capacitive load because current could flow through the input protection diode if the power-off time is short.
It is recommended to keep the load capacitance connected to an input pin below 500 pF. If it is exceeded, insert a resistor as shown in Figure 2. Note that there will also be a delay in the input signal in this case.

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