SCLS577B March 2004 – April 2020 SN74HC74-Q1
PRODUCTION DATA.
Refer to the PDF data sheet for device specific package drawings
Toggle switches are typically large, mechanically complex and relatively expensive. It is desirable to use a momentary switch instead because they are small, mechanically simple and low cost. Some systems require a toggle switch's functionality but are space or cost constrained and must use a momentary switch instead. The SN74HC74-Q1 together with a dual Schmitt-trigger buffer such as SN74LVC2G17 can be used to convert a momentary switch to a toggle switch.
If the data input (D) of the SN74HC74-Q1 is tied to the inverted output (Q), then each clock pulse will cause the value at the output (Q) to toggle. The momentary switch can be debounced and connected to the buffered clock input (CLK) to toggle the output. These connections are shown in Figure 9