1. General description
The 74HC109; 74HCT109 is a dual positive edge triggered JK flip-flop featuring individual J and
K inputs, clock (CP) inputs, set (SD) and reset (RD) inputs and complementary Q and Q outputs.
The set and reset are asynchronous active LOW inputs and operate independently of the clock
input. The J and K inputs control the state changes of the flip-flops as described in the mode
select function table. The J and K inputs must be stable one set-up time prior to the LOW-to-HIGH
clock transition for predictable operation. The JK design allows operation as a D-type flip-flop by
connecting the J and K inputs together. This device features reduced input threshold levels to allow
interfacing to TTL logic levels. Inputs also include clamp diodes, this enables the use of current
limiting resistors to interface inputs to voltages in excess of VCC.
Schmitt-trigger action in the clock input makes the circuit highly tolerant to slower clock rise and fall
times.
2. Features and benefits
• J and K inputs for easy D-type flip-flop
• Toggle flip-flop or "do nothing" mode
• Wide supply voltage range:
• For 74HC109: from 2.0 V to 6.0 V
• For 74HCT109: from 4.5 V to 5.5 V
• CMOS low power dissipation
• High noise immunity
• Input levels:
• For 74HC109: CMOS level
• For 74HCT109: TTL level
• Latch-up performance exceeds 100 mA per JESD 78 Class II Level B
• 74HC109 complies with JEDEC standards:
• JESD8C (2.7 V to 3.6 V)
• JESD7A (2.0 V to 6.0 V)
• 74HCT109 complies with JEDEC standard JESD7A (2.0 V to 6.0 V)
• ESD protection:
• HBM JESD22-A114F exceeds 2000 V
• MM JESD22-A115-A exceeds 200 V
• Specified from -40 °C to +85 °C and from -40 °C to +125 °C