
2003 Jul 10 2
Philips Semiconductors Product specification
Dual D-type flip-flop with set and reset;
positive-edge trigger 74HC74; 74HCT74
FEATURES
•Wide supply voltage range from 2.0 to 6.0 V
•Symmetrical output impedance
•High noise immunity
•Low power dissipation
•Balanced propagation delays
•ESD protection:
HBM EIA/JESD22-A114-A exceeds 2000 V
MM EIA/JESD22-A115-A exceeds 200 V.
GENERAL DESCRIPTION
The 74HC/HCT74 is a high-speed Si-gate CMOS device
and is pin compatible with low power Schottky TTL
(LSTTL). They are specified in compliance with JEDEC
standard no. 7A.
The74HC/HCT74aredualpositive-edgetriggered,D-type
flip-flops with individual data (D) inputs, clock (CP) inputs,
set (SD) and reset (RD) inputs; also complementary
Q and Q outputs.
The set and reset are asynchronous active LOW inputs
and operate independently of the clock input. Information
on the data input is transferred to the Q output on the
LOW-to-HIGH transition of the clock pulse. The D inputs
must be stable one set-up time prior to the LOW-to-HIGH
clock transition for predictable operation.
Schmitt-trigger action in the clock input makes the circuit
highly tolerant to slower clock rise and fall times.
QUICK REFERENCE DATA
GND = 0 V; Tamb =25°C; tr=t
f=6ns
Notes
1. CPD is used to determine the dynamic power dissipation (PDin µW).
PD=C
PD ×VCC2×fi×N+Σ(CL×VCC2×fo) where:
fi= input frequency in MHz;
fo= output frequency in MHz;
CL= output load capacitance in pF;
VCC = supply voltage in Volts;
N = total load switching outputs;
Σ(CL×VCC2×fo) = sum of the outputs.
2. For 74HC74 the condition is VI= GND to VCC.
For 74HCT74 the condition is VI= GND to VCC −1.5 V.
SYMBOL PARAMETER CONDITIONS TYPICAL UNIT
HC HCT
tPHL/tPLH propagation delay CL= 15 pF; VCC =5V
nCP to nQ, nQ1415ns
n
SD to nQ, nQ1518ns
n
RD to nQ, nQ1618ns
f
max maximum clock frequency 76 59 MHz
CIinput capacitance 3.5 3.5 pF
CPD power dissipation capacitance per flip-flop notes 1 and 2 24 29 pF