Philips Semiconductors
Octal D-type flip-flop with reset;
positive-edge trigger
Product specification
74AHC273; 74AHCT273
FEATURES
• Ideal buffer for MOS microcontroller or memory
• Common clock and master reset
• ESD protection:
HBM EIA/JESD22-A114-A exceeds 2000 V
MM EIA/JESD22-A115-A exceeds 200 V
CDM EIA/JESD22-C101 exceeds 1000 V
• Balanced propagation delays
• All inputs have Schmitt trigger actions
• Inputs accepts voltages higher than VCC
• See ‘377’ for clock enable version
• See ‘373’ for transparent latch version
• See ‘374’ for 3-state version
• For AHC only: operates with CMOS input levels
• For AHCT only: operates with TTL input levels
• Specified from −40 to +85 °C and −40 to +125 °C.
DESCRIPTION
The 74AHC/AHCT273 are high-speed Si-gate CMOS
devices and are pin compatible with low power Schottky
TTL (LSTTL). They are specified in compliance with
JEDEC standard no. 7A.
The 74AHC/AHCT273 have eight edge-triggered, D-type
flip-flops with individual D inputs and Q outputs.
The common clock (CP) and master reset (MR) inputs load
and reset (clear) all flip-flops simultaneously.
The state of each D input, one set-up time before the
LOW-to-HIGH clock transition, is transferred to the
corresponding output (Qn) of the flip-flop.
All outputs will be forced LOW independently of clock or
data inputs by a LOW on the MR input.
The device is useful for applications where the true output
only is required and the clock and master reset are
common to all storage elements.
QUICK REFERENCE DATA
Ground = 0 V; Tamb = 25 °C; tr = tf ≤ 3.0 ns.
SYMBOL
PARAMETER
CONDITIONS
tPHL/tPLH
fmax
CI
CO
CPD
propagation delay
CP to Qn
MR to Qn
maximum clock frequency
input capacitance
output capacitance
power dissipation
capacitance
CL = 15 pF; VCC = 5 V
CL = 15 pF; VCC = 5 V
VI = VCC or GND
CL = 50 pF; f = 1 MHz;
notes 1 and 2
Notes
1. CPD is used to determine the dynamic power dissipation (PD in µW).
PD = CPD × VCC2 × fi + ∑ (CL × VCC2 × fo) where:
fi = input frequency in MHz;
fo = output frequency in MHz;
∑ (CL × VCC2 × fo) = sum of outputs;
CL = output load capacitance in pF;
VCC = supply voltage in Volts.
2. The condition is VI = GND to VCC.
TYPICAL
AHC
AHCT
4.2
4.0
3.7
3.9
120
120
3.0
3.0
4.0
4.0
14.0
18.0
UNIT
ns
ns
MHz
pF
pF
pF
1999 Sep 01
2