Octal D-type transparent latch; 3-state
• 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
• Common 3-state output enable input
• Functionally identical to the ‘533’, ‘563’ and ‘573’
• 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.
The 74AHC/AHCT373 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/AHCT373 are octal D-type transparent
latches featuring separate D-type inputs for each latch and
3-state outputs for bus oriented applications. A Latch
Enable (LE) input and an Output Enable (OE) input are
common to all latches.
The ‘373’ consists of eight D-type transparent latches with
3-state true outputs. When LE is HIGH, data at the
Dn inputs enters the latches. In this condition the latches
are transparent, i.e. a latch output will change state each
time its corresponding D-input changes.
When LE is LOW the latches store the information that
was present at the D-inputs a set-up time preceding the
HIGH-to-LOW transition of LE. When OE is LOW, the
contents of the 8 latches are available at the outputs.
When OE is HIGH, the outputs go to the high-impedance
OFF-state. Operation of the OE input does not affect the
state of the latches.
The ‘373’ is functionally identical to the ‘533’, ‘563’ and
‘573’, but the ‘533’ and ‘563’ have inverted outputs and the
‘563’ and ‘573’ have a different pin arrangement.
QUICK REFERENCE DATA
Ground = 0 V; Tamb = 25 °C; tr = tf ≤ 3.0 ns.
Dn to Qn; LE to Qn
CL = 15 pF; VCC = 5 V
VI = VCC or GND
CL = 50 pF; f = 1 MHz;
notes 1 and 2
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.
1999 Nov 23