74HC7540 Datasheet, PDF (2/7 Pages) NXP Semiconductors – Octal Schmitt trigger buffer/line driver; 3-state; inverting

Philips Semiconductors
Octal Schmitt trigger buffer/line driver;
3-state; inverting
Product specification
74HC/HCT7540
FEATURES
• Inverting outputs
• Schmitt trigger action on all data inputs
• Output capability: bus driver
• I_CC category: MSI
GENERAL DESCRIPTION
The 74HC/HCT7540 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 74HC/HCT7540 are octal Schmitt trigger inverting
buffer/line drivers with 3-state outputs. The 3-state outputs
are controlled by the output enable inputs OE₁ and OE₂.
A HIGH on OE_n causes the outputs to assume a high
impedance OFF-state.
The Schmitt trigger action in the data inputs transforms
slowly changing input signals into sharply defined
jitter-free output signals.
The “7540” is identical to the “540” but has hysteresis on
the data inputs.
QUICK REFERENCE DATA
GND = 0 V; T_amb = 25 °C; t_r = t_f = 6 ns
SYMBOL PARAMETER
CONDITIONS
t_PHL/ t_PLH
C_I
C_PD
propagation delay A_n to Y_n
input capacitance
power dissipation capacitance per buffer
C_L = 15 pF; V_CC = 5 V
notes 1 and 2
Notes
1. C_PD is used to determine the dynamic power dissipation (P_D in µW):
P_D = C_PD × V_CC2 × f_i + ∑ (C_L × V_CC2 × f_o) where:
f_i = input frequency in MHz
f_o = output frequency in MHz
∑ (C_L × V_CC2 × f_o) = sum of outputs
C_L = output load capacitance in pF
V_CC = supply voltage in V
2. For HC the condition is V_I = GND to V_CC
For HCT the condition is V_I = GND to V_CC − 1.5 V
ORDERING INFORMATION
See “74HC/HCT/HCU/HCMOS Logic Package Information”.
TYPICAL
HC
HCT
11
16
3.5
3.5
29
31
UNIT
ns
pF
pF
December 1990
2