器件名称: 74HCT244
功能描述: Octal buffer/line driver; 3-state
文件大小: 127.32KB 共22页
简 介:74HC244; 74HCT244
Octal buffer/line driver; 3-state
Rev. 03 — 22 December 2005 Product data sheet
1. General description
The 74HC244; 74HCT244 is a high-speed Si-gate CMOS device and is pin compatible with Low-power Schottky TTL (LSTTL). The 74HC244; 74HCT244 has octal non-inverting buffer/line drivers with 3-state outputs. The 3-state outputs are controlled by the output enable inputs 1OE and 2OE. A HIGH on nOE causes the outputs to assume a high-impedance OFF-state. The 74HC244; 74HCT244 is identical to the 74HC240; 74HCT240 but has non-inverting outputs.
2. Features
s s s s Octal bus interface Non-inverting 3-state outputs Complies with JEDEC standard no. 7A ESD protection: x HBM EIA/JESD22-A114-C exceeds 2000 V x MM EIA/JESD22-A115-A exceeds 200 V s Multiple package options s Specied from 40 °C to +85 °C and from 40 °C to +125 °C
3. Quick reference data
Table 1: Quick reference data GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns Symbol Parameter 74HC244 tPHL, tPLH Ci CPD propagation delay nAn to nYn input capacitance power dissipation capacitance propagation delay nAn to nYn input capacitance power dissipation capacitance per buffer; VI = GND to (VCC 1.5 V)
[1]
Conditions VCC = 5 V; CL = 15 pF
Min -
Typ 9 3.5 35
Max -
Unit ns pF pF
per buffer; VI = GND to VCC VCC = 5 V; CL = 15 pF
[1]
-
74HCT244 tPHL, tPLH Ci CPD
[1]
-
11 3.5 35
-
ns pF pF
CPD is used to determine the dynamic power dissipation (PD in W): PD = CPD × VCC2 × fi × N + ∑(CL × VCC2 × fo) where:
Phi……