Document
NTE74LS641 Integrated Circuit TTL− Non−Inverting Octal Bus Transceiver with Open−Collector Outputs
Description: The NTE74LS641 is an octal bus transceiver in a 20−Lead DIP type package designed for asynchronous two−way communication between data buses. This device transmits data from the A bus to the B bus or from the B bus to the A bus depending upon the level at the direction control (DIR) input. The enable pin (G) can be used to disable the device so the buses are effectively isolated. Features: D Bi−Directional Bus Transceiver D Hysteresis at Bus Inputs Improves Noise Margins D Non−Inverting (True) Logic D Open−Collector Outputs Absolute Maximum Ratings: (Note 1) Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V Input Voltage, All Inputs and I/O Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7V Operating Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0C to +70C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65C to +150C Note 1. Voltage values are with respect to network ground terminal. Recommended Operating Conditions:
Parameter Supply Voltage High−Level Input Voltage Low−Level Input Voltage High−Level Output Voltage Low Level Output Current Operating Temperature Range Symbol VCC VIH VIL VOH IOL TA Min 4.75 2 − − − 0 Typ 5.0 − − − − − Max 5.25 − 0.6 5.5 24 +70 Unit V V V mA mA C
Electrical Characteristics: (Note 2, Note 3)
Parameter Input Clamp Voltage Hysteresis High Level Output Current Low Level Output Voltage Input Current A or B DIR or G High Level Input Current Low Level Input Current Supply Current Outputs High Outputs Low Outputs at Hi−Z IIH IIL ICC VCC = MAX, VI = 2.7V VCC = MAX, VI = 0.4V VCC = MAX, Outputs Open Symbol VIK IOH VOL II Test Conditions VCC = MIN, II = −18mA VCC = MIN, VIH = 2V, VIL = MAX, VOH = 5.5V VCC = MIN, VIH = 2V, VIL = MAX VCC = MAX IOL = 12mA IOL = MAX VI = 5.5V VI = 7V Min − 0.2 − − − − − − − − − − Typ − 0.4 − 0.25 0.35 − − − − 48 62 64 Max −1.5 − 0.1 0.4 0.5 0.1 0.1 20 −0.4 70 90 95 Unit V V mA V V mA mA A mA mA mA mA
VT+ − VT− VCC = MIN, A or B Input
Note 2. .For conditions shown as MIN or MAX, use the appropriate value specified under “Recommended Operation Conditions”. Note 3. All typical values are at VCC = 5V, TA = +25C. AC Electrical Characteristics: (VCC = 5V, TA = +25C unless otherwise specified)
Parameter Propagation Delay Time (From A Input to B Output) (From B Input to A Output) Propagation Delay Time (From A Input to B Output) (From B Input to A Output) Output Disable Time (From G, DIR Input to A Output) (From G, DIR Input to B Output) Output Enable Time (From G, DIR Input to A Output) (From G, DIR Input to B Output) tPHL tPLH tPHL Symbol tPLH Test Conditions CL = 45pF, RL = 667 Min − − − − − − − − Typ 17 17 16 16 23 25 34 37 Max 25 25 25 25 40 40 50 50 Unit ns ns ns ns ns ns ns ns
Function Table: Control Inputs Operation G DIR
L L H L H X B Data to A Bus A Data to B Bus Isolation
H = HIGH Level, L = LOW Level, X = Irrelevant
Pin Connection Diagram
DIR 1 A1 2 A2 3 A3 4 A4 5 A5 6 A6 7 A7 8 A8 9 GND 10
20 VCC 19 G 18 B1 17 B2 16 B3 15 B4 14 B5 13 B6 12 B7 11 B8
20 1
11 10 .300 (7.62)
1.200 (30.5) Max .200 (5.08) Max .100 (2.54) Min .100 (2.54) Typ
.260 (6.6) Max
.012 (0.30) .350 (8.89)
.