Document
TC74AC245,640P/F/FT
TOSHIBA CMOS Digital Integrated Circuit Silicon Monolithic
TC74AC245P, TC74AC245F, TC74AC245FT TC74AC640P, TC74AC640F, TC74AC640FT
Octal Bus Transceiver TC74AC245P/F/FT 3-State, Non-Inverting TC74AC640P/F/FT 3-State, Inverting
TC74AC245P, TC74AC640P
The TC74AC245, 640 are advanced high speed CMOS OCTAL BUS TRANSCEIVERs fabricated with silicon gate and double-layer metal wiring C2MOS technology.
They achieve the high speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS low power dissipation.
They are intended for two-way asynchronous communication between data busses. The direction of data transmission is determined by the level of the DIR input.
The enable input ( G ) can be used to disable the device so that the busses are effectively isolated.
All inputs are equipped with protection circuits against static discharge or transient excess voltage.
TC74AC245F, TC74AC640F
Features (Note 1)(Note 2)
TC74AC245FT, TC74AC640FT
• High speed: tpd = 3.9 ns (typ.) at VCC = 5 V • Low power dissipation: ICC = 8 μA (max) at Ta = 25°C • High noise immunity: VNIH = VNIL = 28% VCC (min) • Symmetrical output impedance:
|IOH| = IOL = 24 mA (min) Capability of driving 50 Ω transmission lines. • Balanced propagation delays: tpLH ∼− tpHL • Wide operating voltage range: VCC (opr) = 2 V to 5.5 V • Pin and function compatible with 74F245/640
Note 1: Do not apply a signal to any bus terminal when it is in the output mode. Damage may result.
Weight DIP20-P-300-2.54A SOP20-P-300-1.27A TSSOP20-P-0044-0.65A
: 1.30 g (typ.) : 0.22 g (typ.) : 0.08 g (typ.)
Note 2: All floating (high impedance) bus terminals must have their input levels fixed by means of pull up or pull down resistors.
Start of commercial production
1986-05
1
2014-03-01
Pin Assignment
DIR 1 A1 2 A2 3 A3 4 A4 5 A5 6 A6 7 A7 8 A8 9 GND 10
TC74AC245 (top view)
IEC Logic Symbol
20 VCC 19 G 18 B1 17 B2 16 B3 15 B4 14 B5 13 B6 12 B7 11 B8
G (19) DIR (1)
TC74AC245
G3 3 EN 1 [BA] 3 EN 2 [AB]
(2)
A1
1
2
(3) A2
(4) A3
(5) A4
(6) A5
(7) A6
(8) A7
(9) A8
(18) B1
(17) B2
(16) B3
(15) B4
(14) B5
(13) B6
(12) B7
(11) B8
TC74AC245,640P/F/FT
DIR 1 A1 2 A2 3 A3 4 A4 5 A5 6 A6 7 A7 8 A8 9 GND 10
TC74AC640 (top view)
20 VCC 19 G 18 B1 17 B2 16 B3 15 B4 14 B5 13 B6 12 B7 11 B8
G (19) DIR (1)
TC74AC640
G3 3 EN 1 [BA] 3 EN 2 [AB]
(2)
A1
1
2 (3) A2
(4) A3
(5) A4
(6) A5
(7) A6
(8) A7
(9) A8
(18) B1
(17) B2
(16) B3
(15) B4
(14) B5
(13) B6
(12) B7
(11) B8
2
2014-03-01
TC74AC245,640P/F/FT
Truth Table
Inputs
G DIR
L
L
L
H
H
X
Function
A Bus
B Bus
Output
Input
Input
Output
Z
X: Don’t care Z: High impedance
Outputs
AC245
AC640
A=B
A= B
B=A
B= A
Z
Z
Absolute Maximum Ratings (Note 1)
Characteristics
Symbol
Rating
Unit
Supply voltage range DC input voltage DC output voltage Input diode current Output diode current DC output current DC VCC/ground current Power dissipation Storage temperature
VCC VIN VOUT IIK IO.