Fairchild Semiconductor DM74ALS245AWMX, DM74ALS245AWM, DM74ALS245ASJX, DM74ALS245ASJ, DM74ALS245AN Datasheet

September 1986

Revised February 2000

DM74ALS245A

Octal 3-STATE Bus Transceiver

General Description

This advanced low power Schottky device contains 8 pairs of 3-STATE logic elements configured as octal bus transceivers. These circuits are designed for use in memory, microprocessor systems and in asynchronous bidirectional data buses. Two way communication between buses is controlled by the (DIR) input. Data transmits either from the A bus to the B bus or from the B bus to the A bus. Both the driver and receiver outputs can be disabled via the (G) enable input which causes outputs to enter the high impedance mode so that the buses are effectively isolated.

Features

■Advanced oxide-isolated, ion-implanted Schottky TTL process

■Non-inverting logic output

■Glitch free bus during power up and down

■3-STATE outputs independently controlled on A and B buses

■Low output impedance to drive terminated transmission lines to 133Ω

■Switching response specified into 500Ω/50 pF

■Specified to interface with CMOS at VOH = VCC − 2V

■PNP inputs to reduce input loading

■Switching specifications guaranteed over full temperature and VCC range

Ordering Code:

Order Number	Package Number	Package Description
DM74ALS245AWM	M20B	20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide
DM74ALS245ASJ	M20D	20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS245AMSA	MSA20	20-Lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3mm Wide
DM74ALS245AN	N20A	20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide

Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Connection Diagram	Function Table
				Control
				Inputs			Operation
		G				DIR
			L			L	B Data to A Bus
			L			H	A Data to B Bus
			H			X	Hi-Z

H = HIGH Logic Level

L = LOW Logic Level

X = Either HIGH or LOW Logic Level

Transceiver Bus STATE-3 Octal DM74ALS245A

© 2000 Fairchild Semiconductor Corporation

DS006213

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DM74ALS245A

Absolute Maximum Ratings(Note 1)

Supply Voltage	7V
Input Voltage
Control Inputs	7V
I/O Ports	5.5V
Operating Free Air Temperature Range	0°C to +70°C
Storage Temperature Range	−65°C to +150°C
Typical θJA
N Package	53.0°C/W
M Package	72.0°C/W

Note 1: The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation.

Recommended Operating Conditions

Symbol	Parameter	Min	Typ	Max	Units
VCC	Supply Voltage	4.5	5	5.5	V
VIH	HIGH Level Input Voltage	2			V
VIL	LOW Level Input Voltage			0.8	V
IOH	HIGH Level Output Current			−15	mA
IOL	LOW Level Output Current			24	mA
TA	Operating Free Air Temperature	0		70	°C

Electrical Characteristics

over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C.

Symbol	Parameter		Conditions		Min	Typ	Max	Units
VIK	Input Clamp Voltage	VCC = 4.5V, IIN = −18 mA					−1.5	V
VOH	HIGH Level	VCC = 4.5V, IOH = −3 mA			2.4	3.2		V
	Output Voltage	VCC = 4.5V, IOH = Max			2	2.3		V
		IOH = −0.4 mA, VCC = 4.5V to 5.5V			VCC − 2			V
VOL	LOW Level Output Voltage	VCC = 4.5V	IOL = 24 mA			0.35	0.5	V
II	Input Current at Maximum	VCC = 5.5V	VIN = 7V	Control Inputs			0.1	mA
	Input Voltage		VIN = 5.5V	A or B Ports			0.1
IIH	HIGH Level Input Current	VCC = 5.5V, VIN = 2.7V					20	μA
IIL	LOW Level Input Current	VCC = 5.5V, VIN = 0.4V					−0.1	mA
IO	Output Drive Current	VCC = 5.5V, VOUT = 2.25V			−30		−112	mA
ICC	Supply Current	VCC = 5.5V	Outputs HIGH			30	45	mA
			Outputs LOW			36	55	mA
			3-STATE			38	58	mA

Switching Characteristics		(Note 2)
over recommended operating free air temperature range
Symbol	Parameter		Circuit Configuration	Min	Max	Units
tPLH	Propagation Delay Time			3	10	ns
	LOW-to-HIGH Level Output
tPHL	Propagation Delay Time			3	10	ns
	HIGH-to-LOW Level Output
tPZL	Output Enable Time to LOW Level			5	20	ns
tPZH	Output Enable Time to HIGH Level			5	20	ns
tPLZ	Output Disable Time from LOW Level			4	15	ns
tPHZ	Output Disable Time from HIGH Level			2	10	ns

Note 2: Switching characteristic conditions are VCC = 4.5V to 5.5V, RL = 500Ω, CL = 50 pF.

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