ST 74LCX245 User Manual

74LCX245

LOW VOLTAGE CMOS OCTAL BUS TRANSCEIVER (3-STATE) WITH 5V TOLERANT INPUTS AND OUTPUTS

■5V TOLERANT INPUTS AND OUTPUTS

■HIGH SPEED:

tPD = 7.0 ns (MAX.) at VCC = 3V

■POWER DOWN PROTECTION ON INPUTS AND OUTPUTS

■SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 24mA (MIN) at VCC = 3V

■PCI BUS LEVELS GUARANTEED AT 24 mA

■BALANCED PROPAGATION DELAYS: tPLH tPHL

■OPERATING VOLTAGE RANGE:

VCC(OPR) = 2.0V to 3.6V (1.5V Data Retention)

■PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 245

■LATCH-UP PERFORMANCE EXCEEDS 500mA (JESD 17)

■ESD PERFORMANCE:

HBM > 2000V (MIL STD 883 method 3015); MM > 200V

DESCRIPTION

The 74LCX245 is a low voltage CMOS OCTAL BUS TRANSCEIVER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology. It is ideal for low power and high speed 3.3V applications; it can be interfaced to 5V signal environment for both inputs and outputs.

SOP TSSOP

Table 1: Order Codes

PACKAGE	T & R
SOP	74LCX245MTR
TSSOP	74LCX245TTR

It has same speed performance at 3.3V than 5V AC/ACT family, combined with a lower power consumption.

This IC is intended for two way asynchronous communication between data buses; the direction of data transmission is determined by DIR input. The enable input G can be used to disable the device so that the buses are effectively isolated.

All inputs and outputs are equipped with protection circuits against static discharge, giving them 2KV ESD immunity and transient excess voltage.

All floating bus terminals during High Z state must be held HIGH or LOW.

Figure 1: Pin Connection And IEC Logic Symbols

September 2004	Rev. 4
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74LCX245

Figure 2: Input And Output Equivalent Circuit

Table 2: Pin Description

PIN N°	SYMBOL			NAME AND FUNCTION
1	DIR			Directional Control
2, 3, 4, 5, 6, 7, 8, 9	A1 to A8			Data Inputs/Outputs
18, 17, 16, 15, 14, 13, 12, 11	B1 to B8			Data Inputs/Outputs
19		G		Output Enable Input
10	GND			Ground (0V)
20	VCC			Positive Supply Voltage
Table 3: Truth Table

		INPUTS				FUNCTION		OUTPUT
	G			DIR	A BUS		B BUS
	L			L	OUTPUT		INPUT	A = B
	L			H	INPUT		OUTPUT	B = A
	H			X	Z		Z	Z

X : Don’t Care

Z : High Impedance

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				74LCX245
Table 4: Absolute Maximum Ratings
Symbol	Parameter	Value			Unit
VCC	Supply Voltage	-0.5 to +7.0			V
VI	DC Input Voltage	-0.5 to +7.0			V
VO	DC Output Voltage (OFF State)	-0.5 to +7.0			V
VO	DC Output Voltage (High or Low State) (note 1)	-0.5 to VCC + 0.5			V
IIK	DC Input Diode Current	- 50			mA
IOK	DC Output Diode Current (note 2)	- 50			mA
IO	DC Output Current	±	50		mA
ICC	DC Supply Current per Supply Pin	±	100		mA
IGND	DC Ground Current per Supply Pin	±	100		mA
Tstg	Storage Temperature	-65 to +150			°C
TL	Lead Temperature (10 sec)	300			°C

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied

1)IO absolute maximum rating must be observed

2)VO < GND

Table 5: Recommended Operating Conditions

Symbol	Parameter	Value		Unit
VCC	Supply Voltage (note 1)	2.0 to 3.6		V
VI	Input Voltage	0 to 5.5		V
VO	Output Voltage (OFF State)	0 to 5.5		V
VO	Output Voltage (High or Low State)	0 to VCC		V
IOH, IOL	High or Low Level Output Current (VCC = 3.0 to 3.6V)	±	24	mA
IOH, IOL	High or Low Level Output Current (VCC = 2.7V)	±	12	mA
Top	Operating Temperature	-55 to 125		°C
dt/dv	Input Rise and Fall Time (note 2)	0 to 10		ns/V

1)Truth Table guaranteed: 1.5V to 3.6V

2)VIN from 0.8V to 2V at VCC = 3.0V

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74LCX245

Table 6: DC Specifications

Test Condition

Value

Symbol

Parameter

VCC

-40 to 85 °C

-55 to 125 °C

Unit

(V)

Min.

Max.

Min.

Max.

VIH

High Level Input

2.0

2.0

V

Voltage

2.7 to 3.6

VIL

Low Level Input

0.8

0.8

V

Voltage

VOH

High Level Output

2.7 to 3.6

IO=-100 A

VCC-0.2

VCC-0.2

Voltage

2.7

IO=-12 mA

2.2

2.2

V

3.0

IO=-18 mA

2.4

2.4

IO=-24 mA

2.2

2.2

VOL

Low Level Output

2.7 to 3.6

IO=100 A

0.2

0.2

Voltage

2.7

IO=12 mA

0.4

0.4

V

3.0

IO=16 mA

0.4

0.4

IO=24 mA

0.55

0.55

II

Input Leakage

2.7 to 3.6

VI = 0 to 5.5V

± 5

± 5

A

Current

Ioff

Power Off Leakage

0

VI or VO = 5.5V

10

10

A

Current

IOZ

High Impedance

2.7 to 3.6

VI = VIH or VIL

± 5

± 5

A

Output Leakage

VO = 0 to VCC

Current

ICC

Quiescent Supply

2.7 to 3.6

VI = VCC or GND

10

10

A

Current

VI or VO= 3.6 to 5.5V

± 10

± 10

∆ ICC

ICC incr. per Input

2.7 to 3.6

VIH = VCC - 0.6V

500

500

A

Table 7: Dynamic Switching Characteristics

Test Condition

Value

Symbol

Parameter

VCC

TA = 25 °C

Unit

(V)

Min.

Typ.

Max.

VOLP

Dynamic Low Level Quiet

3.3

CL = 50pF

0.8

V

Output (note 1)

VIL = 0V, VIH = 3.3V

VOLV

-0.8

1) Number of outputs defined as "n". Measured with "n-1" outputs switching from HIGH to LOW or LOW to HIGH. The remaining output is measured in the LOW state.

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