ST 74LVX245 User Manual

74LVX245

LOW VOLTAGE CMOS OCTAL BUS TRANSCEIVER

(3-STATE) WITH 5V TOLERANT INPUTS

■ HIGH SPEED:

t

=4.7ns (TY P.) at VCC = 3.3V

PD

■ 5V TOLERANT INPUTS

■ POWER-DOWN PROTECTION ON INPUTS

■ INPUT VOLTAGE LEVEL:

V

= 0.8V, VIH = 2V at VCC =3V

IL

■ LOW POWER DISSIPATION:

I

= 4 µA (MAX.) at TA=25°C

CC

■ LOW NOISE:

V

= 0.5V (TYP.) at VCC =3.3V

OLP

■ SYMMETRICAL OUTPUT IMPEDANCE:

|I

| = IOL = 4 mA (MIN) at VCC =3V

OH

■ BALANCED PROPAGATION DELAYS:

t

≅ t

PLH

PHL

■ OPERATING VOLTAGE RANGE:

V

(OPR) = 2V to 3.6V (1.2V Data Retention)

CC

■ PIN AND FUNCTION COMPATIBLE WITH

74 SERIES 245

■ IMPROVED LATCH-UP IMMUNITY

DESCRIPTION

The 74LVX245 is a low voltage CMOS OCTAL
BUS BUFFER (3-STATE) fabricated with
sub-micron silicon gate and double-layer metal
wiring C

2

MOS technology. It is ideal for low
power, battery operated and low noise 3.3V
applications.
This IC is intended for two-way asynchronous
communication between data busses; the
direction of data transmission is determined by

TSSOPSOP

Table 1: Order Codes

PACKAGE T & R

SOP 74LVX245MTR

TSSOP 74LVX245TTR

DIR input. The enable input G

can be used to
disable the device so that the busses are
effectively isol ated .
Power down protection is provided on all inputs
and 0 to 7V can be accepted on inputs with no
regard to the supply voltage.
This device can be used to interface 5V to 3V. It
combines high speed performance with the true
CMOS low power consumption.
All inputs and outputs are equipped with
protection circuits against static disc harge, 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 C onnection And IEC Logic Symbol s

Rev. 5

1/12August 2004

74LVX245

Figure 2: Input Equivalent Circuit Table 2: Pin Description

PIN N° SYMBOL NAME AND FUNCTION

1 DIR Directional Control

2, 3, 4, 5, 6,

7, 8, 9

18, 17, 16,
15, 14, 13,

12, 11

19 G
10 GND Ground (0V)
20 V

Table 3: Truth Table

A1 to A8 Data Inputs/Outputs

B1 to B8 Data Inputs/Outputs

Output Enable Input

CC

Positive Supply Voltage

INPUTS FUNCTION

OUTPUT

G

DIR A BUS B BUS

L L OUTPUT INPUT A = B
L H INPUT OUTPUT B = A

HXZZZ

X :Don‘t Care
Z : High Impedance

Table 4: Absolute Maximum Ratings

Symbol Parameter Value Unit

V

V

V

I

I

OK

I

or I

I

CC

T

T

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

Supply Voltage

CC

DC Input Voltage

I

DC Output Voltage -0.5 to VCC + 0.5

O

DC Input Diode Current

IK

DC Output Diode Current
DC Output Current

O

DC VCC or Ground Current

GND

Storage Temperature

stg

Lead Temperature (10 sec)

L

-0.5 to +7.0 V

-0.5 to +7.0 V
V

- 20 mA

± 20 mA
± 25 mA
± 50 mA

-65 to +150 °C

300 °C

Table 5: Recommended Operating Conditions

Symbol Parameter Value Unit

V

V
V
T

dt/dv

1) Truth T abl e guarante ed: 1.2V to 3.6V

2) V

from 0.8V to 2.0V

IN

Supply Voltage (note 1)

CC

Input Voltage

I

Output Voltage 0 to V

O

Operating Temperature

op

Input Rise and Fall Time (note 2) (V

CC

= 3V)

2 to 3.6 V
0 to 5.5 V

CC

-55 to 125 °C
0 to 100 ns/V

2/12

V

Table 6: DC Specifications

Symbol Parameter

V

V

V

High Level Input

IH

Voltage

V

Low Level Input

IL

Voltage

High Level Output

OH

Voltage

Low Level Output

OL

Voltage

High Impedance

I

OZ

Output Leakage
Current

I

Input Leakage

I

Current

I

Quiescent Supply

CC

Current

74LVX245

Test Condition Value

= 25°C

T

V

CC

(V)

A

Min. Typ. Max. Min. Max. Min. Max.

2.0 1.5 1.5 1.5

2.0 2.0 2.0

3.6

2.4 2.4 2.4

2.0 0.5 0.5 0.5

3.6 0.8 0.8 0.8
=-50 µA

2.0

3.0

2.0

3.0

3.6

3.6

3.6

V

VO = VCC or GND

V

V

I

I

O

=-50 µA

I

O

=-4 mA

I

O

IO=50 µA
I

=50 µA

O

=4 mA

I

O

= VIH or V

I

= 5V or GND

I

= VCC or GND

1.9 2.0 1.9 1.9

2.9 3.0 2.9 2.9

2.58 2.48 2.4

0.0 0.1 0.1 0.1

0.0 0.1 0.1 0.1

IL

±0.25 ± 2.5 ± 5 µA

-40 to 85°C -55 to 125°C

0.36 0.44 0.55

± 0.1 ± 1 ± 1 µA

44040µA

Unit

V3.0

V3.0 0.8 0.8 0.8

V3.0

V3.0

Table 7: Dynamic Switching Characteristics

Test Condition Value

= 25°C

Symbol Parameter

V
V

Dynamic Low

OLP

Voltage Quiet

OLV

Output (note 1, 2)

V

CC

(V)

3.3

T

A

Min. Typ. Max. Min. Max. Min. Max.

0.5 0.8

-0.8 -0.5

Dynamic High

V

IHD

Voltage Input

3.3 2.0

= 50 pF

C

L

(note 1, 3)
Dynamic Low

V

ILD

Voltage Input

3.3 0.8

(note 1, 3)

1) Worst case package.

2) Max number of outp ut s defined as (n). Data inp ut s are driven 0V to 3.3V, (n-1) outputs switc hi ng and one out put at GND.

3) Max number of data inputs (n) switching. (n-1) switching 0V to 3.3V. Inputs under test switching: 3.3V to threshold (V
), f=1MHz.

(V

IHD

-40 to 85°C -55 to 125°C

ILD

Unit

V

), 0V to thresho l d

3/12

74LVX245

Table 8: AC Electrical Characteristics (Input tr = tf = 3ns)

Test Condition Value

= 25°C

Symbol Parameter

t

Propagation Delay

PLH

t

t
t

t
t

t

OSLH

t

OSHL

1) Skew is defined as the absolute value of the difference between the actual propagation delay for any two outputs of the same device switch-

ing in the sa m e di rection, ei ther HIGH or LOW

2) Param eter guaran teed by design

(*) Voltage range is 3.3V ±

Time

PHL

Output Enable

PZL

Time

PZH

Output Disable

PLZ

Time

PHZ

Output to Output
Skew Time (note
1,2)

0.3V

V

C

CC

(V)

L

(pF)

2.7 15 6.1 11.4 1.0 13.5 1.0 15.0

2.7 50 8.6 14.9 1.0 17.0 1.0 18.0

(*)

3.3

3.3

15 4.5 7.1 1.0 8.5 1.0 9.5

(*)

50 7.2 10.6 1.0 12.0 1.0 13.0

2.7 15 7.1 13.8 1.0 16.5 1.0 17.5

2.7 50 9.6 17.3 1.0 20.0 1.0 21.0

(*)

3.3

3.3

15 5.5 8.8 1.0 10.5 1.0 12.

(*)

50 8.0 12.3 1.0 14.0 1.0 15.0

2.7 50 11.6 16.0 1.0 19.0 1.0 20.5

(*)

3.3

50 9.7 11.4 1.0 13.0 1.0 14.5

2.7 50 0.5 1.0 1.5 1.5

(*)

3.3

50 0.5 1.0 1.5 1.5

T

A

Min. Typ. Max. Min. Max. Min. Max.

-40 to 85°C -55 to 125°C

Unit

ns

ns

ns

ns

Table 9: Capacitive Characteristics

Test Condition Value

= 25°C

Symbol Parameter

C
C

C

Input Capacitance

IN

Input/Output

i/o

Capacitance
Power Dissipation

PD

Capacitance

V

CC

(V)

3.3 5 10 10 pF

3.3 10 15 15 pF

= 10MHz

3.3

f

IN

T

A

Min. Typ. Max. Min. Max. Min. Max.

32 pF

(note 1)

1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without

load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. I

-40 to 85°C -55 to 125°C

= CPD x VCC x fIN + ICC/8 (per c ircuit )

CC(opr)

Unit

4/12