ST 74VHC244 User Manual

74VHC244

OCTAL BUS BUFFER

WITH 3 STATE OUTPUTS (NON INVERTED)

■ HIGH SPEED: t

■ LOW POWER DISSIPATION:

I

= 4 µA (MAX.) at TA=25°C

CC

■ HIGH NOISE IMMUNITY:

V

= V

NIH

■ POWER DOWN PROTECTION ON INPUTS

■ SYMMETRICAL OUTPUT IMPEDANCE:

|I

OH

■ BALANCED PROPAGATION DELAYS:

t

PLH

■ OPERATING VOLTAGE RANGE:

V

CC

■ PIN AND FUNCTION COMPATIBLE WITH

NIL

| = IOL = 8 mA (MIN)

≅ t

PHL

(OPR) = 2V to 5.5V

= 3.9 ns (TYP.) at VCC = 5V

PD

= 28% VCC (MIN.)

74 SERIES 244

■ IMPROVED LATCH-UP IMMUNITY

■ LOW NOISE: V

= 0.9V (MAX.)

OLP

DESCRIPTION

The 74VHC244 is an advanced high-speed CMOS OCTAL BUS BUFFER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C G

output enable governs four BUS BUFFERs.

2

MOS technology.

This device is designed to be used with 3 state memory address drivers, etc.

TSSOPSOP

Table 1: Order Codes

PACKAGE T & R

SOP 74VHC244MTR

TSSOP 74VHC244TTR

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

Figure 1: Pin Connection And IEC Logic Symbols

Rev. 3

1/12November 2004

74VHC244

Figure 2: Input Equivalent Circuit Table 2: Pin Description

PIN N° SYMBOL NAME AND FUNCTION

11G 2, 4, 6, 8 1A1 to 1A4 Data Inputs 9, 7, 5, 3 2Y1 to 2Y4 Data Outputs

11, 13, 15, 172A1 to 2A4 Data Inputs

18, 16, 14, 121Y1 to 1Y4 Data Outputs

Output Enable Input

19 2G

Output Enable Input 10 GND Ground (0V) 20 V

CC

Positive Supply Voltage

Table 3: Truth Table

INPUTS OUTPUT

G

An Yn

LLL LHH

HXZ

X : Don‘t Care Z : High Impedance

Table 4: Absolute Maximum Ratings

Symbol Parameter Value Unit

V

I

OK

I

or I

I

CC

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 ± 75 mA

-65 to +150 °C

300 °C

Table 5: Recommended Operating Conditions

Symbol Parameter Value Unit

V

V V T

dt/dv

1) VIN from 30 % t o 70% of V

Supply Voltage

CC

Input Voltage

I

Output Voltage 0 to V

O

Operating Temperature

op

Input Rise and Fall Time (note 1) (V (V

CC

= 3.3 ± 0.3V)

CC

= 5.0 ± 0.5V)

CC

2 to 5.5 V 0 to 5.5 V

CC

-55 to 125 °C 0 to 100

0 to 20

2/12

V

ns/V

Table 6: DC Specifications

Symbol Parameter

V

High Level Input

IH

Voltage

V

Low Level Input

IL

Voltage

High Level Output

OH

Voltage

Low Level Output

OL

Voltage

I

High Impedance

OZ

Output Leakage Current

Input Leakage

I

Current

I

Quiescent Supply

CC

Current

74VHC244

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

3.0 to

5.5

0.7V

CC

2.0 0.5 0.5 0.5

3.0 to

5.5

2.0

3.0

4.5

3.0

4.5

2.0

3.0

4.5

3.0

4.5

5.5

0 to

5.5

IO=-50 µA I

=-50 µA

O

=-50 µA

I

O

=-4 mA

I

O

=-8 mA

I

O

IO=50 µA

=50 µA

I

O

=50 µA

I

O

=4 mA

I

O

=8 mA

I

O

= VIH or V

V

I

IL

VO = VCC or GND

V

= 5.5V or GND

I

= VCC or GND

V

I

1.9 2.0 1.9 1.9

2.9 3.0 2.9 2.9

4.4 4.5 4.4 4.4

2.58 2.48 2.4

3.94 3.8 3.7

0.3V

0.0 0.1 0.1 0.1

±0.25 ± 2.5 ± 2.5 µA

-40 to 85°C -55 to 125°C

CC

0.7V

CC

0.3V

CC

0.7V

CC

0.36 0.44 0.55

± 0.1 ± 1 ± 1 µA

44040µA

0.3V

CC

Unit

V

3/12

74VHC244

Table 7: AC Electrical Characteristics (Input tr = tf = 3ns)

Test Condition Value

Symbol Parameter

t

Propagation Delay

PLH

t

t t

t

OSLH

t

OSHL

Time

PHL

Output Enable

PZL

Time

PZH

PLZ

Output Disable

PHZ

Time Output to Output

Skew time (note 1)

V

3.3

5.0

3.3

5.0

3.3

5.0

3.3

5.0

C

CC

(V)

L

(pF)

(*)

15 5.8 8.4 1.0 10.0 1.0 10.0

(*)

50 8.3 11.9 1.0 13.5 1.0 13.5

(**)

15 3.9 5.5 1.0 6.5 1.0 6.5

(**)

50 5.4 7.5 1.0 8.5 1.0 8.5

(*)

15

(*)

50

(**)

15

(**)

50

(*)

50

(**)

50

(*)

50 1.5 1.5 1.5

(**)

50 1.0 1.0 1.0

R

L

R

L

R

L

R

L

R

L

R

L

= 1KΩ = 1KΩ = 1KΩ = 1KΩ = 1KΩ = 1KΩ

T

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

= 25°C

A

-40 to 85°C -55 to 125°C

6.6 10.6 1.0 12.5 1.0 12.5

9.1 14.1 1.0 16.0 1.0 16.0

4.7 7.3 1.0 8.5 1.0 8.5

6.2 9.3 1.0 10.5 1.0 10.5

10.3 14.0 1.0 16.0 1.0 16.0

6.7 9.2 1.0 10.5 1.0 10.5

Unit

ns

(*) Voltage range is 3.3V ± 0.3V (**) Voltage range is 5.0V ± Note 1: Parameter guaranteed by design. t

0.5V

soLH

= |t

pLHm

- t

pLHn

|, t

soHL

= |t

pHLm

- t

pHLn

|

Table 8: Capacitive Characteristics

Test Condition Value

= 25°C

Symbol Parameter

T

A

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

C

Input Capacitance

IN

Output

OUT

Capacitance Power Dissipation

PD

Capacitance

410 10 10pF 6pF

19 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