ST 74VHCT125A User Manual

74VHCT125A

QUAD BUS BUFFERS (3-STATE)

■HIGH SPEED: tPD = 3.8 ns (TYP.) at VCC = 5V

■LOW POWER DISSIPATION: ICC = 2 A (MAX.) at TA=25°C

■COMPATIBLE WITH TTL OUTPUTS: VIH = 2V (MIN.), VIL = 0.8V (MAX)

■POWER DOWN PROTECTION ON INPUTS & OUTPUTS

■SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 8 mA (MIN)

■BALANCED PROPAGATION DELAYS: tPLH tPHL

■OPERATING VOLTAGE RANGE: VCC(OPR) = 4.5V to 5.5V

■PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 125

■IMPROVED LATCH-UP IMMUNITY

■LOW NOISE: VOLP = 0.8V (MAX.)

DESCRIPTION

The 74VHCT125A is an advanced high-speed CMOS QUAD BUS BUFFERS fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology.

The device requires the 3-STATE control input G to be set high to place the output in to the high impedance state.

SOP		TSSOP
Table 1: Order Codes
PACKAGE		T & R
SOP		74VHCT125AMTR
TSSOP		74VHCT125ATTR

Power down protection is provided on all inputs and outputs 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 since all inputs are equipped with TTL threshold.

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

Figure 1: Pin Connection And IEC Logic Symbols

December 2004	Rev. 6
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74VHCT125A

Figure 2: Input Equivalent Circuit	Table 2: Pin Description
	PIN N°	SYMBOL	NAME AND FUNCTION
	1, 4, 10, 13	1G to 4G	Output Enable Inputs
	2, 5, 9, 12	1A to 4A	Data Inputs
	3, 6, 8, 11	1Y to 4Y	Data Outputs
	7	GND	Ground (0V)
	14	VCC	Positive Supply Voltage
	Table 3: Truth Table
	A	G	Y
	X	H	Z
	L	L	L
	H	L	H

X : Don‘t Care

Z : High Impedance

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 (see note 1)	-0.5 to +7.0		V
VO	DC Output Voltage (see note 2)	-0.5 to VCC + 0.5		V
IIK	DC Input Diode Current	- 20		mA
IOK	DC Output Diode Current	±	20	mA
IO	DC Output Current	±	25	mA
ICC or IGND	DC VCC or Ground Current	±	50	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)Output in OFF State

2)High or Low State

Table 3: RECOMMENDED OPERATING CONDITIONS

Symbol	Parameter	Value	Unit
VCC	Supply Voltage	4.5 to 5.5	V
VI	Input Voltage	0 to 5.5	V
VO	Output Voltage (see note 1)	0 to 5.5	V
VO	Output Voltage (see note 2)	0 to VCC	V
Top	Operating Temperature	-55 to 125	°C
dt/dv	Input Rise and Fall Time (see note 3) (VCC = 5.0 ± 0.5V)	0 to 20	ns/V

1)Output in OFF State

2)High or Low State

3)VIN from 0.8V to 2V

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74VHCT125A

Table 4: DC Specifications

Test Condition

Value

Symbol

Parameter

VCC

TA = 25°C

-40 to 85°C

-55 to 125°C

Unit

(V)

Min.

Typ.

Max.

Min.

Max.

Min.

Max.

VIH

High Level Input

4.5 to

2

2

2

V

Voltage

5.5

VIL

Low Level Input

4.5 to

0.8

0.8

0.8

V

Voltage

5.5

VOH

High Level Output

4.5

IO=-50 A

4.4

4.5

4.4

4.4

V

Voltage

4.5

IO=-8 mA

3.94

3.8

3.7

VOL

Low Level Output

4.5

IO=50 A

0.0

0.1

0.1

0.1

V

Voltage

4.5

IO=8 mA

0.36

0.44

0.55

IOZ

High Impedance

4.5 to

VI = VIH or VIL

±

±

±

A

Output Leakage

0.25

2.5

2.5

Current

5.5

VO = 0V to 5.5V

II

Input Leakage

0 to

VI = 5.5V or GND

±

0.1

±

1.0

±

1.0

A

Current

5.5

ICC

Quiescent Supply

5.5

VI = VCC or GND

2

20

20

A

Current

+ICC

Additional Worst

One Input at 3.4V,

Case Supply

5.5

other input at VCC

1.35

1.5

1.5

mA

Current

or GND

IOPD

Output Leakage

0

VOUT = 5.5V

0.5

5.0

5.0

A

Current

Table 5: AC Electrical Characteristics (Input tr = tf = 3ns)

Test Condition

Value

Symbol

Parameter

VCC

CL

TA = 25°C

-40 to 85°C

-55 to 125°C

Unit

(V)

(pF)

Min.

Typ.

Max.

Min.

Max.

Min.

Max.

tPLH

Propagation Delay

5.0(*)

15

RL = 1 KΩ

3.8

5.5

1.0

6.5

1.0

6.5

ns

tPHL

Time

5.0(*)

50

RL = 1 KΩ

5.3

7.5

1.0

8.5

1.0

8.5

tPZL

Output Disable

5.0(*)

15

RL = 1 KΩ

3.6

5.1

1.0

6.0

1.0

6.0

ns

tPZH

Time

5.0(*)

50

RL = 1 KΩ

5.1

7.1

1.0

8.0

1.0

8.0

tPLZ

Output Enable

5.0(*)

50

RL = 1 KΩ

6.1

8.8

1.0

10.0

1.0

10.0

ns

tPHZ

Time

(*) Voltage range is 5.0V ± 0.5V

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74VHCT125A

Table 6: Capacitive Characteristics

		Test Condition					Value
Symbol	Parameter		TA = 25°C				-40 to 85°C		-55 to 125°C		Unit
			Min.	Typ.	Max.		Min.	Max.	Min.	Max.
CIN	Input Capacitance			4		10		10		10	pF
COUT	Output			10							pF
	Capacitance
CPD	Power Dissipation			18							pF
	Capacitance
	(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. ICC(opr) = CPD x VCC x fIN + ICC/4 (per circuit)

Table 7: Dynamic Switching Characteristics

Test Condition

Value

Symbol

Parameter

VCC

TA = 25°C

-40 to 85°C

-55 to 125°C

Unit

(V)

Min.

Typ.

Max.

Min.

Max.

Min.

Max.

VOLP

Dynamic Low

0.3

0.8

Voltage Quiet

5.0

VOLV

-0.8

-0.3

Output (note 1, 2)

VIHD

Dynamic High

CL = 50 pF

Voltage Input

5.0

2.0

V

(note 1, 3)

VILD

Dynamic Low

Voltage Input

5.0

0.8

(note 1, 3)

1)Worst case package.

2)Max number of outputs defined as (n). Data inputs are driven 0V to 3.0V, (n-1) outputs switching and one output at GND.

3)Max number of data inputs (n) switching. (n-1) switching 0V to 3.0V. Inputs under test switching: 3.0V to threshold (VILD), 0V to threshold (VIHD), f=1MHz.

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