ST 74VHCT541A User Manual

74VHCT541A

OCTAL BUS BUFFER WITH 3 STATE OUTPUTS (NON INVERTED)

■HIGH SPEED: tPD = 4.1 ns (TYP.) at VCC = 5V

■LOW POWER DISSIPATION: ICC = 4 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 541

■IMPROVED LATCH-UP IMMUNITY

■LOW NOISE: VOLP = 0.9V (MAX.)

DESCRIPTION

The 74VHCT541A is an advanced high-speed CMOS OCTAL BUS BUFFER (3-STATE) fabricated with sub-micron silicon gate and double-layer metal wiring C2MOS technology.

The 3 STATE control gate operates as two input AND such that if either G1 and G2 are high, all eight outputs are in the high impedance state.

SOP	TSSOP
Table 1: Order Codes
PACKAGE	T & R
SOP	74VHCT541AMTR
TSSOP	74VHCT541ATTR

In order to enhance PC board layout, the 74VHCT541 offers a pinout having inputs and outputs on opposite sides of the package.

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. 4
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74VHCT541A

Figure 2: Input Equivalent Circuit	Table 2: Pin Description
	PIN N°	SYMBOL	NAME AND FUNCTION
	1, 19	G1, G2	Output Enable Inputs
	2, 3, 4, 5, 6,	A1 to A8	Data Inputs
	7, 8, 9
	18, 17, 16,	Y1 to Y8	Data Outputs
	15, 14, 13,
	12, 11
	10	GND	Ground (0V)
	20	VCC	Positive Supply Voltage

Table 3: Truth Table

			INPUT				OUTPUT
	G1			G2		An	Yn
	H			X		X	Z
	X			H		X	Z
	L			L		H	H
	L			L		L	L
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

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			74VHCT541A
Table 5: 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

Table 6: 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					±	0.25		±	2.5		±	2.5	A
	Output Leakage	5.5		VO = 0V to 5.5V
	Current
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						4			40			40	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 7: 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				4.1		6.0	1.0		6.5	1.0		6.5	ns
tPHL	Time	5.0		50				6.2		8.5	1.0		9.5	1.0		9.5
tPZL	Output Disable	5.0		15	RL = 1KΩ			5.0		7.0	1.0		8.0	1.0		8.0	ns
tPZH	Time	5.0		50				7.5		10.0	1.0	12.0		1.0	12.0
tPLZ	Output Enable	5.0		50	RL = 1KΩ			7.0		10.0	1.0	12.0		1.0	12.0		ns
tPHZ	Time

(*) Voltage range is 5.0V ± 0.5V

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74VHCT541A

Table 8: 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			6		10		10		10	pF
COUT	Output			8							pF
	Capacitance
CPD	Power Dissipation			16							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/8 (per circuit)

Table 9: 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

0.9

1.1

Voltage Quiet

5.0

VOLV

-1.1

-0.9

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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