ST 74LCX16245 User Manual

74LCX16245

Low voltage CMOS 16-bit bus transceiver (3-state) with 5V tolerant inputs and outputs

Features

■5V tolerant inputs and outputs

■High speed:

–tPD = 4.5ns (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 24mA

■Balanced propagation delays:

–tPLH tPHL

■Operating voltage range:

–VCC (Opr) = 2.0V to 3.6V

■Pin and function compatible with 74 series 16245

■Latch-up performance exceeds 500mA (JESD 17)

■ESD performance:

–HBM > 2000V

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

Order codes

TSSOP48

Description

The 74LCX16245 is a low voltage CMOS 16 bit bus transceiver (3-state) fabricated with submicron 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.

This IC is intended for two-way asynchronous communication between data buses; the direction of data transmission is determined by DIR input.

The two enable inputs nG can be used to disable the device so that the buses are effectively isolated.

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

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.

Part number	Package	Packaging
74LCX16245TTR	TSSOP48	Tape and reel

February 2007

Rev 7

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www.st.com

Contents	74LCX16245

Contents

1	Logic symbols and I/O equivalent circuit . . . . . . . . . . . . . . . . . . . . . . .		. 3
2	Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		4
	2.1	Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
	2.2	Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
3	Logic states . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		5
	3.1	Truth table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
4	Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		6
	4.1	Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
5	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		7
6	Test circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		9
7	Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		10
8	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		11
9	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		14

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74LCX16245	Logic symbols and I/O equivalent circuit

1 Logic symbols and I/O equivalent circuit

Figure 1. IEC logic symbols

Figure 2. Input and output equivalent circuit

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Pin settings	74LCX16245

2 Pin settings

2.1Pin connection

Figure 3. Pin connection (top through view)

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74LCX16245 Logic states

2.2	Pin description
	Table 1. Pin description
	Pin N°	Symbol			Name and function
	1	1DIR			Directional control
	2, 3, 5, 6,	1B1 to 1B8			Data inputs/outputs
	8, 9, 11, 12
	13, 14, 16, 17,	2B1 to 2B8			Data inputs/outputs
	19, 20, 22, 23
	24	2DIR			Directional control
	25				Output enable input
		2G
	36, 35, 33, 32,	2A1 to 2A8			Data inputs/outputs
	30, 29, 27, 26
	47, 46, 44, 43,	1A1 to 1A8			Data inputs/outputs
	41, 40, 38, 38
	48				Output enable input
		1G
	4, 10, 15, 21,	GND			Ground (0V)
	28, 34, 39, 45
	7, 18, 31, 42	VCC			Positive supply voltage

3 Logic states

3.1Truth table

Table 2. Truth table

			Inputs				Function		Output
					DIR	A BUS		B BUS	Yn
		G
		L			L	Output		Input	A = B
		L			H	Input		Output	B = A
		H			X	Z		Z	Z
Note:	X : Do not care
	Z : High impedance

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