ST 74LCX138 User Manual

74LCX138MTR

74LCX138

LOW VOLTAGE CMOS 3 TO 8 LINE DECODER (INV.) WITH 5V TOLERANT INPUTS

■5V TOLERANT INPUTS

■HIGH SPEED:

tPD = 6.7ns (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 24 mA

■BALANCED PROPAGATION DELAYS: tPLH tPHL

■OPERATING VOLTAGE RANGE:

VCC(OPR) = 2.0V to 3.6V (1.5V Data Retention)

■PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 138

■LATCH-UP PERFORMANCE EXCEEDS 500mA (JESD 17)

■ESD PERFORMANCE:

HBM > 2000V (MIL STD 883 method 3015); MM > 200V

DESCRIPTION

The 74LCX138 is a low voltage CMOS 3 TO 8 LINE DECODER (INVERTING) fabricated with sub-micron 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 inputs.

If the device is enabled, 3 binary select inputs (A, B and C) determine which one of the outputs will

SOP TSSOP

Table 1: Order Codes

PACKAGE	T & R
SOP	74LCX138MTR
TSSOP	74LCX138TTR

go low. If enable input G1 is held low or either G2A or G2B is held high, the decoding function is inhibited and all the 8 outputs go to high.

Three enable inputs are provided to ease cascade connection and application of address decoders for memory systems.

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.

Figure 1: Pin Connection And IEC Logic Symbols

September 2004	Rev. 4
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74LCX138

Figure 2: Input And Output Equivalent Circuit

Table 2: Pin Description

PIN N°

SYMBOL

NAME AND FUNCTION

1, 2, 3

A, B, C

Address Inputs

4, 5

G2A,

G2B

Enable Inputs

6

G1

Enable Input

15, 14, 13, 12, 11, 10, 9, 7

Y0

to

Y7

Outputs

8

GND

Ground (0V)

16

VCC

Positive Supply Voltage

Table 3: Truth Table

INPUTS

OUTPUTS

ENABLE

SELECT

G2B

G2A

G1

C

B

A

Y0

Y1

Y2

Y3

Y4

Y5

Y6

Y7

X

X

L

X

X

X

H

H

H

H

H

H

H

H

X

H

X

X

X

X

H

H

H

H

H

H

H

H

H

X

X

X

X

X

H

H

H

H

H

H

H

H

L

L

H

L

L

L

L

H

H

H

H

H

H

H

L

L

H

L

L

H

H

L

H

H

H

H

H

H

L

L

H

L

H

L

H

H

L

H

H

H

H

H

L

L

H

L

H

H

H

H

H

L

H

H

H

H

L

L

H

H

L

L

H

H

H

H

L

H

H

H

L

L

H

H

L

H

H

H

H

H

H

L

H

H

L

L

H

H

H

L

H

H

H

H

H

H

L

H

L

L

H

H

H

H

H

H

H

H

H

H

H

L

X : Don’t Care

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74LCX138

Figure 3: Logic Diagram

This logic diagram has not be used to estimate propagation delays

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 (VCC = 0V)	-0.5 to +7.0		V
VO	DC Output Voltage (High or Low State) (note 1)	-0.5 to VCC + 0.5		V
IIK	DC Input Diode Current	- 50		mA
IOK	DC Output Diode Current (note 2)	- 50		mA
IO	DC Output Current	±	50	mA
ICC	DC Supply Current per Supply Pin	±	100	mA
IGND	DC Ground Current per Supply Pin	±	100	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)IO absolute maximum rating must be observed

2)VO < GND

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74LCX138

Table 5: Recommended Operating Conditions

Symbol	Parameter	Value		Unit
VCC	Supply Voltage (note 1)	2.0 to 3.6		V
VI	Input Voltage	0 to 5.5		V
VO	Output Voltage (VCC = 0V)	0 to 5.5		V
VO	Output Voltage (High or Low State)	0 to VCC		V
IOH, IOL	High or Low Level Output Current (VCC = 3.0 to 3.6V)	±	24	mA
IOH, IOL	High or Low Level Output Current (VCC = 2.7V)	±	12	mA
Top	Operating Temperature	-55 to 125		°C
dt/dv	Input Rise and Fall Time (note 2)	0 to 10		ns/V

1)Truth Table guaranteed: 1.5V to 3.6V

2)VIN from 0.8V to 2V at VCC = 3.0V

Table 6: DC Specifications

Test Condition

Value

Symbol

Parameter

Unit

VCC

-40 to 85 °C

-55 to 125 °C

(V)

Min.

Max.

Min.

Max.

VIH

High Level Input

2.0

2.0

V

Voltage

2.7 to 3.6

VIL

Low Level Input

0.8

0.8

V

Voltage

VOH

High Level Output

2.7 to 3.6

IO=-100 A

VCC-0.2

VCC-0.2

Voltage

2.7

IO=-12 mA

2.2

2.2

V

3.0

IO=-18 mA

2.4

2.4

IO=-24 mA

2.2

2.2

VOL

Low Level Output

2.7 to 3.6

IO=100 A

0.2

0.2

Voltage

2.7

IO=12 mA

0.4

0.4

V

3.0

IO=16 mA

0.4

0.4

IO=24 mA

0.55

0.55

II

Input Leakage

2.7 to 3.6

VI = 0 to 5.5V

± 5

± 5

A

Current

Ioff

Power Off Leakage

0

VI or VO = 5.5V

10

10

A

Current

ICC

Quiescent Supply

2.7 to 3.6

VI = VCC or GND

10

10

A

Current

VI or VO= 3.6 to 5.5V

± 10

± 10

∆ ICC

ICC incr. per Input

2.7 to 3.6

VIH = VCC - 0.6V

500

500

A

Table 7: Dynamic Switching Characteristics

Test Condition

Value

Symbol

Parameter

VCC

TA = 25 °C

Unit

(V)

Min.

Typ.

Max.

VOLP

Dynamic Low Level Quiet

3.3

CL = 50pF

0.8

V

Output (note 1)

VIL = 0V, VIH = 3.3V

VOLV

-0.8

1) Number of outputs defined as "n". Measured with "n-1" outputs switching from HIGH to LOW or LOW to HIGH. The remaining output is measured in the LOW state.

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