74LCX138TTR - STMicroelectronics - Datasheet.Directory

July 2006 Rev 5 1/17

74LCX138

Low voltage CMOS 3 to 8 line decoder (Inverter)

with 5V tolerant inputs

Features

■5V tolerant inputs

■High speed:

–t

PD = 6.7ns (Max) at VCC = 3V

■Power down protection on inputs and outputs

■Symmetrical output impedance:

–|I

OH| = IOL = 24mA (Min) at VCC = 3V

■PCI bus levels guaranteed at 24mA

■Balanced propagation delays:

–t

PLH ≅ tPHL

■Operating voltage range:

–V

CC (Opr) = 2.0V to 3.6V

■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

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.

SO-16 TSSOP16

www.st.com

Order codes

Part number Package Packaging

74LCX138MTR SO-16 Tape and reel

74LCX138TTR TSSOP16 Tape and reel

Contents 74LCX138

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Contents

1 Logic symbols and I/O equivalent circuit . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.3 Truth table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.4 Logic diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Maximum rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3.1 Recommended operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Test circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6 Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

74LCX138 Logic symbols and I/O equivalent circuit

3/17

1 Logic symbols and I/O equivalent circuit

Figure 1. IEC logic symbols

Figure 2. Input and output equivalent circuit

Pin settings 74LCX138

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2 Pin settings

2.1 Pin connection

Figure 3. Pin connection (top through view)

2.2 Pin description

Table 1. 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

74LCX138 Pin settings

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2.3 Truth table

Note: X : Do not care

2.4 Logic diagram

Figure 4. Logic diagram

Note: This logic diagram has not to be used to estimate propagation delays

Table 2. Truth table

Inputs Outputs

Enable Select

G2B G2A G1 C B A Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7

X XL XXXHHHHHHHH

XHXXXXHHHHHHHH

HXXXXXHHHHHHHH

LLHLLLLHHHHHHH

L LHL LHHLHHHHHH

L LHLHLHHLHHHHH

L LHLHHHHHLHHHH

L LHHL LHHHHLHHH

L LHHLHHHHHHLHH

L LHHHLHHHHHHLH

L LHHHHHHHHHHHL

Maximum rating 74LCX138

6/17

3 Maximum rating

stressing the device above the rating listed in the “absolute maximum ratings” table may

cause permanent damage to the device. these are stress ratings only and operation of the

device at these or any other conditions above those indicated in the operating sections of

this specification is not implied. exposure to absolute maximum rating conditions for

extended periods may affect device reliability. refer also to the STMicroelectronics sure

program and other relevant quality documents.

3.1 Recommended operating conditions

Table 3. Absolute maximum ratings

Symbol Parameter Value Unit

VCC Supply voltage -0.5 to +7.0 V

VIDC input voltage -0.5 to +7.0 V

VODC output voltage (VCC = 0V) -0.5 to +7.0 V

VODC output voltage (high or low state) (1)

1. IO absolute maximum rating must be observed

-0.5 to VCC + 0.5 V

IIK DC input diode current -50 mA

IOK DC output diode current (2)

2. VO < GND

-50 mA

IODC 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

TLLead temperature (10 sec) 300 °C

Table 4. Recommended operating conditions

Symbol Parameter Value Unit

VCC Supply voltage (1)

1. Truth table guaranteed: 1.5V to 3.6V

2.0 to 3.6 V

VIInput voltage 0 to 5.5 V

VOOutput voltage (VCC = 0V) 0 to 5.5 V

VOOutput 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 -40 to 85 °C

dt/dv Input rise and fall time (2)

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

0 to 10 ns/V

74LCX138 Electrical characteristics

7/17

4 Electrical characteristics

Table 5. DC specifications

Symbol Parameter

Test condition Value

Unit

VCC

(V)

-40 to 85°C

Min Max

VIH High level input voltage

2.7 to 3.6

2.0 V

VIL Low level input voltage 0.8 V

VOH High level output voltage

2.7 to 3.6 IO=-100 µAV

CC-0.2

2.7 IO=-12 mA 2.2

3.0

IO=-18 mA 2.4

IO=-24 mA 2.2

VOL Low level output voltage

2.7 to 3.6 IO=100 µA0.2

2.7 IO=12 mA 0.4

3.0

IO=16 mA 0.4

IO=24 mA 0.55

IIInput leakage current 2.7 to 3.6 VI = 0 to 5.5V ± 5 µA

Ioff Power OFF leakage

current 0VI or VO = 5.5V 10 µA

ICC Quiescent supply current 2.7 to 3.6

VI = VCC or GND 10

µA

VI or VO= 3.6 to 5.5V ± 10

∆ICC I incr. per Input 2.7 to 3.6 VIH = VCC - 0.6V 500 µA

Table 6. Dynamic switching characteristics

Symbol Parameter

Test condition Value

Unit

VCC

(V)

TA = 25 °C

Min Typ Max

VOLP Dynamic low level quiet

output (1)

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.

3.3 CL = 50pF

VIL = 0V, VIH = 3.3V

0.8

VOLV -0.8

Electrical characteristics 74LCX138

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Table 7. AC electrical characteristics

Symbol Parameter

Test condition Value

Unit

VCC

(V)

(pF)

(Ω)

ts = tr

(ns)

-40 to 85 °C

Min Max

tPLH tPHL Propagation delay

time

2.7 50 500 2.5 7.9 ns

3.0 to 3.6 1.5 6.7

tPZL tPZH

Output enable

time to HIGH and

LOW level

2.7

50 500 2.5

6.4

3.0 to 3.6 1.5 5.8

tPLZ tPHZ

Output disable

time to HIGH and

LOW level

2.7

50 500 2.5

7.4

3.0 to 3.6 1.5 6.5

tOSLH

tOSHL

Output to output

skew time (1) (2)

1. Skew is defined as the absolute value of the difference between the actual propagation delay for any two

outputs of the same device switching in the same direction, either HIGH or LOW (tOSLH = | tPLHm - tPLHn|,

tOSHL = | tPHLm - tPHLn|)

2. Parameter guaranteed by design

3.0 to 3.6 50 500 2.5 1.0 ns

Table 8. Capacitive characteristics

Symbol Parameter

Test condition Value

Unit

VCC

(V)

TA = 25 °C

Min Typ Max

CIN Input capacitance 3.3 VIN = 0 to VCC 6pF

CPD

Power dissipation

capacitance (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

3.3 fIN = 10MHz

VIN = 0 or VCC

42 pF

74LCX138 Test circuit

9/17

5 Test circuit

Figure 5. Test circuit

CL = 50pF or equivalent (includes jig and probe capacitance)

RL = 500

Ω

or equivalent

RT = ZOUT of pulse generator (typically 50

Ω

)

Waveforms 74LCX138

10/17

6 Waveforms

Figure 6. Propagation delay for inverting outputs (f = 1MHz; 50% duty cycle)

Figure 7. Propagation delay for non-inverting outputs (f = 1MHz; 50% duty cycle)

74LCX138 Package mechanical data

11/17

7 Package mechanical data

In order to meet environmental requirements, ST offers these devices in ECOPACK®

packages. These packages have a Lead-free second level interconnect . The category of

second level interconnect is marked on the package and on the inner box label, in

compliance with JEDEC Standard JESD97. The maximum ratings related to soldering

conditions are also marked on the inner box label. ECOPACK is an ST trademark.

ECOPACK specifications are available at: www.st.com

Package mechanical data 74LCX138

12/17

DIM.

mm. inch

MIN. TYP MAX. MIN. TYP. MAX.

A 1.75 0.068

a1 0.1 0.25 0.004 0.010

a2 1.64 0.063

b 0.35 0.46 0.013 0.018

b1 0.19 0.25 0.007 0.010

C 0.5 0.019

c1 45° (typ.)

D 9.8 10 0.385 0.393

E 5.8 6.2 0.228 0.244

e 1.27 0.050

e3 8.89 0.350

F 3.8 4.0 0.149 0.157

G 4.6 5.3 0.181 0.208

L 0.5 1.27 0.019 0.050

M 0.62 0.024

S8° (max.)

SO-16 MECHANICAL DATA

0016020D

74LCX138 Package mechanical data

13/17

DIM.

mm. inch

MIN. TYP MAX. MIN. TYP. MAX.

A 1.2 0.047

A1 0.05 0.15 0.002 0.004 0.006

A2 0.8 1 1.05 0.031 0.039 0.041

b 0.19 0.30 0.007 0.012

c 0.09 0.20 0.004 0.0079

D 4.9 5 5.1 0.193 0.197 0.201

E 6.2 6.4 6.6 0.244 0.252 0.260

E1 4.3 4.4 4.48 0.169 0.173 0.176

e 0.65 BSC 0.0256 BSC

K0˚ 8˚0˚ 8˚

L 0.45 0.60 0.75 0.018 0.024 0.030

TSSOP16 MECHANICAL DATA

PIN 1 IDENTIFICATION

A1 L

0080338D

Package mechanical data 74LCX138

14/17

DIM.

mm. inch

MIN. TYP MAX. MIN. TYP. MAX.

A 330 12.992

C 12.8 13.2 0.504 0.519

D 20.2 0.795

N 60 2.362

T 22.4 0.882

Ao 6.45 6.65 0.254 0.262

Bo 10.3 10.5 0.406 0.414

Ko 2.1 2.3 0.082 0.090

Po 3.9 4.1 0.153 0.161

P 7.9 8.1 0.311 0.319

Tape & Reel SO-16 MECHANICAL DATA

74LCX138 Package mechanical data

15/17

DIM.

mm. inch

MIN. TYP MAX. MIN. TYP. MAX.

A 330 12.992

C 12.8 13.2 0.504 0.519

D 20.2 0.795

N 60 2.362

T 22.4 0.882

Ao 6.7 6.9 0.264 0.272

Bo 5.3 5.5 0.209 0.217

Ko 1.6 1.8 0.063 0.071

Po 3.9 4.1 0.153 0.161

P 7.9 8.1 0.311 0.319

Tape & Reel TSSOP16 MECHANICAL DATA

Revision history 74LCX138

16/17

8 Revision history

Table 9. Revision history

Date Revision Changes

15-Sep-2004 4 Ordering Codes Revision - pag. 1.

26-Jul-2006 5 New template, temperature ranges updated

74LCX138

17/17

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