DM74ALS138SJ

DM74ALS138SJ Datasheet

DM74ALS138 3 to 8 Line Decoder/Demultiplexer

Part	Datasheet
DM74ALS138SJ	DM74ALS138SJ (pdf)

Related Parts	Information
DM74ALS138M	DM74ALS138M
DM74ALS138N	DM74ALS138N
DM74ALS138SJX	DM74ALS138SJX
DM74ALS138MX	DM74ALS138MX

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DM74ALS138 3 to 8 Line Decoder/Demultiplexer DM74ALS138 3 to 8 Line Decoder/Demultiplexer These Schottky-clamped circuits are designed to be used in high-performance memory-decoding or data-routing applications, requiring very short propagation delay times. In high-performance memory systems these decoders can be used to minimize the effects of system decoding. When used with high-speed memories, the delay times of these decoders are usually less than the typical access time of the memory. This means that the effective system delay introduced by the decoder is negligible. The DM74ALS138 decodes one-of-eight lines, based upon the conditions at the three binary select inputs and the three enable inputs. Two active-LOW and one active-HIGH enable inputs reduce the need for external gates or inverters when expanding. A 24-line decoder can be implemented with no external inverters, and 32-line decoder requires only one inverter. An enable input can be used as a data input for demultiplexing applications. This decoder/demultiplexer features fully buffered inputs, presenting only one normalized load to its driving circuit. All inputs are clamped with high-performance Schottky diodes to suppress line-ringing and simplify system design. s Designed specifically for high speed: Memory decoders Data transmission systems s 3- to 8-line decoder incorporates 3 enable inputs to sim- plify cascading and/or data reception s Low power mW typ s Switching specifications guaranteed over full tempera- ture and VCC range s Advanced oxide-isolated, ion-implanted Schottky TTL process Ordering Code: Order Number Package Number Package Description DM74ALS138M M16A 16-Lead Small Outline Integrated Circuit SOIC , JEDEC MS-012, Narrow DM74ALS138SJ M16D 16-Lead Small Outline Package SOP , EIAJ TYPE II, 5.3mm Wide DM74ALS138N N16E 16-Lead Plastic Dual-In-Line Package PDIP , JEDEC MS-001, Wide Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Function Table Enable Inputs Select Inputs Outputs G1 G2 C B A Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 Note 1 LH LHH L HHHH HL LHHHHLHHH Note 1 G2 = G2A + G2B 2000 Fairchild Semiconductor Corporation DS006111 DM74ALS138 Logic Diagram DM74ALS138 Absolute Maximum Ratings Note 2 Supply Voltage Input Voltage Operating Free Air Temperature Range 0°C to +70°C Storage Temperature Range −65°C to +150°C Typical N Package 75.5°C/W M Package 104.0°C/W Note 2 The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation. Recommended Operating Conditions VCC VIH VIL IOH IOL TA Parameter Supply Voltage HIGH Level Input Voltage LOW Level Input Voltage HIGH Level Output Current LOW Level Output Current Free Air Operating Temperature Electrical Characteristics over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C. Parameter Conditions Input Clamp Voltage HIGH Level Output Voltage LOW Level Output Voltage Input Current Max. Input Voltage HIGH Level Input Current

PDF Datasheet Preview

DM74ALS138 3 to 8 Line Decoder/Demultiplexer

DM74ALS138 3 to 8 Line Decoder/Demultiplexer

These Schottky-clamped circuits are designed to be used in high-performance memory-decoding or data-routing applications, requiring very short propagation delay times. In high-performance memory systems these decoders can be used to minimize the effects of system decoding. When used with high-speed memories, the delay times of these decoders are usually less than the typical access time of the memory. This means that the effective system delay introduced by the decoder is negligible.

The DM74ALS138 decodes one-of-eight lines, based upon the conditions at the three binary select inputs and the three enable inputs. Two active-LOW and one active-HIGH enable inputs reduce the need for external gates or inverters when expanding. A 24-line decoder can be implemented with no external inverters, and 32-line decoder requires only one inverter. An enable input can be used as a data input for demultiplexing applications.

This decoder/demultiplexer features fully buffered inputs, presenting only one normalized load to its driving circuit. All inputs are clamped with high-performance Schottky diodes to suppress line-ringing and simplify system design.
s Designed specifically for high speed:

Memory decoders

Data transmission systems s 3- to 8-line decoder incorporates 3 enable inputs to sim-
plify cascading and/or data reception s Low power mW typ s Switching specifications guaranteed over full tempera-
ture and VCC range s Advanced oxide-isolated, ion-implanted Schottky TTL
process
Ordering Code:

Order Number Package Number

Package Description

DM74ALS138M

M16A
16-Lead Small Outline Integrated Circuit SOIC , JEDEC MS-012, Narrow

DM74ALS138SJ

M16D
16-Lead Small Outline Package SOP , EIAJ TYPE II, 5.3mm Wide

DM74ALS138N

N16E
16-Lead Plastic Dual-In-Line Package PDIP , JEDEC MS-001, Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.

Connection Diagram

Function Table

Enable Inputs

Select Inputs

Outputs

G1 G2 C B A Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7 Note 1

LH LHH

L HHHH

HL LHHHHLHHH

Note 1 G2 = G2A + G2B
2000 Fairchild Semiconductor Corporation DS006111

DM74ALS138

Logic Diagram

DM74ALS138

Absolute Maximum Ratings Note 2

Supply Voltage

Input Voltage

Operating Free Air Temperature Range 0°C to +70°C

Storage Temperature Range
−65°C to +150°C

Typical N Package
75.5°C/W

M Package
104.0°C/W

Note 2 The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation.

Recommended Operating Conditions

VCC VIH VIL IOH IOL TA

Parameter Supply Voltage HIGH Level Input Voltage LOW Level Input Voltage HIGH Level Output Current LOW Level Output Current Free Air Operating Temperature

Electrical Characteristics
over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C.

Parameter

Conditions

Input Clamp Voltage

HIGH Level

Output Voltage

LOW Level

Output Voltage

Input Current Max.

Input Voltage

HIGH Level Input Current

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Datasheet ID: DM74ALS138SJ 513654