74F138 데이터 시트보기 (PDF) - Philips Electronics
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74F138 Datasheet PDF : 8 Pages
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Philips Semiconductors
1-of-8 decoder/demultiplexer
Product specification
74F138
FEATURE
• Demultiplexing capability
• Multiple input enable for easy expansion
• Ideal for memory chip select decoding
• Industrial temperature range available (–40°C to +85°C)
DESCRIPTION
The 74F138 decoder accepts three binary weighted inputs (A0, A1,
A2) and when enabled, provides eight mutually exclusive, active low
outputs (Q0 – Q7). The device features three enable inputs; two
active low (E0, E1) and one active high (E2). Every output will be
high unless E0 and E1 are low and E2 is high. This multiple enable
function allows easy parallel expansion of the device to 1-of-32
(5 lines to 32 lines) decoder with just four 74F138s and one inverter
(see Figure 1). The device can be used as an eight output
demultiplexer by using one of the active low enable inputs as the
data input and the remaining enable inputs as strobes. Enable
inputs not used must be permanently tied to their appropriate active
high or active low state.
PIN CONFIGURATION
A0 1
A1 2
A2 3
E0 4
E1 5
E2 6
Q7 7
GND 8
16 VCC
15 Q0
14 Q1
13 Q2
12 Q3
11 Q4
10 Q5
9 Q6
SF00174
TYPE
74F138
TYPICAL
PROPAGATION
DELAY
5.8ns
TYPICAL
SUPPLY CURRENT
(TOTAL)
13mA
ORDERING INFORMATION
DESCRIPTION
16-pin plastic DIP
ORDER CODE
COMMERCIAL RANGE
VCC = 5V ±10%, Tamb = 0°C to +70°C
N74F138N
INDUSTRIAL RANGE
VCC = 5V ±10%, Tamb = –40°C to +85°C
I74F138N
16-pin plastic SO
N74F138D
I74F138D
PKG DWG #
SOT38-4
SOT109-1
INPUT AND OUTPUT LOADING AND FAN-OUT TABLE
PINS
DESCRIPTION
74F (U.L.) HIGH/LOW
A0 – A2
Address inputs
1.0/1.0
E0, E1
Enable inputs (active Low)
1.0/1.0
E2
Enable input (active High)
1.0/1.0
Q0 – Q7
Data outputs
50/33
NOTE:
One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6mA in the Low state.
LOAD VALUE HIGH/LOW
20µA/0.6mA
20µA/0.6mA
20µA/0.6mA
1.0mA/20mA
LOGIC SYMBOL
IEC/IEEE SYMBOL
1 23
4
E0
A0 A1 A2
5
E1
6
E2
Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
VCC = Pin 16
GND = Pin 8
15 14 13 12 11 10 9 7
SF00175
DMUX
1
15
0
0
2
G0
1
14
3
3
13
2
2
12
3
11
4
4
&
10
5
5
9
6
6
7
7
SF00176
February 14, 1991
2
853–0343 01719
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