Document
HD74HC138
3-to-8-line Decoder/Demultiplexer with Address Latch
REJ03D0570-0300 Rev.3.00
Mar 25, 2009
Description
The HD74HC138 has 3 binary select inputs (A, B and C). If the device is enabled these inputs determine which one of the eight normally high outputs will go low. Two active low and one active high enables (G1, G2A and G2B) are provided to ease the cascading of decoders.
Features
• High Speed Operation: tpd (A, B, C to Y) = 16.5 ns typ (CL = 50 pF) • High Output Current: Fanout of 10 LSTTL Loads • Wide Operating Voltage: VCC = 2 V to 6 V • Low Input Current: 1 µA max • Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C) • Ordering Information
Part Name
Package Type
Package Code (Previous Code)
HD74HC138P
DILP-16 pin
PRDP0016AE-B (DP-16FV)
HD74HC138FPEL
SOP-16 pin (JEITA)
PRSP0016DH-B (FP-16DAV)
HD74HC138RPEL
SOP-16 pin (JEDEC)
PRSP0016DG-A (FP-16DNV)
HD74HC138TELL
TSSOP-16 pin
PTSP00016JB-A (TTP-16DAV)
Note: Please consult the sales office for the above package availability.
Package Abbreviation
P
FP
RP
T
Taping Abbreviation (Quantity)
—
EL (2,000 pcs/reel)
EL (2,500 pcs/reel)
ELL (2,000 pcs/reel)
REJ03D0570-0300 Rev.3.00 Mar 25, 2009 Page 1 of 7
HD74HC138
Function Table
Inputs
Enable
Select
Outputs
G1 G2A G2B
C
B
A
Y0 Y1 Y2 Y3 Y4 Y5 Y6 Y7
XXHXXXHHHHHHHH
XHXXXXHHHHHHHH
L XXXXXHHHHHHHH
HL L L L L LHHHHHHH
HL L L LHHLHHHHHH
HL L LHLHHLHHHHH
HL L LHHHHHLHHHH
HL LHL LHHHHLHHH
HL LHLHHHHHHLHH
HL LHHL HHHHHHLH
HL LHHHHHHHHHHL
H : High level
L : Low level
X : Irrelevant
Pin Arrangement
A1
Select Inputs
B2
C3
Enable Inputs
G2A 4 G2B 5
G1 6
Output Y7 7
GND 8
A B Y0
C Y1
G2A
Y2
G2B G1
Y3 Y4
Y7 Y5 Y6
(Top view)
16 VCC 15 Y0 14 Y1 13 Y2 12 Y3 Outputs 11 Y4 10 Y5 9 Y6
Absolute Maximum Ratings
Item
Symbol
Rating
Unit
Supply voltage range Input voltage Output voltage Output current DC current drain per VCC, GND DC input diode current DC output diode current Power dissipation per package Storage temperature
VCC VIN VOUT IOUT ICC, IGND IIK IOK PT Tstg
–0.5 to +7.0 –0.5 to VCC + 0.5 –0.5 to VCC + 0.5
±25 ±50 ±20 ±20 500 –65 to +150
V V V mA mA mA mA mW °C
Note: The absolute maximum ratings are values, which must not individually be exceeded, and furthermore, no two of which may be realized at the same time.
REJ03D0570-0300 Rev.3.00 Mar 25, 2009 Page 2 of 7
HD74HC138
Recommended Operating Conditions
Item
Symbol
Ratings
Supply voltage Input / Output voltage Operating temperature
VCC VIN, VOUT
Ta
2 to 6 0 to VCC –40 to 85
Input rise / fall time*1
0 to 1000 tr, tf 0 to 500
0 to 400
Note: 1. This item guarantees maximum limit when one input switches.
Waveform: Refer to test circuit of switching characteristics.
Unit V V °C
ns
Conditions
VCC = 2.0 V VCC = 4.5 V VCC = 6.0 V
Electrical Characteristics
Item Input voltage
Output voltage
Input current Quiescent supply current
Symbol VIH VIL VOH
VOL Iin
VCC (V)
2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 4.5 6.0 2.0 4.5 6.0 4.5 6.0 6.0
Ta = 25°C Min Typ Max 1.5 — — 3.15 — — 4.2 — — — — 0.5 — — 1.35 — — 1.8 1.9 2.0 — 4.4 4.5 — 5.9 6.0 — 4.18 — — 5.68 — — — 0.0 0.1 — 0.0 0.1 — 0.0 0.1 — — 0.26 — — 0.26 — — ±0.1
Ta = –40 to+85°C Unit
Min Max
Test Conditions
1.5 —
3.15 — V
4.2 —
— 0.5
— 1.35 V
— 1.8
1.9 —
4.4 —
IOH = –20 µA
5.9 — V Vin = VIH or VIL
4.13 —
IOH = –4 mA
5.63 —
IOH = –5.2 mA
— 0.1
— 0.1
IOL = 20 µA
— 0.1 V Vin = VIH or VIL
— 0.33
IOL = 4 mA
— 0.33
IOL = 5.2 mA
— ±1.0 µA Vin = VCC or GND
ICC 6.0 — — 4.0 —
40 µA Vin = VCC or GND, Iout = 0 µA
REJ03D0570-0300 Rev.3.00 Mar 25, 2009 Page 3 of 7
HD74HC138
Switching Characteristics (CL = 50 pF, Input tr = tf = 6 ns)
Item
Propagation delay time
Output rise/fall time Input capacitance
Symbol VCC (V)
tPHL tPLH tPHL tPLH tPHL tPLH tTLH, tTHL Cin
2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 2.0 4.5 6.0 —
Ta = 25°C
Ta = –40 to +85°C Unit
Min Typ Max Min Max
Test Conditions
— — 175 —
220
— 17 35
—
44 ns
— — 30 — — 150
— —
37 190
A, B or C to Y
— 16 30
—
38 ns
— — 26
—
33
— — 150 —
190
— 16 30
—
38 ns
— — 26 — — 150
— —
33 190
G1 to Y
— 17 30
—
38 ns
— — 26
—
33
— — 175 —
220
— 15 35
—
44 ns
— — 30 — — 150
— —
37 190
G2A or G2B to Y
— 17 30
—
38 ns
— — 26
—
33
— — 75
—
90
— 5 15
—
19 ns
— — 13
—
16
— 5 10
—
10 pF
Test Circuit
Measurement point
CL*
Note: CL includes the probe and fig capacitance.
REJ03D0570-0300 Rev.3.00 Mar 25, 2009 Page 4 of 7
HD74HC138
Waveforms
Input
tr
10 %
90 % 50 %
tPLH
tf
90 % 50 %
10 %
tPHL
Same-phase output
50 % 10 %
90 %
tPHL tTLH
90 %
50 % 10 %
tPLH
tTHL
VCC 0V
VOH VOL
Inverse-phase output
90 %
50 % 10 %
50 % 10 %
90 %
VOH VOL
tTHL
tTLH
Notes: 1. Input waveform: PRR ≤ 1 MHz, Zo = 50 Ω, tr ≤ 6 ns, tf ≤ 6 ns 2. The output are measured one at a time with one transition per measurement.
REJ03D0570-0300 Rev.3.00 Mar 25, 2009 Page 5 of 7
HD74HC138
Package D.