74VHCT125A
QUAD BUS BUFFERS (3-STATE)
s
s
s
s
s
s
s
s
s
s
HIGH SPEED: t
PD
= 3.8 ns (TYP.) at V
CC
= 5V
LOW POWER DISSIPATION:
I
CC
= 2
µA
(MAX.) at T
A
=25°C
COMPATIBLE WITH TTL OUTPUTS:
V
IH
= 2V (MIN.), V
IL
= 0.8V (MAX)
POWER DOWN PROTECTION ON INPUTS
& OUTPUTS
SYMMETRICAL OUTPUT IMPEDANCE:
|I
OH
| = I
OL
= 8 mA (MIN)
BALANCED PROPAGATION DELAYS:
t
PLH
≅
t
PHL
OPERATING VOLTAGE RANGE:
V
CC
(OPR) = 4.5V to 5.5V
PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 125
IMPROVED LATCH-UP IMMUNITY
LOW NOISE: V
OLP
= 0.8V (MAX.)
SOP
TSSOP
Table 1: Order Codes
PACKAGE
SOP
TSSOP
T&R
74VHCT125AMTR
74VHCT125ATTR
DESCRIPTION
The 74VHCT125A is an advanced high-speed
CMOS QUAD BUS BUFFERS fabricated with
sub-micron silicon gate and double-layer metal
wiring C
2
MOS technology.
The device requires the 3-STATE control input G
to be set high to place the output in to the high
impedance state.
Power down protection is provided on all inputs
and outputs and 0 to 7V can be accepted on
inputs with no regard to the supply voltage. This
device can be used to interface 5V to 3V since all
inputs are equipped with TTL threshold.
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
December 2004
Rev. 6
1/12
74VHCT125A
Figure 2: Input Equivalent Circuit
Table 2: Pin Description
PIN N°
1, 4, 10, 13
2, 5, 9, 12
3, 6, 8, 11
7
14
SYMBOL
1G to 4G
1A to 4A
1Y to 4Y
GND
V
CC
NAME AND FUNCTION
Output Enable Inputs
Data Inputs
Data Outputs
Ground (0V)
Positive Supply Voltage
Table 3: Truth Table
A
X
L
H
X : Don‘t Care
Z : High Impedance
G
H
L
L
Y
Z
L
H
Table 4: Absolute Maximum Ratings
Symbol
V
CC
V
I
V
O
V
O
I
IK
I
OK
I
O
T
stg
T
L
Supply Voltage
DC Input Voltage
DC Output Voltage (see note 1)
DC Output Voltage (see note 2)
DC Input Diode Current
DC Output Diode Current
DC Output Current
Storage Temperature
Lead Temperature (10 sec)
Parameter
Value
-0.5 to +7.0
-0.5 to +7.0
-0.5 to +7.0
-0.5 to V
CC
+ 0.5
- 20
±
20
±
25
±
50
-65 to +150
300
Unit
V
V
V
V
mA
mA
mA
mA
°C
°C
I
CC
or I
GND
DC V
CC
or Ground Current
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) Output in OFF State
2) High or Low State
Table 3: RECOMMENDED OPERATING CONDITIONS
Symbol
V
CC
V
I
V
O
V
O
T
op
dt/dv
Supply Voltage
Input Voltage
Output Voltage (see note 1)
Output Voltage (see note 2)
Operating Temperature
Input Rise and Fall Time (see note 3) (V
CC
= 5.0
±
0.5V)
Parameter
Value
4.5 to 5.5
0 to 5.5
0 to 5.5
0 to V
CC
-55 to 125
0 to 20
Unit
V
V
V
V
°C
ns/V
1) Output in OFF State
2) High or Low State
3) V
IN
from 0.8V to 2V
2/12
74VHCT125A
Table 4: DC Specifications
Test Condition
Symbol
Parameter
V
CC
(V)
4.5 to
5.5
4.5 to
5.5
4.5
4.5
4.5
4.5
4.5 to
5.5
0 to
5.5
5.5
5.5
0
I
O
=-50
µA
I
O
=-8 mA
I
O
=50
µA
I
O
=8 mA
V
I
= V
IH
or V
IL
V
O
= 0V to 5.5V
V
I
= 5.5V or GND
V
I
= V
CC
or GND
One Input at 3.4V,
other input at V
CC
or GND
V
OUT
= 5.5V
T
A
= 25°C
Min.
2
0.8
4.4
3.94
0.0
0.1
0.36
±0.25
±
0.1
2
1.35
0.5
4.5
4.4
3.8
0.1
0.44
±
2.5
±
1.0
20
1.5
5.0
Typ.
Max.
Value
-40 to 85°C
Min.
2
0.8
4.4
3.7
0.1
0.55
±
2.5
±
1.0
20
1.5
5.0
Max.
-55 to 125°C
Min.
2
0.8
Max.
V
V
V
V
µA
µA
µA
mA
µA
Unit
V
IH
V
IL
V
OH
V
OL
I
OZ
High Level Input
Voltage
Low Level Input
Voltage
High Level Output
Voltage
Low Level Output
Voltage
High Impedance
Output Leakage
Current
Input Leakage
Current
Quiescent Supply
Current
Additional Worst
Case Supply
Current
Output Leakage
Current
I
I
I
CC
+I
CC
I
OPD
Table 5: AC Electrical Characteristics
(Input t
r
= t
f
= 3ns)
Test Condition
Symbol
Parameter
V
CC
(V)
5.0
(*)
5.0
(*)
5.0
(*)
5.0
(*)
5.0
(*)
C
L
(pF)
15
50
15
50
50
RL = 1 K
Ω
RL = 1 K
Ω
RL = 1 K
Ω
RL = 1 K
Ω
RL = 1 K
Ω
T
A
= 25°C
Min.
Typ.
3.8
5.3
3.6
5.1
6.1
Max.
5.5
7.5
5.1
7.1
8.8
Value
-40 to 85°C
Min.
1.0
1.0
1.0
1.0
1.0
Max.
6.5
8.5
6.0
8.0
10.0
-55 to 125°C
Min.
1.0
1.0
1.0
1.0
1.0
Max.
6.5
8.5
6.0
8.0
10.0
ns
Unit
t
PLH
t
PHL
t
PZL
t
PZH
t
PLZ
t
PHZ
Propagation Delay
Time
Output Disable
Time
Output Enable
Time
ns
ns
(*) Voltage range is 5.0V
±
0.5V
3/12
74VHCT125A
Table 6: Capacitive Characteristics
Test Condition
Symbol
Parameter
T
A
= 25°C
Min.
C
IN
C
OUT
C
PD
Input Capacitance
Output
Capacitance
Power Dissipation
Capacitance
(note 1)
Typ.
4
10
18
Max.
10
Value
-40 to 85°C
Min.
Max.
10
-55 to 125°C
Min.
Max.
10
pF
pF
pF
Unit
1) C
PD
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. I
CC(opr)
= C
PD
x V
CC
x f
IN
+ I
CC
/4 (per circuit)
Table 7: Dynamic Switching Characteristics
Test Condition
Symbol
Parameter
V
CC
(V)
5.0
T
A
= 25°C
Min.
Typ.
0.3
-0.8
C
L
= 50 pF
2.0
-0.3
V
Max.
0.8
Value
-40 to 85°C
Min.
Max.
-55 to 125°C
Min.
Max.
Unit
V
OLP
V
OLV
V
IHD
V
ILD
Dynamic Low
Voltage Quiet
Output (note 1, 2)
Dynamic High
Voltage Input
(note 1, 3)
Dynamic Low
Voltage Input
(note 1, 3)
5.0
5.0
0.8
1) Worst case package.
2) Max number of outputs defined as (n). Data inputs are driven 0V to 3.0V, (n-1) outputs switching and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to 3.0V. Inputs under test switching: 3.0V to threshold (V
ILD
), 0V to threshold
(V
IHD
), f=1MHz.
4/12
74VHCT125A
Figure 5: Test Circuit
TEST
t
PLH
, t
PHL
t
PZL
, t
PLZ
t
PZH
, t
PHZ
C
L
=15/50pF or equivalent (includes jig and probe capacitance)
R
L
= R1 = 1KΩ or equivalent
R
T
= Z
OUT
of pulse generator (typically 50Ω)
SWITCH
Open
V
CC
GND
Figure 6: Waveform - Propagation Delays
(f=1MHz; 50% duty cycle)
5/12
微控制器 MCU
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