ST 74LVX257 User Manual
74LVX257
LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER
(3-STATE) WITH 5V TOLERANT INPUTS
■ HIGH SPEED:
t
=5.8ns (TY P.) at VCC = 3.3V
PD
■ 5V TOLERANT INPUTS
■ POWER-DOWN PROTECTION ON INPUTS
■ INPUT VOLTAGE LEVEL:
V
= 0.8V, VIH = 2V at VCC =3V
IL
■ LOW POWER DISSIPATION:
I
= 4 µA (MAX.) at TA=25°C
CC
■ LOW NOISE:
V
= 0.3V (TYP.) at VCC =3.3V
OLP
■ SYMMETRICAL OUTPUT IMPEDANCE:
|I
| = IOL = 4 mA (MIN) at VCC =3V
OH
■ BALANCED PROPAGATION DELAYS:
t
≅ t
PLH
PHL
■ OPERATING VOLTAGE RANGE:
V
(OPR) = 2V to 3.6V (1.2V Data Retention)
CC
■ PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 257
■ IMPROVED LATCH-UP IMMUNITY
DESCRIPTION
The 74LVX257 i s a low voltage CMOS QUAD 2
CHANNEL MULTIPLEXER (3-STATE) fabricated
with sub-micron silicon gate and double-layer
metal wiring C
2
MOS technology. It is ideal for low
power, battery operated and low noise 3.3V
applications.
It is composed of four independent 2-channel
multiplexers with common SELECT and ENA BLE
(OE
) INPUT. The 74LVX257 is a non-inverting
TSSOPSOP
Table 1: Order Codes
PACKAGE T & R
SOP 74LVX257MTR
TSSOP 74LVX257TTR
multiplexer. When the ENABLE INPUT is held
"High", all outputs become in high impedance
state. If SELECT INPUT is held "Low", "A" dat a is
selected, when SELECT INPUT is "High", "B" data
is chosen.
Power down protection is provided on all inputs
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. It
combines high speed performance with the true
CMOS low power consumption.
All inputs and outputs are equipped with
protection circuits against static disc harge, giving
them 2KV ESD immunity and transient excess
voltage.
Figure 1: Pin C onnection And IEC Logic Symbol s
Rev. 3
1/13August 2004
74LVX257
Figure 2: Input Equivalent Circuit Table 2: Pin Description
PIN N° SYMBOL NAME AND FUNCTION
1 SELECT Common Data Select
Inputs
2, 5, 11, 14 1A to 4A Data Inputs From Source
A
3, 6, 10, 13 1B to 4B Data Inputs From Source
B
Table 3: Truth Table
4, 7, 9, 12 1Y to 4Y 3 State Multiplexer
15 OE
8 GND Ground (0V)
16 V
INPUTS OUTPUT
CC
Outputs
3 State Output Enable
Inputs (Active LOW)
Positive Supply Voltage
OE
HXXXZ
LLLXL
LLHXH
LHXLL
LHXHH
X :Don‘t Care
Z : High Impedance
Figure 3: Logic Diagram
SELECT A B Y
This logi c di agram has not be used to est i m ate propagation delays
2/13
74LVX257
Table 4: Absolute Maximum Ratings
Symbol Parameter Value Unit
V
V
V
I
I
OK
I
or I
I
CC
T
T
Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
Table 5: Recommended Operating Conditions
Symbol Parameter Value Unit
V
V
V
T
dt/dv
Supply Voltage
CC
DC Input Voltage
I
DC Output Voltage -0.5 to VCC + 0.5
O
DC Input Diode Current
IK
DC Output Diode Current
DC Output Current
O
DC VCC or Ground Current
GND
Storage Temperature
stg
Lead Temperature (10 sec)
L
Supply Voltage (note 1)
CC
Input Voltage
I
Output Voltage 0 to V
O
Operating Temperature
op
Input Rise and Fall Time (note 2) (V
CC
= 3V)
-0.5 to +7.0 V
-0.5 to +7.0 V
- 20 mA
± 20 mA
± 25 mA
± 50 mA
-65 to +150 °C
300 °C
2 to 3.6 V
0 to 5.5 V
CC
-55 to 125 °C
0 to 100 ns/V
V
V
1) Truth T abl e guarante ed: 1.2V to 3.6V
2) V
from 0.8V to 2.0V
IN
Table 6: DC Specifications
Symbol Parameter
V
V
V
High Level Input
IH
Voltage
V
Low Level Input
IL
Voltage
High Level Output
OH
Voltage
Low Level Output
OL
Voltage
High Impedance
I
OZ
Output Leakage
Current
I
Input Leakage
I
Current
I
Quiescent Supply
CC
Current
Test Condition Value
V
(V)
CC
T
A
Min. Typ. Max. Min. Max. Min. Max.
-40 to 85°C -55 to 125°C
= 25°C
2.0 1.5 1.5 1.5
2.0 2.0 2.0
3.6
2.4 2.4 2.4
2.0 0.5 0.5 0.5
3.6 0.8 0.8 0.8
2.0
3.0
2.0
3.0
3.6
3.6
3.6
IO=-50 µA
=-50 µA
I
O
=-4 mA
I
O
IO=50 µA
I
=50 µA
O
=4 mA
I
O
= VIH or V
V
I
IL
VO = VCC or GND
= 5.5V or GND
V
I
= VCC or GND
V
I
1.9 2.0 1.9 1.9
2.9 3.0 2.9 2.9
2.58 2.48 2.4
0.0 0.1 0.1 0.1
0.0 0.1 0.1 0.1
0.36 0.44 0.55
±0.25 ± 2.5 ± 5 µA
± 0.1 ± 1 ± 1 µA
44040µA
Unit
V3.0
V3.0 0.8 0.8 0.8
V3.0
V3.0
3/13
74LVX257
Table 7: Dynamic Switching Characteristics
Test Condition Value
= 25°C
Symbol Parameter
V
V
Dynamic Low
OLP
Voltage Quiet
OLV
Output (note 1, 2)
V
CC
(V)
3.3
T
A
Min. Typ. Max. Min. Max. Min. Max.
0.3 0.5
-0.5 -0.3
Dynamic High
V
IHD
Voltage Input
3.3 2.0
= 50 pF
C
L
(note 1, 3)
Dynamic Low
V
ILD
Voltage Input
3.3 0.8
(note 1, 3)
1) Worst case package.
2) Max number of outp ut s defined as (n). Data inp ut s are driven 0V to 3.3V, (n-1) outputs switc hi ng and one out put at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to 3.3V. Inputs under test switching: 3.3V to threshold (V
(V
), f=1MHz.
IHD
Table 8: AC Electrical Characteristics (Input tr = tf = 3ns)
Test Condition Value
-40 to 85°C -55 to 125°C
ILD
Unit
V
), 0V to thresho l d
= 25°C
Symbol Parameter
t
Propagation Delay
PLH
t
t
t
t
t
t
t
t
OSLH
t
OSHL
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 sa m e di rection, ei ther HIGH or LOW
2) Param eter guaran teed by design
(*) Voltage range is 3.3V ±
Time
PHL
A, B, to Y
Propagation Delay
PLH
Time
PHL
SELECT to Y
Output Enable
PZL
Time
PZH
Output Disable
PLZ
Time
PHZ
Output to Output
Skew Time (note
1,2)
0.3V
V
C
CC
(V)
L
(pF)
2.7 15 7.0 13.0 1.0 15.4 1.0 16.4
2.7 50 9.5 18.0 1.0 20.3 1.0 21.3
(*)
3.3
3.3
15 5.8 9.3 1.0 11.0 1.0 12.0
(*)
50 8.3 12.8 1.0 14.5 1.0 15.5
2.7 15 8.5 15.4 1.0 18.2 1.0 20.0
2.7 50 10.5 20.3 1.0 23.1 1.0 24.5
(*)
3.3
3.3
15 7.0 11.0 1.0 13.0 1.0 14.0
(*)
50 9.5 14.5 1.0 16.5 1.0 18.0
2.7 15 8.0 14.7 1.0 17.5 1.0 18.5
2.7 50 10.5 19.6 1.0 22.4 1.0 24.0
(*)
3.3
3.3
15 6.7 10.5 1.0 12.5 1.0 13.5
(*)
50 9.2 14.0 1.0 16.0 1.0 17.0
2.7 50 9.5 16.8 1.0 18.9 1.0 20.0
(*)
3.3
50 8.6 12.0 1.0 13.5 1.0 15.0
2.7 50 0.5 1.0 1.5 1.5
(*)
3.3
50 0.5 1.0 1.5 1.5
T
A
-40 to 85°C -55 to 125°C
Min. Typ. Max. Min. Max. Min. Max.
Unit
ns
ns
ns
ns
ns
4/13
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