pca9542pw NXP Semiconductors, pca9542pw Datasheet - Page 5

• Manufacturer Part Number: pca9542pw
• Description: 2-channel I2c Multiplexer And Interrupt Controller
• Manufacturer: NXP Semiconductors

Philips Semiconductors
VOLTAGE TRANSLATION
The pass gate transistors of the PCA9542 are constructed such that
the V
be passed from one I
2004 Oct 01
V
2-channel I
pass
DD
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
voltage can be used to limit the maximum voltage that will
2.0
2.5
2
Figure 5. V
TYPICAL
2
C-bus to another.
C multiplexer and interrupt logic
3.0
V
pass
MAXIMUM
3.5
pass
vs. V
DD
voltage
V
4.0
DD
4.5
MINIMUM
5.0
SW00820
5.5
5
Figure 5 shows the voltage characteristics of the pass gate
transistors (note that the graph was generated using the data
specified in the DC Characteristics section of this datasheet). In
order for the PCA9542 to act as a voltage translator, the V
voltage should be equal to, or lower than the lowest bus voltage. For
example, if the main bus was running at 5 V, and the downstream
buses were 3.3 V and 2.7 V, then V
2.7 V to effectively clamp the downstream bus voltages. Looking at
Figure 5, we see that V
PCA9542 supply voltage is 3.5 V or lower so the PCA9542 supply
voltage could be set to 3.3 V. Pull-up resistors can then be used to
bring the bus voltages to their appropriate levels (see Figure 12).
More Information can be found in Application Note AN262 PCA954X
family of I
2
C/SMBus multiplexers and switches.
pass
(max.) will be at 2.7 V when the
pass
should be equal to or below
PCA9542
Product data sheet
pass