PCA9544D NXP Semiconductors, PCA9544D Datasheet - Page 6

• Manufacturer Part Number: PCA9544D
• Manufacturer: NXP Semiconductors

Specifications of PCA9544D

• Logical Function: I2C Multiplexer
• Configuration: 1 x 4:1
• Number Of Inputs: 4
• Number Of Outputs: 1
• Operating Supply Voltage (typ): 2.5/3.3/5V
• Operating Supply Voltage (min): 2.3V
• Operating Supply Voltage (max): 5.5V
• Power Dissipation: 400mW
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 20
• Package Type: SO
• Lead Free Status / Rohs Status: Compliant

Philips Semiconductors
VOLTAGE TRANSLATION
The pass gate transistors of the PCA9544 are constructed such that
the V
be passed from one I
2004 Sep 29
V
4-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 6. V
TYPICAL
2
C-bus to another.
C multiplexer with 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
6
Figure 6 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 PCA9544 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 6, we see that V
PCA9544 supply voltage is 3.5 V or lower so the PCA9544 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 13).
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
PCA9544
Product data sheet
pass