PCA9544A_16 Datasheet, PDF (1/35 Pages) Texas Instruments – SMBus Multiplexer With Interrupt Logic

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PCA9544A
SCPS146E – OCTOBER 2005 – REVISED JUNE 2014
PCA9544A Low Voltage 4-Channel I²C and SMBus Multiplexer With Interrupt Logic
1 Features
•1 1-of-4 Bidirectional Translating Switches
• I²C Bus and SMBus Compatible
• Four Active-Low Interrupt Inputs
• Active-Low Interrupt Output
• Three Address Pins, Allowing up to Eight Devices
on the I²C Bus
• Channel Selection Via I²C Bus
• Power Up With All Switch Channels Deselected
• Low R_ON Switches
• Allows Voltage-Level Translation Between 1.8-V,
2.5-V, 3.3-V, and 5-V Buses
• No Glitch on Power Up
• Supports Hot Insertion
• Low Standby Current
• Operating Power-Supply Voltage Range of
2.3 V to 5.5 V
• 5.5-V Tolerant Inputs
• 0 to 400-kHz Clock Frequency
• Latch-Up Performance Exceeds 100 mA Per
JESD 78
• ESD Protection Exceeds JESD 22
– 2000-V Human-Body Model (A114-A)
– 200-V Machine Model (A115-A)
– 1000-V Charged-Device Model (C101)
2 Applications
• Servers
• Routers (Telecom Switching Equipment)
• Factory Automation
• Products With I²C Slave Address Conflicts (For
Example, Multiple, Identical Temp Sensors)
3 Description
The PCA9544A is a quad bidirectional translating
switch controlled via the I²C bus. The SCL/SDA
upstream pair fans out to four downstream pairs, or
channels. One SCL/SDA pair can be selected at a
time, and this is determined by the contents of the
programmable control register. Four interrupt inputs
(INT3–INT0), one for each of the downstream pairs,
are provided. One interrupt output (INT) acts as an
AND of the four interrupt inputs.
A power-on reset function puts the registers in their
default state and initializes the I²C state machine,
with no channel selected.
The pass gates of the switches are constructed such
that the V_CC pin can be used to limit the maximum
high voltage, which will be passed by the PCA9544A.
This allows the use of different bus voltages on each
pair, so that 1.8-V, 2.5-V, or 3.3-V parts can
communicate with 5-V parts, without any additional
protection. External pull-up resistors pull the bus up
to the desired voltage level for each channel. All I/O
pins are 5-V tolerant.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
PCA9544A
TSSOP (20)
6.50 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
4 Simplified Application Diagram
I2C or SMBus
Master
(e.g. µProcessor)
SDA
V_CC
SCL
INT
PCA9544A
A0
A1
A2
GND
Channel 0
SD0
SC0
INT0
SD1 ^{Channel 1}
SC1
INT1
SD2 ^{Channel 2}
SC2
INT2
SD3 ^{Channel 3}
SC3
INT3
Slaves A0, A1...AN
Slaves B0, B1...BN
Slaves B0, B1...BN
Slaves B0, B1...BN
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.