PCA9849PWJ Datasheet, PDF (1/30 Pages) NXP Semiconductors – 4-channel ultra-low voltage, Fm+ I2C-bus multiplexer with reset

PCA9849
4-channel ultra-low voltage, Fm+ I²C-bus multiplexer with
reset
Rev. 1 — 16 November 2015
Product data sheet
1. General description
The PCA9849 is an ultra-low voltage, quad bidirectional translating multiplexer controlled
via the I²C-bus. The SCL/SDA upstream pair fans out to four downstream pairs, or
channels. A single SCx/SDx channel can be selected, determined by the programmable
control register. This feature allows multiple devices with the same I²C-bus address to
reside on the same bus. The multiplexer device can also separate a heavily loaded
I²C-bus into separate bus segments, eliminating the need for a bus buffer.
An active LOW reset input allows the PCA9849 to recover from a situation where one of
the downstream I²C-buses is stuck in a LOW state. Pulling the RESET pin LOW resets
the I²C-bus state machine and deselects all the channels, as does the internal
Power-On Reset (POR) function.
The pass gates of the switches are constructed such that the V_DD1 pin is used to limit the
maximum high voltage which is passed by the PCA9849. This allows the use of different
bus voltages on each channel, so that 0.8 V, 1.8 V, 2.5 V or 3.3 V parts can communicate
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 3.6 V tolerant.
2. Features and benefits
 Ultra-low voltage operation, down to 0.8 V to interface with next-generation CPUs
 1-of-4 bidirectional translating multiplexer
 Fm+ I²C-bus interface logic; compatible with SMBus standards
 Active LOW reset input
 2 address pins allowing up to 16 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 0.8 V, 1.8 V, 2.5 V and 3.3 V buses
 Reset via I²C-bus software command
 I²C Device ID function
 No glitch on power-up
 Supports hot insertion since all channels are de-selected at power-on
 Low standby current