PCA9515 Philips Semiconductors (Acquired by NXP), PCA9515 Datasheet - Page 3

• Manufacturer Part Number: PCA9515
• Description: PCA9515; I2C Bus Repeater
• Manufacturer: Philips Semiconductors (Acquired by NXP)

Philips Semiconductors
The output pull-down of each internal buffer is set for approximately
0.5 V, while the input threshold of each internal buffer is set about
0.07 V lower, when the output is internally driven low. This prevents
a lock-up condition from occurring.
FUNCTIONAL DESCRIPTION
The PCA9515 BiCMOS integrated circuit contains two identical
buffer circuits which enable I
extended without degradation of system performance.
The PCA9515 BiCMOS integrated circuit contains two bi-directional,
open drain buffers specifically designed to support the standard
low-level-contention arbitration of the I
arbitration or clock stretching, the PCA9515 acts like a pair of
non-inverting, open drain buffers, one for SDA and one for SCL.
Enable
The EN pin is active high with an internal pull up and allows the user
to select when the repeater is active. This can be used to isolate a
badly behaved slave on power up until after the system power up
reset. It should never change state during an I
disabling during a bus operation will hang the bus and enabling part
way through a bus cycle could confuse the I
The enable pin should only change state when the global bus and
the repeater port are in an idle state to prevent system failures.
2002 May 13
I
2
C bus repeater
EN
2
SDA0
SCL0
C and similar bus systems to be
2
C-bus. Except during
PCA9515
2
C parts being enabled.
2
C operation because
RESISTOR
PULL-UP
Figure 2. Block Diagram: PCA9515
3
V
GND
CC
with standard mode and fast mode I
I
As with the standard I
provide the logic HIGH levels on the Buffered bus. (Standard
open-collector configuration of the I
pull-up resistors depends on the system, but each side of the
repeater must have a pull-up resistor. This part designed to work
devices. Standard mode I
this limits the termination current to 3 mA in a generic I
where standard mode devices and multiple masters are possible.
Under certain conditions higher termination currents can be used.
Please see Application Note AN255 “I
and Expanders” for additional information on sizing resistors and
precautions when using more than one PCA9515/PCA9516 in a
system or using the PCA9515/16 in conjunction with the P82B96.
2
C Systems
2
C system, pull-up resistors are required to
2
C devices only specify 3 mA output drive,
SDA1
SCL1
2
2
C-bus). The size of these
C devices in addition to SMBus
2
C & SMBus Repeaters, Hubs
PCA9515
SU01323
2
C system
Product data