Datasheet

PCA9646 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 1 — 1 March 2011 11 of 22
NXP Semiconductors
PCA9646
Buffered 4-channel 2-wire bus switch
Fig 14. PCA9646 typical buffer application
002aaf375
BUS MASTER
U3
V
DD
SCL
SDA
R8
1.1 kΩ
SC0
SD0
SCL
SDA
PCA9646
V
DD
SC0
SD0
U1
RESET
3.3 V
SCL
SDA
V
DD
MASTER/
SLAVE
U4
SCL
SDA
V
DD
SLAVE
U5
SCL
SDA
V
DD
SLAVE
U6
R7
1.1 kΩ
R1
1.1 kΩ
R2
1.1 kΩ
SC2
SD2
SC2
SD2
R3
1.1 kΩ
R4
1.1 kΩ
SC3
SD3
SC3
SD3
R5
1.1 kΩ
R6
1.1 kΩ
400 pF load at 1 MHz
or 4 nF load at 100 kHz
400 pF load at 1 MHz
or 4 nF load at 100 kHz
400 pF load at 1 MHz
or 4 nF load at 100 kHz
A0
A1
A2
V
SS
R10
1.1 kΩ
SC1
SD1
SC1
SD1
SCL
SDA
V
DD
SLAVE
U7
SCL
SDA
V
DD
SLAVE
U8
R9
1.1 kΩ
400 pF load at 1 MHz
or 4 nF load at 100 kHz
400 pF load at 1 MHz
or 4 nF load at 100 kHz
Fig 15. PCA9646 as a 30 mA line driver
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BUS
MASTER
U1
V
DD
SCL
SDA
R4
180 Ω
SCL
SDA
PCA9646
V
DD
SC0
SC1
U2
RESET
5 V
R3
180 Ω
R1 R2
A0
A1
e.g., PC/TV
receiver or
decoder box
SD0
SD1
etc.
SC2
SC3
A2
SD2
SD3
SCL
SDA
PCA9646
V
DD
SC0
SC1
U3
RESET
A0
A1
SD0
SD1
SC2
SC3
A2
SD2
SD3
address address
backplane or
long cable run
with 30 mA
pull-up current
SLAVE
U4
V
DD
SCL
SDA
R6R5
e.g., monitor,
flat TV, LED array