PCA9525D NXP [NXP Semiconductors], PCA9525D Datasheet - Page 12

• Manufacturer Part Number: PCA9525D
• Description: Simple 2-wire bus buffer
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
PCA9525
Product data sheet
Multiplexers such as the PCA9544A are simple analog switches which provide no
capacitive load isolation between connected branches.
enhancing an I
branch.
being an excellent way to eliminate the requirement for a master to dedicate pins to
enabling multiple PCA9525 devices.
Fig 15. PCA9525 with masters on both sides of buffer
Fig 16. PCA9525 multiplexer isolation application
U1
BUS MASTER
U2
BUS MASTER
Figure 17
V
CC
Alternately, using the PCA9546A, (which allows multiple outputs to be selected) you would simply
place a PCA9525 on each output on the right hand side, rather than a single PCA9525 on the
left hand side.
V
5 V
DD
SDA
SCL
1.5 kΩ
SDA
SCL
2
IRQ
All information provided in this document is subject to legal disclaimers.
C-bus multiplexer application by isolating the load capacitance of each
R1
and
U3
R2
1.5 kΩ
Rev. 1 — 25 February 2011
MASTER/
Figure 18
SLAVE
U2
SCL_IN
SDA_IN
EN
DIR
PCA9525
V
R1
DD
SDA_OUT
SCL_OUT
show alternate forms of bus multiplexing, with the latter
master U4 requests SCL
direction change from
R2
master U2 using IRQ
1.1 kΩ
U1
SCL_IN
SDA_IN
EN
DIR
R3
PCA9525
V
R4
1.1 kΩ
DD
SDA_OUT
SCL_OUT
3.3 V
U3
SCL
SDA
INT[3:0]
A0
A1
A2
R3
Figure 16
PCA9544A
V
U4
DD
MASTER
SC0
SD0
SC1
SD1
SC2
SD2
SC3
SD3
Simple 2-wire bus buffer
002aaf344
shows the PCA9525
R4
PCA9525
U5
© NXP B.V. 2011. All rights reserved.
Using the PCA9525,
up to 400 pF may be
connected to each
and every bus 0
through bus 3.
SLAVE
002aaf343
SCL
SDA
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