pca9549bs NXP Semiconductors, pca9549bs Datasheet - Page 6

• Manufacturer Part Number: pca9549bs
• Description: Octal Bus Switch With Individually I2c-bus Controlled Enables
• Manufacturer: NXP Semiconductors

Philips Semiconductors
PCA9549_1
Product data sheet
6.3 RESET input
6.4 Power-on reset
6.5 CBT characteristic over V
Table 4.
Write = channel selection; read = channel status.
[1]
The RESET input is an active LOW signal which may be used to recover from a bus fault
condition. By asserting this signal LOW for a minimum of t
registers and I
connected to V
When power is applied to V
a reset state until V
the PCA9549 registers and I
zeroes causing all the bits to be open (high-impedance state).
The bus switch is optimized at 5.0 V but can operate over the entire supply range with
lower V
B7
X
X
X
X
X
X
X
0
1
Several bits can be enabled at the same time. For example, B7 = 0, B6 = 1, B5 = 0, B4 = 0, B3 = 1, B2 = 1,
B1 = 0, B0 = 0, means that bit 8, bit 6, bit 5, bit 2, and bit 1 are disabled and bit 7, bit 4, and bit 3 are
enabled.
o(sw)
Control register
B6
X
X
X
X
X
X
X
0
1
voltage and higher gate resistance.
2
DD
C-bus state machine and will open all bits. The RESET input must be
through a pull-up resistor.
DD
B5
X
X
X
X
X
X
X
0
1
has reached V
Rev. 01 — 11 July 2006
Octal bus switch with individually I
DD
B4
2
X
X
X
X
X
X
X
0
1
C-bus state machine are initialized to their default states, all
, an internal Power-On Reset (POR) holds the PCA9549 in
DD
B3
POR
range
X
X
X
X
X
X
X
0
1
. At this point, the reset condition is released and
B2
X
X
X
X
X
X
X
0
1
B1
X
X
X
X
X
X
X
0
1
w(rst)L
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
2
B0
, the PCA9549 will reset its
C-bus controlled enables
X
X
X
X
X
X
X
0
1
Command
bit 1 disabled
bit 1 enabled
bit 2 disabled
bit 2 enabled
bit 3 disabled
bit 3 enabled
bit 4 disabled
bit 4 enabled
bit 5 disabled
bit 5 enabled
bit 6 disabled
bit 6 enabled
bit 7 disabled
bit 7 enabled
bit 8 disabled
bit 8 enabled
PCA9549
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