Final Datasheet Rev 1.0
July 21, 2017
Semtech
Proprietary & Confidential
Table 3 defines the possible configuration sequences. These sequences are intended to be used in the system primarily during
initial setup (usually on system power-up). These commands are “sticky”, that is to say, once one is written, that corresponding
configuration remains in effect until such a time as power is removed, thereby re-setting the part. Upon reset, the configuration
will return to its default state. The default configuration settings are shown in the table.
Table 3: Configuration Page--Valid Configuration Sequences
C3 C2 C1 C0 Configuration
0 0 0 0 Reserved
0 0 0 1 Set Over-Current Shutdown Set to 00
0 0 1 0 Set Over-Current Shutdown Set to 01
0 0 1 1 Set Over-Current Shutdown Set to 10
0 1 0 0 Set Over-Current Shutdown Set to 11 (default)
0 1 0 1 Reserved
0 1 1 0 Reserved
0 1 1 1 Reserved
1 0 0 0 Reserved
1 0 0 1 Reserved
1 0 1 0 Reserved
1 0 1 1 Reserved
1 1 0 0 Reserved
1 1 0 1 Reserved
1 1 1 0 Reserved
1 1 1 1 Poll State (No Operation)
Each device monitors the CLK line regardless of the address; however only the device with the (AD2 AD1 AD0) pins configured to
match the (A2 A1 A0) field sent via the CLK pin will respond to the Command bits (C3 C2 C1 C0). If two or more devices on the CLK
bus have address pins wired alike, those devices will all respond to the same command. However, doing this may lead to DATA
bus conflicts when the device Status Values are reported.
The command is executed after the status values are shifted out to avoid interference on the status values caused by transients in
the system.
ON Commands
Four modes of closing the switch are available:
1. ON, Immediate: When this command sequence is sent, the switch will be closed after the status values are shifted out. The
system must comprehend the time it takes to complete the sequence in order to place the switch in the closed state at the
desired time.
2. ON, Zero Crossing: When this command sequence is sent, the switch will close on the first occurrence of a polarity change
in the voltage across the switch (V
SW1
-V
SW2
changes sign to indicate a voltage zero-crossing) after the switch receives the
command and the status values are shifted out. This should not be used for DC applications.
3. ON, Immediate with Dithering: This command closes the switch as in ON, Immediate, above, but puts the device into
Dither mode as well. Dithering opens the switch after an interval of T
DRTY
for a period of time, T
DOFF
when the system
voltage drops below V
DON
. This allows the C
SYS
capacitor to be re-charged. See the Dither Functionality Section for more
details.
4. ON, Zero Crossing with Dithering: This command closes the switch as in ON, Zero Crossing, but enables the Dither mode
as described above.
OFF Commands
Two modes of opening the switch are available:
1. OFF, Immediate: When the OFF, Immediate sequence is sent, the switch will transition to the open state after the status
values are shifted out.
2. OFF, Zero Crossing: When the OFF, Zero-Crossing sequence is received, the switch will open on the first occurrence of the
load-current dropping within I
TURN_OFF
after the status values are shifted out.
