ISL78226 Datasheet, PDF (8/94 Pages) Intersil Corporation – Cycle-by-cycle peak current limiting

ISL78226
Pin Description (Continued)
PIN NAME
ISEN2A
ISEN2B
ISEN3A
ISEN3B
BAT12
ISEN4A
ISEN4B
ISEN5A
ISEN5B
I/O PIN #
DESCRIPTION
I 38 Current Sense Amplifier (CSA) 2 input. With a combination of ISEN2B and gain setting resistors, R_SET2A and R_SET2B, the
current flowing at Current Sense Resistor-2 will be converted to the sensed current signal and forwarded into the device.
Connect ISEN2A at the negative side of Current Sense Resistor-2 in Buck mode configuration. Ultimately senses the
BAT12 voltage side of the current sensing shunt through the filter, refer to Figure 4 on page 12. The resistive shunt MUST
be Kelvin connected, do not allow this connection to take place anywhere else on the BAT12 plane. The sensed current
information is used for peak current mode control, average current control, and overcurrent protections.
I 39 The other side of Current Sense Amplifier (CSA) 2 input. With a combination of ISEN2A and gain setting resistors, R_SET2A
and R_SET2B, the current flowing at Current Sense Resistor-2 will be converted to the sensed current signal and forwarded
into the device. Connect ISEN2B at the positive side of Current Sense Resistor-2 in Buck mode configuration. Ultimately
senses the inductor side of the current sensing shunt through the filter, refer to Figure 4. The resistive shunt MUST be
Kelvin connected. The sensed current information is used for peak current mode control, average current control, and
overcurrent protections.
I 40 Current Sense Amplifier (CSA) 3 input. With a combination of ISEN3B and gain setting resistors, R_SET3A and R_SET3B, the
current flowing at Current Sense Resistor-3 will be converted to the sensed current signal and forwarded into the device.
Connect ISEN3A at the negative side of Current Sense Resistor-3 in Buck mode configuration. Ultimately senses the
BAT12 voltage side of the current sensing shunt through the filter, refer to Figure 4. The resistive shunt MUST be Kelvin
connected, do not allow this connection to take place anywhere else on the BAT12 plane. The sensed current information
is used for peak current mode control, average current control, and overcurrent protections. If this phase is not used,
connect the ISEN3A to BAT12.
I
41 The other side of Current Sense Amplifier (CSA) 3 input. With a combination of ISEN3A and gain setting resistors, R_SET3A
and R_SET3B, the current flowing at Current Sense Resistor-3 will be converted to the sensed current signal and forwarded
into the device. Connect ISEN3B at the positive side of Current Sense Resistor-3 in Buck mode configuration. Ultimately
senses the inductor side of the current sensing shunt through the filter, refer to Figure 4. The resistive shunt MUST be
Kelvin connected. The sensed current information is used for peak current mode control, average current control, and
overcurrent protections. If this phase is not used, float or do not connect the ISEN3B pin.
I 42 Power supply for Internal Current Sense Amplifier. Connect to 12V side of current sense resistor with an RC filter (10Ω
resistor and 0.1µF ceramic capacitor).
I 43 Current Sense Amplifier (CSA) 4 input. With a combination of ISEN4B and gain setting resistors, R_SET4A and R_SET4B, the
current flowing at Current Sense Resistor-4 will be converted to the sensed current signal and forwarded into the device.
Connect ISEN4A at the negative side of Current Sense Resistor-4 in Buck mode configuration. Ultimately senses the
BAT12 voltage side of the current sensing shunt through the filter, refer to Figure 4. The resistive shunt MUST be Kelvin
connected, do not allow this connection to take place anywhere else on the BAT12 plane. The sensed current information
is used for peak current mode control, average current control, and overcurrent protections. If this phase is not used,
connect the ISEN4A to BAT12.
I 44 The other side of Current Sense Amplifier (CSA) 4 input. With a combination of ISEN4A and gain setting resistors, R_SET4A
and R_SET4B, the current flowing at Current Sense Resistor-4 will be converted to the sensed current signal and forwarded
into the device. Connect ISEN4B at the positive side of Current Sense Resistor-4 in Buck mode configuration. Ultimately
senses the inductor side of the current sensing shunt through the filter, refer to Figure 4. The resistive shunt MUST be
Kelvin connected. The sensed current information is used for peak current mode control, average current control, and
overcurrent protections. If this phase is not used, float or do not connect the ISEN4B pin.
I 45 Current Sense Amplifier (CSA) 5 input. With a combination of ISEN5B and gain setting resistors, R_SET5A and R_SET5B, the
current flowing at Current Sense Resistor-5 will be converted to the sensed current signal and forwarded into the device.
Connect ISEN5A at the negative side of Current Sense Resistor-5 in Buck mode configuration. Ultimately senses the
BAT12 voltage side of the current sensing shunt through the filter, refer to Figure 4. The resistive shunt MUST be Kelvin
connected, do not allow this connection to take place anywhere else on the BAT12 plane. The sensed current information
is used for peak current mode control, average current control, and overcurrent protections. If this phase is not used,
connect the ISEN5A to BAT12.
I 46 The other side of Current Sense Amplifier (CSA) 5 input. With a combination of ISEN5A and gain setting resistor R_SET5A
and R_SET5B, the current flowing at Current Sense Resistor-5 will be converted to the sensed current signal and forwarded
into the device. Connect ISEN5B at the positive side of Current Sense Resistor-5 in Buck mode configuration. Ultimately
senses the inductor side of the current sensing shunt through the filter, refer to Figure 4. The resistive shunt MUST be
Kelvin connected. The sensed current information is used for peak current mode control, average current control, and
overcurrent protections. If this phase is not used, float or do not connect the ISEN5B pin.
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FN8887.0
November 7, 2016