InnoSwitch3-CE
Cable Drop Compensation (CDC)
The amount of cable drop compensation is a function of the load with
respect to the constant current regulation threshold as illustrated in
Figure 8.
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ꢓꢗꢜꢖe Dꢝꢑꢞ
ꢓꢑꢟꢞeꢎꢏꢗꢐꢘꢑꢎ
Auto-Restart Thresholds
The FEEDBACK pin includes a comparator to detect when the output
voltage falls below VFB(AR) of VFB, for a duration exceeding tFB(AR). The
secondary controller will relinquish control when this fault condition is
sensed. This threshold is meant to limit the range of constant current
(CC) operation.
ꢊꢋꢌ
SECONDARY BYPASS Pin Overvoltage Protection
The InnoSwitch3-CE secondary controller features a SECONDARY
BYPASS pin OV feature similar to the PRIMARY BYPASS pin OV
feature. When the secondary is in control: in the event the
SECONDARY BYPASS pin current exceeds IBPS(SD) (~7 mA) the
secondary will send a command to the primary to initiate an
auto-restart off-time (tAR(OFF)) or latch-off event (see Secondary Fault
Response in Feature Code Addendum).
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ꢍꢎꢏeꢐ ꢑꢒ ꢓꢓ
Reꢔꢕꢖꢗꢐꢘꢑꢎ
ꢀoꢁꢂ Cꢃꢄꢄꢅnt
ꢀꢁꢂ80ꢃꢄꢂ0ꢅꢆꢄ1ꢇ
Figure 8. Cable Drop Compensation Characteristics.
During normal operation, the secondary will stop requesting pulses
from the primary to initiate an auto-restart cycle when the FEEDBACK
pin voltage falls below the VFB(OFF) threshold. The deglitch filter on the
protection mode is on for less than ~10 ms. By this mechanism, the
secondary will relinquish control after detecting that the FEEDBACK
pin is shorted to ground.
Output Constant Current
The InnoSwitch3-CE regulates the output current through an external
current sense resistor between the ISENSE and SECONDARY
GROUND pins where the voltage generated across the resistor is
compared to an internal reference of ISV(TH) (~35 mV). If constant
current regulation is not required, the ISENSE pin must be tied to
SECONDARY GROUND pin.
Reꢐꢈeꢑꢉ ꢒꢓꢔꢕꢌꢖ
ꢇꢈꢉꢊꢈꢉ ꢋꢌꢍꢉꢎꢏe
ꢀiꢁꢂ
ꢀiꢁꢂ
Figure 9. Intelligent Quasi-Resonant Mode Switching.
7
Rev. D 08/18
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