L6520 STMICROELECTRONICS [STMicroelectronics], L6520 Datasheet - Page 13

• Manufacturer Part Number: L6520
• Description: Highly integrated ballast controller for TL and CFL
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

L6520, L6521
5.8
Table 7.
Hard switching
driving pulse
Overcurrent
End Of Life
saturation
Minimum
duration
Inductor
Fault
Summary of protections
Figure 3.
Table of faults
Active during
PH Ign Run
Summary of protections
Driving pulses shorter than 1 µs
HBCS TxL and TxM thresholds
crossed in less than 255 ns
OR
Higher threshold crossing
PWM_det higher than 2.35 V at
LSD turn on
HBCS TxL and TxM thresholds
crossing (different values during
ignition or run mode)
EOL voltage outside the limits of
the window comparator
Condition
Doc ID 16998 Rev 3
- The drivers are stopped after
200 ms of minimum pulse
duration events
- The IC is shut down in low
consumption mode
LS driver turned off and a new
frequency is calculated.
If the situation is not recovered
after 200 ms, the IC is shut down
in low consumption mode
IC is shut down in low
consumption mode after 200 ms
of HSW events
Frequency increase proportional
to the failure.
If the situation is not recovered
after 200 ms the IC is shut down
in low consumption mode
- Delay time started
- If EOL voltage is outside the
limits of the window comparator at
the end of the timer count than
the IC is shut down (latched)
Ic behaviour
Functions description
Required
V
V
V
V
V
CC
CC
CC
CC
CC
action
cycle
cycle
cycle
cycle
cycle
13/19