BD9415FS
2.2 List of the Protection Function Detection Condition (Typical Condition)
Detection Condition
Protection
Function
Detection
Pin
Release
Condition
LEDx > 0.2V(*2)
(3clk)
LEDx < 6.7xVLSP Auto Restart in
Protection Type
Detection Condition
SS
PWM
After
Soft start
Auto Restart in
relevant CH
LED Open
LED Short
LEDx
LEDx
Sx
LEDx < 0.2V
LEDx > 6.7×VLSP
Sx > 0.6V
H(4clk)
After
Soft start
H(4clk)
(3clk)
relevant CH
LED Driver
FET D-S Short
Whole Auto
Restart
―
―
―
Sx < 0.6V
LEDx < 0.2V
And
LEDx > 0.2V
Or
SSFB < 3.6V
LED GND
Short
Whole Auto
Restart
LEDx
H
SSFB > 4.0V
Return
OVP
SCP
OVP
OVP
OVP > 3.0V
OVP < 0.2V
VCC < 7.2V
UVLO < 2.4V
―
―
―
―
―
―
―
―
OVP < 2.9V
OVP > 0.25V
VCC > 7.5V
UVLO > 2.5V
immediately.
Whole Auto
Restart
Return
immediately.
Return
immediately.
Return
VCCUVLO
UVLO
VCC
UVLO
OCP
CS
CS > 0.45V
―
―
―
―
―
immediately.
(Pulse by Pulse)
DUTYON = H
And
PWM interval > setting
by DUTYP resistor
Over PWM
duty(*1)
Return
immediately.
PWM
H
The clock number of timer operation corresponds to the boost pulse clock.
(*1)When PWM Duty count starts, PWM=H → L is input, when PWM=L → H is input, the ODP is reset.
The G (1 to 4) output, the N pin output maintain L until PWM=H → L is input in PWM = 100% again when ODP works once.
(*2) The release condition of OPEN protection depends on its release timing.
No.
1
The timing of release of LEDx voltage (LEDx > 0.2V)
LED pin voltage is released during PWM=H.
The Release Condition
LED pin voltage is normal range during 3clk (3 positive edge)
As PWM=L, LED pin voltage do not exceed Short protection
voltage (VLSP) during more than 3clk or PWM positive edge is
input when LED pin voltage do not exceed VLSP for more than
3clk.
2
LED pin voltage is released during PWM=L.
2.3 List of Protection function
Protection function
Operation of the Protection Function
DC/DC Gate
Output
Stop N output
LED Driver
Soft-start
FAILB Pin
HiZ
STB
Stop immediately
Discharge immediately
Normal operation
(Stop when all LED
CH stop)
Stop after 214 count
Stop in relevant CH
Stop after 214 count
Stop in relevant CH
LED Open
Normal operation
Low after timer latch
LED Short
Normal operation
Normal operation
Low after timer latch
Low after timer latch
LED Driver
FET D-S Short
Stop after 214 count
Stop after 214 count
Discharge after stop
Only detected LED ch
stops after CP count
Other LED ch stop
operation
Stop after
（CP*+26） Discharge
LED GND Short
Low after timer latch
(CP*+26)count
after count
after（CP*+26）count
VCCUVLO
UVLO
OVP
Stop N output
Stop N output
Stop N output
Stop N output
Stop immediately
Stop immediately
Normal operation
Normal operation
Discharge immediately
Discharge immediately
Normal operation
HiZ
HiZ
HiZ
SCP
Normal operation
Low after timer latch
Stop N output
(Pulse by Pulse)
Normal operation
OCP
Normal operation
Normal operation
Normal operation
HiZ
HiZ
Over PWM duty
Stop in relevant CH
※CP ： Count movement after detection of D-S SHORT, LED_OPEN, SHORT.
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TSZ02201-0F2F0C100140-1-2
23.May.2016 Rev.001
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