BD9415FS Datasheet, PDF (10/34 Pages) Rohm – White LED Driver for 4Ch Large LCD Panels (DC/DC converter type)

BD9415FS
2.2 List of the Protection Function Detection Condition (Typical Condition)
Protection
Function
LED Open
Detection
Pin
LEDx
Detection Condition
Detection Condition PWM
LEDx < 0.2V
H(4clk)
SS
After
Soft start
Release
Condition
LEDx > 0.2V^(*2)
(3clk)
LED Short
LEDx
LEDx > 6.7×VLSP
H(4clk)
After
Soft start
LEDx < 6.7xVLSP
(3clk)
LED Driver
FET D-S Short
Sx
Sx > 0.6V
―
―
Sx < 0.6V
LED GND
Short
LEDx
LEDx < 0.2V
And
SSFB > 4.0V
H
LEDx > 0.2V
―
Or
SSFB < 3.6V
OVP
OVP
OVP > 3.0V
―
―
OVP < 2.9V
SCP
OVP
OVP < 0.2V
―
―
OVP > 0.25V
VCCUVLO
VCC
VCC < 7.2V
―
―
VCC > 7.5V
UVLO
UVLO
UVLO < 2.4V
―
―
UVLO > 2.5V
OCP
CS
CS > 0.45V
―
―
―
DUTYON = H
Over PWM
duty^(*1)
PWM
And
PWM interval > setting
H
―
―
by DUTYP resistor
The clock number of timer operation corresponds to the boost pulse clock.
Protection Type
Auto Restart in
relevant CH
Auto Restart in
relevant CH
Whole Auto
Restart
Whole Auto
Restart
Return
immediately.
Whole Auto
Restart
Return
immediately.
Return
immediately.
Return
immediately.
(Pulse by Pulse)
Return
immediately.
(*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. The timing of release of LEDx voltage (LEDx > 0.2V)
The Release Condition
1
LED pin voltage is released during PWM=H. LED pin voltage is normal range during 3clk (3 positive edge)
As PWM=L, LED pin voltage do not exceed Short protection
2
LED pin voltage is released during PWM=L.
voltage (VLSP) during more than 3clk or PWM positive edge is
input when LED pin voltage do not exceed VLSP for more than
3clk.
2.3 List of Protection function
Protection function
DC/DC Gate
Output
Operation of the Protection Function
LED Driver
Soft-start
STB
LED Open
LED Short
LED Driver
FET D-S Short
LED GND Short
Stop N output
Normal operation
(Stop when all LED
CH stop)
Normal operation
Stop after 2¹⁴ count
Stop after
(CP^*+2⁶)count
Stop immediately
Stop after 2¹⁴ count
Stop in relevant CH
Stop after 2¹⁴ count
Stop in relevant CH
Stop after 2¹⁴ count
Only detected LED ch
stops after CP count
Other LED ch stop
operation
after（CP^*+2⁶）count
Discharge immediately
Normal operation
Normal operation
Discharge after stop
（CP^*+2⁶） Discharge
after count
VCCUVLO
Stop N output
Stop immediately Discharge immediately
UVLO
Stop N output
Stop immediately Discharge immediately
OVP
Stop N output
Normal operation
Normal operation
SCP
Stop N output
Normal operation
Normal operation
OCP
Stop N output
(Pulse by Pulse)
Normal operation
Normal operation
Over PWM duty
Normal operation
Stop in relevant CH
Normal operation
※CP ： Count movement after detection of D-S SHORT, LED_OPEN, SHORT.
FAILB Pin
HiZ
Low after timer latch
Low after timer latch
Low after timer latch
Low after timer latch
HiZ
HiZ
HiZ
Low after timer latch
HiZ
HiZ
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TSZ22111・15・001
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TSZ02201-0F2F0C100140-1-2
23.May.2016 Rev.001