BD93942F Datasheet, PDF (21/30 Pages) Rohm – White LED Driver for large LCD Panels (DCDC Converter type)

BD93942F
Datasheet
List of Protect Function (typ condition)
Protection
Name
Detection
Pin
Detection Conditions
Cancellation
Detection pin PWM LED_OK ^Conditions
LED OPEN
LEDｘ
LEDx < 0.2V
H
After
LED_OK
LEDx > 0.2V
LED SHORT
LEDｘ
LEDx > 5V
H
After
LED_OK
LEDx < 5V
LED
GND SHORT
LEDｘ
LEDx < 0.2V
and
H
SSFB > 4.0V
-
ISET
GND SHORT
ISET
Under
ISET×90%
-
-
REG58 UVLO REG58
REG58<2.4V
-
-
VCC UVLO
VCC
VCC<7.3V
-
-
OVP
OVP
OVP>3.0V
-
-
SCP
OVP
OVP<0.1V
-
-
OCP
CS
OCP>0.45V
-
-
To clear the latch type, STB should be set to “L” once, and then to “H”.
LEDx > 0.2V
or
SSFB < 3.6V
Above
ISET×90%
REG58>2.6V
VCC>7.5V
OVP<2.9V
OVP>0.1V
-
Timer
2¹² count
2¹² count
Protection Type
Immediately
Auto-Restart
after detection
(Judge
periodically
whether normal
or not)
Immediately
Auto-Restart
after detection
(Judge
periodically
whether normal
or not)
(2¹²+2⁷) count
Latch
Immediately
Detect
Immediately
Detect
Immediately
Detect
Immediately
Detect
2¹² count
Immediately
Detect
Auto-Restart
Auto-Restart
Auto-Restart
Auto-Restart
Auto-Restart
Pulse-by-Pulse
Protection Function
LED OPEN
LED SHORT
LED GND SHORT
ISET GND SHORT
STB
REG58 UVLO
VCC UVLO
OVP
SCP
OCP
* CP= 20ms (RT=75KΩ)
Operation after the protection function detected
DC/DC
LED Driver
Soft-start
Continue to operate
Continue to operate
Stop
after (CP+2⁷) count
Only detected LED ch
stops after CP count
Only detected LED ch
stops after CP count
Only detected LED ch
stops after CP count
Other LED ch stop operation
after (CP+2⁷) count
Continue to operate
Continue to operate
Discharge
after (CP+2⁷) count
Stop immediately
Stop immediately
Stop immediately
Stop immediately
Stop
(and when REG58<2.4V)
Stop immediately
Continue to operate
Discharge immediately
Discharge immediately
Stop immediately
Stop immediately
(N pin only)
Stop immediately
(N pin only)
N pin limits DUTY
Stop immediately
Continue to operate
Stop after CP count
Continue to operate
Discharge immediately
Continue to operate
Discharge after CP count
Continue to operate
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TSZ22111・15・001
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TSZ02201-0F5F0C100050-1-2
12.Aug.2015 Rev.002