Datasheet

Operation description LED7707
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5 Operation description
The device can be divided into two sections: the boost section and the backlight driver
section. These sections are described in the next paragraphs.
Figure 3 provides an overview of the internal blocks of the device.
Figure 3. Simplified block diagram
LDO5
BILIM
COMP
SYNC
FSW
RILIM
EN
FAULT
ROW4
PGND
LX
ROW6
DIM
VIN
ROW1
SLOPE
AVCC
ROW3
CONTROL
LOGIC
ROW2
+
_
Thermal
Shutdown
ROW5
OVSEL
+
_
SGND
Ext Sync
Detector
OSC
OVP
Boost_EN
1.2V
4V
MODE
Boost_EN
0.7V
Min Voltage
Selector
UVLO
UVLO
Detector
+5V
LDO
Ramp
Generator
Current Sense
1.172V
Soft Start
OVP
CTRL1
CTRL6
V
ROW1
V ROW2
V ROW5
V ROW4
V ROW3
V ROW6
CTRL2
V TH,FLT
CTRL5
CTRL3
CTRL4
CTRL2
UVLO
CTRL3
CTRL4
CTRL5
CTRL6
Current
Generator 2
Current
Generator 3
Current
Generator 4
Current
Generator 5
Current
Generator 6
Current
Generator 1
Current Limit
+
+
LOGIC
Boost
Control
Logic
ZCD
+
_
g m
+
_
I to V
I to V
SS
MODE
÷2
Prot_EN
Prot_EN
LDO5
BILIM
COMP
SYNC
FSW
RILIM
EN
FAULT
ROW4
PGND
LX
ROW6
DIM
VIN
ROW1
SLOPE
AVCC
ROW3
CONTROL
LOGIC
ROW2
+
_
Thermal
Shutdown
ROW5
OVSEL
+
_
+
_
SGND
Ext Sync
Detector
OSC
OVP
Boost_EN
1.2V
4V
MODE
Boost_EN
0.7V
Min Voltage
Selector
UVLO
UVLO
Detector
+5V
LDO
Ramp
Generator
Current Sense
1.172V
Soft Start
OVP
CTRL1
CTRL6
V
ROW1
V ROW2
V ROW5
V ROW4
V ROW3
V ROW6
CTRL2
V TH,FLT
CTRL5
CTRL3
CTRL4
CTRL2
UVLO
CTRL3
CTRL4
CTRL5
CTRL6
Current
Generator 2
Current
Generator 3
Current
Generator 4
Current
Generator 5
Current
Generator 6
Current
Generator 1
Current Limit
+
+
LOGIC
Boost
Control
Logic
ZCD
+
_
g m
+
_
I to V
I to V
SS
MODE
÷2
Prot_EN
Prot_EN