STEVAL-ILL021V1 STMicroelectronics, STEVAL-ILL021V1 Datasheet - Page 29

• Manufacturer Part Number: STEVAL-ILL021V1
• Description: BOARD EVAL LCD BACKLIGHT LED7707
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ILL021V1

• Design Resources: STEVAL-ILL021V1 Bill of Material STEVAL-ILL021V1 Schematic
• Current - Output / Channel: 85mA
• Outputs And Type: 6, Non-Isolated
• Voltage - Output: 36 V
• Features: Dimmable, Extra 5V Output
• Voltage - Input: 4.5 ~ 36 V
• Utilized Ic / Part: LED7707
• Description/function: LCD backlight demonstration board
• Operating Voltage: 4.5 V to 36 V
• Product: Display Modules
• Core Chip: LED7707
• No. Of Outputs: 1
• Output Voltage: 36V
• Dimming Control Type: PWM
• Mcu Supported Families: LED7707
• Lead Free Status / RoHS Status: Lead free by exemption / RoHS compliant by exemption
• For Use With/related Products: LED7707
• Other names: 497-10044

LED7707
Equation 22
where n
voltage and n
Equation 23
The LED7707 is housed in a 24 leads 4x4-VFQFPN package with exposed pad that allows
good thermal performance. However it is also important to design properly the
demonstration board layout in order to assure correct heat dissipation.
Figure 20
infrared camera. The chip temperature, in those application conditions, is kept below 50 °C.
Figure 20. Demonstration board thermographic analysis
d)
ROWs
V
V
I
I
V
V
F
F
D
D
T
T
LDO losses, due to the dissipation of the 5 V linear regulator:
ROW
ROW
shows a picture of the LED7707 application demonstration board taken using an
SW
SW
IN
IN
OUT
OUT
amb
amb
DIM
DIM
LEDs
= 12V
= 12V
is the number of active rows, ΔV
= 660kHz
= 660kHz
= 25°C
= 25°C
= 60mA
= 60mA
= 30V
= 30V
= 100%
= 100%
is the number of LEDs per row.
P
GEN
=
I
ROW
⋅
(
P
n
, D
ROWs
LDO
64°C
64°C
−
=
1
(
)
V
⋅
IN
(
V
f,LEDs
IFB
−
V
LDO
+
Δ
is the spread of the LEDs forward
50°C
50°C
V
)
⋅
, f
I
LEDs
LDO
⋅
n
LEDs
)
Application information
⋅
D
DIM
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