MAX753 Maxim, MAX753 Datasheet - Page 11

• Manufacturer Part Number: MAX753
• Description: CCFL Backlight and LCD Contrast Controllers
• Manufacturer: Maxim

Table 3. Spreadsheet Design Equations
CCFL Specifications
Strike Voltage (V
Discharging Tube Current (I
Discharging Tube Voltage (V
LCD Contrast Voltage Specifications
Bias Voltage
Output Current
Royer Specifications
T1 Turns Ratio (Sec/Pri)
T1 Resonating Inductance
C9 Value
C10 Value
Royer Frequency
MAX754 Specifications
Reference Voltage
Second Volts Constant
CCFL Circuit Calculations
R8 Current-Sensing Resistor
Secondary Voltage Phase vs. Tube
Voltage
T1 Center-Tap Peak Voltage
Secondary Limit Voltage
T1 Center-Tap Limit Peak Voltage
R5/R6
LCD Circuit Calculations
V
L2 Inductance
L2 Peak Currrent
R4/R3
Application Circuit Operating Range
Input Voltage
IN(min)
Full-Load Switching Period
PARAMETER
S
)
______________________________________________________________________________________
L
L
)
)
R
R
V
I
SYMBOL
LAMP,RMS
LAMP,RMS
OTP,RATIO
LCD,RATIO
V
V
L
V
C
C
V
TAP,PK
V
S,RMS
I
LCD
MAG
phi
T
V
LCD
sV
R8
L2
REF
RES
BAL
LIM
w
n
FL
IN
= (2 / PI()) * V
I
= V
LAMP,RMS(max)
= L2(max) * 0.8
0.000008
LCD(max)
= 0.28 *
LCD Contrast Controllers
0.0245
1100
MIN
TAP,PK
/ 2
CCFL Backlight and
= -SQRT(2) * I
= sV(min) / V
= V
= SQRT [1 / (L
= ATAN (-I
(C
= PI() * V
= V
(C
(V
BAL
= SQRT(2) * V
REF
(2 * I
= V
BAL
REF
LCD(max)
* w * + V
S,RMS(max)
/ (V
LAMP,RMS(max)
* w * SIN(phi)) / n
/ (D25 - 0.6 - V
0.000045
2.2E-07
1.5E-11
REF
LCD(max)
LAMP,RMS(max)
IN(min)
TYP
1.25
435
171
LAMP,RMS(max)
MAG
* SQRT(2) /
- V
LAMP,RMS
IN(min)
LIM
+ sV(min) /
* 0.9
* C
- V
/ n
REF
RES
)
REF
)
)
)]
)
/
)
/
= sV(min) ^ 2 / (2 * T
V
= sV(max) / L2(min)
LCD(max)
2.4E-05
0.005
MAX
1500
32.6
18
* I
LCD(min)
FL
11
)
*