MAX1610CSE Maxim Integrated Products, MAX1610CSE Datasheet - Page 18

• Manufacturer Part Number: MAX1610CSE
• Description: IC SMD SO16 BACKLGT
• Manufacturer: Maxim Integrated Products

Specifications of MAX1610CSE

• Display Type: CCFL - Cold Cathode Fluorescent Lamp
• Interface: 2-Wire SMBus
• Current - Supply: 1.5mA
• Voltage - Supply: 4.75 V ~ 26 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Configuration: -
• Digits Or Characters: -
• Other names: 146982A

minimum 9% duty cycle. DAC code 00000 shuts off the
lamp entirely (0% duty cycle). Figure 14 shows the
chopped waveforms with the DAC set to mid-scale.
__________ Applications Information
The MAX1610/MAX1611 can directly regulate the CCFL
current by tapping into the secondary of T1 (Figure 15).
This allows more precise setting of the maximum lamp
current (I
the secondary-to-ground voltage is twice that shown in
Figure 4, increasing the likelihood of the thermometer
effect, where one end of the lamp is brighter than the
other. Figure 15 uses the same component values as
Figure 4, except for R1, R40, D40, and D41. D40 and
D41 are the same type of diode as D1. R1 should be
0.68
Use a 107
of 5mA
types without component adjustments.
Table 7 lists three different sources for C1. C1 requires
a low dissipation factor to prevent overheating as energy
is cycled between C1 and the T1 magnetizing induc-
Digitally Controlled CCFL Backlight
Power Supplies
Figure 15. Directly Regulating the CCFL Current
18
C8
______________________________________________________________________________________
±10% to set a peak current limit of about 735mA.
Directly Regulating the Lamp Current
RMS
C9
C4
C3
L
R5
R6
). The disadvantage of this approach is that
. This circuit accepts a wide range of lamp
VIN
±1% resistor for R40 to set a lamp current
+
16
5
6
4
9
8
BATT
SS
CC
SYNC
REF
MINDAC
MAX1610
MAX1611
Component Suppliers
CSAV
GND
OTP
BST
CS
VL
LX
12
14
15
10
11
7
13
D3
R7
C7
D2
C6
tance in the Royer resonant tank. Table 8 lists suppliers
for the high-voltage ballast capacitor, C2.
Figure 14. Chopped Waveforms
R3
R4
L1
BATT = 15V, MINDAC = VL, SS = OPEN, CC = 0.1 F,
C2 = 15pF, MID-SCALE SETTING, D/A VALUE = 10000
D1
C5
T1
1
500 s/div
10
Q1
R1
C2
2
C1
CCFL
R2
Q2
3 4
D40
6
5
R40
4V
0V
0V
SS
VOLTAGE
15V
T1
CENTER-TAP
VOLTAGE
D41