DS3988T+T&R Maxim Integrated Products, DS3988T+T&R Datasheet - Page 22

• Manufacturer Part Number: DS3988T+T&R
• Description: Display Drivers 8-Ch CCFL Controller All N-FET Drive, La
• Manufacturer: Maxim Integrated Products

Specifications of DS3988T+T&R

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8-Channel Cold-Cathode
Fluorescent Lamp Controller
Table 5. Transformer Specifications
Note 11: Primary should be Bifilar wound with center tap connection.
Note 12: Turns ratio is defined as secondary winding divided by the sum of both primary windings.
Note 13: 40:1 is the nominal turns ratio for driving a 438mm x 2.2mm lamp with a 12V supply. Refer to AN3375 for more information.
Table 6. Resistor and Capacitor Selection Guide
22
Turns Ratio (Secondary/Primary)
Frequency
Output Power
Output Current
Primary DCR
Secondary DCR
Primary Leakage
Secondary Leakage
Primary Inductance
Secondary Inductance
Center Tap Voltage
Secondary Output Voltage
DESIGNATOR
____________________________________________________________________
R1
R2
R3
R4
R5
R6
R7
R8
C1
C2
C3
C4
C5
PARAMETER
2/DS3988
1/Ch
1/Ch
1/Ch
1/Ch
1/Ch
QTY
1
1
1
1
1
1
1
12.5kΩ to
VALUE
20kΩ to
18kΩ to
105kΩ
100nF
4.7kΩ
4.7kΩ
4.7kΩ
0.1µF
10kΩ
40kΩ
45kΩ
140Ω
10pF
27nF
33µF
(Notes 11, 12, 13)
Center tap to one end
100ms minimum
Continuous
TOLERANCE
25°C
(%)
10
20
10
CONDITIONS
1
1
1
1
5
5
5
1
5
5
TEMPERATURE
COEFFICIENT
±1000ppm/°C
≤153ppm/°C
≤153ppm/°C
Any grade
Any grade
Any grade
Any grade
X7R
X7R
X7R
—
—
—
2000
1000
—
See the Setting the SVM Threshold Voltage section.
2% or less total tolerance. See the Lamp Frequency
Configuration section to determine value.
2% or less total tolerance. See the Lamp Frequency
Configuration section to determine value.
—
—
—
See the Setting the RMS Lamp Current section.
C ap aci tor val ue w i l l al so affect LC M Bi as vol tag e d ur i ng
p ow er - up . A l ar g er cap aci tor m ay cause a l ong er ti m e
for V
2kV to 4kV breakdown voltage required.
C ap aci tor val ue w i l l al so affect LC M Bi as vol tag e d ur i ng
p ow er - up . A l ar g er cap aci tor m ay cause a l ong er ti m e
for V
—
Place close to V
MIN
10.8
40
DCB
DCB
to r each i ts nor m al op er ati ng p oi nt.
to r each i ts nor m al op er ati ng p oi nt.
TYP
200
500
185
500
CC
40
12
70
12
5
and GND on DS3988.
NOTES
MAX
13.2
80
6
8
UNITS
V
kHz
mΩ
mH
mH
mA
µH
µH
RMS
W
Ω
V