LT1932ES6#PBF Linear Technology, LT1932ES6#PBF Datasheet - Page 9

• Manufacturer Part Number: LT1932ES6#PBF
• Description: IC LED DRIVER CONST CURRENT/BOOST SOT236
• Manufacturer: Linear Technology

Specifications of LT1932ES6#PBF

• Led Driver Application: Cell Phones, Digital Cameras
• No. Of Outputs: 1
• Output Current: 550mA
• Output Voltage: 36V
• Input Voltage: 1V To 10V
• Topology: Boost, Constant Current
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIO S I FOR ATIO
Board Layout Considerations
As with all switching regulators, careful attention must be
paid to the PCB board layout and component placement.
To maximize efficiency, switch rise and fall times are made
as short as possible. To prevent radiation and high fre-
quency resonance problems, proper layout of the high
frequency switching path is essential. Minimize the length
and area of all traces connected to the SW pin and always
use a ground plane under the switching regulator to
minimize interplane coupling. The signal path including
the switch, output diode D1 and output capacitor C2,
contains nanosecond rise and fall times and should be
kept as short as possible. In addition, the ground connec-
tion for the R
pin and not be shared with any other component, ensuring
a clean, noise-free connection. Recommended compo-
nent placement is shown in Figure 10.
200mA/DIV
5V/DIV
Figure 8. Input Current at Start-Up Without Soft-Start
V
OUT
I
IN
SET
resistor should be tied directly to the GND
U
100 s/DIV
U
V
IN
I
IN
W
C1
4.7 F
Figure 7. Soft-Start Circuit for the LT1932
1932 F08
5
U
SHDN
R
V
SET
IN
6
4
R
1.50k
LT1932
6.8 H
SET
L1
GND
SW
LED
1
2
3
D1
200mA/DIV
5V/DIV
V
Figure 9. Input Current at Start-Up with Soft-Start
Figure 10. Recommended Component Placement
2N3904
OUT
I
IN
Q1
SOFT-START
CIRCUIT
GND
C2
D1
R1
1.5k
C3
0.047 F
V
OUT
1
2
3
L1
100 s/DIV
1932 F07
C2
1 F
R
C1
SET
6
5
4
1932 F10
1932 F09
LT1932
V
SHDN
DIMMING
CONTROL
IN
9
1932f