LT3498
PIN FUNCTIONS
V
(Pin 7): Drain of Output Disconnect PMOS.
SW1 (Pin 11): Switch Pin. Connect the inductor of the
white LED driver at this pin. Minimize metal trace area at
this pin to minimize EMI.
OUT2
Place a bypass capacitor from this pin to GND. See the
Applications Information section.
CAP2 (Pin 8): Output of the OLED Driver. This pin is
connected to the cathode of the internal Schottky diode.
Place a bypass capacitor from this pin to GND.
CAP1 (Pin 12): Output of the White LED Driver. This pin is
connectedtothecathodeoftheinternalSchottky. Connect
theoutputcapacitortothispinandthesenseresistorfrom
this pin to the LED1 pin.
SW2 (Pin 9): Switch Pin. This is the collector of the in-
ternal NPN power switch. Minimize the metal trace area
connected to this pin to minimize EMI.
Exposed Pad (Pin 13): Ground. The Exposed Pad must
be soldered to the PCB.
V
(Pin 10): Input Supply Pin. Must be locally by-
IN
passed.
BLOCK DIAGRAM
L2
10µF
L1
15µF
C
IN
4.7µF
9
10
V
11
SW1
CAP1
SW2
COMPARATOR
IN
12
CAP2
–
+
8
R
Q
Q1
A2
S
C2
0.47µF
OVERVOLTAGE
PROTECTION
START-UP
CONTROL
DRIVER
A3
+
–
R
R
SENSE1
10Ω
Σ
RAMP
GENERATOR
C1
1µF
V
OUT2
7
DRIVER
2.3MHz
OSCILLATOR
+
SWITCH
CONTROL
C3
10µF
Q2
–
+
+
A4
LED1
DISCONNECT
CONTROL
1
–
A1
R
C
SHUNT
CONTROL
C
C
R
FB2
2.21MΩ
+
VREF
+
A5
–
182kΩ
GND2
FB2
CTRL2
CTRL1 GND1
2 3
4
6
5
3498 BD
3498f
7
Linear [ Linear ]
