Datasheet

LT3483/LT3483A
5
3483fc
PIN FUNCTIONS
FB (Pin 1/Pin 3): Feedback. Place resistor to negative
output here. Set resistor value R1 = V
OUT
/10µA.
GND (Pins 2, 3/Pin 2): Ground. For DFN package, tie both
pin 2 and pin 3 together to ground.
SW (Pin 4/Pin 1): Switch. Connect to external inductor
L1 and positive terminal of transfer capacitor.
V
IN
(Pin 5/Pin 6): Input Supply. Must be locally bypassed
with 1µF or greater.
NC (Pin 6/NA): No Internal Connection.
D (Pin 7/Pin 5) : Anode Terminal of Integrated Schottky
Diode. Connect to negative terminal of transfer capaci-
tor and external inductor L2 (flyback configuration) or
to cathode of external Schottky diode (inverting charge
pump configuration).
SHDN (Pin 8/Pin 4): Shutdown. Connect to GND to turn
device off. Connect to supply to turn device on.
Exposed Pad (Pin 9/NA): GND. The exposed pad should
be soldered to the PCB ground to achieve the rated thermal
performance.
(DFN/TSOT-23)
BLOCK DIAGRAM
–
+
–
+
6
3
1
2
5
A3
300ns
DELAY
1.250V
REFERENCE
S
Q1
20mV
(LT3483)
SW D
L1BL1A
C
F LY
C
OUT
V
OUT
0.1Ω 0.1Ω
GND
3483 BD
–
+
25mV
D1
Q
R Q
A1
A2
125k
R1
R2
V
OUT
D
D2
V
IN
V
IN
FB
OPTIONAL CHARGE PUMP CONFIGURATION.
L1B REPLACED WITH:
PIN NUMBERS CORRESPOND TO THE
6-PIN TSOT-23 PACKAGE
V
OUT
• •