LTC3603
6
3603fc
For more information www.linear.com/LTC3603
pin Functions
INTV
CC
(Pin 1/Pin 3): Output of Internal 5V LDO.
SYNC/MODE (Pin 2/Pin 4): Mode Select and External Clock
Synchronization Input. Do not leave this pin floating.
PGOOD (Pin 3/Pin 5): Power Good Output. Open-drain
logic output that is pulled to ground when the output volt
-
age is not within ±10% of regulation point.
R
T (Pin 4/Pin 6):
Frequency Set Pin.
ITH (Pin 5/Pin 7): Error Amplifier Compensation Point.
V
FB
(Pin 6/Pin 8): Feedback Pin.
SGND (Pin 7, Exposed Pad Pin 17/Pin 9, Exposed Pad
Pin 21): Signal Ground. Exposed pad is signal ground
and must be soldered to the PCB for rated thermal
per
formance.
RUN (Pin 8/Pin 10):
Run Control Input. This pin may be tied
to PV
IN
to enable the chip. Do not leave this pin floating.
TRACK/SS (Pin 9/Pin 11): Tracking Input for the Controller
or Optional External Soft-Start Input. This pin allows the
start-up of V
OUT
to “track” the external voltage at this pin
using an external resistor divider. An external soft-start can
be programmed by connecting a capacitor between this
pin and ground. Leave this pin floating to use the internal
1ms soft-start clamp. Do not tie this pin to INTV
CC
or to
PV
IN
.
PGND (Pins 10, 11/Pins 12, 13, 14, 15): Power
Ground.
SW (Pins 12, 13/Pins 16, 17, 18, 19): Switch Node Con
-
nection to the Inductor.
BOOST (Pin 14/Pin
20): Bootstrapped Supply to the Top
Side Floating Gate Driver.
PV
IN
(Pins 15, 16/Pins 1,2): Power Input Supply. Decouple
this pin with a capacitor to PGND
MSE/UF Package
Load Regulation
5V LDO Output Voltage
vs Temperature
TRACK/SS Current
vs Temperature
LOAD CURRENT (A)
0
–0.20
∆V
OUT
/V
OUT
(%)
–0.10
0
0.10
0.5 1 1.5 2
3603 G18
2.5
3
FIGURE 6 CIRCUIT
V
IN
= 12V
TEMPERATURE (°C)
–50
4.90
LDO OUTPUT VOLTAGE (V)
4.92
4.96
4.98
5.00
5.04
0
50
75
3603 G19
4.94
5.06
5.08
5.02
–25
25
100
125
TEMPERATURE (°C)
–50
TRACK/SS CURRENT (µA)
1.30
1.35
25 75
3603 G20
1.25
1.20
–25 0
50 100 125
1.15
1.10
typical perForMance characteristics
