LT1118-2.5_15 Datasheet, PDF (6/8 Pages) Linear Technology – 800mA, Source and Sink Regulators Adjustable and Fixed 2.5V, 2.85V, 5V Output

LT1118/LT1118-2.5/
LT1118-2.85/LT1118-5
OPERATION
connected to the die substrate. Table 1 shows measured
thermal resistance from junction to ambient for the LT1118
connected to various sized PC board ground planes. The
power dissipated in the LT1118 varies with input voltage
and loading. When the regulator is sourcing current the
power which must be dissipated by the package is:
P_D = (V_IN – V_OUT) • I_LOAD
When the regulator is sinking load current, power dissipa-
tion is nearly independent of V_IN and can be calculated
as:
P_D = V_OUT • I_LOAD
Heat sinking to the IC package must consider the worst
case power dissipation which may occur.
Table 1. Measured Thermal Resistance from Junction to Ambient
for the LT1118
S8 Package
SOT-223
Free Air
1 Sq Inch Copper
120°C/W
55°C/W
95°C/W
53°C/W
4 Sq Inch Copper
35°C/W
38°C/W
TYPICAL APPLICATIONS
SCSI Active Terminator
TERMPWR
IN LT1118-2.85 OUT
+
GND
5V
2.2μF
110Ω
•••• _110Ω
110Ω
110Ω
•••• _110Ω
1μF
27 LINES
1118 TA03
Power Supply Splitter
V_IN
5V
5V
1μF
IN LT1118-2.5 OUT
GND
ANALOG
COMMON
2.5V
1μF
1118 TA04
1118fd
6