LT6654_12 LINER [Linear Technology], LT6654_12 Datasheet - Page 16

• Manufacturer Part Number: LT6654_12
• Description: SOT-23 Precision Wide Supply High Output Drive Low Noise Reference
• Manufacturer: LINER [Linear Technology]

LT6654
APPLICATIONS INFORMATION
Power Dissipation
The power dissipation in the LT6654 is dependent on V
load current and the package. The LT6654 package has
a thermal resistance, or θ
illustrates allowed power dissipation versus temperature
for the 6-lead SOT-23 package is shown in Figure 9. The
power dissipation of the LT6654-2.5 as a function of input
voltage is shown in Figure 10. The top curve shows power
dissipation with a 10mA load and the bottom curve shows
power dissipation with no load. When operated within
its specifi ed limits of V
LT6654-2.5 consumes about 335mW at room temperature.
The power-derating curve in Figure 9 shows the LT6654-
2.5 can only safely dissipate 130mW at 125°C, which is
less than its maximum power output. Care must be taken
when designing the circuit so that the maximum junction
temperature is not exceeded. For best performance, junc-
tion temperature should be kept below 125°C.
The LT6654 includes output current limit circuitry, as well
as thermal limit circuitry, to protect the reference from
damage in the event of excessive power dissipation. The
LT6654 is protected from damage by a thermal shutdown
circuit. However, changes in performance may occur as
a result of operation at high temperature.
16
Figure 9. Maximum Allowed Power Dissipation of the LT6654
0.1
0.7
0.6
0.5
0.4
0.3
0.2
0
0
20
40
TEMPERATURE (°C)
IN
= 36V and sourcing 10mA, the
60
JA
, of 192°C/W. A curve that
80
100
JA
= 192°C/W
T = 150°C
130mW
120
6654 F09
140
IN
,
Figure 11b. LT6654 LS8 Thermal Hysteresis –40°C to 125°C
Figure 11a. LT6654 S6 Thermal Hysteresis –40°C to 125°C
Figure 10. Typical Power Dissipation of the LT6654
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
50
40
30
20
10
0
–150
0
6
5
4
3
2
1
0
0
–40 –30 –20 –10
25°C TO 125°C TO 25°C
MAX AVG HOT CYCLE
25°C TO –40°C TO 25°C
AND 25°C TO 125°C TO 25°C
5
–100
10
DISTRIBUTION (ppm)
DISTRIBUTION (ppm)
–50
10mA LOAD
15
V
IN
20
0
0
(V)
25°C TO –40°C TO 25°C
MAX AVG COLD CYCLE
NO LOAD
25
10
50
20
30
100
335mW
30
35
6654 F11
6654 F11b
6654 F10
150
40
40
6654fc