LT1360 datasheet(13/20 Pages) AD

13 / 20 page

LT1210

Rev C

For more information www.analog.com

APPLICATIONS INFORMATION

T7 Package, 7-Lead TO-220

Thermal Resistance (Junction-to-Case) = 5°C/W

Calculating Junction Temperature

The junction temperature can be calculated from the

equation:

TJ = (PD)(θJA) + TA

where:

TJ = Junction Temperature

TA = Ambient Temperature

PD = Device Dissipation

θJA = Thermal Resistance (Junction-to-Ambient)

As an example, calculate the junction temperature for the

circuit in Figure 7 for the SO and R packages assuming a

70°C ambient temperature.

The device dissipation can be found by measuring the

supply currents, calculating the total dissipation and

then subtracting the dissipation in the load and feed-

back network.

PD = (76mA)(10V) – (1.4V)2/ 10 = 0.56W

Figure 7.

then:

TJ = (0.56W)(46°C/W) + 70°C = 96°C

for the SO package with 1000 sq. mm topside

heat sinking

TJ = (0.56W)(27°C/W) + 70°C = 85°C

for the R package with 1000 sq. mm topside heat

sinking

Since the maximum junction temperature is 150°C,

both packages are clearly acceptable.

–

LT1210

–5V

680Ω

220Ω

10Ω

VO = 1.4VRMS

76mA

1210 F07

–2V

LT1360 Datasheet(PDF) 13 Page - Analog Devices

LT1360 Datasheet(HTML) 13 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Datasheet Download

Link URL