LT6200/LT6200-5
LT6200-10/LT6201
22
62001ff
applicaTions inForMaTion
200°C/W,
θJA. Operating on ±5V supplies driving 50Ω
loads, the worst-case power dissipation is given by:
PD(MAX) = (10 23mA) + (2.5)2/50
= 0.23 + 0.125 = 0.355W
The maximum ambient temperature that the part is
allowed to operate is:
TA = TJ – (PD(MAX) 200°C/W)
= 150°C – (0.355W 200°C/W) = 79°C
To operate the device at a higher ambient temperature,
connect more metal area to the V– pin to reduce the
thermal resistance of the package, as indicated in Table 1.
DD Package Heat Sinking
The underside of the DD package has exposed metal
(4mm2) from the lead frame where the die is attached.
This provides for the direct transfer of heat from the die
junction to printed circuit board metal to help control the
maximumoperatingjunctiontemperature.Thedual-in-line
pin arrangement allows for extended metal beyond the
ends of the package on the topside (component side) of
a PCB. Table 2 summarizes the thermal resistance from
the die junction-to-ambient that can be obtained using
various amounts of topside metal (2oz copper) area. On
multilayerboards,furtherreductionscanbeobtainedusing
additional metal on inner PCB layers connected through
vias beneath the package.
Table 2. LT6200 8-Lead DD Package
COPPER AREA
TOPSIDE (mm2)
THERMAL RESISTANCE
(JUNCTION-TO-AMBIENT)
4
160C/W
16
135C/W
32
110C/W
64
95C/W
130
70C/W
The LT6200 amplifier family has thermal shutdown to
protect the part from excessive junction temperature. The
amplifier will shut down to approximately 1.2mA supply
current per amplifier if 160°C is exceeded. The LT6200
will remain off until the junction temperature reduces to
about 150°C, at which point the amplifier will return to
normal operation.