HSSR-7110 Datasheet, PDF (10/11 Pages) AVAGO TECHNOLOGIES LIMITED – 90 V/1.0 , Hermetically Sealed, Power MOSFET Optocoupler QML-38534

ISOTHERMAL CHAMBER
HSSR-7110
I_F
1
8+
+2
7
V _OS
-3
6
4
5-
Figure 19. Voltage Offset Test Setup.
HSSR-7110
1
8
2
7
V _IN
R _IN
3
6
200
5.5 V
4
5
DIGITAL
NANOVOLTMETER
R _OUT
1.0
V _O (SEE NOTE)
R _OUT
1.0
T _je
T _jf1
T _jd
T _jf2
104
15
15
15
T_C
CA
T_A
T _je = LED JUNCTION TEMPERATURE
T _jf1 = FET 1 JUNCTION TEMPERATURE
T _jf2 = FET 2 JUNCTION TEMPERATURE
T _jd = FET DRIVER JUNCTION TEMPERATURE
T _C = CASE TEMPERATURE (MEASURED AT CENTER
OF PACKAGE BOTTOM)
T _A = AMBIENT TEMPERATURE (MEASURED 6" AWAY
FROM THE PACKAGE)
CA ^{= CASE-TO-AMBIENT THERMAL RESISTANCE}
ALL THERMAL RESISTANCE VALUES ARE IN ˚C/W
Figure 21. Thermal Model.
NOTE:
IN ORDER TO DETERMINE V _OUT CORRECTLY, THE CASE TO AMBIENT THERMAL IMPEDANCE MUST
BE MEASURED FOR THE BURN-IN BOARDS TO BE USED. THEN, KNOWING _CA , DETERMINE THE
CORRECT OUTPUT CURRENT PER FIGURES 2 AND 4 TO INSURE THAT THE DEVICE MEETS THE
DERATING REQUIREMENTS AS SHOWN.
Figure 20. Burn-In Circuit.
Applications Information
Thermal Model
The steady state thermal model for the HSSR-7110 is
shown in Figure 21. The thermal resistance values given
in this model can be used to calculate the temperatures
at each node for a given operating condition. The thermal
resistances between the LED and other internal nodes
are very large in comparison with the other terms and
are omitted for simplicity. The components do, however,
interact indirectly through θCA, the case-to-ambient
thermal resistance. All heat generated flows through θ_CA,
which raises the case temperature TC accordingly. The val-
ue of θCA depends on the conditions of the board design
and is, therefore, determined by the designer.
The maximum value for each output MOSFET junction-
to-case thermal resistance is specified as 15°C/W . The
thermal resistance from FET driver junction-to-case is also
15°C/W/W. The power dissipation in the FET driver, how-
ever, is negligible in comparison to the MOSFETs.
On-Resistance and Rating Curves
The output on-resistance, R_ON, specified in this data sheet,
is the resistance measured across the output contact
when a pulsed current signal (I_O = 800 mA) is applied to
the output pins. The use of a pulsed signal (≤ 30 ms) im-
plies that each junction temperature is equal to the am-
bient and case temperatures. The steadystate resistance,
R_SS, on the other hand, is the value of the resistance mea-
sured across the output contact when a DC current signal
is applied to the output pins for a duration sufficient to
reach thermal equilibrium. R_SS includes the effects of the
temperature rise of each element in the thermal model.
Rating curves are shown in Figures 2 and 4. Figure 2 speci-
fies the maximum average output current allowable for a
given ambient temperature. Figure 4 specifies the output
power dissipation allowable for a given ambient tempera-
ture. Above 55°C (for θ_CA = 80°C/W) and 107°C (for θ_CA =
40°C/W/W), the maximum allowable output current and
power dissipation are related by the expression RSS =
P_O(max)/ (I_O(max))² from which R_SS can be calculated. Stay-
ing within the safe area assures that the steady-state junc-
tion temperatures remain less than 150°C. As an example,
for T_A = 95°C and θ_CA = 80°C/W , Figure 2 shows that the
output current should be limited to less than 610 mA. A
check with Figure 4 shows that the output power dissipa-
tion at T_A = 95°C and I_O = 610 mA, will be limited to less
than 0.35 W. This yields an RSS of 0.94 Ω.
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