FOD3180 Datasheet, PDF (11/13 Pages) Fairchild Semiconductor – 2A Output Current, High Speed MOSFET Gate Driver Optocoupler

Reflow Profile
300
245 C, 10–30 s
250
260 C peak
200
150
100
Time above 183C, <160 sec
50
Ramp up = 2–10C/sec
0
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Time (Minute)
• Peak reflow temperature: 260 C (package surface temperature)
• Time of temperature higher than 183 C for 160 seconds or less
• One time soldering reflow is recommended
Output Power Derating
The maximum package power dissipation is 295mW. The pack-
age is limited to this level to ensure that under normal operating
conditions and over extended temperature range that the semi-
conductor junction temperatures do not exceed 125°C. The
package power is composed of three elements; the LED, static
operating power of the output IC, and the power dissipated in
the output power MOSFET transistors. The power rating of the
output IC is 250mW. This power is divided between the static
power of the integrated circuit, which is the product of I_DD times
the power supply voltage (V_DD – V_EE). The maximum IC static
output power is 150mW, (V_DD – V_EE) = 25V, I_DD = 6mA. This
maximum condition is valid over the operational temperature
range of -40°C to +100°C. Under these maximum operating
conditions, the output of the power MOSFET is allowed to dissi-
pate 100mW of power.
The absolute maximum output power dissipation versus ambi-
ent temperature is shown in Figure 12. The output driver is
capable of supplying 100mW of output power over the tempera-
ture range from -40°C to 87°C. The output derates to 90mW at
the absolute maximum operating temperature of 100°C.
Fig. 12 Absolute Maximum Power Dissipation
vs. Ambient Temperature
0.15
VDD – VEE = Max. = 25V
IDD = 6mA
LED Power = 45mW
The output power is the product of the average output current
squared times the output transistor’s R_DS(ON):
P_O(AVG) = I_O(AVG)2 • R_DS(ON)
The I_O(AVG) is the product of the duty factor times the peak
current flowing in the output. The duty factor is the ratio of the
‘on’ time of the output load current divided by the period of the
operating frequency. An R_DS(ON) of 2.0Ω results in an average
output load current of 200mA. The load duty factor is a ratio of
the average output time of the power MOSFET load circuit and
period of the driving frequency.
The maximum permissible, operating frequency is determined
by the load supplied to the output at its resulting output pulse
width. Figure 13 shows an example of a 0.03µF gate to source
capacitance with a series resistance of 8.50Ω. This reactive
load results in a composite average pulse width of 1.5µs. Under
this load condition it is not necessary to derate the absolute
maximum output current until the frequency of operation
exceeds 63kHz.
Fig. 13 Output Current Derating vs. Frequency
2.5
2
1.5
TA = -40°C to 100°C
0.1
Load = .03µF +8.5Ω
VDD = 20V
1
IF = 12mA
LED Duty Factor = 50%
Output Pulse Width = 1.5µs
0.05
0.5
0
1
10
100
0
-40
-20
0
20
40
60
80
100
F – Frequency (kHz)
T_A – Ambient Temperature (°C)
11
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FOD3180 Rev. 1.0.3