Datasheet NDS8947 (Fairchild) - 6

Typical Thermal Characteristics
4.5 2.5 1a 4 Total Power for Dual Operation 2 3.5 1a 1.5 Power for Single Operation 1 b 3 1c 1 1 b 1c 2.5 4.5"x5" FR-4 Board 4.5"x5" FR-4 Board T = 2 5 o C A T = 2 5 o C A Still Air Still Air D-I , STEADY-STATE DRAIN CURRENT (A) V = -10V G S STEADY-STATE POWER DISSIPATION (W) 0.5 2 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 0.4 0.5 2oz COPPER MOUNTING PAD AREA (in ) 2 2oz COPPER MOUNTING PAD AREA (in ) 2
Figure 12. SO-8 Dual Package Maximum Figure 13. Maximum Steady- State Drain Steady-State Power Dissipation versus Current versus Copper Mounting Pad Copper Mounting Pad Area. Area.
5 0 100us 2 0 1 0 ) 1ms (A 5 RDS(ON) LIMIT T 10ms N E R 100ms R 1 U C 0.5 1s IN A 10s R V = -10V GS DC 0.1 SINGLE PULSE D-I , D 0.05 R = See Note 1c θJAT = 25°C A 0.010.1 0.2 0.5 1 2 5 1 0 3 0 5 0 - V , DRAIN-SOURCE CURRENT (V) DS
Figure 14. Maximum Safe Operating Area.
1 0 .5 D = 0.5 0 .2 0.2 R (t) = r(t) * R θJA θJA 0 .1 0.1 R = See Note 1c θJA 0 .0 5 0.05 0.02 P(pk) 0 .0 2 0.01 t 0 .0 1 1 Single Pulse t 2 0 .0 0 5 T - T = P * R (t) r(t), NORMALIZED EFFECTIVE J A θJA 0 .0 0 2 Duty Cycle, D = t / t 1 2 TRANSIENT THERMAL RESISTANCE 0 .0 0 1 0 .0001 0 .001 0 .0 1 0 .1 1 1 0 1 0 0 3 0 0 t , TIME (sec) 1
Figure 15. Transient Thermal Response Curve
. Note: Thermal characterization performed using the conditions described in note 1c. Transient thermal response will change depending on the circuit board design. NDS8947.SAM