SN75374 datasheet(9/13 Pages) TI

9 / 13 page

SN75374

QUADRUPLE MOSFET DRIVER

SLRS028 – SEPTEMBER 1988

3–9

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

THERMAL INFORMATION

PL, PH, PLH, and PHL are the respective instantaneous levels of power dissipation, C is the load capacitance.

VC is the voltage across the load capacitance during the charge cycle shown by the equation

VC = VOH – VOL

PS(AV) may be ignored for power calculations at low frequencies.

In the following power calculation, all four channels are operating under identical conditions: f = 0.2 MHz,

VOH = 19.9 V and VOL = 0.15 V with VCC1 = 5 V, VCC2 = 20 V, VCC3 = 24 V, VC = 19.75 V, C = 1000 pF, and the

duty cycle = 60%. At 0.2 MHz for CL < 2000 pF, PS(AV) is negligible and can be ignored. When the output voltage

is low, ICC2 is negligible and can be ignored.

On a per-channel basis using data sheet values,

DC(AV) +

(5 V) 4mA

) (20 V) * 2.2 mA

) (24 V) 2.2 mA

(0.6)

)

(5 V)

31 mA

) (20 V) 0mA

) (24 V) 16 mA

(0.4)

PDC(AV) = 58.2 mW per channel

Power during the charging time of the load capacitance is

PC(AV) = (1000 pF) (19.75 V)2 (0.2 MHz) = 78 mW per channel

Total power for each driver is

PT(AV) = 58.2 mW + 78 mW = 136.2 mW

The total package power is

PT(AV) = (136.2) (4) = 544.8 mW

SN75374 Datasheet(PDF) 9 Page - Texas Instruments