DRV593 Datasheet, PDF (12/22 Pages) Texas Instruments – 3−A HIGH−EFFICIENCY PWM POWER DRIVER

DRV593
DRV594
SLOS401A - SEPTEMBER 2002 REVISED - OCTOBER 2002
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HEATING MODE
Figure 19 shows the DRV593 and DRV594 in heating mode. The H/C output is at VDD and the PWM output is
proportional to the voltage across the load.
The differential voltage across the load is determined using equation (3). The variables are the same as used
previously for equations (1) and (2).
VLoad + –(1–D) V_DD
(3)
For example, a 50% duty cycle, shown in Figure 19, results in -2.5 V across the load for VDD = 5 V. The differential
voltage across the load is defined as the voltage measured after the filter on the PWM output relative to the H/C output.
VDD
PWM
0
VDD
H/C
0
Load
Voltage
0
- VDD/2
- VDD
Figure 19. Heating Mode
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