si8235 Silicon Laboratories, si8235 Datasheet - Page 16

• Manufacturer Part Number: si8235
• Description: 0.5 And 4.0 A Isodrivers
• Manufacturer: Silicon Laboratories

Si823x
5.6.3. Control Inputs
VIA, VIB, and PWM inputs are high-true, TTL level-compatible logic inputs. A logic high signal on VIA or VIB
causes the corresponding output to go high. For PWM input versions (Si8231/4), VOA is high and VOB is low when
the PWM input is high, and VOA is low and VOB is high when the PWM input is low.
5.6.4. Disable Input
When brought high, the DISABLE input unconditionally drives VOA and VOB low regardless of the states of VIA
and VIB. Device operation terminates within tSD after DISABLE = V
DISABLE = V
5.7. Programmable Dead Time and Overlap Protection
All high-side/low-side drivers (Si8230/1/3/4) include programmable overlap protection to prevent outputs VOA and
VOB from being high at the same time. These devices also include programmable dead time, which adds a user-
programmable delay between transitions of VOA and VOB (Figure 2.3a). When enabled, dead time is present on
all transitions, even after overlap recovery (Figure 2.3b). The amount of dead time delay (DT) is programmed by a
single resistor (RDT) connected from the DT input to ground per Equation 5.
16
VDDI
VDDA
VIA
DISABLE
VOA
UVLO+
UVLO-
UVLO+
UVLO-
tSTART
IL
. The DISABLE input has no effect if VDDI is below its UVLO level (i.e. VOA, VOB remain low).
Figure 8. Device Behavior during Normal Operation and Shutdown
tSD
DT 11 RDT
where:
DT
and
RDT
tSTART
=
≈
=
dead time (ns)
dead time programming resistor (kΩ )
×
Preliminary Rev. 0.11
Equation 5.
tSTART
tSD
tRESTART
IH
and resumes within tRESTART after
tPHL
tPLH