mc33899vwr2 Freescale Semiconductor, Inc, mc33899vwr2 Datasheet - Page 13

• Manufacturer Part Number: mc33899vwr2
• Description: Programmable H-bridge Power Ic
• Manufacturer: Freescale Semiconductor, Inc

INPUT CONTROL OF H-BRIDGE (PWM)
PWM’ing high-side and low-side MOSFETs. A logic [1]
commands the appropriate low-side MOSFET (M2 or M4) ON
and the appropriate high-side MOSFET (M1 or M3) OFF. A
logic [0] commands the appropriate low-side MOSFETs (M2
or M4) OFF and the appropriate high-side MOSFETs (M1 or
M3) ON. The high- and low-side MOSFETs that are PWM’ed
are determined by the commanded direction (FWD or REV).
Analog Integrated Circuit Device Data
Freescale Semiconductor
The PWM input pin controls the sequencing of the
EN1
0
1
1
PWM
REV
FWD
S0
S1
EN2
1
0
1
Disabled (Standby Mode)
Disabled (Standby Mode)
Enabled (Run Mode)
Figure 7. 33899 Operation in Current Reversal
Status
Both High Side
FET’s ON until
next PWM Rising
Edge
Reverse Current
Forward Current
Load Current
High Side FET
Body Diode
If a shorted condition exists, the particular output MOSFET
will be latched off after 5.0 µs to 10 µs. Subsequent PWM
edges will retry to turn on the same MOSFET. Only when a
thermal fault is reached are all outputs latched off until the
clear fault bit is set by the microprocessor. Any PWM high-to-
low-to-high pulse that is shorter than 500 ns keeps the low-
side MOSFET from starting to turn off. The rising edge of this
short pulse re-enables the low-side MOSFET if the pulse
width is at least 200 µs long (if a short circuit latch-off had
occurred during the previous positive PWM pulse). The PWM
input has a 50 µA pull-down to ground that disables all the
outputs should an open circuit condition occur.
Low Side FET
Body Diode
Current in Load
reverses polarity
FUNCTIONAL PIN DESCRIPTION
FUNCTIONAL DESCRIPTION
33899
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