MC33899VW FREESCALE [Freescale Semiconductor, Inc], MC33899VW Datasheet - Page 13

• Manufacturer Part Number: MC33899VW
• Description: Programmable H-Bridge Power IC
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

ENABLE INPUTS (EN1, EN2)
four of the output drivers (refer to
or EN2 is at logic [1], the 33899 is still capable of detecting
open circuit and short circuit faults on all of the outputs
interfacing with the external load(s). The EN1 and EN2 inputs
have 50
when open circuit conditions occur.
INPUT CONTROL OF H-BRIDGE (PWM)
PWM’ing high side and low side MOSFETs. A logic [1]
Analog Integrated Circuit Device Data
Freescale Semiconductor
PWM
REV
FWD
Logic [0] in either of the Enables (EN1 or EN2) disables all
The PWM input pin controls the sequencing of the
EN1
S0
S1
0
0
1
1
μ
A pull-downs to ground that disable the outputs
Table 6. Enable Truth Table
EN2
0
1
0
1
Disabled (Standby Mode)
Disabled (Standby Mode)
Disabled (Sleep Mode)
Table
Enabled (Run Mode)
Figure 7. 33899 Operation in Current Reversal
6). While either EN1
Status
Both High Side
FET’s ON until
next PWM Rising
Edge
Reverse Current
Forward Current
Load Current
High Side FET
Body Diode
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).
If a shorted condition exists, the particular output MOSFET
will be latched off after 5.0μs to 10μs. 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 500ns 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 50μA pull-down to ground that disables all the
outputs should an open circuit condition occur.
Low Side FET
Body Diode
FUNCTIONAL PIN DESCRIPTION
FUNCTIONAL DESCRIPTION
Current in Load
reverses polarity
33899
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