908E621_07 Datasheet, PDF (39/62 Pages) Freescale Semiconductor, Inc – Integrated Quad Half-Bridge and Triple High-Side with Embedded MCU and LIN for High End Mirror

FUNCTIONAL DEVICE OPERATION
OPERATIONAL MODES
Half-Bridge Overvoltage/Undervoltage Protection
The half-bridge outputs are protected against
undervoltage and overvoltage conditions. This protection is
done by the low and high voltage interrupt circuitry. If one of
this flags (LVIF, HVIF) is set, the outputs are automatically
disabled if the VIS bit in the System Control Register
(SYSCTL) is cleared.
The overvoltage and undervoltage status flags are cleared
(and the outputs reenabled) by writing a “1” to the LVIF / HVIF
flags in the Interrupt Flag Register (IFR) or by a reset.
Clearing this flag has no effect as long as the high voltage or
low voltage condition is still present.
Half-Bridge Status and Control Register (HBSCTL)
Register Name and Address: HBSCTL - $03
Bit7
6
5
4
3
2
1
Bit0
Read
0
0
0 HB4 HB3 HB2 HB1
CRM
OCF OCF OCF ^OCF
Write
Reset 0
0
0
0
0
0
0
0
CRM — Current Recirculation Mode bit
This read/write bit selects the recirculation mode during
PWM.
Reset clears the CRM bit.
1 = recirculation via switched on low-side MOSFET
0 = recirculation via low-side free wheeling diode
HBxOCF — Half Bridges Overcurrent Flag Bit
This read/write bit indicates that an overcurrent condition
on either the LS or the HS FET on HBx has occurred.
Clear HBxOCF and enable Half Bridge by writing a logic
[1] to HBxOCF. Writing a logic [0] to HBxOCF has no effect.
Reset clears the HBxOCF bit.
1 = overcurrent condition on HBx occurred
0 = no overcurrent condition on HBx
High-Side Drivers
The high-side outputs are low resistive high-side switches,
targeted for driving lamps. The high-sides are protected
against overtemperature, overcurrent and overvoltage/
undervoltage.
VSUP
PSON
HSxON
HSxPWM
PWM
Control
on/off
Status
Current
Limit
HS - Driver
charge pump
over-current protection
inrush current limiter
PWM
HSx
Figure 23. HS circuitry
HIGH-SIDE OPERATING MODES
The High-sides outputs are enabled if the PSON bit in the
System Control Register (SYSCTL) is set.
Each high-side output is permanently switched on, if the
HSxON bit in the High-Side Output Register (HSOUT) is set.
PWM control of the output is enabled, if the HSxPWM bit
High-Side Output Register (HSOUT) is set. In this operating
mode the high-side MOSFET is on, if the input PWM signal
(PWM terminal) is high.
The below table shows the behavior of the high-side
MOSFETs depending on the HSONx and PWMHSx bits.
Analog Integrated Circuit Device Data
Freescale Semiconductor
908E621
39