MLX81100_14 Datasheet, PDF (12/19 Pages) Melexis Microelectronic Systems – DC-Motor Controller

MLX81100
DC-Motor Controller
3.7 Seat Heating and Climatisation
In this sample application the IC drives 2 separate heat elements via high side drivers and 2 motors via the
low side drivers. The high side N-FET driving is done with a bootstrap output stage. The current control of
the high side FET is realized via shunt measurement and the shunt voltage is amplified with a differential
amplifier connected to the ADC.
The reverse polarity protection of the low side FET must be realized with an external power FET connected
to the ground line. Short circuits of the single FET will be detected with integrated comparators and in this
case the FET will be switched off. Weak short circuits must be monitored with an external temperature
sensor.
VBAT
4.7 ..10uF
100nF
VS
RTG
VBAT ^47uF
Fan 1
1uF
M
VDD5V
100nF
V1V8
100nF
PS
SW6
VBAT
Fan 2
M
LS1
SW2
SW3
SW7
V_BAT
VCC
10
LIN
180p
LS2
SW4
SW5
IO4
IO5
IO0
IO1
IO2
IO3
LIN
GND
GND
VDRV
CLKO
HSBC2
HS2
BRMID2
SW1
100nF
V_BAT
100nF
Shunt
Heater 2
HSBC1
HS1
BRMID1
SW0
GND
SHNT_L
CWD
TI0
TI1
TO
GND
GND
100nF
VBAT
Shunt
Heater 1
CWD
Figure 8 - Application circuitry for seat heating and seat climatisation
MLX81100 – Product Abstract
Page 12 of 19
June 2012
Rev 021