AS8410 View Datasheet(PDF) - austriamicrosystems AG
Part Name
Description
Manufacturer
AS8410 Datasheet PDF : 19 Pages
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PWM DC Motor Regulator – Data Sheet
AS8410
Meaning and Settings of the external devices
Sym-
bol
ROSC
Rmeas
Rint2
Cint2
Cint1
SRC1
SRC2
RIN
RMODE
RTP1
RTP2
Description
Typical value
Application Note
Regulation loop settings / slew rate regulation
Resistor of the refer-
100 kΩ
The voltage at the pin OSC is regu-
ence current genera-
tion Iref
lated to VOSC = 1 V. The reference cur-
rent is therefore 10 µA.
This current is used for three functions:
1. The oscillator frequency (Iref = 10µA
generates fOSC = 18 kHz, fOSC is a
linear function of Iref)
2. Generation of the internal set value
voltage in OM1 together with the
resistor Rint2.
100% set value is build by a volt-
age of 2 V at pin Cint2:
VCint2(100%) = Iref * Rint2 = 2 V
3. Reference current for the power
FET driver / Slew rate regulation
(linear function between Iref and
driver output current IOUT)
Motor current meas- Dependent on the The voltage drop over the Rmeas must
urement resistor
nominal motor
be 50 mV for the nominal motor cur-
current Imotor_nom
rent: Rmeas = 50 mV / Imotor_nom
Resistor to convert
the incoming duty
200 kΩ
VCint2(100%) = Iref * Rint2 = 2 V
ratio of the set value
in OM1 to the set
value voltage VCint2
Filter capacitor of the
set value conversion
in OM1
Capacitor to set the
> 2.2 µF
100 nF
Dependent on the incoming PWM fre-
quency fIN_PWM
fIN_PWM = 10 Hz à Cint2 > 2.2 µF
The time constant of the failure han-
regulation loop time
constant and failure
handling time con-
stant
dling Tfail is determined by the max.
current at pin Cint2 (ICint1_max = 10 µA
… 15 µA) and the min. voltage to start
the PWM generator (1.66 V):
Tfail = (Cint1 * 1.66 V ) / ICint1_max
Feedback circuitry of Dependent on the Application Support of Austria Mikro
the slew rate regula- application (motor Systeme AG will be guaranteed
tion
and environment)
Protection Resistors
Protection resistor of
the pin IN
330 Ω
Needed in automotive applications
Protection resistor of
the pin MODE
1 kΩ
Needed in automotive applications
Temperature Sensor
Resistor divider of the RTP1 + RTP2 < 10 kΩ The threshold voltage at the pin TP
temperature sensor
must be 0.5 *VDD or (RTP1 = RTP2)
Rev. 1.0, December 2000
page 8 of 19
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