L6229Q STMicroelectronics, L6229Q Datasheet - Page 13
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L6229Q
Manufacturer Part Number
L6229Q
Description
Motor / Motion / Ignition Controllers & Drivers DMOS Driver for 3-phase DC motor
Manufacturer
STMicroelectronics
Type
3 Phase Brushless DC Motor Controllerr
Datasheet
1.L6229Q.pdf
(28 pages)
Specifications of L6229Q
Operating Temperature Classification
Commercial
Operating Supply Voltage (min)
8V
Operating Supply Voltage (max)
52V
Product
Stepper Motor Controllers / Drivers
Operating Supply Voltage
8 V to 52 V
Supply Current
3.55 A
Mounting Style
SMD/SMT
Package / Case
VQFN-32
Operating Temperature
+ 150 C
Lead Free Status / RoHS Status
Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
L6229Q
Manufacturer:
ST
Quantity:
20 000
L6229Q
5.3
PWM current control
The L6229Q includes a constant off time PWM current controller. The current control circuit
senses the bridge current by sensing the voltage drop across an external sense resistor
connected between the source of the three lower power MOS transistors and ground, as
shown in
resistor increases proportionally. When the voltage drop across the sense resistor becomes
greater than the voltage at the reference input pin VREF the sense comparator triggers the
monostable switching the bridge off. The power MOS remain off for the time set by the
monostable and the motor current recirculates around the upper half of the bridge in slow
decay mode as described in the next section. When the monostable times out, the bridge
will again turn on. Since the internal dead time, used to prevent cross conduction in the
bridge, delays the turn on of the power MOS, the effective off time t
monostable time plus the dead time.
Figure 10
across the sensing resistor, the pin RC voltage and the status of the bridge. More details
regarding the synchronous rectification and the output stage configuration are included in
the next section.
Immediately after the power MOS turn on, a high peak current flows through the sense
resistor due to the reverse recovery of the freewheeling diodes. The L6229Q provides a 1 µs
blanking time t
prematurely re trigger the monostable.
Figure 9.
C
OFF
5V
5mA
Figure
(0)
shows the typical operating waveforms of the output current, the voltage drop
PWM current controller simplified schematic
RCOFF
R
TO GATE
OFF
BLANK
(1)
LOGIC
9. As the current in the motor increases the voltage across the sense
2.5V
Q
that inhibits the comparator output so that the current spike cannot
+
-
S
R
MONOSTABLE
BLANKING TIME
MONOSTABLE
Doc ID 15209 Rev 3
SET
1μs
COMPARATOR
SENSE
BLANKER
DEAD TIME
DRIVERS
GATE DRIVERS
+
-
FROM THE
LOW-SIDE
+
R SENSE
VREF
VS
B
SENSE B
DEAD TIME
DRIVERS
+
SENSE A
OFF
DEAD TIME
DRIVERS
is the sum of the
Circuit description
+
D02IN1380
VS
A
VS
OUT 2
OUT 3
OUT 1
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