L6229QTR STMicroelectronics, L6229QTR Datasheet - Page 16

• Manufacturer Part Number: L6229QTR
• Description: IC DRIVER DMOS DC MOTOR 32VFQFPN
• Manufacturer: STMicroelectronics
• Type: 3 Phase Brushless DC Motor Driverr

Specifications of L6229QTR

• Applications: DC Motor Driver, Brushless (BLDC), 3 Phase
• Number Of Outputs: 1
• Current - Output: 2.8A
• Voltage - Supply: 12 V ~ 52 V
• Operating Temperature: -40°C ~ 150°C
• Mounting Type: Surface Mount
• Package / Case: 32-VFQFN, 32-VFQFPN
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Load: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-8495-2

Circuit description
5.4
5.5
16/28
Slow decay mode
Figure 13
any time only two legs of the three-phase bridge are active, therefore only the two active
legs of the bridge are shown in the figure and the third leg will be off. At the start of the Off
Time, the lower power MOS is switched off and the current recirculates around the upper
half of the bridge. Since the voltage across the coil is low, the current decays slowly. After
the dead time the upper power MOS is operated in the synchronous rectification mode
reducing the impedance of the freewheeling diode and the related conducting losses. When
the monostable times out, upper MOS that was operating the synchronous mode turns off
and the lower power MOS is turned on again after some delay set by the dead time to
prevent cross conduction.
Figure 13. Slow decay mode output stage configurations
Decoding logic
The decoding logic section is a combinatory logic that provides the appropriate driving of the
three-phase bridge outputs according to the signals coming from the three hall sensors that
detect rotor position in a 3-phase BLDC motor. This novel combinatory logic discriminates
between the actual sensor positions for sensors spaced at 60, 120, 240 and 300 electrical
degrees. This decoding method allows the implementation of a universal IC without
dedicating pins to select the sensor configuration.
There are eight possible input combinations for three sensor inputs. Six combinations are
valid for rotor positions with 120 electrical degrees sensor phasing (see
1, 2, 3a, 4, 5 and 6a) and six combinations are valid for rotor positions with 60 electrical
degrees phasing (see
common (1, 2, 4 and 5) whereas there are two combinations used only in 120 electrical
degrees sensor phasing (3a and 6a) and two combinations used only in 60 electrical
degrees sensor phasing (3b and 6b).
The decoder can drive motors with different sensor configuration simply by following the
Table
OUT
configuration 6a is the same than 6b.
The sequence of the Hall codes for 300 electrical degrees phasing is the reverse of 60 and
the sequence of the Hall codes for 240 phasing is the reverse of 120. So, by decoding the 60
2
8. For any input configuration (H
A) ON TIME
and OUT
shows the operation of the bridge in the slow decay mode during the off time. At
3
). The output configuration 3a is the same than 3b and analogously output
D01IN1336
Figure
B) 1μs DEAD TIME
15, positions 1, 2, 3b, 4, 5 and 6b). Four of them are in
Doc ID 15209 Rev 3
1
, H
2
and H
3
) there is one output configuration (OUT
C) SYNCHRONOUS
RECTIFICATION
Figure
D) 1μs DEAD TIME
14, positions
L6229Q
1
,