L6235QTR STMicroelectronics, L6235QTR Datasheet - Page 9

• Manufacturer Part Number: L6235QTR
• Description: Motor / Motion / Ignition Controllers & Drivers DMOS 3-Phase Brushless DC Motor
• Manufacturer: STMicroelectronics

Specifications of L6235QTR

• Product Category: Motor / Motion / Ignition Controllers & Drivers
• Rohs: yes

L6235Q
4
4.1
Circuit description
Power stages and charge pump
The L6235Q integrates a 3-phase bridge, which consists of 6 power MOSFETs connected
as shown in
with intrinsic fast freewheeling diode. Switching patterns are generated by the PWM current
controller and the Hall effect sensor decoding logic
conduction protection is implemented by using a dead time (t
internal timing circuit between the turn-off and turn-on of two power MOSFETs in one leg of
a bridge.
Pins VS
Using an N-channel power MOSFET for the upper transistors in the bridge requires a gate
drive voltage above the power supply voltage. The bootstrapped supply (V
through an internal oscillator and a few external components to realize a charge pump
circuit, as shown in
(typically) with 10 V amplitude. Recommended values/part numbers for the charge pump
circuit are shown in
Table 5.
Figure 5.
A
and VS
Figure
Charge pump external component values
Charge pump circuit
Component
C
B
BOOT
C
R
D1
D2
must be connected together to the supply voltage (V
1, each power MOSFET has an R
P
P
Figure
Table
5.
5. The oscillator output (pin VCP) is a square wave at 600 kHz
Doc ID 018997 Rev 2
VCP
D1
R
C
P
P
D2
VBOOT
C
BOOT
VS
A
VS
(Chapter 4.3 on page
B
DS(ON)
V
= 0.3 Ω (typical value @ 25 °C)
S
DT
1N4148
1N4148
220 nF
100
Value
10 nF
= 1 µs typical value) set by
Ω
Circuit description
S
).
11). Cross
BOOT
) is obtained
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