L6235QTR STMicroelectronics, L6235QTR Datasheet - Page 18

• 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

Circuit description
4.7
18/33
Figure 18. t
Non-dissipative overcurrent detection and protection
The L6235Q integrates an overcurrent detection circuit (OCD) for full protection. With this
internal overcurrent detection, the external current sense resistor normally used and its
associated power dissipation are eliminated.
overcurrent detection circuit.
To implement the overcurrent detection, a sensing element that delivers a small but precise
fraction of the output current is implemented with each high-side power MOSFET. Since this
current is a small fraction of the output current there is very little additional power
dissipation. This current is compared with an internal reference current I
output current reaches the detection threshold (typically I
comparator signals a fault condition. When a fault condition is detected, an internal open
drain MOSFET with a pull-down capability of 4 mA connected to pin DIAG is turned on.
Pin DIAG can be used to signal the fault condition to a µC or to shut down the 3-phase
bridge simply by connecting it to pin EN and adding an external R-C (see R
PULSE
vs. C
1 . 10
1 . 10
100
10
4
3
PUL
1
Doc ID 018997 Rev 2
and R
R
PUL
PUL
= 20kΩ
R
Figure 19
PUL
Cpul [nF]
= 47kΩ
1
0
R
PUL
shows a simplified schematic of the
= 100kΩ
SOVER
= 5.6 A), the OCD
1
0
0
REF
. When the
EN
, C
EN
).
L6235Q