L6230PD STMicroelectronics, L6230PD Datasheet - Page 13

• Manufacturer Part Number: L6230PD
• Description: Motor / Motion / Ignition Controllers & Drivers DMOS Driver 3-Phase Brushless DC Motor
• Manufacturer: STMicroelectronics
• Type: DMOS Driverr

Specifications of L6230PD

• Product: Fan / Motor Controllers / Drivers
• Operating Supply Voltage: 8 V to 52 V
• Supply Current: 1.4 A
• Mounting Style: SMD/SMT
• Package / Case: PowerSO-36
• Operating Temperature: - 40 C to + 125 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L6230
5.3
Non-dissipative overcurrent detection and protection
The L6230 integrates an overcurrent detection circuit (OCD) for full protection. This circuit
provides output-to-output and output-to-ground short circuit protection as well. With this
internal over current detection, the external current sense resistor normally used and its
associated power dissipation are eliminated.
overcurrent detection circuit.
To implement the over current detection, a sensing element that delivers a small but precise
fraction of the output current is implemented with each high side power MOS. 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 MOS with a pull down capability of 4 mA connected to pin DIAG is turned on.
The pin DIAG-EN can be used to signal the fault condition to a μC and to shut down the
three-phase bridge simply by connecting the pin to an external R-C (see R
Figure 10. Overcurrent protection simplified schematic
Figure 11
recovering normal operation can be easily programmed by means of the accurate
thresholds of the logic inputs. It is affected whether by C
magnitude is reported in
an overcurrent has been detected depends only by C
Figure 13
C
Therefore the value of C
tolerable delay time and the R
time.
The resistor R
values for R
disable time.
EN
μC or LOGIC
V
DD
is also used for providing immunity to pin DIAG\EN against fast transient noises.
R
C
EN
EN
shows the overcurrent detection operation. The disable time t
EN
DIAG\ EN
EN
and C
should be chosen in the range from 2.2 kΩ to 180 kΩ. Recommended
TO GATE
40Ω TYP.
R
LOGIC
DS(ON)
EN
POWER SENSE
EN
are respectively 100 kΩ and 5.6 nF that allow obtaining 200 μs
Figure
OPEN-DRAIN
INTERNAL
1 cell
should be chosen as big as possible according to the maximum
COMPARATOR
EN
Doc ID 18094 Rev 1
OCD
12. The delay time t
HIGH SIDE DMOS
value should be chosen according to the desired disable
POWER DMOS
OVER TEMPERATURE
n cells
I
1
OUT
I
1
/ n
1
I
I
I
REF
REF
1
+I
Figure 10
VS
2
+
/ n
A
OUT
I
2
DELAY
/ n
2
POWER DMOS
HIGH SIDE DMOS
I
2
EN
n cells
shows a simplified schematic for the
EN
value. Its magnitude is reported in
SOVER
before turning off the bridge when
and R
D02IN1381
POWER SENSE
I
= 2.8 A) the OCD
3
1 cell
/ n
EN
values and its
OUT
DISABLE
Circuit description
3
POWER DMOS
REF
I
3
VS
n cells
EN
. When the
B
HIGH SIDE DMOS
, C
before
EN
POWER SENSE
).
1 cell
13/24