Datasheet
SENSE OUT
I
SENSE
16 PA
LM5060
V
DS
Fault
Comparator
500:
1 k:
I
OUT-EN
8 PA
V
OUT
V
IN
R
S
R
O
4 mA
max
25 mA
max
LM5060
GATE
OUT
V
IN
TIMER
GND
SENSE
VIN
OVP
UVLO
EN
D1
D2
C1
R2
R1
Q3
Q1
Q2
D6
GND
GND
V
OUT
nPGD
D4
D5
D7
D3
36V
R3
12 k:
R4
10 k:
2 k:
68 nF
C2
100 nF
75A, 40V
75A, 40V
0.6A, 40V
10 k:
R5
49.9 k:
R6
5.62 k:
R7
5.11 k:
Status
Enable
LM5060
SNVS628F –OCTOBER 2009–REVISED APRIL 2013
www.ti.com
When Q1 and Q2 are turned on, R1 does not cause any delay because the GATE pin is driven with a 24 µA
current source. D6, Q3 and R2 protect Q2 from V
GS
damage in the event of reverse input polarity. Diodes D5
and D7 are only necessary if the output load is highly capacitive. Such a capacitive load in combination with a
high reverse polarity input voltage condition can exceed the power rating of the internal zener diode between
OUT pin and GATE pin as well as the internal diode between the OUT pin and SENSE pin. External diodes D5
and D7 should be used in reverse polarity protected applications with large capacitive loads.
Figure 34 Example Circuit Specification
Operating Voltage Range 9V to 24V
Current max 30A
OVP setting 27V typical
UVLO setting 9V typical
Figure 34. Application with Reverse Polarity Protection with Diodes for OUT Pin Protection
REVERSE POLARITY PROTECTION WITH A RESISTOR
An alternative to using external diodes to protect the LM5060 OUT pin in the reverse polarity input condition is a
resistor in series with the OUT pin. Adding an OUT pin resistor may require modification of the resistor in series
with the SENSE pin. A resistor in series with the OUT pin will limit the current through the internal zener diode
between OUT and GATE as well as through the diode between OUT and SENSE. The value of these resistors
should be calculated to limit the current through the diode across the input terminals of the V
DS
fault comparator
to be no more than 4 mA. Figure 35 shows the internal circuitry relevant for calculating the values of the resistor
R
O
in the OUT path to limit the current into the OUT pin to 4 mA.
Figure 35. Current Limiting Resistor for Negative SENSE Condition
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