LTC4253AIGN Linear Technology, LTC4253AIGN Datasheet - Page 30

• Manufacturer Part Number: LTC4253AIGN
• Description: MS-Hot Swap/High Voltage, Neg. 48V Hot Swap With 1% UV, Sequencer
• Manufacturer: Linear Technology

Specifications of LTC4253AIGN

• Family Name: LTC4253A
• Package Type: SSOP N
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 3.99mm
• Product Height (mm): 1.5mm
• Mounting: Surface Mount
• Pin Count: 16
• Lead Free Status / Rohs Status: Not Compliant

APPLICATIO S I FOR ATIO
LTC4253/LTC4253A
Power Limit Circuit Breaker
Figure 16 shows the LTC4253A in a power limit circuit
breaking application. The SENSE pin is modulated by
board voltage V
to be the same as the lowest operating voltage,
V
operating voltage, V
power as available at V
R4 are selected by:
30
SUPPLY(MIN)
R
R
4
3
RESET
(LONG PIN)
– 48V RTN
(LONG PIN)
– 48V RTN
(SHORT PIN)
– 48V
(LONG PIN)
=
V
30.1k
392k
SUPPLY MAX
1%
1%
R2
R1
= 43V. If the goal is to have the high supply
V
SUPPLY
CB
(
C1
10nF
U
0.1µF
SUPPLY(MAX)
C
C
SS
SQ
. The zener voltage, V
SUPPLY(MIN)
)
33nF
15k(1/4W)/6
U
C
0.68µF
OV
UV
RESET
SS
SQTIMER
TIMER
T
2.5k
R
LTC4253A
IN
V
V
EE
IN
, then resistors R3 and
PWRGD1
PWRGD2
PWRGD3
= 71V give the same
W
DRAIN
SENSE
BZV85C43
GATE
Figure 16. Power Limit Circuit Breaker Application
EN3
EN2
1µF
C
V
IN
IN
D1
Z
of D1, is set
R3
31.6k
U
10nF
22Ω
R4
C
C
R5
5.6k
R
D
1M
(16)
R
10Ω
C
†
Q1
IRF530S
R
0.02Ω
S
R6
5.6k
If R4 is 22Ω, then R3 is 31.6k. The peak circuit breaker
power limit is:
when V
POWER MAX
EN2
†
V
†
SUPPLY
IN
(
R7
5.6k
100µF
C2
†
)
+
= 0.5 • (V
= 57V
=
=
R8
•
0.1µF
POWER AT V
1 064
(
4
V
.
C3
•
SUPPLY MIN
POWER
MODULE 1
OUTPUT
V
SUPPLY MIN
•
SUPPLY(MIN)
POWER AT V
EN3
MODULE 1
EN
(
POWER
(
SUPPLY MIN
)
+
)
V
•
SUPPLY MAX
V
†
V
MOC207
+ V
†
IN
SUPPLY MAX
(
SUPPLY MIN
MODULE 2
EN
MODULE 2
SUPPLY(MAX)
OUTPUT
POWER
POWER
)
(
R9
(
4253 F16
(
)
)
2
)
)
MODULE 3
EN
425353afc
POWER
)
(17)