Rainbow Electronics MAX5043 - Manual (Page 19)

Determining Hot-Swap Inrush Current
Calculate the hot-swap inrush current using the follow-
ing formula:
where:
C IN = the load capacitance,
S HSLR is the MAX5042 hot-swap slew rate magnitude
given in the Electrical Characteristics table.
For example, assuming an input bulk capacitance of
100µF, and using the typical value of 10V/ms for the
slew rate, the calculated inrush current is 1A. See Table
1 for suggested external hot-swap MOSFETs.
I C
dV
dt
C S
C IN
HSDRAIN
IN HSLR
IN
= =
MAX5042/MAX5043
Two-Switch Power ICs with Integrated
Power MOSFETs and Hot-Swap Controller
______________________________________________________________________________________ 19
Table 1. MAX5042 Suggested External
Hot-Swap MOSFETs
MAXIMUM I LOAD (A) SUGGESTED EXTERNAL MOSFET
0.25 IRFL110
0.5 IRFL4310
1 IRFR3910
2 IRF540NS
3 IRF1310NS
4 IRF1310NS
RAMP
RCFF
REG9
DRVIN
FLTINT
DRVDEL
SYNC
PWMSD
REG5
R22
10kΩ
C25
0.22µF
R20
10kΩ
R14
10kΩ
R13
1MΩ
C12
0.1µF
C3
1µF
C9
220pF
R12
200kΩ
1%
C20
0.1µF
100V
C1
220µF
100V
C30
0.68µF
100V
V IN+
32V TO 72V
NEGIN
C13
1µF
R15
24.9kΩ
1%
C14
100pF
RCOSC
C11
0.1µF
CSS
N1
(HOT-SWAP MOSFET)
NEGIN HSGATE HSDRAIN
PWMNEG,
CSN PWMPNEG OPTO
R21
1.24kΩ
1%
MAX5042
C6
0.1µF
BST
XFRMRH
XFRMRL
C7
1µF
R9
15Ω D4
R10
33mΩ
1%
D1
D2
REG15
CSP, SRC
POSINPWM
HSEN
DRNH UVLO
R6
200Ω
1%
C8
0.33µF
R11
20Ω
1%
C16
0.001µF
C5
0.0047µF
D3
L1
4.4µH
C17
150µF
6.3V
C18
150µF
6.3V
C4
0.1µF
5V
8A
SGND
R1
25.5kΩ
1%
R2
8.25kΩ
1%
R5
10Ω
1%
R4
10Ω
C15
0.1µF
C19
0.15µF
R3
150Ω
1%
U2
FOD2712
E
C
LED
FB
COMP
GND
U1
T1
Figure 7. MAX5042 Typical Application Circuit (48V Power Supply with Hot-Swap Capability)
Typical Application Circuits