SMH4804 Datasheet, PDF (24/41 Pages) Summit Microelectronics, Inc. – -48V Programmable Hot Swap Sequencing Power Controller

Timing Diagram
SMH4804
−48₀V_VRTN (0V)
NTC
50kΩ
@TMAX
1MΩ
+
–
LMV331
50kΩ
R3
RD
6.8kΩ
½W
1kΩ
EN/TS
PG4#
UV
R2
OV
PD1#
PD2#
FAULT#
RESET#
MODE
A0
A1
A2
SCL
SDA
PG3#
SMH4804
PG2#
5VREF
PG1#
−48V RTN (00VV)
100kΩ
3
MMBTA06LT1
100kΩ
MMBTA06LT1
100kΩ
MMBTA06LT1
100kΩ
MMBTA06LT1
100kΩ
–48V
Notes:
24
2
R1
130.30nFF
50V
C1
100nF
RS
20mΩ
1 ^RG
10Ω
R4
1kΩ
C2
10nF
100V
100nF
50V
R_T ⁴
68kΩ
D_D
MMBD-
1401
100nF
50V
Figure 16. Over-temperature Shutdown
100µF
100V
2050 Fig17
–48V
The 10Ω resistor (R_G) must be located as close as possible to the MOSFET.
Optional bypass capacitor. If a larger value is required an 11V Zener must be connected in parallel.
Optional interface circuit. The PG[4:1]# outputs can be directly connected to the power module if the input voltage to the
module is within tolerance and the voltage on the PG[4:1]# outputs doesn't exceed 15V.
The DRAIN Sense function may cause nuisance tripping due to voltage transients on the –48V line or when using multiple
lines. This may be avoided by one of the following methods:
A. Disable the function by connecting the DRAIN Sense pin to V_SS directly. The components RT and DD are eliminated.
B. Add a capacitor from Drain Sense to V_SS. The exact capacitance value depends upon the magnitude and duration of
the voltage transient appearing at the drain of the MOSFET.
2050 3.7 10/30/02
Summit Microelectronics