SMH4804 Datasheet, PDF (25/41 Pages) Summit Microelectronics, Inc. – -48V Programmable Hot Swap Sequencing Power Controller

SMH4804
Timing Diagram
−4₀8V_VRTN (0V)
R_D
R3
6.8kΩ
½W
100kΩ
–48V
Notes:
EN/TS
PG4#
3
MMBTA06LT1
+VIN +VOUT
V4
–VIN –VOUT
0V
ON/OFF
UV
R2
OV
PD1#
PD2#
FAULT#
RESET#
MODE
PG3#
SMH4804
PG2#
5VREF
PG1#
R1
2
100nF 3.3nF
50V
C1
100nF
R4
1kΩ
1 ^RG
C2
10Ω 10nF
100V
RS
R_T ⁴
68kΩ
D_D
MMBD-
1401
100kΩ
MMBTA06LT1
100kΩ
MMBTA06LT1
100kΩ
MMBTA06LT1
100kΩ
100nF
50V
100µF
100V
+VIN +VOUT
–VIN –VOUT
ON/OFF
+VIN +VOUT
–VIN –VOUT
ON/OFF
+VIN +VOUT
–VIN –VOUT
ON/OFF
DC / DC
Converters
with
Active Low
On/Off Control
V3
ISOLATED
DC
OUTPUTS
V2
V1
2050 Fig18
Figure 17. Typical Application Sequencing Four DC/DC Converter
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 R_T and D_D 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.
Summit Microelectronics
2050 3.7 10/30/02
25