Application Information, cont’d.
Unfortunately this will also cause some delay in responding to
UV conditions. If this UV delay is not acceptable, then separate
resistor dividers can be provided for OV and UV with a capacitor
connected from OV pin to the VEE pin (Application Circuit 6).
HV301/HV311
Using Short Connector Pin
In some systems short connector pins are used to guarantee that
the power pins are fully mated before the hotswap control circuit
is enabled. For these systems the positive (VDD) end of the R1,
R2, and R3 resistor divider should be connected to the short pin
(Application Circuit 7).
GND
R1
475kΩ
R2
16.2kΩ
-48V
8
VDD
PWRGD / PWRGD 1
3
UV
R3
511kΩ
2
OV
R4
10kΩ
HV311
ENABLE / ENABLE
Cload
DC/DC
PWM
CONVERTER
+5V
COM
RAMP VEE
7
4
SENSE GATE
5
6
C2
C1
10nF
R5
12.5mΩ
Q1
IRF530
Note: capacitor may be needed to slow PWRGD dv/dt if
oscillations are observed when VIN is close to OV.
Application Circuit 6
Long
Pin
GND
Short
Pin
GND R1
487kΩ
R2
6.81kΩ
R3
9.76kΩ
-48V
Long
Pin
8
VDD
3 UV
2 OV
PWRGD / PWRGD 1
HV301/
HV311
ENABLE / ENABLE +5V
Cload
DC/DC
PWM
COM
CONVERTER
RAMP VEE
7
4
SENSE GATE
5
6
C1
10nF
R4
12.5mΩ
Q1
IRF530
Note: capacitor may be needed to slow PWRGD dv/dt if
oscillations are observed when VIN is close to OV.
Application Circuit 7
13