HV301/HV311
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).
Using Short Connector Pin
Insomesystemsshortconnectorpinsareusedtoguaranteethat
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).
8
GND
V
DD
PWRGD / PWRGD
1
R1
475kΩ
ENABLE / ENABLE
+5V
3
2
UV
Cload
R3
511kΩ
R2
16.2kΩ
HV311
DC/DC
PWM
COM
OV
CONVERTER
R4
10kΩ
RAMP
V
4
SENSE GATE
EE
7
5
6
C2
C1
10nF
-48V
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
8
GND
Short
Pin
V
DD
PWRGD / PWRGD
1
GND
R1
487kΩ
ENABLE / ENABLE
Cload
3
2
+5V
UV
R2
6.81kΩ
HV301/
HV311
DC/DC
PWM
CONVERTER
COM
OV
R3
9.76kΩ
RAMP
V
4
SENSE GATE
EE
7
5
6
C1
10nF
Long
Pin
-48V
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