13

HV301/HV311

Application Information, cont’d.

Application Circuit 7

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 (V

R2, and R3 resistor divider should be connected to the short pin

(Application Circuit 7).

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 V

Application Circuit 6

VDD

UV

OV

VEE

SENSE GATE

RAMP

-48V

R5

12.5m

Ω

R1

475k

Ω

R2

16.2k

Ω

R3

511k

Ω

Q1

IRF530

Cload

+5V

HV311

8

3

2

5

74

COM

1

GND

C1

10nF

C2

R4

10k

Ω

DC/DC

PWM

CONVERTER

PWRGD / PWRGD

ENABLE / ENABLE

6

Note: capacitor may be needed to slow PWRGD dv/dt if

oscillations are observed when V

VDD

UV

OV

VEE

SENSE GATE

RAMP

-48V

R4

12.5m

Ω

R1

487k

Ω

R2

6.81k

Ω

R3

9.76k

Ω

Q1

IRF530

Cload

+5V

HV301/

HV311

8

3

2

5

74

COM

1

GND

C1

10nF

Long

Pin

Short

Pin

Long

Pin

GND

6

DC/DC

PWM

CONVERTER

PWRGD / PWRGD

ENABLE / ENABLE

Note: capacitor may be needed to slow PWRGD dv/dt if

oscillations are observed when V