HV300 Datasheet, PDF (1/6 Pages) Supertex, Inc – Hotswap, Inrush Current Limiter Controllers

HV300/HV310
HV300
HV310
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Hotswap, Inrush Current Limiter Controllers
(Negative Supply Rail)
Features
General Description
❏ HV300, PWRGD=Active HIGH
❏ HV310, PWRGD=Active LOW
❏ -10V to -90V Input Voltage Range
❏ Few External Components
❏ 0.33mA Typical Standby Supply Current
❏ Programmable Over/Under Voltage Limits with
Hysteresis
❏ Programmable Current Limit
❏ Active control during all phases of start-up
❏ Programmable timing
❏ 8 Lead SOIC
Applications
❏ Central Office Switching
❏ Servers
❏ POTS Line Cards
❏ ISDN Line Cards
❏ xDSL Line Cards
❏ PBX Systems
❏ Powered Ethernet for VoIP
❏ Distributed Power Systems
❏ Negative Power Supply Control
❏ Antenna and Fixed Wireless Systems
Ordering Information
V_EE
Min Max
-90V
-90V
-10V
-10V
Package Options
Power Good
Signal
8 Pin SOIC
Active HIGH HV300LG
Active LOW HV310LG
The Supertex HV300 (and HV310), Hotswap Controller, Negative
Supply control power supply connection during insertion of
cards or modules into live backplanes. They may be used in
traditional ‘negative 48V’ powered systems or for higher voltage
busses up to negative 90V.
Operation during the initial power up prevents turn-on glitches,
and after complete charging of load capacitors (typically found
in filters at the input of DC-DC converters) the HV300 (and
HV310) issues a power good signal. This signal is typically
used to enable the DC-DC converter.
The only difference between the HV300 and the HV310 is the
polarity of the PWRGD signal line to accommodate different
DC-DC converter models. Once PWRGD signal has been
established the device sleeps in a low power state, important
for large systems with many individual hotswap cards or
modules.
An external power MOSFET is required as the pass element,
plus a ramp capacitor, and resistors to establish current limiting
and over and under voltage lockouts. There is no need for
additional external snubber components.
Features are programmable over voltage and under voltage
detection of the input voltage which locks out the load connection
if the bus (input) voltage is out of range. An internal voltage
regulator creates a stable reference, and maintains accurate
gate drive voltage. The unique control loop scheme provides
full current control and limiting during start up.
Theory of Operation
Initially the external N-channel MOSFET is held off by the gate
signal, preventing an input glitch. After a delay (while internal
circuits are activated) the inrush current to the load is limited by
the gate control output. The current may ramp up and limit at
a maximum value programmed by an external resistor. Initial
time delay, to allow for contact bounce, and charging operation
is determined by the single external ramp capacitor connected
to the RAMP pin. When the load capacitor is fully charged, the
controller emerges from current limit mode, an additional time
delay occurs before the external N-channel MOSFET pass
transistor is switched to full conduction, and the PWRGD
output signal is activated. The controller will then transition to
a low power standby mode.
The HV300LG PWRGD is active high (open drain), while the
HV310LG PWRGD is active low (V_EE).
08/26/02
Supertex Inc. does not recommend the use of its products in life support applications and will not knowingly sell its products for use in such applications unless it receives an adequate "products liability
indemnification insurance agreement." Supertex does not assume responsibility for use of devices described and limits its liability to the replacement of devices determined to be defective due to
workmanship. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications, refer to the
Supertex website: http://www.supertex.com. For complete liability information on all Supertex prod₁ucts, refer to the most current databook or to the Legal/Disclaimer page on the Supertex website.