HV320
Initial Release
Accurate, Re-Settable Electronic Circuit Breaker
(Negative Supply Rail)
Features
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General Description
The Supertex HV320 re-settable electronic circuit breaker is
designed to provide fast, consistent and accurate current
limiting and load isolation during fault conditions. It may be
used in a variety of applications in such markets as telecom,
power, automotive, industrial, medical and security as well
as in systems where active control is implemented in the
negative supply lead. The current trip threshold is
programmed by a sense resistor and operates from voltages
ranging from 10V to 90V differentially.
The HV320 can easily replace popular positive temperature
coefficient (PTC) products such
as Raychem™
PolySwitches™ or re-settable polyfuses. HV320 overcomes
numerous performance shortcomings of existing PTC’s,
including trip point inaccuracy, increased device resistance
after initial reset, slow response time, susceptibility to
temperature variations and very high trip current to
operating current.
During initial application of power, the gate of the external
pass device is clamped low to suppress contact bounce
glitches. Thereafter, the UV/OV supervisors and power-on
reset work together to suppress gate turn on until the input
power bounce ends. Once ON, HV320 continues to monitor
the input voltage and the load current level. If a load fault
occurs, the electronic circuit breaker will trip and the pass
element will be turned off. To restart, the UV or OV pins
must be toggled (for example by resetting the input voltage).
Differential 10V to 90V operation (+V
IN
/ -V
EE
)
UV and OV Lock Out
Power-On-Reset (POR) for debouncing
Sense resistor programs circuit breaker
Noise filter prevents false trip
Programmable circuit breaker trip time
Latched Operation
Low Power, <0.4mA
Small SO-8 package
Applications
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-48V Central Office Switching
-24V Cellular and Fixed Wireless Systems
-24V PBX Systems
Telecom Line Cards
-48V Powered Ethernet for VoIP
Distributed Power Systems
Power Supply Input/Output Fault Isolator
Electronic Circuit Breaker
Servers and SANS – replaceable modules
Automotive and Industrial Circuit Breakers
BUS Networks (CAN BUS, etc.)
Typical Application Circuit
GND
R1
487k
Vin
UV
R2
6.81k
HV320
OV
Vee
Load
Sense
R5
1k
C2
10nF
Gate
R3
9.76 k
C1
-48V
R4
5 mOhm
IRFB4710
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 products, refer to the most current data book or to the
Legal/Disclaimer page on the Supertex website.
SUPERTEX [ Supertex, Inc ]
