HV300 Hotswap, Inrush Current Limiter Controllers (Negative Supply Rail) Features General Description The Supertex HV300, Hotswap Controller, Negative Supply controls the power PWRGD = Active HIGH supply connection during insertion of cards or modules into live backplanes. -10V to -90V input voltage range It may be used in traditional negative 48V powered systems or for higher Few external components voltage busses up to negative 90V. 0.33mA typical standby supply current Programmable over/under voltage limits with Operation during the initial power up prevents turn-on glitches, and after hysteresis complete charging of load capacitors (typically found in lters at the input of DC-DC converters) the HV300 issues a power good signal. This signal is Programmable current limit typically used to enable the DC-DC converter. Once a PWRGD signal has Active control during all phases of start-up been established, the device sleeps in a low power state, important for large Programmable timing systems with many individual hotswap cards or modules. 8-Lead SOIC package 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 Applications lockouts. There is no need for additional external snubber components. Central ofce switching Features are programmable over voltage and under voltage detection of the Servers input voltage which locks out the load connection if the bus (input) voltage POTS line cards is out of range. An internal voltage regulator creates a stable reference, ISDN line cards and maintains accurate gate drive voltage. The unique control loop scheme provides full current control and limiting during start up. xDSL line cards PBX Systems Powered Ethernet for VoIP Theory of Operation Distributed power systems Initially the external N-channel MOSFET is held off by the gate signal, Negative power supply control preventing an input glitch. After a delay (while internal circuits are activated) Antenna and xed wireless systems 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. Typical Application Circuit Long Pin GND Jumper 8 VDD Short Pin PWRGD GND 1 R1 ENABLE 487k 3 +5V UV HV300 R2 C DC/DC 6.81k LOAD 2 COM PWM OV CONVERTER R3 RAMP VEE SENSE GATE 9.76k NOTES: 1. Undervoltage Shutdown (UV) set to 35V. 6 7 4 5 C1 2. Overvoltage Shutdown (OV) set to 65V. 10nF 3. Remove jumper if short pin is used. Long Pin -48V R4 Q1 50m IRF530 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.comHV300 Ordering Information Package Option 8-Lead SOIC Device 4.90x3.90mm body 1.75mm height (max) 1.27mm pitch HV300 HV300LG-G -G indicates package is RoHS compliant (Green) Pin Conguration Absolute Maximum Ratings 1 8 PWRGD VDD Parameter Value 2 7 RAM P OV V referenced to VDD pin +0.3 to -100V EE UV 3 6 GATE V referenced to V voltage -0.3 to +100V PWRGD EE VEE 4 5 SENSE Operating ambient temperature -40C to +85C 8-Lead SOIC (LG) Operating junction temperature -40C to +125C (top view) Storage temperature -65C to +150C Product Marking UV and OV referenced to V -0.3 to +12V EE Y = Last Digit of Year Sealed YWW Absolute Maximum Ratings are those values beyond which damage to the WW = Week Sealed device may occur. Functional operation under these conditions is not implied. HV300 L = Lot Number Continuous operation of the device at the absolute rating level may affect L L L L device reliability. All voltages are referenced to device ground. = Green Packaging Package may or may not include the following marks: Si or 8-Lead SOIC (LG) Electrical Characteristics (V = -10 to -90V, -40C T +85C unless otherwise noted) IN A Sym Parameter Min Typ Max Units Conditions Supply (Referenced to VDD pin) V Supply voltage -90 - -10 V --- EE Supply current - 550 650 A V = -48V, mode = limiting EE I EE Standby mode supply current - 330 400 A V = -48V, mode = standby EE OV and UV Control (Referenced to VEE pin) V UV high threshold - 1.26 - V Low to high transition UVH V UV low threshold - 1.16 - V High to low transition UVL V UV hysteresis - 100 - mV --- UVHY V OV high threshold - 1.26 - V Low to high transition OVH V OV low threshold - 1.16 - V High to low transition OVL V OV hysteresis - 100 - mV --- OVHY 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com 2