MIC2588/MIC2594 Single-Channel, Negative High-Voltage Hot Swap Power Controllers - Micrel - #1

Text version of the page

September 2005 1 M9999-083005 MIC2588/MIC2594 Micrel MIC2588/MIC2594 Single-Channel, Negative High-Voltage Hot Swap Power Controllers General Description The MIC2588 and the MIC2594 are single-channel, negative- voltage hot swap controllers designed to address the need for safe insertion and removal of circuit boards into “live” high-voltage system backplanes, while using very few external components. The MIC2588 and the MIC2594 are each available in an 8-pin SOIC package and work in conjunction with an external N-Channel MOSFET for which the gate drive is controlled to provide inrush current limiting and output voltage slew-rate control. Overcurrent fault protection is also provided and includes a programmable overcurrent threshold. During an output overload condition, a constant-current regulation loop is engaged to ensure that the system power supply maintains regulation. If a fault condition exceeds a built-in 400ìs nuisance-trip delay, the MIC2588 and the MIC2594 will latch the circuit breaker’s output off and will remain in the off state until reset by cycling either the UV/OFF pin or the power to the IC. A master Power-Good signal is provided to indicate that the output voltage of the soft-start circuit is within its valid output range. This signal can be used to enable one or more DC-DC converter modules. All support documentation can be found on Micrel’s web site at www.micrel.com. Typical Application /PWRGDDRAINUVOVVDDSENSEGATEVEE18765432R1698kÙ1%R312.4kÙ1%R211.8kÙ1%C11uFRSENSE0.01Ù5%*D1SMAT70A100VM1SUM110N10-09RFDBK15kÙC30.22uFCFDBK6.8nF100VR410Ù-48VOUT-48V RTNC5100uFC40.1uF-48VIN(Long Pin)-48V RTN(Long Pin)*C60.33uFMIC2588-2BM-48V RTN(Short Pin)DC-DCCONVERTERIN-IN+ON/OFF#OUT+OUT-+2.5V RTN+2.5VOUTVDD*C222nFNominal Undervoltage and Overvoltage Thresholds: VUV= 36.5V VOV= 71.2V* Optional components (See Applications Information for more details)# An external pull-up resistor for the power-good signal is necessary for DC-DC supplies (and all other load modules) not equipped with internal pull-up impedence Features • MIC2588: Pin-for-pin functional equivalent to the LT1640/LT1640A/LT4250 • Provides safe insertion and removal from live –48V (nominal) backplanes • Operates from –19V to –80V • Electronic circuit breaker function • Built-in 400ìs “nuisance-trip” delay (tFLT) • Regulated maximum output current into faults • Programmable inrush current limiting • Fast response to short circuit conditions (< 1ìs) • Programmable undervoltage and overvoltage lockouts (MIC2588-xBM) • Programmable UVLO hysteresis (MIC2594-xBM) • Fault reporting: Active-HIGH (-1BM) and Active-LOW (-2BM) Power-Good output signal Applications • Central office switching • –48V power distribution • Distributed power systems • Server Networks Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com