MIC2588/MIC2594 Single-Channel, Negative High-Voltage Hot Swap Power Controllers0 pages

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