MIC2778 Micrel Semiconductor, MIC2778 Datasheet
MIC2778
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MIC2778 Summary of contents
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General Description The MIC2592B is a dual-slot power controller supporting the power distribution requirements for Peripheral Component Interconnect Express (PCI Express) Hot-Plug compliant systems. The MIC2592B provides complete power control support for two PCI Express slots, including the 3.3VAUX defi ...
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Typical Application +12V System Power +3.3V Supply VSTBY V STBY C1 100k 100k 100k 100k /FORCE_ONA /FORCE_ONB GPI_A0 GPI_B0 V STBY AUXENA AUXENB ONA ONB V STBY Hot-Plug Controller /PWRGDA /PWRGDB /FAULTA /FAULTB SMBus Base Address V STBY 10k x ...
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Pin Confi guration /FAULTA CFILTERA 12VGATEA GPI_A0 12VINA /PWRGDA 12VSENSEA /FORCE_ONA 12VOUTA VSTBYA 3VINA Slot A Interface March 2005 Hot-Plug Control Interface ...
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Pin Description Pin Number Pin Number Pin Number Pin Number Pin Name Pin Name Pin Name Pin Name 12VINA 12VINA 12VINA 12VINB 12VINB 12VINB 12VINB 3VINA 3VINA 3VINA 3VINA ...
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Pin Description (continued) Pin Number Pin Number Pin Number Pin Number Pin Name Pin Name Pin Name Pin Name VSTBYA VSTBYA VSTBYA VSTBYB VSTBYB VSTBYB VSTBYB VAUXA VAUXA VAUXA ...
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Pin Description (continued) Pin Number Pin Number Pin Number Pin Name Pin Name Pin Name ...
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Absolute Maximum Ratings Supply Voltages 12VIN[A/B] ............................................................... 14V 3VIN[A/B], VSTBY[A/B] ............................................... 7V Any Logic Pin ......................... –0.5V (min) to 3.6V (max) Output Current (/FAULT[A/B], /INT, SDA) ................... 10mA Power Dissipation ..................................... Internally Limited Lead Temperature (IR Refl ow, Peak Temperature) ...
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Electrical Characteristics (continued) Symbol Symbol Symbol Symbol Symbol Symbol Symbol Parameter Parameter Parameter Parameter Parameter Parameter Parameter C Overcurrent DelayTime, Pin 20 grounded through RFILTER[A&B] = 110 kΩ, 1% FILTER Overcurrent Delay Overcurrent Delay FILTER Scaling ...
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Electrical Characteristics (continued) Symbol Symbol Symbol Symbol Symbol Symbol Symbol Parameter Parameter Parameter Parameter Parameter Parameter Parameter I Auxiliary Output Current Limit Auxiliary Output Current Limit Auxiliary Output Current Limit Auxiliary Output Current Limit Auxiliary Output Current Limit Auxiliary Output ...
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Timing Diagrams SCL SDA Data In SDA Data Out V – SENSE V THFAST V THILIMIT 12VGATE 0V t OFF(12V) Figure 2. 12V Current Limit Response Timing Must Trip I AUX(THRESH) May Not Trip OUT(AUX) ...
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Typical Characteristics Supply Current vs. Temperature 5.0 4.5 4.0 3.5 12V 3.0 2.5 2.0 STBY 1.5 1 TEMPERATURE ...
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Typical Characteristics (cont.) Overcurrent Delay Scaling Factor vs. Temperature 5.6 5.4 5.2 5.0 4.8 4.6 4.4 4.4 4 TEMPERATURE (°C) Test Circuit +12V ...
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Functional Characteristics Turn-On Response Slot A TIME (2.5ms/div.) 3V Overcurrent Fault Response R = 0.4Ω LOAD Slot A TIME (5ms/div.) Auxiliary Overcurrent Fault Response R = 3.3Ω LOAD Overcurrent on Slot B TIME (5ms/div.) March 2005 GATE Output Turn-On Response ...
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Functional Characteristics cont. 3V Undervoltage Fault Response +3VIN /FAULT +12VIN VSTBY MAIN(12V and 3.3V) Supplies ENABLED Slot A TIME (500µs/div.) 3V Ouput Discharge Response V UV(3V) TIME (25ms/div.) March 2005 V UVLO(3V) Output disabled by ON pin C = 1000µF ...
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Functional Block Diagram 12VSENSE[A/B] 50mV 12VIN[A/B] 3VSENSE[A/B] 50mV 3VIN[A/B] ON/OFF 100mV* ON/OFF 100mV* Overcurrent Detection V STBY(REF) I REF Current Mirror CFILTER[A/B] RFILTER[A&B] /FORCE_ON[A/B] GPI_[A0/B0] * MIC2592B-3BTQ fast threshold is 150mV MIC2592B-5BTQ fast threshold is disabled Contact factory for availabilty ...
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Functional Description Hot Swap Insertion When circuit boards are inserted into systems carrying live supply voltages (“hot-plugged”), high inrush currents often result due to the charging of bulk capacitance that resides across the circuit board’s supply pins. This transient inrush ...
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Inrush Current and Load Dominated Start-up The expected maximum inrush current can be calculated by using the following equation: C LOAD INRUSH I GATE C GATE where I is the GATE pin current, I ...
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MAIN outputs (12VIN[A/B] and 3VIN[A/B]). Should the MAIN supply inputs move below their respective UVLO thresholds, VAUX[A/B] will still function as long as VSTBY[A/B] is present. Prior to standby mode, ONA and ONB (or the ...
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Thermal Shutdown The internal VAUX[A/B] MOSFETs are protected against damage not only by current limiting, but by dual-mode overtemperature protection as well. Each slot controller on the MIC2592B is thermally isolated from the other. Should an overcurrent condition raise the ...
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UVLO VSTBY 0 AUXEN[A/ POR VAUX_OUT[A/ LIM(AUX AUX_OUT[A/B] STEADY-STATE 0 ON[A/B] 0 12VOUT[A/B] 0 3VOUT[A/B] 0 /PWRGD_[A/ LIM(3V 3VOUT[A/B] STEADY-STATE 0 /FAULT_[A/B] 0 /INT* 0 MIC2592B Device Address S 1 ...
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CNTRL[A/B] Register Bit D[2] should read Logical “0.” Once /FORCE_ON[A/B] inputs are asserted, all output voltages are present with all circuit protection features disabled, including overtemperature ...
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Detailed Register Descriptions Control Register, Slot A (CNTRLA) 8-Bits, Read/Write D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[6] D[6] D[6] D[6] D[6] D[6] D[6] D[6] read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only ...
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Control Register, Slot B (CNTRLB) 8-Bits, Read/Write D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[6] D[6] D[6] D[6] D[6] D[6] D[6] D[6] read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only AUXBPG ...
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Status Register Slot A (STATA) 8-Bits, Read-Only D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[6] D[6] D[6] D[6] D[6] D[6] D[6] D[6] read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only FAULTA ...
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Status Register Slot B (STATB) 8-Bits, Read-Only D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[6] D[6] D[6] D[6] D[6] D[6] D[6] D[6] read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only read-only FAULTB ...
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Common Status Register (CS) 8-Bits, Read/Write D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[7] D[6] D[6] D[6] D[6] D[6] D[6] D[6] D[6] read-write read-write read-write read-write read-write read-write read-write read-write read-write read-write read-write read-write read-write read-write read-write read-write Reserved Reserved ...
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Applications Information Sense Resistor Selection The 12V and the 3.3V supplies employ internal current sens- ing circuitry to detect overcurrent conditions that may trip the circuit breaker. An external sense resistor is used to monitor the current that passes through ...
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Finally, the use of plated-through vias will be necessary to make circuit connection to the power, ground, and signal planes on multi-layer PCBs. R SENSE contact pads Power Trace From V IN PCB Track Width: 0.03" per ...
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Current Flow to the Load W Via to GND Plane Via to signal plane (GATE pin connection) ***C FILTER W - DRAWING IS NOT TO SCALE AND NOT ALL PINS SHOWN FOR CLARITY- *See Table 4 for part numbers and ...
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MOSFET and Sense Resistor Vendors Device types, part numbers, and manufacturer contact infor- mation for power MOSFETs and sense resistors are provided in Table 4. Some of the recommended MOSFETs include a metal (tab) heat sink on the bottom side ...
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Package Information MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 1 (408) 944-0800 TEL The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel ...