MIC20XX Family Fixed and Adjustable Current Limiting Power Distribution Switches General Description Features MIC20XX family of switches are current limiting, high-side power switches, designed for general purpose power distribution and control in digital televisions (DTV), printers, set top boxes (STB), PCs, PDAs, and other peripheral devices. See Functionality Table on page 6 and Pin Configuration Drawings on page 7. MIC20XX family's primary functions are current limiting and power switching. They are thermally protected and will shutdown should their internal temperature reach unsafe levels, protecting both the device and the load, under high current or fault conditions Features include fault reporting, fault blanking to eliminate noise-induced false alarms, output slew rate limiting, under voltage detection, automatic-on output, and enable pin with choice of either active low or active high enable. The FET is self-contained, with a fixed or user adjustable current limit. The MIC20XX family is ideal for any system where current limiting and power control are desired. The MIC201X (3 x 9) subfamily offers a unique new patented feature: KICKSTARTTM, which allows momentary high current surges up to the secondary current limit (ILIMIT_2nd) without sacrificing overall system safety. The MIC20XX family is offered, depending on the desired features, in a space saving 5-pin SOT-23, 6-pin SOT-23, (R) and 2mm x 2mm MLF packages. Data sheets and support documentation can be found on Micrel's web site at www.micrel.com. * * * * * * * * * * * * * 70m typical on-resistance @ 5V 170m typical on-resistance @ 5V (MIC2005A) Enable active high or active low * 2.5V - 5.5V operating range Pre-set current limit values of 0.5A, 0.8A, and 1.2A * User adjustable current limit from 0.2A to 2.1A * Under voltage lock-out (UVLO) Variable UVLO allows adjustable UVLO thresholds * Automatic load discharge for capacitive loads * Soft start prevents large current inrush Adjustable slew rate allows custom slew rates * Automatic-on output after fault Thermal Protection * Available on some family members Applications * * * * * * * * Digital televisions (DTV) Set top boxes PDAs Printers USB / IEEE 1394 power distribution Desktop and laptop PCs Game consoles Docking stations _________________________________________________________________________________________________________ Typical Application 5V Supply MIC20X5 Logic Controller VIN VOUT (2,3) GND VIN ON/OFF OVERCURRENT/ 1F EN IADJ VBUS 120F USB Port (1,3) FAULT/ Figure 1. Typical Application Circuit Notes: (1) Depending on the family member this pin can function as FAULT/, IADJ, or VUVLO. (2) Depending on the family member this pin can function as IADJ, or CSLEW. (3) See Pin Configuration and Functional Diagram. KICKSTART is a trademark of Micrel, Inc. MLF and MicroLeadFrame are registered trademarks of Amkor Technology, Inc. CableCARD is a trademark of CableLabs. Protected by U.S. Patent No. 7,170,732 Micrel Inc. * 2180 Fortune Drive * San Jose, CA 95131 * USA * tel +1 (408) 944-0800 * fax + 1 (408) 474-1000 * http://www.micrel.com January 2009 M9999-012109-A Micrel, Inc. MIC20XX Family Ordering Information MIC2003/2013 (1) Part Number (2) Marking Current Limit MIC2003-0.5YM5 FD05 0.5A MIC2003-0.8YM5 FD08 0.8A MIC2003-1.2YM5 FD12 1.2A MIC2003-0.5YML D05 0.5A MIC2003-0.8YML D08 0.8A MIC2003-1.2YML D12 1.2A MIC2013-0.5YM5 FL05 0.5A MIC2013-0.8YM5 FL08 0.8A MIC2013-1.2YM5 FL12 1.2A MIC2013-0.5YML L05 0.5A MIC2013-0.8YML L09 0.8A MIC2013-1.2YML L12 1.2A Kickstart Package 5-Pin SOT-23 No (R) 6-Pin 2mm x 2mm MLF 5-Pin SOT-23 Yes (R) 6-Pin 2mm x 2mm MLF MIC2004/2014 (1) Part Number Notes: (2) Marking Current Limit MIC2004-0.5YM5 FE05 0.5A MIC2004-0.8YM5 FE08 0.8A MIC2004-1.2YM5 FE12 1.2A MIC2004-0.5YML E05 0.5A MIC2004-0.8YML E08 0.8A MIC2004-1.2YML E12 1.2A MIC2014-0.5YM5 FM05 0.5A MIC2014-0.8YM5 FM08 0.8A MIC2014-1.2YM5 FM12 1.2A MIC2014-0.5YML M05 0.5A MIC2014-0.8YML M09 0.8A MIC2014-1.2YML M12 1.2A Kickstart Package 5-Pin SOT-23 No (R) 6-Pin 2mm x 2mm MLF 5-Pin SOT-23 Yes (R) 6-Pin 2mm x 2mm MLF 1. All MIC20XX Family parts are RoHS compliant lead free. 2. Over/Under-bar symbol ( / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the marking. January 2009 2 M9999-012109-A Micrel, Inc. MIC20XX Family Ordering Information (continued) MIC2005 (1) Part Number (2) Marking Current Limit Enable MIC2005-0.5YM6 FF05 0.5A Active High MIC2005-0.8YM6 FF08 0.8A Active High MIC2005-1.2YM6 FF12 1.2A Active High MIC2005-0.5YML F05 0.5A Active High MIC2005-0.8YML F08 0.8A Active High MIC2005-1.2YML F12 1.2A Active High Current Limit Enable Kickstart Package 6-Pin SOT-23 No (R) 6-Pin 2mm x 2mm MLF MIC2005L (1) Part Number (2) Marking MIC2005-0.5LYM5 5LFF 0.5A Active Low MIC2005-0.8LYM5 8LFF 0.8A Active Low MIC2005-1.2LYM5 4LFF 1.2A Active Low Current Limit Enable Kickstart Package No 5-Pin SOT-23 Kickstart Package MIC2005A (1) Part Number (2) Marking MIC2005A-1YM5 FA51 0.5A Active High MIC2005A-2YM5 FA52 0.5A Active Low MIC2005A-1YM6 FA53 0.5A Active High MIC2005A-2YM6 FA54 0.5A Active Low Current Limit Enable 5-Pin SOT-23 No 6-Pin SOT-23 MIC2015 (1) Part Number (2) Marking MIC2015-0.5YM6 FN05 0.5A Active High MIC2015-0.8YM6 FN08 0.8A Active High MIC2015-1.2YM6 FN12 1.2A Active High MIC2015-0.5YML N05 0.5A Active High MIC2015-0.8YML N08 0.8A Active High MIC2015-1.2YML N12 1.2A Active High Notes: Kickstart Package 6-Pin SOT-23 Yes (R) 6-Pin 2mm x 2mm MLF 1. All MIC20XX Family parts are RoHS compliant lead free. 2. Over/Under-bar symbol ( / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the marking. January 2009 3 M9999-012109-A Micrel, Inc. MIC20XX Family Ordering Information (continued) MIC2006/2016 (1) Part Number Notes: (2) Marking Current Limit MIC2006-0.5YM6 FG05 0.5A MIC2006-0.8YM6 FG08 0.8A MIC2006-1.2YM6 FG12 1.2A MIC2006-0.5YML G05 0.5A MIC2006-0.8YML G08 0.8A MIC2006-1.2YML G12 1.2A MIC2016-0.5YM6 FP05 0.5A MIC2016-0.8YM6 FP08 0.8A MIC2016-1.2YM6 FP12 1.2A MIC2016-0.5YML P05 0.5A MIC2016-0.8YML P09 0.8A MIC2016-1.2YML P12 1.2A Kickstart Package 6-Pin SOT-23 No (R) 6-Pin 2mm x 2mm MLF 6-Pin SOT-23 Yes (R) 6-Pin 2mm x 2mm MLF 1. All MIC20XX Family parts are RoHS compliant lead free. 2. Over/Under-bar symbol ( / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the marking. January 2009 4 M9999-012109-A Micrel, Inc. MIC20XX Family Ordering Information (continued) MIC2007/2017 (1) Part Number (2) Marking MIC2007YM6 FHAA MIC2007YML HAA MIC2017YM6 FQAA MIC2017YML QAA Current Limit Kickstart No 0.2A - 2.0A Yes Package 6-Pin SOT-23 (R) 6-Pin 2mm x 2mm MLF 6-Pin SOT-23 (R) 6-Pin 2mm x 2mm MLF MIC2008/2018 (1) Part Number (2) Marking MIC2008YM6 FJAA MIC2008YML JAA MIC2018YM6 FRAA MIC2018YML RAA Current Limit Kickstart No 0.2A - 2.0A Yes Package 6-Pin SOT-23 (R) 6-Pin 2mm x 2mm MLF 6-Pin SOT-23 (R) 6-Pin 2mm x 2mm MLF MIC2009/2019 (1) Part Number Notes: (2) Marking MIC2009YM6 FKAA MIC2009YML KAA MIC2019YM6 FSAA MIC2019YML SAA Current Limit Kickstart No 0.2A - 2.0A Yes Package 6-Pin SOT-23 (R) 6-Pin 2mm x 2mm MLF 6-Pin SOT-23 (R) 6-Pin 2mm x 2mm MLF 1. All MIC20XX Family parts are RoHS compliant lead free. 2. Over/Under-bar symbol ( / _ ) may not be to scale. On the package the over/under symbol begins above/below the first character of the marking. January 2009 5 M9999-012109-A Micrel, Inc. MIC20XX Family MIC20XX Family Member Functionality Part Number Normal Limiting Pin Function Kickstart (1) I Limit ILIMIT ENABLE High ENABLE Low CSLEW FAULT/ (6) (6) (6) (5) VUVLO Load Discharge 2003 2013 2004 2014 2005 2015 2005L (2) 2005A-1 (2) 2005A-2 (2) 2006 2016 2007 2017 2008 2018 2009 2019 Notes: 1. 2. 3. 4. 5. 6. Fixed Adj. (3) (4) Kickstart provides an alternate start-up behavior; however, pin-outs are identical. Kickstart not available. Fixed = Factory programmed current limit. Adj. = User adjustable current limit. VUVLO = Variable UVLO (Previously called DML). CSLEW not available in 5-pin package. MIC20XX Family Member Pin Configuration Table Part Number Pin Number Normal Limiting Kickstart 2003 1 2 3 4 5 6 2013 VIN GND VOUT 2004 2014 VIN GND EN VOUT 2005 2015 VIN GND EN FAULT/ CSLEW 2005L 2005A (1) (1) 2006 2016 2007 2017 2008 2018 2009 2019 Notes: 1. 2. 3. 4. 5. I Limit Fixed (2) VIN VIN Adj. (3) GND EN GND EN FAULT/ FAULT/ (4) VOUT CSLEW (5) VOUT CSLEW (5) VOUT VIN GND EN VUVLO CSLEW VOUT VIN GND EN IADJ CSLEW VOUT VIN GND EN IADJ CSLEW VOUT VIN GND EN FAULT/ IADJ VOUT Kickstart not available. Fixed = Factory programmed current limit. Adj. = User adjustable current limit. VUVLO = Variable UVLO (Previously called DLM). CSLEW not available in 5-pin package. January 2009 6 M9999-012109-A Micrel, Inc. MIC20XX Family MIC20XX Family Member Pin Configuration Drawings Fixed Current Limit VIN 1 5 VOUT GND 2 NC 3 4 NC VOUT 1 6 VIN NC 2 5 GND NC 3 4 NC (Top View) MIC20X3 VIN 1 5 VOUT GND 2 ENABLE 3 4 NC VOUT 1 6 VIN NC 2 5 GND NC 3 4 ENABLE (Top View) MIC20X4 VIN 1 VIN 1 5 VOUT GND 2 ENABLE 3 4 FAULT/ 6 VOUT GND 2 5 CSLEW ENABLE 3 4 FAULT/ VOUT 1 6 VIN CSLEW 2 5 GND FAULT/ 3 4 ENABLE (Top View) MIC2005-X.XL / MIC2005A VIN 1 MIC20X5 6 VOUT GND 2 5 CSLEW ENABLE 3 4 VUVLO MIC20X5 VOUT 1 6 VIN CSLEW 2 5 GND VUVLO 3 4 ENABLE (Top View) MIC20X6 January 2009 7 M9999-012109-A Micrel, Inc. MIC20XX Family MIC20XX Family Member Pin Configuration Drawings (continued) Adjustable Current Limit VIN 1 GND 2 ENABLE 3 6 VOUT 5 CSLEW 4 ILIMIT VOUT 1 6 VIN CSLEW 2 5 GND ILIMIT 3 4 ENABLE (Top View) MIC20X7 / 20X8 VIN 1 6 VOUT VOUT 1 6 VIN GND 2 5 ILIMIT ILIMIT 2 5 GND FAULT/ 3 4 ENABLE ENABLE 3 4 FAULT/ (Top View) MIC20X9 January 2009 8 M9999-012109-A Micrel, Inc. MIC20XX Family Descriptions These pin and signal descriptions aid in the differentiation of a pin from electrical signals and components connected to that pin. For example, VOUT is the switch's output pin, while VOUT is the electrical signal output voltage present at the VOUT pin. Pin Descriptions Pin Name Type Description VIN Input GND ENABLE Input FAULT/ Output CSLEW Input VOUT Output VUVLO Input Variable Under Voltage Lockout (VUVLO): Monitors the input voltage through a resistor divider between VIN and GND. Shuts the switch off if voltage falls below the threshold set by the resistor divider. Previously called VUVLO. ILIMIT Input Set current limit threshold via a resistor connected from ILIMIT to GND. Supply input. This pin provides power to both the output switch and the switch's internal control circuitry. Ground. Switch Enable (Input): Fault status. A logic LOW on this pin indicates the switch is in current limiting, or has been shut down by the thermal protection circuit. This is an open-drain output allowing logical OR'ing of multiple switches. Slew rate control. Adding a small value capacitor between this pin and VIN slows turn-ON of the power FET. Switch output. The load being driven by the switch is connected to this pin. Signal Descriptions Signal Name Type VIN Input GND VEN Input Electrical signal input voltage present at the ENABLE pin. VFAULT/ Output Electrical signal output voltage present at the FAULT/ pin. CSLEW Component VOUT Output Electrical signal output voltage present at the VOUT pin. VVUVLO_TH Internal VUVLO internal reference threshold voltage. This voltage is compared to the VUVLO pin input voltage to determine if the switch should be disabled. Reference threshold voltage has a typical value of 250mV. CLOAD Component IOUT Output Electrical signal output current present at the VOUT pin. ILIMIT Internal Switch's current limit. Fixed at factory or user adjustable. January 2009 Description Electrical signal input voltage present at the VIN pin. Ground. Capacitance value connected to the CSLEW pin. Capacitance value connected in parallel with the load. Load capacitance. 9 M9999-012109-A Micrel, Inc. MIC20XX Family Absolute Maximum Ratings(1) Operating Ratings(2) VIN, VOUT.................................................. -0.3V to 6V All other pins ............................................ -0.3V to 5.5V Power Dissipation (PD) .......................Internally Limited Continuous Output Current...................................2.25A Continuous Output Current (MIC2005A) ................0.9A Maximum Junction Temperature (TJ) .................. 150C Storage Temperature (Ts)...................-65C to +150C Supply Voltage ..............................................2.5V to 5.5V Continuous Output Current Range...................0A to 2.1A Ambient Temperature Range (TA)............ -40C to+85C (3) Package Thermal Resistance SOT-23-5/6 (JA) .......................................... 230C/W 2mm x 2mm MLF-6 (JA)................................ 90C/W 2mm x 2mm MLF-6 (JC) ............................... 45C/W Electrical Characteristics(4) VIN = 5V, TA = 25C unless otherwise specified. Bold indicates -40C to +85C limits; CIN = 1F. Symbol Parameter VIN Switch Input Voltage Condition Min Internal Supply Current Switch = OFF All except: VEN = 0V MIC2005-X.XLYM5 Switch = ON, IOUT = 0A MIC2005A VEN = 1.5V Switch = OFF Internal Supply Current MIC2005-X.XLYM5 IIN VEN = 1.5V Switch = ON, IOUT = 0A VEN = 0V Switch = OFF MIC2005A-1, VEN = 0V Internal Supply Current MIC2005A Typ Max Units 5.5 V 1 5 A 80 330 A 8 15 A 80 300 A 1 5 A 8 15 A 80 300 A 12 100 A 1 5 2.5 Switch = OFF MIC2005A-2, VEN = 1.5V Switch = ON MIC2005A-1, VEN = 1.5V MIC2005A-2, VEN = 0V Switch = OFF, VOUT = 0V ILEAK Output Leakage Current Active Low; ENABLE = 1.5V Active High; ENABLE = 0V IEN Enable Input Current 0V VEN 5V ICSLEW CSLEW Input Current 0V VOUT 0.8VIN Power Switch Resistance RDS(ON) All except MIC2005A Power Switch Resistance Only MIC2005A RDSCHG ILIMIT Load Discharge Resistance MIC20X4 & MIC20X7 Fixed Current Limit MIC20X3 - MIC20X6 January 2009 0.175 70 VIN = 5V, IOUT = 100mA 100 125 170 VIN = 5V, IOUT = 100mA 220 m 275 VIN = 5V, ISINK = 5mA 70 MIC20XX-0.5, VOUT = 0.8 * VIN 0.5 0.7 0.9 MIC20XX-0.8, VOUT = 0.8 * VIN 0.8 1.1 1.5 MIC20XX-1.2, VOUT = 0.8 * VIN 1.2 1.6 2.1 10 A A 126 200 A M9999-012109-A Micrel, Inc. MIC20XX Family Electrical Characteristics (continued) Symbol CLF ILIMIT_2nd UVLOTHRESHOLD UVLOHysteresis VVUVLO_TH Parameter Condition Min Typ Max Variable Current Limit Factor MIC20X7 - MIC20X9 IOUT = 2A, VOUT = 0.8VIN 210 250 286 IOUT = 1A, VOUT = 0.8VIN 190 243 293 RSET () = CLF (V) IOUT (A) IOUT = 0.5A, VOUT = 0.8VIN 168 235 298 IOUT = 0.2A, VOUT = 0.8VIN 144 225 299 VIN = 2.5V 2.2 4 6 VIN Rising 2 2.25 2.5 VIN Falling 1.9 2.15 2.4 Secondary current limit MIC201X (All Kickstart parts only) Under Voltage Lock Out Threshold Undervoltage Lock Out Hysteresis 0.1 Variable UVLO Threshold 225 MIC20X6 (5) VEN ENABLE Input Voltage VFAULT Fault status Output Voltage OTTHRESHOLD Over-temperature Threshold 250 VIL (MAX) VIH (MIN) 275 1.5 0.25 TJ Increasing 145 TJ Decreasing 135 V A V V 0.5 IOL = 10mA Units 0.4 mV V V C AC Characteristics Symbol Parameter tRISE Output Turn-on rise time Condition Min Typ Max Units 500 1000 1500 s 20 32 49 RL = 10 , CLOAD = 1F, VOUT = 10% to 90% *CSLEW = Open Delay before asserting or releasing FAULT/ MIC200X tD_FAULT Delay before asserting or releasing FAULT/ MIC201X tD_LIMIT tRESET Time from current limiting to FAULT/ state change Time from IOUT continuously exceeding primary current limit condition to FAULT/ state change Delay before current limiting MIC201X Delay before resetting Kickstart current limit delay, tD_LIMIT MIC201X Out of current limit following a current limit event. ms 77 128 192 77 128 192 ms 77 128 192 ms 1000 1500 s 700 s RL = 43, CL = 120F, tON_DLY Output Turn-on Delay VEN = 50% to VOUT = 10% *CSLEW = Open RL = 43, CL = 120F, tOFF_DLY Output Turn-off Delay VEN = 50% to VOUT = 90% *CSLEW = Open Note: * Whenever CSLEW is present. January 2009 11 M9999-012109-A Micrel, Inc. MIC20XX Family Electrical Characteristics (continued) ESD (6) Symbol Parameter VESD_HB Electro Static Discharge Voltage: Human Body Model VESD_MCHN Condition Min VOUT and GND 4 All other pins 2 Typ Max Units kV All pins Electro Static Discharge Voltage; Machine Model 200 Machine Model V Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Requires proper thermal mounting to achieve this performance 4. Specifications for packaged product only. 5. VIL (MAX) = maximum positive voltage applied to the input which will be accepted by the device as a logic low. VIH (MIN) = minimum positive voltage applied to the input which will be accepted by the device as a logic high. 6. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. Timing Diagrams tFALL tRISE 90% 90% 10% 10% Rise and Fall Times ENABLE 50% 50% tON_DLY tOFF_DLY 90% VOUT 10% Switching Delay Times January 2009 12 M9999-012109-A Micrel, Inc. MIC20XX Family Typical Characteristics 16 25C SUPPLY CURRENT (A) -40C 80 85C 60 40 20 0 2 3 4 VIN (V) 5 2 3 1.40 4 VIN (V) 5 25C 6 1.00 5V 3V 2.5V 1.06 0.80 0.60 0.20 3V Note: Please note that the 3 plots overlay each V FALLING 5V 0.98 2.5V 120 100 60 40 20 2.1 January 2009 1.00 150 0 2 90 RON vs. 80 2.2 0 50 100 TEMPERATURE (C) 1.02 0.96 -50 -30 -10 10 30 50 70 TEMPERATURE (C) 90 Supply Voltage 100 (MIC20xx - 0.5) 1.04 RON vs. V RISING 2.15 1.00 5V 90 ILIMIT vs. Temperature 1.10 0.00 -50 -30 -10 10 30 50 70 TEMPERATURE (C) UVLO Threshold vs. Temperature 2.25 0.60 0.40 0.20 1.08 0.40 Switch Leakage Current OFF 1.40 1.20 1.00 0.80 1.20 2.5V 90 2.00 1.80 1.60 0.00 -50 -30 -10 10 30 50 70 TEMPERATURE (C) ILIMIT (A) ILIMIT (A) 1.02 RON (mOhm) ILIMIT (A) 4 (MIC20xx - 0.8) 0.94 -50 -30 -10 10 30 50 70 TEMPERATURE (C) THRESHOLD (V) 85C 6 ILIMIT vs. Temperature 1.04 2.05 -50 8 (MIC20xx - 1.2) 1.06 2.3 10 0 2 6 1.08 0.96 -40C 12 ILIMIT vs. Temperature 1.10 0.98 14 RON (mOhm) SUPPLY CURRENT (A) 100 Supply Current Output Disabled LEAKAGE CURRENT (A) Supply Current Output Enabled Temperature 3.3V 2.5V 80 5V 60 40 20 2.5 3 3.5 4 4.5 VIN (V) 13 5 5.5 0 -50 -30 -10 10 30 50 70 TEMPERATURE (C) 90 M9999-012109-A Micrel, Inc. MIC20XX Family Functional Characteristics January 2009 14 M9999-012109-A Micrel, Inc. MIC20XX Family Functional Characteristics (continued) January 2009 15 M9999-012109-A Micrel, Inc. MIC20XX Family Functional Diagram VUVLO MIC20X6 ENABLE MIC20X4 - MIC20X9 FAULT/ MIC20X5 & MIC20X9 VUVLO Under Voltage Detector VIN Current Mirror FET Control Logic and Delay Timer Power FET Gate Control Load Discharge MIC20X4 & MIC20X7 Thermal Sensor CSLEW MIC20X5 - MIC20X8 VOUT Slew Rate Control VREF Current Limit Control Loop GND ILIM Factory Adjusted MIC20X3 - MIC20X6 ILIM User Adjustable MIC20X7 - MIC20X9 Figure 2 MIC20XX Family Functional Diagram January 2009 16 M9999-012109-A Micrel, Inc. MIC20XX Family of Kickstart operation is shown below. Functional Description VIN and VOUT VIN is both the power supply connection for the internal circuitry driving the switch and the input (Source connection) of the power MOSFET switch. VOUT is the Drain connection of the power MOSFET and supplies power to the load. In a typical circuit, current flows from VIN to VOUT toward the load. Since the switch is bidirectional when enabled, if VOUT is greater than VIN, current will flow from VOUT to VIN. When the switch is disabled, current will not flow to the load, except for a small unavoidable leakage current of a few microamps. However, should VOUT exceed VIN by more than a diode drop (~0.6 V), while the switch is disabled, current will flow from output to input via the power MOSFET's body diode. If discharging CLOAD is required by your application, consider using MIC20X4 or MIC20X7; these MIC20XX family members are equipped with a discharge FET to insure complete discharge of CLOAD. Figure 3. Kickstart Operation Figure 3 Label Key: A) MIC201X is enabled into an excessive load (slew rate limiting not visible at this time scale) The initial current surge is limited by either the overall circuit resistance and power supply compliance, or the secondary current limit, whichever is less. B) RON of the power FET increases due to internal heating (effect exaggerated for emphasis). C) Kickstart period. D) Current limiting initiated. FAULT/ goes LOW. E) VOUT is non-zero (load is heavy, but not a dead short where VOUT = 0V. Limiting response will be the same for dead shorts). F) Thermal shutdown followed by thermal cycling. G) Excessive load released, normal load remains. MIC201X drops out of current limiting. H) FAULT/ delay period followed by FAULT/ going HIGH. Current Sensing and Limiting MIC20XX protects the system power supply and load from damage by continuously monitoring current through the on-chip power MOSFET. Load current is monitored by means of a current mirror in parallel with the power MOSFET switch. Current limiting is invoked when the load exceeds the set over-current threshold. When current limiting is activated the output current is constrained to the limit value, and remains at this level until either the load/fault is removed, the load's current requirement drops below the limiting value, or the switch goes into thermal shutdown. Kickstart 2003 2004 2005 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 Only parts in white boxes have Kickstart. (Not available in 5-pin SOT-23 packages) Under Voltage Lock Out Under voltage lock-out insures no anomalous operation occurs before the device's minimum input voltage of UVLOTHRESHOLD which is 2V minimum, 2.25V typical, and 2.5V maximum had been achieved. Prior to reaching this voltage, the output switch (power MOSFET) is OFF and no circuit functions, such as FAULT/ or ENABLE, are considered to be valid or operative. The MIC201X is designed to allow momentary current surges (Kickstart) before the onset of current limiting, which permits dynamic loads, such as small disk drives or portable printers to draw the energy needed to overcome inertial loads without sacrificing system safety. In this respect, the Kickstart parts (MIC201X) differs markedly from the non-Kickstart parts (MIC200X) which immediately limit load current, potentially starving the motor and causing the appliance to stall or stutter. During this delay period, typically 128ms, a secondary current limit is in effect. If the load demands a current in excess the secondary limit, MIC201X acts immediately to restrict output current to the secondary limit for the duration of the Kickstart period. After this time the MIC201X reverts to its normal current limit. An example January 2009 17 M9999-012109-A Micrel, Inc. MIC20XX Family Because FAULT/ is an open-drain it must be pulled HIGH with an external resistor and it may be wire-OR'd with other similar outputs, sharing a single pull-up resistor. FAULT/ may be tied to a pull-up voltage source which is higher than VIN, but no greater than 5.5V. Variable Under Voltage Lock Out (VUVLO) 2003 2004 2005 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 Only parts in white boxes have VUVLO. VUVLO functions as an input voltage monitor when the switch in enabled. The VIN pin is monitored for a drop in voltage, indicating excessive loading of the VIN supply. When VIN is less than the VULVO threshold voltage (VVUVLO_TH) for 32ms or more, the MIC20XX disables the switch to protect the supply and allow VIN to recover. After 128ms has elapsed, the MIC20X6 enables switch. This disable and enable cycling will continue as long as VIN deceases below the VUVLO threshold voltage (VVUVLO_TH) which has a typical value of 250mV. The VUVLO voltage is commonly established by a voltage divider from VIN to GND. Soft-start Control Large capacitive loads can create significant inrush current surges when charged through the switch. For this reason, the MIC20XX family of switches provides a built-in soft-start control to limit the initial inrush currents. Soft-start is accomplished by controlling the power MOSFET when the ENABLE pin enables the switch. CSLEW 2004 2005 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 ENABLE pin is a logic compatible input which activates the main MOSFET switch thereby providing power to the VOUT pin. ENABLE is either an active HIGH or active LOW control signal. The MIC20XX can operate with logic running from supply voltages as low as 1.8V. ENABLE may be driven higher than VIN, but no higher than 5.5V and not less than -0.3V. 2004 2005 2006 2007 2008 2009 2014 2015 2016 2017 2018 2019 Only parts in white boxes have FAULT/ pin. FAULT/ is an N-channel open-drain output, which is asserted (LOW true) when switch either begins current limiting or enters thermal shutdown. FAULT/ asserts after a brief delay when events occur that may be considered possible faults. This delay insures that FAULT/ is asserted only upon valid, enduring, over-current conditions and that transitory event error reports are filtered out. In MIC200X FAULT/ asserts after a brief delay period, of 32ms typical. After a fault clears, FAULT/ remains asserted for the delay period of 32ms MIC201X's FAULT/ asserts at the end of the Kickstart period which is 128ms typical. This masks initial current surges, such as would be seen by a motor load starting up. If the load current remains above the current limit threshold after the Kickstart has timed out, then the FAULT/ will be asserted. After a fault clears, FAULT/ remains asserted for the delay of 128ms. January 2009 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 Thermal Shutdown Thermal shutdown is employed to protect the MIC20XX family of switches from damage should the die temperature exceed safe operating levels. Thermal shutdown shuts off the output MOSFET and asserts the FAULT/ output if the die temperature reaches 145C. The switch will automatically resume operation when the die temperature cools down to 135C. If resumed operation results in reheating of the die, another shutdown cycle will occur and the switch will continue cycling between ON and OFF states until the overcurrent condition has been resolved. Depending on PCB layout, package type, ambient temperature, etc., hundreds of milliseconds may elapse from the incidence of a fault to the output MOSFET being shut off. This delay is due to thermal time constants within the system itself. In no event will the device be damaged due to thermal overload because die temperature is monitored continuously by on-chip circuitry. FAULT/ 2013 2005 The CSLEW pin is provided to increase control of the output voltage ramp at turn-on. This input allows designers the option of decreasing the output's slew rate (slowing the voltage rise) by adding an external capacitance between the CSLEW and VIN pins. Only parts in white boxes have ENABLE pin. 2003 2004 Only parts in white boxes have CSLEW pin. (Not available in 5-pin SOT-23 packages) ENABLE 2003 2003 18 M9999-012109-A Micrel, Inc. MIC20XX Family ILIMIT vs. IOUT measured The MIC20XX's current limiting circuitry, during current limiting, is designed to act as a constant current source to the load. As the load tries to pull more than the allotted current, VOUT drops and the input to output voltage differential increases. When VIN - VOUT exceeds 1V, IOUT drops below ILIMIT to reduce the drain of fault current on the system's power supply and to limit internal heating of the switch. When measuring IOUT it is important to bear this voltage dependence in mind, otherwise the measurement data may appear to indicate a problem when none really exists. This voltage dependence is illustrated in Figures 4 and 5. In Figure 4 output current is measured as VOUT is pulled below VIN, with the test terminating when VOUT is 1V below VIN. Observe that once ILIMIT is reached IOUT remains constant throughout the remainder of the test. In Figure 5 this test is repeated but with VIN - VOUT exceeding 1V. When VIN - VOUT > 1V, switch's current limiting circuitry responds by decreasing IOUT, as can be seen in Figure 5. In this demonstration, VOUT is being controlled and IOUT is the measured quantity. In real life applications VOUT is determined in accordance with Ohm's law by the load and the limiting current. Application Information Setting ILIMIT The MIC2009/2019's current limit is user programmable and controlled by a resistor connected between the ILIMIT pin and Ground. The value of this resistor is determined by the following equation: ILIMIT = CurrentLim itFactor(CLF) R SET R SET = CurrentLim itFactor(V) ILIMIT (A) or For example: Set ILIMIT = 1.25 A Looking in the Electrical specifications we will find CLF at ILIMIT = 1 A. Min Typ Max Units 190 243 293 V For the sake of this example, we will say the typical value of CLF at an IOUT of 1A is 243V. Applying the equation above: R SET () = 243V = 194.4 1.25A RSET = 196 (the closest standard 1% value) Designers should be aware that variations in the measured ILIMIT for a given RSET resistor, will occur because of small differences between individual ICs (inherent in silicon processing) resulting in a spread of ILIMIT values. In the example above we used the typical value of CLF to calculate RSET. We can determine ILIMIT's spread by using the minimum and maximum values of CLF and the calculated value of RSET. ILIMIT_MIN = 190V = 0.97 A 196 ILIMIT_MIN = 260V = 1.5 A 196 Figure 4. IOUT in Current Limiting for VIN - VOUT < 1V Giving us a maximum ILIMIT variation over temperature of: ILIMIT_MIN ILIMIT_TYP ILIMIT_MAX 0.97 A 1.25 A 1.5 A or 1.25 A - 22% and 1.25 A + 20% January 2009 19 M9999-012109-A Micrel, Inc. MIC20XX Family CSLEW 2003 2004 2005 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 Only parts in white boxes have CSLEW pin. (Not available in 5-pin SOT-23 packages). The CSLEW pin is provided to increase control of the output voltage ramp at turn-on. This input allows designers the option of decreasing the output's slew rate (slowing the voltage rise) by adding an external capacitance between the CSLEW and VIN pins. This capacitance slows the rate at which the pass FET gate voltage increases and thus, slows both the response to an Enable command as well as VOUT's ascent to its final value. Figure 8 illustrates effect of CSLEW on turn-on delay and output rise time. - VOUT > 1V Figure 5. IOUT in Current Limiting for VIN Typical Turn-on Times Capacitance vs. External C NORMALIZED OUTPUT CURRENT (A) 0.0088 6 0.006 4 0.004 1.0 2 0.002 0.8 0 TRISE 0 4 4.5 2 2.5 3 3.5 0 0.5 0 1 0 1.5 0 0 0 0 0 0 0 CSLEW (nF) 0.6 0.4 Figure 8. 0.2 0 1.2 TDELAY 10 0.01 0 1 2 3 4 5 OUTPUT VOLTAGE (V) CSLEW's effect on ILIMIT An unavoidable consequence of adding CSLEW capacitance is a reduction in the MIC20X5 - 20X8's ability to quickly limit current transients or surges. A sufficiently large capacitance can prevent both the primary and secondary current limits from acting in time to prevent damage to the MIC20X5 - 20X8 or the system from a short circuit fault. For this reason, the upper limit on the value of CSLEW is 4nF. 6 Figure 6. Normalized Output Current vs. Output Voltage (2.5V) 1.0 Variable Under Voltage Lock Out (VUVLO) 0.8 2003 2004 2005 2006 2007 2008 2009 0.6 2013 2014 2015 2016 2017 2018 2019 Only parts in white boxes have VUVLO pin and functionality. 0.4 Power conscious systems, such as those implementing ACPI, will remain active even in their low power states and may require the support of external devices through both phases of operation. Under these conditions, the current allowed these external devices may vary according to the system's operating state and as such 0.2 0 0 0.5 1.0 1.5 2.0 2.5 OUTPUT VOLTAGE (V) 3.0 Figure 7. January 2009 TON 12 0.012 Normalized Output Current vs. Output Voltage (5V) 1.2 SLEW 14 0.014 TIME (mS) NORMALIZED OUTPUT CURRENT (A) This folding back of ILIMIT can be generalized by plotting ILIMIT as a function of VOUT, as shown below in Figures 6 and 7. The slope of VOUT between IOUT = 0V and IOUT = ILIMIT (where ILIMIT = 1A) is determined by RON of the switch and ILIMIT. 20 M9999-012109-A Micrel, Inc. MIC20XX Family VUVLO and Kickstart operate independently in the MIC2016. If the high current surge allowed by Kickstart causes VIN to dip below the VUVLO trip point for more than 32ms, VUVLO will disengage the load even though the Kickstart timer has not timed out. require dual current limits on their peripheral ports. The MIC20X6 is designed for systems demanding two primary current limiting levels but without the use of a control signal to select between current limits. To better understand how the MIC20X6 provides this, imagine a system whose main power supply supports heavy loads during normal operation, but in sleep mode is reduced to only few hundred milliamps of output current. In addition, this system has several USB ports which must remain active during sleep. In normal operation, each port can support a 500mA peripheral, but in sleep mode their combined output current is limited to what the power supply can deliver minus whatever the system itself is drawing. If a peripheral device is plugged in which demands more current than is available, the system power supply will sag, or crash. The MIC20X6 prevents this by monitoring both the load current and VIN. During normal operation, when the power supply can source plenty of current, the MIC20X6 will support any load up to its factory programmed current limit. When the weaker, standby supply is in operation, the MIC20X6 monitors VIN and will shut off its output should VIN dip below a predetermined value. This predetermined voltage is user programmable and set by the selection of the resistor divider driving the VUVLO pin. To prevent false triggering of the VUVLO feature, the MIC20X6 includes a delay timer to blank out momentary excursions below the VUVLO trip point. If VIN stays below the VUVLO trip point for longer than 32ms (typical), then the load is disengaged and the MIC20X6 will wait 128ms before reapplying power to the load. If VIN remains below the VUVLO trip point, then the load will be powered for the 32ms blanking period and then again disengaged. This is illustrated in the scope plot below. If VIN remains above the VUVLO trip point MIC20X6 resumes normal operation. IIN_LOAD Input Supply VIN VOUT R1 + + VUVLO R2 Calculating VUVLO resistor divider values Selection of R1 and R2 is driven by the input voltage at which VUVLO should go into effect and the allowed loading of the input supply. The VUVLO pin input voltage is the result of the voltage division of VIN by the voltage divider comprised of R1 and R2. We know VVUVLO_TH = 250 mV, then by choosing a VIN trip voltage (VTRIP) we know the voltage divider ratio formed by R1 and Then an R2.is chosen such that the series resistance R1 + R2 results in a small IIN_LOAD. And then the VUVLO trip voltage as it relates to the comparator threshold and the resistor divider: VVUVLO_TH VTRIP = R2 =X (R 2 + R1 ) Rearranging these: R1 = X *R (1 - X ) 2 Choose an R2 that minimizes the IIN_LOAD current yet at the same time is less than input impedance of the VUVLO pin. The VUVLO pin internally is connected to a comparator with an extremely high input impedance. It is recommended that R2 not exceed 1 M. R2 can then be calculated from the equation above. For example: VTRIP = 4.75V for a 5V supply VVUVLO_TH = 250mV R2 = 750k Substituting these values into the equation above: X = R1 = VTRIP 0.05263 = 4.75 V = 0.05263 0.25 V (1 - 0.05263 ) * 750 k = 41,667k R1 = 41,667k Figure 9. VUVLO Operation January 2009 VVUVLO_TH 21 M9999-012109-A Micrel, Inc. MIC20XX Family In this example we have used the nominal value of VVUVLO_TH. By substituting in the min and max values of VVUVLO_TH, R1 and R2 the VUVLO trip point window can be established. The VUVLO comparator uses no Hysteresis. This is because the VUVLO blanking timer prevents any chattering that might otherwise occur if VIN varies about the trigger point. The timer is reset by upward crossings of the trip point such that VIN must remain below the trip point for the full 32ms period for load disengagement to occur. In selecting a VTRIP voltage the designer is cautioned to not make this value less than 2.5V. A minimum of 2.5V is required for the MIC20X6's internal circuitry to operate properly. VUVLO trip points below 2.5V will result in erratic or unpredictable operation. Figure 10. Kickstart Kickstart 2003 2004 2005 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 Automatic Load Discharge Only parts in white boxes have Kickstart. (Not available in 5-pin SOT-23 packages). 2004 2005 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 Only parts in white boxes have automatic load discharge. Kickstart allows brief current surges to pass to the load before the onset of normal current limiting, which permits dynamic loads to draw bursts of energy without sacrificing system safety. Functionally, Kickstart is a forced override of the normal current limiting function provided by the switch. The Kickstart period is governed by an internal timer which allows current to pass up to the secondary current limit (ILIMIT_2nd) to the load for 128ms and then normal (primary) current limiting goes into action. During Kickstart a secondary current limiting circuit is monitoring output current to prevent damage to the switch, as a hard short combined with a robust power supply can result in currents of many tens of amperes. This secondary current limit is nominally set at 4A and reacts immediately and independently of the Kickstart period. Once the Kickstart timer has finished its count the primary current limiting circuit takes over and holds IOUT to its programmed limit for as long as the excessive load persists. Once the switch drops out of current limiting the Kickstart timer initiates a lock-out period of 128ms such that no further bursts of current above the primary current limit, will be allowed until the lock-out period has expired. Kickstart may be over-ridden by the thermal protection circuit and if sufficient internal heating occurs, Kickstart will be terminated and IOUT AE 0A. Upon cooling, if the load is still present IOUT AE ILIMIT, not ILIMIT_2nd. January 2009 2003 Automatic discharge is a valuable feature when it is desirable to quickly remove charge from the VOUT pin. This allows for a quicker power-down of the load. This also prevents any charge from being presented to a device being connected to the VOUT pin, for example, USB, 1394, PCMCIA, and CableCARDTM. Automatic discharge is performed by a shunt MOSFET from VOUT pin to GND. When the switch is disabled, a break before make action is performed turning off the main power MOSFET and then enabling the shunt MOSFET. The total resistance of the MOSFET and internal resistances is typically 126. Supply Filtering A minimum 1F bypass capacitor positioned close to the VIN and GND pins of the switch is both good design practice and required for proper operation of the switch. This will control supply transients and ringing. Without a bypass capacitor, large current surges or a short may cause sufficient ringing on VIN (from supply lead inductance) to cause erratic operation of the switch's control circuitry. For best performance good quality, low ESR capacitors are recommended, preferably ceramic. When bypassing with capacitors of 10F and up, it is good practice to place a smaller value capacitor in parallel with the larger to handle the high frequency components of any line transients. Values in the range of 0.01F to 0.1F are recommended. Again, good quality, low ESR capacitors should be chosen. 22 M9999-012109-A Micrel, Inc. MIC20XX Family Power Dissipation Power dissipation depends on several factors such as the load, PCB layout, ambient temperature, and supply voltage. Calculation of power dissipation can be accomplished by the following equation: Die Temperature vs. Output Current (T CASE=85C) 160 140 120 PD = R DS(ON) x (IOUT ) 100 2 MLF 80 To relate this to junction temperature, the following equation can be used: 60 40 TJ = PD x R (J- A) + TA 20 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 OUTPUT CURRENT (A) Where: TJ = junction temperature, TA = ambient temperature R(J-A) is the thermal resistance of the package In normal operation the switch's Ron is low enough that 2 no significant I R heating occurs. Device heating is most often caused by a short circuit, or very heavy load, when a significant portion of the input supply voltage appears across the switch's power MOSFET. Under these conditions the heat generated will exceed the package and PCB's ability to cool the device and thermal limiting will be invoked. In Figure 11 die temperature is plotted against IOUT assuming a constant case temperature of 85C. The plots also assume a worst case RON of 140m at a die temperature of 135C. Under these conditions it is clear that an SOT-23 packaged device will be on the verge of thermal shutdown, typically 140C die temperature, when operating at a load current of 1.25A. For this (R) reason we recommend using MLF packaged switch s for any design intending to supply continuous currents of 1A or more. January 2009 SOT-23 Figure 11. Die Temperature vs. IOUT 23 M9999-012109-A Micrel, Inc. MIC20XX Family Package Information 5-Pin SOT-23 (M5) 6-Pin SOT-23 (M6) January 2009 24 M9999-012109-A Micrel, Inc. MIC20XX Family (R) 6 Pin 2mm x 2mm MLF (ML) MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting from such use or sale. (c) 2008 Micrel, Incorporated. January 2009 25 M9999-012109-A