MIC2005A-2YM5

MIC2005A MICREL | Alldatasheet

Document overview

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Technical content

Features

• 70m Ω typical on-resistance @ 5V
• 170m Ω 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 VIN VOUT MIC20X5 VBUS USB PortGND (2,3) IADJ EN (1,3) FAULT/ 5V Supply VIN Logic Controller ON/OFF OVERCURRENT/ 1µF 120µF

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.

Micrel, Inc. MIC20XX Family January 2009 2 M9999-012109-A

Ordering Information

Part Number(1) Marking (2) Current Limit Kickstart Package MIC2003-0.5YM5 FD 05 0.5A MIC2003-0.8YM5 FD 08 0.8A MIC2003-1.2YM5 FD 12 1.2A 5-Pin SOT-23 MIC2003-0.5YML D05 0.5A MIC2003-0.8YML D08 0.8A MIC2003-1.2YML D12 1.2A No 6-Pin 2mm x 2mm MLF® MIC2013-0.5YM5 FL 05 0.5A MIC2013-0.8YM5 FL 08 0.8A MIC2013-1.2YM5 FL 12 1.2A 5-Pin SOT-23 MIC2013-0.5YML L05 0.5A MIC2013-0.8YML L09 0.8A MIC2013-1.2YML L12 1.2A Yes 6-Pin 2mm x 2mm MLF® MIC2004/2014 Part Number(1) Marking (2) Current Limit Kickstart Package MIC2004-0.5YM5 FE 05 0.5A MIC2004-0.8YM5 FE 08 0.8A MIC2004-1.2YM5 FE 12 1.2A 5-Pin SOT-23 MIC2004-0.5YML E05 0.5A MIC2004-0.8YML E08 0.8A MIC2004-1.2YML E12 1.2A No 6-Pin 2mm x 2mm MLF® MIC2014-0.5YM5 FM 05 0.5A MIC2014-0.8YM5 FM 08 0.8A MIC2014-1.2YM5 FM 12 1.2A 5-Pin SOT-23 MIC2014-0.5YML M05 0.5A MIC2014-0.8YML M09 0.8A MIC2014-1.2YML M12 1.2A Yes 6-Pin 2mm x 2mm MLF® Notes: 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.

Micrel, Inc. MIC20XX Family January 2009 3 M9999-012109-A Ordering Information (continued) MIC2005 Part Number(1) Marking (2) Current Limit Enable Kickstart Package MIC2005-0.5YM6 FF 05 0.5A Active High MIC2005-0.8YM6 FF 08 0.8A Active High MIC2005-1.2YM6 FF 12 1.2A Active High 6-Pin SOT-23 MIC2005-0.5YML F05 0.5A Active High MIC2005-0.8YML F08 0.8A Active High MIC2005-1.2YML F12 1.2A Active High No 6-Pin 2mm x 2mm MLF® MIC2005L Part Number(1) Marking (2) Current Limit Enable Kickstart Package MIC2005-0.5LYM5 5L FF 0.5A Active Low MIC2005-0.8LYM5 8L FF 0.8A Active Low MIC2005-1.2LYM5 4L FF 1.2A Active Low No 5-Pin SOT-23 MIC2005A Part Number(1) Marking (2) Current Limit Enable Kickstart Package MIC2005A-1YM5 FA 51 0.5A Active High MIC2005A-2YM5 FA 52 0.5A Active Low 5-Pin SOT-23 MIC2005A-1YM6 FA 53 0.5A Active High MIC2005A-2YM6 FA 54 0.5A Active Low No 6-Pin SOT-23 MIC2015 Part Number(1) Marking (2) Current Limit Enable Kickstart Package MIC2015-0.5YM6 FN 05 0.5A Active High MIC2015-0.8YM6 FN 08 0.8A Active High MIC2015-1.2YM6 FN 12 1.2A Active High 6-Pin SOT-23 MIC2015-0.5YML N05 0.5A Active High MIC2015-0.8YML N08 0.8A Active High MIC2015-1.2YML N12 1.2A Active High Yes 6-Pin 2mm x 2mm MLF® Notes: 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.

Micrel, Inc. MIC20XX Family January 2009 4 M9999-012109-A Ordering Information (continued) MIC2006/2016 Part Number(1) Marking (2) Current Limit Kickstart Package MIC2006-0.5YM6 FG 05 0.5A MIC2006-0.8YM6 FG 08 0.8A MIC2006-1.2YM6 FG 12 1.2A 6-Pin SOT-23 MIC2006-0.5YML G05 0.5A MIC2006-0.8YML G08 0.8A MIC2006-1.2YML G12 1.2A No 6-Pin 2mm x 2mm MLF® MIC2016-0.5YM6 FP 05 0.5A MIC2016-0.8YM6 FP 08 0.8A MIC2016-1.2YM6 FP 12 1.2A 6-Pin SOT-23 MIC2016-0.5YML P05 0.5A MIC2016-0.8YML P09 0.8A MIC2016-1.2YML P12 1.2A Yes 6-Pin 2mm x 2mm MLF® Notes: 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.

Micrel, Inc. MIC20XX Family January 2009 5 M9999-012109-A Ordering Information (continued) MIC2007/2017 Part Number(1) Marking (2) Current Limit Kickstart Package MIC2007YM6 FH AA 6-Pin SOT-23 MIC2007YML HAA No 6-Pin 2mm x 2mm MLF® MIC2017YM6 FQ AA 6-Pin SOT-23 MIC2017YML QAA 0.2A – 2.0A Yes 6-Pin 2mm x 2mm MLF® MIC2008/2018 Part Number(1) Marking (2) Current Limit Kickstart Package MIC2008YM6 FJ AA 6-Pin SOT-23 MIC2008YML JAA No 6-Pin 2mm x 2mm MLF® MIC2018YM6 FR AA 6-Pin SOT-23 MIC2018YML RAA 0.2A – 2.0A Yes 6-Pin 2mm x 2mm MLF® MIC2009/2019 Part Number(1) Marking (2) Current Limit Kickstart Package MIC2009YM6 FK AA 6-Pin SOT-23 MIC2009YML KAA No 6-Pin 2mm x 2mm MLF® MIC2019YM6 FS AA 6-Pin SOT-23 MIC2019YML SAA 0.2A – 2.0A Yes 6-Pin 2mm x 2mm MLF® Notes: 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.

Micrel, Inc. MIC20XX Family January 2009 6 M9999-012109-A MIC20XX Family Member Functionality Part Number Pin Function Normal Limiting Kickstart(1) I Limit ILIMIT ENABLE High ENABLE Low CSLEW FAULT/ VUVLO (5) Load Discharge 2005L ─ (2) Fixed (3) 2006 2016 2009 2019 Adj.(4) Notes: 1. Kickstart provides an alternate start-up behavior; however, pin-outs are identical. 2. Kickstart not available. 3. Fixed = Factory programmed current limit. 4. Adj. = User adjustable current limit. 5. VUVLO = Variable UVLO (Previously called DML). 6. CSLEW not available in 5-pin package. MIC20XX Family Member Pin Configuration Table Part Number Pin Number Normal Limiting Kickstart I Limit 1 2 3 4 5 6 2003 2013 VIN GND ─ ─ ─ VOUT 2004 2014 VIN GND EN ─ ─ VOUT 2005 2015 VIN GND EN FAULT/ CSLEW VOUT 2005L ─ (1) VIN GND EN FAULT/ CSLEW(5) VOUT 2005A ─ (1) VIN GND EN FAULT/ CSLEW(5) VOUT 2006 2016 Fixed(2) VIN GND EN VUVLO(4) CSLEW VOUT 2007 2017 VIN GND EN IADJ CSLEW VOUT 2008 2018 VIN GND EN IADJ CSLEW VOUT 2009 2019 Adj.(3) VIN GND EN FAULT/ IADJ VOUT Notes: 1. Kickstart not available. 2. Fixed = Factory programmed current limit. 3. Adj. = User adjustable current limit. 4. VUVLO = Variable UVLO (Previously called DLM). 5. CSLEW not available in 5-pin package.

Micrel, Inc. MIC20XX Family January 2009 7 M9999-012109-A MIC20XX Family Member Pin Configuration Drawings Fixed Current Limit VIN 1 5 GND NC VOUT NC 1VOUT NC NC 6V I N GND NC (Top View) MIC20X3 VIN 1 5 GND ENABLE VOUT NC 1VOUT NC NC 6V I N GND ENABLE (Top View) MIC20X4 VIN 1 5 GND ENABLE VOUT FAULT/ VIN 52GND ENABLE VOUT FAULT/ CSLEW 1VOUT CSLEW FAULT/ 6V I N GND ENABLE (Top View) MIC2005-X.XL / MIC2005A MIC20X5 MIC20X5 VIN 52GND ENABLE VOUT VUVLO CSLEW 1VOUT CSLEW VUVLO 6V I N GND ENABLE (Top View) MIC20X6

Micrel, Inc. MIC20XX Family January 2009 8 M9999-012109-A MIC20XX Family Member Pin Configuration Drawings (continued) Adjustable Current Limit VIN 52GND ENABLE VOUT ILIMIT CSLEW 1VOUT CSLEW ILIMIT 6V I N GND ENABLE (Top View) MIC20X7 / 20X8 VIN 52GND ENABLE VOUT FAULT/ ILIMIT 1VOUT ILIMIT FAULT/ 6V I N GND ENABLE (Top View) MIC20X9

Micrel, Inc. MIC20XX Family January 2009 9 M9999-012109-A 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 V OUT is the electrical signal output voltage present at the VOUT pin. Pin Descriptions Pin Name Type Description VIN Input Supply input. This pin provides power to both the output switch and the switch’s internal control circuitry. GND ─ Ground. ENABLE Input Switch Enable (Input): FAULT/ Output 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. CSLEW Input Slew rate control. Adding a small value capacitor between this pin and VIN slows turn-ON of the power FET. VOUT Output Switch output. The load being driven by the switch is connected to this pin. 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. Signal Descriptions Signal Name Type Description VIN Input Electrical signal input voltage present at the VIN pin. GND ─ Ground. VEN Input Electrical signal input voltage present at the ENABLE pin. VFAULT/ Output Electrical signal output voltage present at the FAULT/ pin. CSLEW Component Capacitance value connected to the CSLEW pin. 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 Capacitance value connected in parallel with the load. Load capacitance. IOUT Output Electrical signal output current present at the VOUT pin. ILIMIT Internal Switch’s current limit. Fixed at factory or user adjustable.

Micrel, Inc. MIC20XX Family January 2009 10 M9999-012109-A Absolute Maximum Ratings(1) Maximum Junction Temperature (T Operating Ratings(2) Ambient Temperature Range (T Package Thermal Resistance(3) Electrical Characteristics(4) VIN = 5V, TA = 25°C unless otherwise specified. Bold indicates –40°C to +85°C limits; CIN = 1µF. Symbol Parameter Condition Min Typ Max Units VIN Switch Input Voltage 2.5 5.5 V Switch = OFF VEN = 0V 1 5 µA Internal Supply Current All except: MIC2005-X.XLYM5 MIC2005A Switch = ON, IOUT = 0A VEN = 1.5V 80 330 µA Switch = OFF VEN = 1.5V 8 15 µA Internal Supply Current MIC2005-X.XLYM5 Switch = ON, IOUT = 0A VEN = 0V 80 300 µA Switch = OFF MIC2005A-1, VEN = 0V 1 5 µA Switch = OFF MIC2005A-2, VEN = 1.5V 8 15 µA IIN Internal Supply Current MIC2005A Switch = ON MIC2005A-1, VEN = 1.5V MIC2005A-2, VEN = 0V 80 300 µA ILEAK Output Leakage Current Switch = OFF, VOUT = 0V Active Low; ENABLE = 1.5V Active High; ENABLE = 0V 100 µA IEN Enable Input Current 0V ≤ VEN ≤ 5V 1 5 µA ICSLEW C SLEW Input Current 0V ≤ VOUT ≤ 0.8VIN 0.175 µA 70 100 Power Switch Resistance All except MIC2005A VIN = 5V, IOUT = 100mA 125 170 220 RDS(ON) Power Switch Resistance Only MIC2005A VIN = 5V, IOUT = 100mA 275 mΩ RDSCHG Load Discharge Resistance MIC20X4 & MIC20X7 VIN = 5V, ISINK = 5mA 70 126 200 Ω MIC20X3 – MIC20X6 A

Micrel, Inc. MIC20XX Family January 2009 11 M9999-012109-A Electrical Characteristics (continued) Symbol Parameter Condition Min Typ Max Units IOUT = 2A, VOUT = 0.8VIN 210 250 286 IOUT = 1A, VOUT = 0.8VIN 190 243 293 IOUT = 0.5A, VOUT = 0.8VIN 168 235 298 CLF Variable Current Limit Factor MIC20X7 – MIC20X9 RSET (Ω) = CLF (V) IOUT (A) IOUT = 0.2A, VOUT = 0.8VIN 144 225 299 V ILIMIT_2nd Secondary current limit MIC201X (All Kickstart parts only) VIN = 2.5V 2.2 4 6 A VIN Rising 2 2.25 2.5 UVLOTHRESHOLD Under Voltage Lock Out Threshold VIN Falling 1.9 2.15 2.4 V UVLOHysteresis Undervoltage Lock Out Hysteresis 0.1 V VVUVLO_TH Variable UVLO Threshold MIC20X6 225 250 275 mV VIL (MAX) 0.5 VEN ENABLE Input Voltage(5) VIH (MIN) 1.5 V VFAULT Fault status Output Voltage I OL = 10mA 0.25 0.4 V TJ Increasing 145 OTTHRESHOLD Over-temperature Threshold TJ Decreasing 135 AC Characteristics Symbol Parameter Condition Min Typ Max Units tRISE Output Turn-on rise time RL = 10 Ω, CLOAD = 1µF, VOUT = 10% to 90% *CSLEW = Open 500 1000 1500 µs Delay before asserting or releasing FAULT/ MIC200X Time from current limiting to FAULT/ state change 20 32 49 tD_FAULT Delay before asserting or releasing FAULT/ MIC201X Time from IOUT continuously exceeding primary current limit condition to FAULT/ state change 77 128 192 ms tD_LIMIT Delay before current limiting MIC201X 77 128 192 ms tRESET Delay before resetting Kickstart current limit delay, tD_LIMIT MIC201X Out of current limit following a current limit event. 77 128 192 ms tON_DLY Output Turn-on Delay RL = 43Ω, CL = 120µF, VEN = 50% to VOUT = 10% *CSLEW = Open 1000 1500 µs tOFF_DLY Output Turn-off Delay RL = 43Ω, CL = 120µF, VEN = 50% to VOUT = 90% *CSLEW = Open 700 µs Note: * Whenever CSLEW is present.

Micrel, Inc. MIC20XX Family January 2009 12 M9999-012109-A Electrical Characteristics (continued) ESD(6) Symbol Parameter Condition Min Typ Max Units VOUT and GND ±4 VESD_HB Electro Static Discharge Voltage: Human Body Model All other pins ±2 kV VESD_MCHN Electro Static Discharge Voltage; Machine Model All pins Machine Model ±200 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. V IL (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. Timing Diagrams 90% 10% 90% 10% tFALLtRISE Rise and Fall Times ENABLE VOUT 50% 90% 10% tON_DLY tOFF_DLY 50% Switching Delay Times

Micrel, Inc. MIC20XX Family January 2009 13 M9999-012109-A Typical Characteristics 100 23456 SUPPLY CURRENT (µA) VIN (V) Supply Current Output Enabled -40°C 85°C 25°C 23456 SUPPLY CURRENT (µA) VIN (V) Supply Current Output Disabled -40°C 85°C 25°C Switch Leakage Current OFF 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 - 5 0 - 3 0 - 1 0 1 03 05 07 09 0 LEAKAGE CURRENT (µA) TEMPERATURE (°C) 0.94 0.96 0.98 1.00 1.02 1.04 1.06 1.08 1.10 - 5 0 - 3 0 - 1 0 1 03 05 07 09 0 ILIMIT (A) TEMPERATURE (°C) 2.5V ILIMIT vs. Temperature (MIC20xx - 1.2) 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 -50 -30 -10 10 30 50 70 90 ILIMIT (A) TEMPERATURE (°C) 2.5V ILIMIT vs. Temperature (MIC20xx - 0.8) Note: Please note that the 3 plots overlay each 0.96 0.98 1.00 1.02 1.04 1.06 1.08 1.10 - 5 0 - 3 0 - 1 0 1 03 05 07 09 0 ILIMIT (A) TEMPERATURE (°C) 2.5V ILIMIT vs. Temperature (MIC20xx - 0.5) 2.05 2.1 2.15 2.2 2.25 2.3 -50 0 50 100 150 THRESHOLD (V) TEMPERATURE (°C) UVLO Threshold vs. Temperature V RISING V FALLING 100 22 . 533 . 544 . 555 . 5 RON (mOhm) VIN (V) RON vs. Supply Voltage 100 120 -50 -30 -10 10 30 50 70 90 RON (mOhm) TEMPERATURE (°C) RON vs. Temperature 2.5V 3.3V

Micrel, Inc. MIC20XX Family January 2009 14 M9999-012109-A Functional Characteristics

Micrel, Inc. MIC20XX Family January 2009 15 M9999-012109-A Functional Characteristics (continued)

Micrel, Inc. MIC20XX Family January 2009 16 M9999-012109-A Functional Diagram CSLEW MIC20X5 - MIC20X8 FAULT/ MIC20X5 & MIC20X9 ENABLE MIC20X4 - MIC20X9 VIN VOUT Slew Rate Control Thermal Sensor Under Voltage Detector Gate Control VREF Current Limit Control Loop Current Mirror FET Power FET GND Control Logic and Delay Timer VUVLOVUVLO MIC20X6 ILIM Factory Adjusted MIC20X3 - MIC20X6 ILIM User Adjustable MIC20X7 - MIC20X9 Load Discharge MIC20X4 & MIC20X7 Figure 2 MIC20XX Family Functional Diagram

Micrel, Inc. MIC20XX Family January 2009 18 M9999-012109-A 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 V IN supply. When V IN is less than the VULVO threshold voltage (VVUVLO_TH) for 32ms or more, the MIC20XX disables the switch to protect the supply and allow V IN to recover. After 128ms has elapsed, the MIC20X6 enables switch. This disable and enable cycling will continue as long as V IN 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. ENABLE 2003 2004 2005 2006 2007 2008 2009 2013 2014 2015 2016 2017 2018 2019 Only parts in white boxes have ENABLE pin. ENABLE pin is a logic compatible input which activates the main MOSFET switch thereby providing power to the V OUT 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 V IN, but no higher than 5.5V and not less than –0.3V. FAULT/ 2003 2004 2005 2006 2007 2008 2009 2013 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. 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 V IN, but no greater than 5.5V. 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 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. 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 145°C. The switch will automatically resume operation when the die temperature cools down to 135°C. 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.

Micrel, Inc. MIC20XX Family January 2009 19 M9999-012109-A

Application Information

The MIC2009/2019’s current limit is user programmable and controlled by a resistor connected between the I LIMIT pin and Ground. The value of this resistor is determined by the following equation: SET LIMIT R LF)itFactor(CCurrentLimI = or (A)I )itFactor(VCurrentLimR LIMIT SET = For example: Set I LIMIT = 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 I OUT of 1A is 243V. Applying the equation above: Ω==Ω 4.1941.25A 243V)(RSET R SET = 196Ω (the closest standard 1% value) Designers should be aware that variations in the measured I LIMIT for a given R SET resistor, will occur because of small differences between individual ICs (inherent in silicon processing) resulting in a spread of I LIMIT 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 R SET. A97.0196 190VILIMIT_MIN =Ω= A5.1196 260VILIMIT_MIN =Ω= Giving us a maximum ILIMIT variation over temperature of: I LIMIT_MIN ILIMIT_TYP I LIMIT_MAX 0.97 A 1.25 A 1.5 A or 1.25 A – 22% and 1.25 A + 20% 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, V OUT drops and the input to output voltage differential increases. When V IN - V OUT exceeds 1V, I OUT drops below I LIMIT to reduce the drain of fault current on the system’s power supply and to limit internal heating of the switch. When measuring I OUT 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 V OUT is pulled below V IN, with the test terminating when V OUT is 1V below V IN. Observe that once I LIMIT is reached I OUT remains constant throughout the remainder of the test. In Figure 5 this test is repeated but with V IN - V OUT exceeding 1V. When VIN - V OUT > 1V, switch’s current limiting circuitry responds by decreasing I OUT, as can be seen in Figure 5. In this demonstration, V OUT 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. Figure 4. IOUT in Current Limiting for VIN - VOUT < 1V

control signal to select between current limits. whatever the system itself is drawing. divider driving the VUVLO pin. MIC20X6 resumes normal operation. Figure 9. VUVLO Operation the Kickstart timer has not timed out. resistance R1 + R2 results in a small IIN_LOAD. calculated from the equation above.

erratic or unpredictable operation. Only parts in white boxes have Kickstart. (Not available in 5-pin SOT-23 packages). (primary) current limiting goes into action. supply can result in currents of many tens of amperes. load is still present IOUT Æ ILIMIT, not ILIMIT_2nd. Figure 10. Kickstart Only parts in white boxes have automatic load discharge. desirable to quickly remove charge from the VOUT pin. USB, 1394, PCMCIA, and CableCARD™. internal resistances is typically 126Ω. practice and required for proper operation of the switch. ESR capacitors are recommended, preferably ceramic. quality, low ESR capacitors should be chosen.

Figure 11. Die Temperature vs. IOUT

Micrel, Inc. MIC20XX Family January 2009 24 M9999-012109-A

Package Information

5-Pin SOT-23 (M5) 6-Pin SOT-23 (M6)

Micrel, Inc. MIC20XX Family January 2009 25 M9999-012109-A

6 Pin 2mm x 2mm MLF® (ML)

MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 US A 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. © 2008 Micrel, Incorporated.