MIC2003/2013 Current Limiting Circuit Protector General Description Features MIC2003 and MIC2013 are high-side current limiting devices, designed for power distribution applications in PCs, PDAs, printers and peripheral devices. MIC2003 and MIC2013 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. Both devices are fully self-contained, with the current limit value being factory set to one of several convenient levels. • 70mΩ typical on-resistance • 2.5V - 5.5V operating range • Pre-set current limit values of 0.5A, 0.8A and 1.2A MIC2013 offers a unique new feature: Kickstart™, which allows momentary high current surges to pass unrestricted without sacrificing overall system safety. MIC2003 and MIC2013 are excellent choices for USB and IEEE 1394 (FireWire) applications or for any system where current limiting and power control are desired. The MIC2003 and MIC2013 are offered in space saving 6 pin SOT-23 and 2mm x 2mm MLF packages. Data sheets and support documentation can be found on Micrel’s web site at www.micrel.com. • • • • Kickstart™ Thermal Protection Under voltage lock-out Low quiescent current Applications • • • • • • • • USB / IEEE 1394 Power Distribution Desktop and Laptop PCs Set top boxes Game consoles PDAs Printers Docking stations Chargers _________________________________________________________________________________________________________ Typical Application Figure 1. Typical Application Circuit Kickstart is a trademark of Micrel, Inc MLF and MicroLeadFrame are trademarks of Amkor Technology, Inc. Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com October 2005 M9999-xxxx04 (408) 955-1690 Micrel MIC2003/MIC20013 MIC2000 Family Members Part Number Pin Function Enable CSLEW FAULT/ DLM* -- -- -- -- -- Load Discharge -- -- ▲ -- -- -- ▲ -- ▲ ▲ ▲ -- -- ▲ -- ▲ -- ▲ -- -- ▲ ▲ -- -- -- -- ▲ -- -- Kickstart 2003 2013 2004 2014 2005 2015 2006 2016 -- ▲ 2007 2017 ▲ ▲ 2008 2018 ▲ ▲ 2009 2019 ▲ ▲ * Dynamic Load Management I Limit I Adj. Normal Limiting Fixed Adj. Adj = Adjustable current limit Fixed = Factory programmed current limit Ordering Information Part Number Marking(1) 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 Pb-Free Package SOT-23-5 No Yes 2mmX2mm MLF SOT-23-5 Yes 2mmX2mm MLF Note: 1. Under-bar symbol ( _ ) may not be to scale October 2005 2 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Pin Configuration GND 6 VIN VOUT 1 PAD ON BACKSIDE IS GROUND NIC 2 NIC 3 NIC 3 2 VIN 1 5 GND 4 NIC 4 NIC 5 VOUT SOT 23-5 (M5) Top View 6-Lead 2mmX2mm MLF (ML) Top View Pin Description Pin Number SOT-23 Pin Number MLF Pin Name 1 6 VIN Input 2 5 GND -- Ground. 3 4 NIC -- No internal connection. An electrical signal to this pin will have no effect on device operation. 4 3 NIC -- No internal connection. An electrical signal to this pin will have no effect on device operation. 2 NIC -- No internal connection. An electrical signal to this pin will have no effect on device operation. 1 VOUT Output Switch output. The load being driven by MIC2003/2013 is connected to this pin. 5 October 2005 Type Description Supply input. This pin provides power to both the output switch and the MIC2003/2013’s internal control circuitry. 3 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Absolute Maximum Ratings(1) Operating Ratings(2) VIN, VOUT ............................................................ –0.3 to 6V All other pins .................................................. –0.3 to 5.5V Power Dissipation.................................. Internally Limited Continuous Output Current..................................... 2.25A Maximum Junction Temperature ........................... 150°C Storage Temperature .............................. –65°C to 150°C Supply Voltage............................................. 2.5V to 5.5V Continuous Output Current Range .................... 0 to 2.1A Ambient Temperature Range .................... –40°C to 85°C Package Thermal Resistance (θJA) SOT-23-5 ............................................. MLF 2x2 mm(5) ......................................... 230°C/W 90°C/W Electrical Characteristics VIN = 5V, TAMBIENT = 25°C unless specified otherwise. Bold indicates –40°C to +85°C limits. Symbol Parameter VIN Switch Input Voltage IIN Internal Supply Current IIN Internal Supply Current Conditions Min Typ Max Units 5.5 V 1 5 µA 80 300 µA 2.5 Switch = OFF, ENABLE = 0V Switch = ON, IOUT = 0 ENABLE = 1.5V ILEAK Output Leakage Current VIN = 5V, VOUT = 0 V, ENABLE =0 12 100 µA RDS(ON) Power Switch Resistance VIN = 5V, IOUT = 100 mA 70 100 mΩ 125 mΩ ILIMIT Current Limit: –0.5 VOUT = 0.8VIN to VOUT = 1V 0.5 0.7 0.9 A ILIMIT Current Limit: –0.8 VOUT = 0.8VIN to VOUT = 1V 0.8 1.1 1.5 A ILIMIT Current Limit: –1.2 VOUT = 0.8VIN, to VOUT = 1V 1.2 1.6 2.1 A ILIMIT_2nd Secondary current limit (Kickstart) MIC2013, VIN = 2.7V 2.2 4 6 A OTTHRESHOLD Over-temperature Threshold TJ increasing 145 TJ decreasing 135 October 2005 4 °C M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 AC Characteristics Symbol Parameter Condition Min Typ Max Units tLIMIT Delay before current limiting Secondary current limit 77 128 192 ms tRESET Delay before resetting Kickstart current limit delay, tLIMIT Out of current limit following a current limit. 77 128 192 ms Symbol Parameter Condition Min Typ Max Units VESD_HB Electro Static Discharge Voltage: Human Body Model VOUT and GND ±4 ±2 kV ± 200 V (MIC2013) (MIC2013) ESD VESD_MCHN Electro Static Discharge Voltage; Machine Model All other pins All pins kV Machine Model Notes: 1. Exceeding the absolute maximum rating may damage the device. 2. The device is not guaranteed to function outside its operating rating. 3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF. 4. Specification for packaged product only. 5. Requires proper thermal mounting to achieve this performance. October 2005 5 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Timing Diagrams ENABLE 50% 50% tON_DLY tOFF_DLY 90% VOUT 10% Switching Delay Times tFALL tRISE 90% 90% 10% 10% Rise and Fall Times tRISE 90% VOUT 10% Output Rise Time October 2005 6 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Typical Characteristics Supply Current Output Enabled 1.00 0.90 25°C 85°C 60 40 20 3 4 VIN (V) 5 3 4 5 VIN (V) 6 0.40 0.30 0.20 0.10 0 -50 -30 -10 10 30 50 70 TEMPERATURE (°C) 7 1.65 1.60 ILIMIT (A) 247.0 246.5 246.0 1.45 1.2 IN VIN = 3V V = 5V IN 1.40 0.5A 0.6 1.2A 0.2 1.25 -50 -30 -10 10 30 50 70 TEMPERATURE (°C) 90 0.8 0.4 1.30 245.0 -50 -30 -10 10 30 50 70 TEMPERATURE (°C) 0.8A 1.0 1.35 245.5 Temperature 1.4 V = 2.5V 1.50 0 -50 -30 -10 10 30 50 70 TEMPERATURE (°C) 90 ILIMIT vs. Temperature ILIMIT vs. Temperature RON vs. (MIC20xx - 0.8) (MIC20xx - 0.5) Supply Voltage 0.75 0.73 1.20 ILIMIT (A) 1.00 0.80 0.60 0.40 5V Note: 0.20 3V Please note that the 3 2.5V plots overlay each 0.00 -50 -30 -10 10 30 50 70 TEMPERATURE (°C) 90 100 0.65 0.63 0.61 90 80 0.71 0.69 0.67 RON (mOhm) 1.40 90 ILIMIT vs. vs. Temperature (MIC20xx-1.2) 1.55 ILIMIT (A) 0.80 0.70 0.60 0.50 LIMIT 247.5 THRESHOLD (mV) 85°C 25°C I UVSD Threshold vs. Temperature 248.0 -40°C 0.10 0 2 6 1.00 0.90 ILIMIT (A) 0 2 0.80 0.70 0.60 0.50 0.40 0.30 0.20 Switch Leakage Current - OFF (µA) -40°C 80 SUPPLY CURRENT (µA) SUPPLY CURRENT (µA) 100 Supply Current Output Disabled 5V 0.59 3V 0.57 2.5V 0.55 -50 -30 -10 10 30 50 70 TEMPERATURE (°C) 60 40 20 90 0 2 2.5 3 3.5 4 4.5 VIN (V) 5 5.5 RON vs. 120 RON (mOhm) 100 Temperature 3.3V 2.5V 80 60 5V 40 20 0 -50 -30 -10 10 30 50 70 TEMPERATURE (°C) October 2005 90 7 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Functional Characteristics Kickstart Response Normal Load with Temporary High Load Current Limit Response Thermal Shutdown VIN = 5.0V RLOAD CLOAD = 47µF VOUT (1V/div) VOUT (1V/div) IOUT (250mA/div) IOUT (0.5A/div) 0 50 100 150 200 250 300 Time (ms) 350 400 450 500 0 550 VOUT (1V/div) VOUT (1V/div) IOUT (0.5A/div) IOUT (0.5A/div) 50 100 150 200 250 300 350 Time (ms) 400 100 150 200 250 300 350 Time (ms) 400 450 500 550 Kickstart Response Normal Load with Temporary Short Circuit Kickstart Response No Load to Short Circuit 0 50 450 500 550 0 50 100 150 Inrush Current Response MIC20xx-0.5 200 250 300 350 Time (ms) 400 450 500 550 Turn-On/Turn-Off VIN = 5.0V RLOAD CLOAD = 100nF 0µF 10µF 22µF47µF 100µF VOUT (1V/div) VOUT (1V/div) 220µF 470µF IOUT (200mA/div) IOUT (200mA/div) 0 October 2005 4 8 12 16 20 24 Time (ms) 28 32 36 0 40 8 2 4 6 8 Time (ms) 10 12 14 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 UVLO Decreasing UVLO Increasing VOUT (1V/div) VOUT (1V/div) VIN (1/div) VIN (1/div) 0 4 8 12 16 20 24 28 Time (µs) 32 36 40 44 0 48 4 8 12 16 20 24 28 Time (µs) 32 36 40 44 48 UVSD VOUT (1V/div) VIN (1/div) 0 October 2005 20 40 60 80 100 120 Time (µs) 140 160 180 200 9 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Functional Diagram Under Voltage Detector VIN Curre nt Mirror FE T Control Logic and Delay T imer Power FET Gate Control VOUT Thermal Sensor Slew Rate Control VREF Curre nt L imit control Loop GND Factory a dju ste d Figure 2 MIC2003/2013 Block Diagram October 2005 10 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 duration of the Kickstart period. After this time the MIC2013 reverts to its normal current limit. An example of Kickstart operation is shown below. Functional Description Input and Output 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 (~0.6V), while the switch is disabled, current will flow from output to input via the power MOSFET’s body diode. This effect can be used to advantage when large bypass capacitors are placed on MIC2003/2013’s’s output. When power to the switch is removed, the output capacitor will be automatically discharged. If discharging CLOAD is required by your application, consider using MIC2003/2013 or MIC2007/2017 in place of MIC2003/2013. These MIC2000 family members are equipped with a discharge FET to insure complete discharge of CLOAD. OUT OUT Figure 3. Kickstart Operation Picture Key: A) MIC2013 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 = 0. Limiting response will be the same for dead shorts). F) Thermal shutdown followed by thermal cycling. G) Excessive load released, normal load remains. MIC2013 drops out of current limiting. H) FAULT/ delay period followed by FAULT/ going HIGH. Current Sensing and Limiting MIC2003/2013 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 an internally 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 MIC2003/2013 goes into thermal shutdown. Kickstart (MIC2013 only) The MIC2013 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 MIC2013 differs markedly from MIC2003 and its peers, which immediately limit load current, potentially starving the motor and causing the appliance to stall or stutter. During this delay period, typically 128 ms, a secondary current limit is in effect. If the load demands a current in excess the secondary limit, MIC2013 acts immediately to restrict output current to the secondary limit for the October 2005 Slew Rate Control Large capacitive loads can create significant current surges when charged through a high-side switch such as the MIC2003/2013. For this reason, MIC2003/2013 provides built-in slew rate control to limit the initial inrush currents upon enabling the power MOSFET switch. Slew rate control is active upon powering up, and upon re-enabling the load. At shutdown, the discharge slew rate is controlled by the external load and output capacitor. 11 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 MIC2003/2013 will continue cycling between ON and OFF states until the offending load has been removed. 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. Thermal Shutdown Thermal shutdown is employed to protect MIC2003/2013 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. MIC2003/2013 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 October 2005 12 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Application Information ILIMIT vs. IOUT measured MIC2003/2013’s’s current limiting circuitry 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 MIC2003/2013. 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, MIC2003/2013’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. Figure 5. IOUT in Current Limiting for VOUT >1V NORMALIZED OUTPUT CURRENT (A) This folding back of ILIMIT can be generalized by plotting ILIMIT as a function of VOUT, as shown below. The slope of VOUT between IOUT = 0 and IOUT = ILIMIT (where ILIMIT = 1) is determined by RON of MIC2003/2013 and ILIMIT. 1.2 Normalized Output Current vs. Output Voltage (5V) 1.0 0.8 0.6 0.4 0.2 0 0 1 2 3 4 5 OUTPUT VOLTAGE (V) 6 Figure 6. Figure 4. IOUT in Current Limiting for VOUT ≤1V October 2005 13 M9999-102605 [email protected] or (408) 955-1690 MIC2003/MIC20013 NORMALIZED OUTPUT CURRENT (A) Micrel 1.2 Normalized Output Current vs. Output Voltage (2.5V) 1.0 0.8 0.6 VOUT 0.4 0.2 0 0 0.5 1.0 1.5 2.0 2.5 OUTPUT VOLTAGE (V) Kickstart 3.0 Current Limiting IOUT Figure 7. Load Removed 0 Kickstart (MIC2013) 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 MIC2013. The Kickstart period is governed by an internal timer which allows current to pass unimpeded 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 MIC2013, 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 4 Amps 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 MIC2013 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 Æ 0. Upon cooling, if the load is still present IOUT Æ ILIMIT, not IKICKSTART. 100 200 300 Time (ms) 400 500 600 Figure 9. Kickstart Supply Filtering A 0.1µF to 1µF bypass capacitor positioned close to the VIN and GND pins of MIC2003/2013 is both good design practice and required for proper operation of MIC2003/2013. This will control supply transients and ringing. Without a bypass capacitor, large current surges or an output short may cause sufficient ringing on VIN (from supply lead inductance) to cause erratic operation of MIC2003/2013’s control circuitry. Good quality, low ESR capacitors, such as Panasonic’s TE or ECJ series, are suggested. When bypassing with capacitors of 10µF 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 0.01µF to 0.1µF are recommended. Again, good quality, low ESR capacitors should be chosen. 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: PD = R DS(ON) × (IOUT )2 To relate this to junction temperature, the following equation can be used: TJ = PD × Rθ (J- A) + TA October 2005 14 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Where: TJ = junction temperature, When operating at higher current levels or in higher temperature environments use of Micrel’s MLF packaging is recommended. MLF packages provide an exposed power paddle on the back side to which electrical and thermal contact can be made with the device. This significantly reduces the package’s thermal resistance and thus extends the MIC2005/2013’s operating range. TA = ambient temperature Rθ(J-A) is the thermal resistance of the package In normal operation MIC2003/2013’s Ron is low enough that no significant I2R 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 MIC2003/2013’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 10 die temperature is plotted against IOUT assuming a constant case temperature of 85°C. The plots also assume a worst case RON of 140 mΩ at a die temperature of 135°C. Under these conditions it is clear that an SOT-23 packaged device will be on the verge of thermal shutdown, typically 140°C die temperature, when operating at a load current of 1.25A. For this reason we recommend using MLF packaged MIC2003/2013s for any design intending to supply continuous currents of 1A or more. 2 Vias 0.3 mm diam. to Ground Plane 1.4 mm 0.8 mm Figure 11. Pad for thermal mounting to PCB Die Temperature vs. Iout for Tcase = 85°C 160 Die Temperature - °C 140 120 100 80 60 40 SOT-23 20 MLF 0 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 Iout - Amps Figure 10. Die Temperature vs. IOUT October 2005 15 M9999-102605 [email protected] or (408) 955-1690 Micrel MIC2003/MIC20013 Package Information 1.90 (0.075) REF 0.95 (0.037) REF 1.75 (0.069) 3.00 (0.118) 1.50 (0.059) 2.60 (0.102) DIMENSIONS: MM (INCH) 1.30 (0.051) 0.90 (0.035) 3.02 (0.119) 2.80 (0.110) 10° 0° 0.50 (0.020) 0.35 (0.014) 0.15 (0.006) 0.00 (0.000) 0.20 (0.008 ) 0.09 (0.004 ) 0.60 (0.024) 0.10 (0.004) 5-Pin SOT-23 (M5) 6 Pin 2mmX2mm 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. © 2005 Micrel, Incorporated. October 2005 16 M9999-102605 [email protected] or (408) 955-1690