MIC5018 IttyBitty™ High-Side MOSFET Driver General Description Features The MIC5018 IttyBitty™ high-side MOSFET driver is designed to switch an N-channel enhancement-type MOSFET from a TTL compatible control signal in high- or low-side switch applications. This driver features the tiny 4-lead SOT-143 package. The MIC5018 is powered from a +2.7V to +9V supply and features extremely low off-state supply current. An internal charge pump drives the gate output higher than the driver supply voltage and can sustain the gate voltage indefinitely. An internal zener diode limits the gate-to-source voltage to a safe level for standard N-channel MOSFETs. In high-side configurations, the source voltage of the MOSFET approaches the supply voltage when switched on. To keep the MOSFET turned on, the MIC5018’s output drives the MOSFET gate voltage higher than the supply voltage. In a typical high-side configuration, the driver is powered from the load supply voltage. Under some conditions, the MIC5018 and MOSFET can switch a load voltage that is slightly higher than the driver supply voltage. In a low-side configuration, the driver can control a MOSFET that switches any voltage up to the rating of the MOSFET. The gate output voltage is higher than the typical 3.3V or 5V logic supply and can fully enhance a standard MOSFET. The MIC5018 is available in the SOT-143 package and is rated for –40°C to +85°C ambient temperature range. • • • • • • • • +2.7V to +9V operation 150µA typical supply current at 5V supply ≤1µA typical standby (off) current Charge pump for high-side low-voltage applications Internal zener diode gate-to-ground MOSFET protection Operates in low- and high-side configurations TTL compatible input ESD protected Applications • • • • Battery conservation Power bus switching Solenoid and motion control Lamp control Typical Applications +5V ‡ 4 On Off VS G C T L GND * International Rectifier 100m , 17A max. TO-220 package IRFZ24* N-Channel MO S F E T 3 1 Low-Voltage High-Side Power Switch * Siliconix 30m , 7A max., 30V VDS max. 8-lead SOIC package Load MIC5018 2 Load 4.7µF VL O AD SU PPL‡Y Load voltage limited only by MOSFET drain-to-source rating +2.7 to +9V 4.7µF MIC5018 2 4 On Off VS G C T L GND 3 1 Si9410DY* N-channel MO S F E T Low-Side Power Switch IttyBitty is a trademark of Micrel, 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 April 2006 M9999-042406 (408) 955-1690 Micrel, Inc. MIC5018 Ordering Information Part Number Standard MIC5018BM4 Making Pb-Free Standard Pb-Free MIC5018YM4 H10 H10 Temp. Range Package –40ºC to +85ºC SOT-143 Pin Configuration VS GND 2 1 Part Identification Early production identification: MH10 H10 H10 3 4 G CTL SOT-143 (M4) Pin Description Pin Number Pin Name 1 GND 2 VS Supply (Input): +2.7V to +9V supply. 3 G Gate (Output): Gate connection to external MOSFET. 4 CTL April 2006 Pin Function Ground: Power return. Control (Input): TTL compatible on/off control input. Logic high drives the gate output above the supply voltage. Logic low forces the gate output near ground. 2 M9999-042406 (408) 955-1690 Micrel, Inc. MIC5018 Absolute Maximum Ratings Operating Ratings Supply Input Voltage (VSUPPLY) .....................................+10V Control Voltage (VCTL) ................................... –0.6V to +16V Gate Voltage (VG).........................................................+16V Ambient Temperature Range (TA)...............–40°C to +85°C Lead Temperature, soldering 10 sec ..........................300ºC Package Thermal Resistance SOT-143 (θJA) ....................................................220°C/W SOT-143 (θJC) ....................................................130°C/W Electrical Characteristics Parameter Conditions(1) Supply Current VSUPPLY = 3.3V Control Input Voltage Min Typ Max Units VCTL = 0V VCTL = 3.3V 0.01 70 1 140 µA µA VSUPPLY = 5V VCTL = 0V VCTL = 5V 0 150 1 300 µA µA 2.7V ≤ VSUPPLY ≤ 9V VCTL for logic 0 input 0 0.8 V 2.7V ≤ VSUPPLY ≤ 5V VCTL for logic 1 input 2.0 VSUPPLY V 5V ≤ VSUPPLY ≤ 9V VCTL for logic 1 input 2.4 VSUPPLY V 1 µA Control Input Current 2.7V ≤ VSUPPLY ≤ 9V Control Input Capacitance (2) Zener Diode Output Clamp VSUPPLY = 9V 13 16 Gate Output Voltage VSUPPLY = 2.7V 6.3 7.1 V VSUPPLY = 3.0V 7.1 8.2 V 11.4 13.4 V 0.01 5 VSUPPLY = 4.5V (3) Gate Output Current VSUPPLY = 5V VOUT = 10V Gate Turn-On Time VSUPPLY = 4.5V CL = 1000pF (4) CL = 3000pF Gate Turn-Off Time VSUPPLY = 4.5V CL = 1000pF (5) CL = 3000pF pF 19 9.5 V µA (4) 0.75 2.1 1.5 4.2 Ms ms (5) 10 30 20 60 µs µs Notes: General Note: Devices are ESD protected, however handling precautions are recommended. 1. Typical values at TA = 25°C. Minimum and maximum values indicate performance at –40°C ≥ TA ≥ +85°C. Parts production tested at 25°C. 2. Guaranteed by design. 3. Resistive load selected for VOUT = 10V. 4. Turn-on time is the time required for gate voltage to rise to 4V greater than the supply voltage. This represents a typical MOSFET gate threshold voltage. 5. Turn-off time is the time required for the gate voltage to fall to 4V above the supply voltage. This represents a typical MOSFET gate threshold voltage. Test Circuit VS U P P L Y 0.1µF MIC5018 2 4 5V 0V April 2006 VS G C T L GND 3 3 1 VOU T CL M9999-042406 (408) 955-1690 Micrel, Inc. MIC5018 Typical Characteristics(4) Supply Current vs. Supply Voltage 1.0 0.8 -40°C 0.6 25°C 0.4 0.2 0 125°C 0 2 4 6 8 10 SUPPLY VOLTAGE (V) Gate Output Voltage vs. Supply Voltage 20 125°C 15 -40°C 25°C 10 5 0 0 2 4 6 8 10 SUPPLY VOLTAGE (V) Note 4: TA = 25°C, VSUPPLY = 5V unless noted. Note 5: Full turn-on time is the time between V CTL rising to 2.5V and the VG rising to 90% of its steady on-state value. Note 6: Full turn-off time is the time between V CTL falling to 0.5V and the VG falling to 10% of its steady on-state value. April 2006 4 M9999-042406 (408) 955-1690 Micrel, Inc. MIC5018 Functional Diagram +2.7V to +9V VS MIC5018 I1 20µA D2 35V Q1 CTL R1 2k D1 16V Q2 R2 15k EN CHARGE PUMP G D3 16V Q3 GND Load On Off Functional Diagram with External Components (High-Side Driver Configuration) approximately: VG = 4 × VSUPPLY – 2.8V, but not exceeding 16V The oscillator operates from approximately 70kHz to approximately 100kHz depending upon the supply voltage and temperature. Functional Description Refer to the functional diagram. The MIC5018 is a noninverting device. Applying a logic high signal to CTL (control input) produces gate drive output. The G (gate) output is used to turn on an external N-channel MOSFET. Gate Output The charge pump output is connected directly to the G (gate) output. The charge pump is active only when CTL is high. When CTL is low, Q3 is turned on by the second inverter and discharges the gate of the external MOSFET to force it off. If CTL is high, and the voltage applied to VS drops to zero, the gate output will be floating (unpredictable). Supply VS (supply) is rated for +2.7V to +9V. An external capacitor is recommended to decouple noise. Control CTL (control) is a TTL compatible input. CTL must be forced high or low by an external signal. A floating input may cause unpredictable operation. A high input turns on Q2, which sinks the output of current source I1, making the input of the first inverter low. The inverter output becomes high enabling the charge pump. ESD Protection D1 and D2 clamp positive and negative ESD voltages. R1 isolates the gate of Q2 from sudden changes on the CTL input. Q1 turns on if the emitter (CTL input) is forced below ground to provide additional input protection. Zener D3 also clamps ESD voltages for the gate (G) output. Charge Pump The charge pump is enabled when CTL is logic high. The charge pump consists of an oscillator and voltage quadrupler (4×). Output voltage is limited to 16V by a zener diode. The charge pump output voltage will be April 2006 5 M9999-042406 (408) 955-1690 Micrel, Inc. MIC5018 Standard MOSFET Standard MOSFETs are fully enhanced with a gate-tosource voltage of about 10V. Their absolute maximum gate-to-source voltage is ±20V. With a 5V supply, the MIC5018 produces a gate output of approximately 15V. Figure 2 shows how the remaining voltages conform. The actual drain-to-source voltage drop across an IRFZ24 is less than 0.1V with a 1A load and 10V enhancement. Higher current increases the drain-to-source voltage drop, increasing the gate-tosource voltage. Application Information Supply Bypass A capacitor from VS to GND is recommended to control switching and supply transients. Load current and supply lead length are some of the factors that affect capacitor size requirements. A 4.7µF or 10µF aluminum electrolytic or tantalum capacitor is suitable for many applications. The low ESR (equivalent series resistance) of tantalum capacitors makes them especially effective, but also makes them susceptible to uncontrolled inrush current from low impedance voltage sources (such as NiCd batteries or automatic test equipment). Avoid instantaneously applying voltage, capable of high peak current, directly to or near tantalum capacitors without additional current limiting. Normal power supply turn-on (slow rise time) or printed circuit trace resistance is usually adequate for normal product usage. +5V Logic High C T L GND 3 1 VG G VG S VLOAD 5V To demonstrate this circuit, trya 2 , 20W load resistor. Logic-Level MOSFET Logic-level N-channel MOSFETs are fully enhanced with a gate-to-source voltage of approximately 5V and generally have an absolute maximum gate-to-source voltage of ±10V. +3.3V 4.7µF VD S Logic High MIC5018 2 4 VS 3 G C T L GND 1 Voltages are approximate * International Rectifier logic-level MOSFET Figure 1. Voltages 9V IRLZ44* approx. 0V 5.7V 3.3V To demonstrate this circuit, try 5 , 5W or 47 , 1/4W load resistors. Figure 3. Using a Logic-Level MOSFET The performance of the MOSFET is determined by the gate-to-source voltage. Choose the type of MOSFET according to the calculated gate-to-source voltage. April 2006 10V The MIC5018 has an internal zener diode that limits the gate-to-ground voltage to approximately 16V. Lower supply voltages, such as 3.3V, produce lower gate output voltages which will not fully enhance standard MOSFETs. This significantly reduces the maximum current that can be switched. Always refer to the MOSFET data sheet to predict the MOSFET’s performance in specific applications. D S IRFZ24* approx. 0V Load 4 G C T L GND 1 Figure 2. Using a Standard MOSFET Load MIC5018 3 15V G * International Rectifier standard MOSFET VS U P P L Y VS 4 VS Voltages are approximate MOSFET Selection The MIC5018 is designed to drive N-channel enhancement type MOSFETs. The gate output (G) of the MIC5018 provides a voltage, referenced to ground, that is greater than the supply voltage. Refer to the “Typical Characteristics: Gate Output Voltage vs. Supply Voltage” graph. The supply voltage and the MOSFET drain-to-source voltage drop determine the gate-to-source voltage. VGS = VG – (VSUPPLY – VDS) where: VGS = gate-to-source voltage (enhancement) VG = gate voltage (from graph) VSUPPLY = supply voltage VDS = drain-to-source voltage (approx. 0V at low current, or when fully enhanced) 2 MIC5018 2 Load 4.7µF Refer to Figure 3 for an example showing nominal voltages. The maximum gate-to-source voltage rating of a logic-level MOSFET can be exceeded if a higher 6 M9999-042406 (408) 955-1690 Micrel, Inc. MIC5018 supply voltage is used. An external zener diode can clamp the gate-to-source voltage as shown in Figure 4. The zener voltage, plus its tolerance, must not exceed the absolute maximum gate voltage of the MOSFET. Split Power Supply Refer to Figure 6. The MIC5018 can be used to control a 12V load by separating the driver supply from the load supply. VS U P P L Y +5V 2 4 VS G C T L GND Logic-leve N-channel MO S F E T 3 1 Logic High MIC5018 2 4 VS 3 15V G C T L GND 1 Voltages are approximate * International Rectifier logic-level MOSFET Load 5V <VZ < 10V Protects gate of logic-level MOSFET IRLZ44* approx. 0V 3V Load 4.7µF MIC5018 +12V 12V To demonstrate this circuit, trya 40 , 5W or 100 , 2W load resistor. Figure 6. 12V High-Side Switch Figure 4. Gate-to-Source Protection A logic-level MOSFET is required. The MOSFET’s maximum current is limited slightly because the gate is not fully enhanced. To predict the MOSFETs performance for any pair of supply voltages, calculate the gate-to-source voltage and refer to the MOSFET data sheet. VGS = VG – (VLOAD SUPPLY – VDS) VG is determined from the driver supply voltage using the “Typical Characteristics: Gate Output Voltage vs. Supply Voltage” graph. A gate-to-source zener may also be required when the maximum gate-to-source voltage could be exceeded due to normal part-to-part variation in gate output voltage. Other conditions can momentarily increase the gate-tosource voltage, such as turning on a capacitive load or shorting a load. Inductive Loads Inductive loads include relays, and solenoids. Long leads may also have enough inductance to cause adverse effects in some circuits. Low-Side Switch Configuration The low-side configuration makes it possible to switch a voltage much higher than the MIC5018’s maximum supply voltage. +2.7V to +9V 4 On Off +80V MIC5018 2 VS G C T L GND 3 * International Rectifier standard MOSFET B VD SS = 100V 1 Load 4.7µF +2.7 to +9V Schottky Diode 4.7µF MIC5018 2 4 On Off Figure 5. Switching an Inductive Load VS G C T L GND 3 1 To demonstrate this circuit, try 1k, 10W or 33k, 1/4W load resistors. IRF540* N-channel MO S F E T Figure 7. Low-Side Switch Configuration Switching off an inductive load in a high-side application momentarily forces the MOSFET source negative (as the inductor opposes changes to current). This voltage spike can be very large and can exceed a MOSFET’s gate-to-source and drain-to-source ratings. A Schottky diode across the inductive load provides a discharge current path to minimize the voltage spike. The peak current rating of the diode should be greater than the load current. In a low-side application, switching off an inductive load will momentarily force the MOSFET drain higher than the supply voltage. The same precaution applies. April 2006 The maximum switched voltage is limited only by the MOSFET’s maximum drain-to-source ratings. 7 M9999-042406 (408) 955-1690 Micrel, Inc. MIC5018 Package Information SOT-143 (M4) 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. © 1997 Micrel, Incorporated. April 2006 8 M9999-042406 (408) 955-1690