 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| MIC5018 Micrel MIC5018 IttyBittyTM High-Side MOSFET Driver Preliminary Information General Description The MIC5018 IttyBittyTM 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 -40C to +85C ambient temperature range. Features * * * * * * * * * * * * +2.7V to +9V operation 150A typical supply current at 5V supply 1A 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 Battery conservation Power bus switching Solenoid and motion control Lamp control Applications Ordering Information Part Number MIC5018BM4 Temp. Range -40C to +85C Package SOT-143 Marking H10 5 Typical Applications +5V Load voltage limited only by MOSFET drain-to-source rating VLOAD SUPPLY 2 4 VS CTL G GND 3 1 +2.7 to +9V 4.7F MIC5018 2 4 On Off 3 1 Load On Off Load Si9410DY* N-channel MOSFET 4.7F MIC5018 IRFZ24* N-Channel MOSFET * Siliconix 30m, 7A max., 30V VDS max. 8-lead SOIC package VS CTL G GND * International Rectifier 100m, 17A max. TO-220 package Low-Voltage High-Side Power Switch Low-Side Power Switch 1997 5-155 MIC5018 Micrel Pin Configuration VS 2 GND 1 Part Identification Early production identification: MH10 3 H10 4 G CTL SOT-143 (M4) Pin Description Pin Number 1 2 3 4 Pin Name GND VS G CTL Pin Function Ground: Power return. Supply (Input): +2.7V to +9V supply. Gate (Output): Gate connection to external MOSFET. 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. 5-156 1997 MIC5018 Micrel Absolute Maximum Ratings Supply Voltage (VSUPPLY) ........................................... +10V Control Voltage (VCTL) ................................. -0.6V to +16V Gate Voltage (VG) ....................................................... +16V Ambient Temperature Range (TA) ............. -40C to +85C Lead Temperature, Soldering 10sec. ........................ 300C Package Thermal Resistance SOT-143 JA ..................................................... 220C/W SOT-143 JC ..................................................... 130C/W Electrical Characteristics Parameter Supply Current Condition (Note 1) VSUPPLY = 3.3V VSUPPLY = 5V Control Input Voltage 2.7V VSUPPLY 9V 2.7V VSUPPLY 5V 5V VSUPPLY 9V Control Input Current Control Input Capacitance Zener Diode Output Clamp Gate Output Voltage VSUPPLY = 9V VSUPPLY = 2.7V VSUPPLY = 3.0V VSUPPLY = 4.5V Gate Output Current Gate Turn-On Time Gate Turn-Off Time VSUPPLY = 5V VSUPPLY = 4.5V VSUPPLY = 4.5V VOUT = 10V, Note 3 CL = 1000pF, Note 4 CL = 3000pF, Note 4 CL = 1000pF, Note 5 CL = 3000pF, Note 5 2.7V VSUPPLY 9V Note 2 13 6.3 7.1 11.4 VCTL = 0V VCTL = 3.3V VCTL = 0V VCTL = 5V VCTL for logic 0 input VCTL for logic 1 input VCTL for logic 1 input 0 2.0 2.4 0.01 5 16 7.1 8.2 13.4 9.5 0.75 2.1 10 30 1.5 4.2 20 60 19 Min Typ 0.01 70 0 150 Max 1 140 1 300 0.8 VSUPPLY VSUPPLY 1 Units A A A A V V V A pF V V V V A ms ms s s 5 General Note: Devices are ESD protected, however handling precautions are recommended. Note 1: Note 2: Note 3: Note 4: Note 5: Typical values at TA = 25C. Minimum and maximum values indicate performance at -40C TA +85C. Parts production tested at 25C. Guaranteed by design. Resistive load selected for VOUT = 10V. 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. 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 VSUPPLY 0.1F 2 4 5V 0V MIC5018 VS CTL G GND 3 1 VOUT CL 1997 5-157 MIC5018 Micrel Typical Characteristics Note 4 Supply Current vs. Supply Voltage 1.0 SUPPLY CURRENT (mA) TURN-ON TIME (ms) 0.8 -40C 0.6 25C 0.4 0.2 0 125C Full Turn-On Time vs. Load Capacitance 20 Note 5 15 VSUPPLY = 3V 10 5V 5 9V 10 0 0 1000 2000 3000 4000 5000 CAPACITANCE (pF) TURN-OFF TIME (s) 8 7 6 5 4 3 2 1 0 0 Full Turn-Off Time vs. Load Capacitance Note 6 VSUPPLY = 3V 5V 9V 0 2 4 6 8 SUPPLY VOLTAGE (V) 1000 2000 3000 4000 5000 CAPACITANCE (pF) Gate Output Voltage vs. Supply Voltage 20 125C Gate Output Current vs. Output Voltage 160 OUTPUT CURRENT (A) OUTPUT CURRENT (A) 120 100 80 60 40 20 0 0 Gate Output Current vs. Output Voltage OUTPUT VOLTAGE (V) 15 -40C 10 25C 120 VSUPPLY = 9V 80 TA = -55C 25C 125C 5 40 5V 3V 0 0 2 4 6 8 SUPPLY VOLTAGE (V) 10 0 0 2 4 6 8 10 12 14 16 OUTPUT VOLTAGE (V) 2 4 6 8 10 12 14 16 OUTPUT VOLTAGE (V) Note 4: Note 5: Note 6: TA = 25C, VSUPPLY = 5V unless noted. Full turn-on time is the time between VCTL rising to 2.5V and the VG rising to 90% of its steady on-state value. Full turn-off time is the time between VCTL falling to 0.5V and the VG falling to 10% of its steady on-state value. 5-158 1997 MIC5018 Micrel Functional Diagram +2.7V to +9V VS I1 20A D2 35V Q1 On Off MIC5018 CTL R1 2k D1 16V Q2 R2 15k EN CHARGE PUMP Q3 G D3 16V Load GND Functional Diagram with External Components (High-Side Driver Configuration) 5 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. 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. Charge Pump The charge pump is enabled when CTL is logic high. The charge pump consists of an oscillator and voltage quadrupler (4x). Output voltage is limited to 16V by a zener diode. The charge pump output voltage will be approximately: VG = 4 x VSUPPLY - 2.8V, but not exceeding 16V. The oscillator operates from approximately 70kHz to approximately 100kHz depending upon the supply voltage and temperature. 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). 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. 1997 5-159 MIC5018 Micrel 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-to-source voltage. +5V 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 4.7F or 10F 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. MOSFET Selection The MIC5018 is designed to drive N-channel enhancementtype 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) VSUPPLY 4.7F MIC5018 2 4 VS CTL G GND 3 1 15V 10V IRFZ24* approx. 0V Logic High Voltages are approximate * International Rectifier standard MOSFET 5V To demonstrate this circuit, try a 2, 20W load resistor . Figure 2. Using a Standard MOSFET The MIC5018 has an internal zener diode that limits the gateto-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. 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 4.7F MIC5018 2 4 VS CTL G GND 3 1 9V 5.7V Logic High Load Load IRLZ44* approx. 0V Voltages are approximate * International Rectifier logic-level MOSFET 3.3V To demonstrate this circuit, try 5, 5W or 47, 1/4W load resistors. MIC5018 2 4 VS CTL G GND 3 1 VG G D VDS S Figure 3. Using a Logic-Level MOSFET 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 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. VSUPPLY VGS VLOAD Figure 1. Voltages The performance of the MOSFET is determined by the gateto-source voltage. Choose the type of MOSFET according to the calculated gate-to-source voltage. Standard MOSFET Standard MOSFETs are fully enhanced with a gate-to-source voltage of about 10V. Their absolute maximum gate-tosource 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 Load MIC5018 2 4 VS CTL G GND 3 1 Logic-level N-channel MOSFET 5V < VZ < 10V Protects gate of logic-level MOSFET Figure 4. Gate-to-Source Protection 5-160 Load 1997 MIC5018 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-to-source 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. +2.7V to +9V Micrel 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. +5V 4.7F MIC5018 2 4 +12V VS CTL G GND 3 1 15V 3V IRLZ44* approx. 0V Logic High Voltages are approximate * International Rectifier logic-level MOSFET 12V To demonstrate this circuit, try a 40, 5W or 100, 2W load resistor. 4.7F MIC5018 2 4 VS CTL G GND 3 1 Figure 6. 12V High-Side Switch 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. Low-Side Switch Configuration The low-side configuration makes it possible to switch a voltage much higher than the MIC5018's maximum supply voltage. +80V * International Rectifier standard MOSFET BVDSS = 100V To demonstrate this circuit, try 1k, 10W or 33k, 1/4W load resistors. On Off Schottky Diode Figure 5. Switching an Inductive Load 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. Load 5 +2.7 to +9V 4.7F MIC5018 2 4 On Off 3 1 Load G VS CTL GND IRF540* N-channel MOSFET Figure 7. Low-Side Switch Configuration The maximum switched voltage is limited only by the MOSFET's maximum drain-to-source ratings. 1997 5-161 |
Price & Availability of MIC5018
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |