Mitel General Description MiC4420, MiC4429 and MIC429 MOSFET drivers are tough, efficient, and easy to use. The MIC 4429 and MIC429 are inverting drivers, while the MIC4420 is a non-inverting driver. They are capable of 6A (peak) output and can drive the largest MOSFETs with an improved safe operating mar- gin. The MIC4420/4429/429 accepts any logic input from 2.4V to Vg without external speed-up capacitors or resistor networks. Proprietary circuits allow the input to swing negative by as much as 5V without damaging the part. Additional circuits protect against damage from electro- static discharge. MIC4420/4429/429 drivers can replace three or more dis- crete components, reducing PCB area requirements, simplifying product design, and reducing assembly cost. Modern BiCMOS/DMOS construction guarantees freedom from latch-up. The rail-to-rail swing capability insures ad- equate gate voltage to the MOSFET during power up/ down sequencing. MIC4420/4429/429 6A-Peak Low-Side MOSFET Driver Bipolar/CMOS/DMOS Process Features * CMOS Construction * Latch-Up Protected: Will Withstand >500mA Reverse Output Current Logic Input Withstands Negative Swing of Up to 5V Matched Rise and Fall Times... cece 25ns * High Peak Output Current .... ... BA Peak Wide Operating Range........ .. 4,5V to 18V + High Capacitive Load Drive... 10,000pF Low Delay Time 00. eceeeeeteetteeeeeeees 55ns Typ * Logic High input for Any Voltage From 2.4V to Vg Low Equivalent input Capacitance (typ) ................ 6pF Low Supply Current... 450uA With Logic 1 input * Low Output Impedance oi eseeettereeretees 2.60 Output Voltage Swing Within 25mV of Ground or Vg + MIL-STD-883 Method 5004/5005 version available Applications * Switch Mode Power Supplies + Motor Controls + Pulse Transformer Driver * Class D Switching Amplifiers Functional Diagram 0.1mA TF 0.4mA Mic4429 INVERTING an | MIC4420 NON-INVERTING GND Ground Unused Inputs 5-32 1997MIC 4420/4429 Micrel Ordering information Part No. Temperature Range Package Configuration MIC44200CN 0C to +70C 8-Pin PDIP Non-inverting MIC 4420BN 40C to +85C 8-Pin PDIP Non-inverting MIC4420CM 0C to +70C 8-Pin SOIC Non-inverting MIC4420BM 40C to +85C 8-Pin SOIC Non-Inverting MIC4420BMM 40C to +85C 8-Pin MM8 Non-inverting MIC4420AJ 55C to +125C 8-Pin CerDIP Non-Inverting 962-8877003PA'| 55C to +125C 8-Pin CerDIP Non-Inverting 5962-8877003HA7] ~55C to +125C 10-Pin CerPak Non-Inverting MIG4420CT 0C to +70C 5-Pin TO-220 Non-Inverting MIC4429CN 0C to +70C 8-Pin PDIP Inverting MIC4429BN ~40C to +85C 8-Pin PDIP Inverting MIC4429CM 0C ta +70C 8-Pin SOIC Inverting MiC-4429BM ~40C to +85C 8-Pin SOIC Inverting MIC4429BMM 40C to +85C 8-Pin MM8 Inverting MIC4429AJ 55C to +125C 8-Pin CerDIP Inverting 5962-8877002PA|_ 55C to +125C 8-Pin CerDIP Inverting 5962-8877002HA*| 55C to +125C 10-Pin CerPak Inverting MIC4429CT 0C to +70C 9-Pin TO-220 Inverting 5962-8877001PA} -55C to +125C 8-Pin CerDIP Inverting 5962-8877001HA} -55C to +125C | 10-Pin CerPak Inverting ' Standard Military Drawing number for MIC4420AJBQ 2 Standard Military Drawing number for MIC4420AWBQ 3 Standard Military Drawing number for MIC4429AJBQ * Standard Military Drawing number for MIC4429AWBQ 5 Standard Military Drawing number for MIC429AJBQ Standard Military Drawing number for MIC429AWBQ Pin Configurations Soic, MM8 CerPack (W) TO-220 (T) DIP (J, N (M, MM) Vg oO Vs 13] Vs Vs [3] a] vs OUTPUT INPUT OUTPUT input Lz] [7] oureur ono NC fe]outeur nc [3] [6 | OUTPUT NC GND s]cno en [4] Fifer.) for proper operation. NOTE: Duplicate pins must both be connected 1997 5-33MIC 4420/4429 Absolute Maximum Ratings (Notes 1, 2 and 3) Power Dissipation, Tampjent S 25C PDIP oon eeseecsssteescssseessseesesstetsansscessneceeseseseesunesers 960W Power Dissipation, Toage $ 25C B-Pin TO-220 ccs ceeeeenseseteeeetetenseteenarens 12.5W Derating Factors (To Ambient) PDIP ccc cceeeeteteeseeneeeecnaesaresenasseeteaeeetes 7.7mWiPC SOIG oo ccc eee eerste rneesseerenenaeees 8.3mW/PC COrDIP eee ccese serene caepsteaeeeneneteeney 10mW/PC B-PIN TO-220 ooo. seccceeseecseeeeeeeteeeeeseneseseeens 17mWiG Micrel Thermat Impedances S-PIN TO-220 Ro jg oersssseececessssseenesseotesenvansscesennnecee 10C/W 8-pin MM8 Re), 250C/W Storage Temperature ..-65C to +150C Operating Temperature (Chip) ..0.0.. cc eceeeeeee 150C Operating Temperature (Ambient) CVOFSION ooo ect eecceneetereeecettseneenenes 0C to +70C B VO@FSION oo... eect eseeseseeseneenesesseceeseees ~40C to +85C A VO@PSION ee cececeesceceneestescoeeeeseenees ~55C to +125C Lead Temperature (10 S@C) oo... eee teeseeeeeeenee 300C Supply Voltage ........ cece ceesscecerseseeseecseeterseserees 20V Input Voltage oo... eee Vg + 0.3V to GND ~ 5V Input Current (Vay > Vig) ec eececcceeectseeensseseeneneees 50mA Electrical Characteristics: (1, = 25C with 4.5v < Vg < 18V unless otherwise specified.) Symbol | Parameter | Conditions | Min | Typ | Max [Units INPUT Vin Logic 1 Input Voltage 2.4 1.4 Vv Vit Lagic 0 Input Voltage 1.4 0.8 v Vin Input Voltage Range -5 Vg+0.3] V lin Input Current OVS Vins Vg 10 10 pA OUTPUT Vou High Output Voltage See Figure 1 Vg-0.025 v VoL Low Output Voltage See Figure 1 0.025 v Ro Output Resistance, lout = 10 MA, Vg = 18 V 17 2.8 Output Low Ro Output Resistance, loyt = 10 MA, Vg = 18 V 1.6 2.5 Q Output High Ip Peak Output Current Vg = 18 V (See Figure 5) 6 A IR Latch-Up Protection >500 mA Withstand Reverse Current SWITCHING TIME (Note 3} tr Rise Time Test Figure 1, C, = 2500 pF 12 35 ns te Fall Time Test Figure 1, C, = 2500 pF 13 35 ns toi Delay Time Test Figure 1 18 75 ns toe Delay Time Test Figure 1 48 78 ns POWER SUPPLY Is Power Suppiy Current Vine 3 0.45 1.5 mA Vin = OV 90 150 BA Vg Operating input Voltage 45 18 Vv 5-34 1997MIC 4420/4429 Micrel Electrical Characteristics: (1, =-55C to +125C with 4.5V < Vg < 18V unless otherwise specified.) Symbol! | Parameter | Conditions Min | Typ | Max | Units INPUT Vin Logic 1 Input Voltage 2.4 v Vit Logic 0 Input Voitage 0.8 Vin Input Voltage Range -5 Vg+0.3] V lin Input Current OV< Vins Vg -10 10 pA OUTPUT Vou High Output Voltage Figure 1 Vg~0.025 Vv VoL Low Output Voltage Figure 1 0.025 v Ro Output Resistance, lout = 10MA, Vg = 18V 3 5 Q Output Low Ro Output Resistance, lout = 10MA, Vg = 18V 2.3 5 Q Output High SWITCHING TIME (Note 3) tr Rise Time Figure 1, CL = 2500pF 32 60 ns te Fall Time Figure 1, C, = 2500pF 34 60 ns toy Delay Time Figure 1 50 100 ns toe Delay Time Figure 1 65 100 ns POWER SUPPLY Ig Power Supply Current Vin = 3V 0.45 3.0 mA Vin = OV 0.06 0.4 mA Vs Operating Input Voltage 45 18 Vv NOTE 1: Functional operation above the absolute maximum stress ratings is not implied. NOTE 2: Static-sensitive device. Store only in conductive containers. Handling personnel and equipment should be grounded to prevent damage from static discharge. NOTE 3: Switching times guaranteed by design. Test Circuits Vg = 18V Vg = 18V Doe & 0.1pF 1.0pF 0.1pF Lt OUT 2500pF o OUT 2500pF Vs 90% OUTPUT Figure 1a. inverting Driver Switching Time Figure 1b. Noninverting Driver Switching Time 1997 5-35MIC 4420/4429 Typical Characteristic Curves Rise Time vs. Supply Voltage Fall Time vs. Supply Voltage Micrel Rise and Fall Times vs. Temperature 60 50 25 = a + +. CL = 2260 pF ; =18V 50 40 re + t 4 20 40 C1= 10,000 pF Pa C= 10,000 pF z @ 30h 4+- - ai] 15 oN & traLL w 30 a oO) ow = C= 4700PF{ 2 29 |. Cy = 4700 pF | = 10 20 i _|...| le, = 2200 pF jo |---|} 4} 5 10 ; | _ tomes fo }- 1. To - 0 0 | L | L | 0 5 7 9 W 13 15 5 7 9 11 139018 0 -20 20 60 100 140 Vs (V) Vg (V) TEMPERATURE (C) Rise Time vs. Capacitive Load Fall Time vs. Capacitive Load Delay Time vs. Supply Voltage oT ann 60 40 | __ Ty anep 50 30 |- -_+--~ PO L. _ L ~ fr : DQ 40 z Vg = 5V i > B20 a1 & w Ww } i | i a = = |} ~tttet}1 3 F 30 F Vg = 12 E > Ns = 18V i 20 10 |}- ot 10 a i Poy 16 coche i i i a : 5 | i el 5 | i 1000 3000 10,000 1000 3000 10,000 4 6 8 10 12 14 16 18 CAPACITIVE LOAD (pF) CAPACITIVE LOAD (pF) SUPPLY VOLTAGE (V) Propagation Delay Time . Ve" Temperature Supply Current vs. Capacitive Load Supply Current vs. Frequency 60 84 1 Vg = 15V C= 2200 pF < = 50 70 Z - = = a 56 5 100 o & 2 G 42 2 F 40 z 500 > a 28 a 10 z s 200 2 20 is 20 10 o 60 -20 20 60 100 140 0 100 1000 10,000 0 100 1000 10,000 TEMPERATURE (C) CAPACITIVE LOAD (pF) FREQUENCY (kHz) 5-36 19975.0V 40 INPUT 8V AND 10V 2 an MIC 4420/4429 Micrel Typical Characteristic Curves (Cont.) Quiescent Power Supply Quiescent Power Supply Voltage vs. Supply Current Current vs. Temperature 1000 LOGIC 1" INPUT Vo = 18V = 800 b E z z ia 600 z LOGIC 1 INPUT i 700 3 3 > 400 > 600 ad ol o a a a & 200 @ 500 LOGIC 0 INPUT 0 0 4 8 12 16 20 40050 -2020~SwSs*NSC*tO SUPPLY VOLTAGE (V) TEMPERATURE (C) High-State Output Resistance Low-State Output Resistance 5 25 N 7 h Se A NN HE = ~ 5 a 10 mA 50 mA a g - 5 2 3 36 & 3 15 2 : 1 5 ? 9 1 (13 15 5 7 9 1 (13 15 Vg () Vg (V) Effect of Input Amplitude on Propagation Delay Crossover Area vs. Supply Voltage 200 2.0 = 2200 pF PER TRANSITION 160 *15 ? : = & 120 [- INPUT 2.4V < % # 4.0 id INPUT < a ii > 6 a a 3 a oO 0 5 6 7 8 9 10 11 12 13 14 15 V5 (V) 5 6 7 8 9 10 11 12 13 14 15 SUPPLY VOLTAGE V, (V) 1997 5-37MIC4420/4429 Applications Information Supply Bypassing Charging and discharging large capacitive loads quickly requires large currents. For example, charging a 2500pF load to 18V in 25ns requires a 1.8 A current from the device power supply. The MIC4420/4429 has double bonding on the supply pins, the ground pins and output pins This reduces parasitic lead inductance. Low inductance enables large currents to be switched rapidly. It also reduces internal ringing that can cause voltage breakdown when the driver is operated at or near the maximum rated voltage. internal ringing can also cause output oscillation due to feedback. This feedback is added to the input signal since it is referenced to the same ground. To guarantee low supply impedance over a wide frequency range, aparallel capacitor combination is recommended for supply bypassing. Low inductance ceramic disk capacitors with short lead lengths (< 0.5 inch) should be used. A 1nF low ESR film capacitor in parallel with two 0.1 HF low ESR ceramic capacitors, (such as AVX RAM GUARD), pro- vides adequate bypassing. Connect one ceramic capacitor directly between pins 1 and 4. Connect the second ceramic capacitor directly between pins 8 and 5. +15 (x2) 1N4448 , 5.6 kQ 560 Q owl 50V Lb =r ut YV 10 (x2 v4 MKS 2 BYV 10 (x2) R67 > __+ 220 uF 50V Micrel Grounding The high current capability of the MIC4420/4429 demands careful PC board layout for best performance Since the MIC 4429 is an inverting driver, any ground lead impedance will appear as negative feedback which can degrade switch- ing speed. Feedback is especially noticeable with slow-rise time inputs. The MIC4429 input structure includes 300mV of hysteresis to ensure clean transitions and freedom from oscillation, but attention to layout is still recommended. Figure 3 shows the feedback effect in detail. As the MIC 4429 input begins to go positive, the output goes negative and several amperes of current flow in the ground lead. As little as 0.0522 of PC trace resistance can produce hundreds of millivolts at the MiC-4429 ground pins. If the driving logic is referenced to power ground, the effective logic input level is reduced and oscillation may result. To insure optimum performance, separate ground traces shouid be provided for the logic and power connections. Connecting the logic ground directly to the MIC4429 GND pins will ensure full logic drive to the input and ensure fast output switching. Both of the MiC4429 GND pins should, however, still be connected to power ground. OUTPUT VOLTAGE vs LOAD CURRENT 30 29 28 VOLTS 27 26 25 o 20 40 60 80 100 120 140 mA Figure 3. Self Contained Voltage Doubler 5-38 1997MIC4420/4429 input Stage The input voltage level of the 4429 changes the quiescent supply current. The N channel MOSFET input stage tran- sistor drives a 450uA current source load. With a logic 1 input, the maximum quiescent supply current is 450yA. Logic 0 input level signals reduce quiescent current to 55uA maximum. The MIC4420/4429 input is designed to provide 300mV of hysteresis. This provides clean transitions, reduces noise sensitivity, and minimizes output stage current spiking when changing states. Input voltage threshold level is approximately 1.5V, making the device TTL compatible over the 4 .5V to 18V operating supply voltage range. Input current is less than 10,A over this range. The MIC-4429 can be directly driven by the TL494, SG1526/ 1527, $G1524, TSC170, MIC38HC42 and similar switch mode power supply integrated circuits. By offloading the power-driving duties to the MIC4420/4429, the power sup- ply controller can operate at lower dissipation. This can improve performance and reliability. The input can be greater than the Vs supply, however, current will flow into the input lead. The propagation delay for Tp2 will increase to as much as 400ns at room tempera- ture. The input currents can be as high as 30mA p-p (6.4mArms) with the input, 6 V greater than the supply voltage. No damage will occur to MIC4420/4429 however, and it will not latch. The input appears as a 7pF capacitance, and does not change even if the input is driven from an AC source. Care should be taken so that the input does not go more than 5 vaits below the negative rail. Power Dissipation CMOS circuits usually permit the user to ignore power dissipation. Logic families such as 4000 and 74C have outputs which can only supply a few milliamperes of current, and even shorting outputs to ground will not force enough +18V Micrel current to destroy the device. The MIC4420/4429 on the other hand, can source or sink several amperes and drive large capacitive loads at high frequency. The package power dissipation limit can easily be exceeded. Therefore, some attention should be given to power dissipation when driving low impedance loads and/or operating at high fre- quency. The supply current vs frequency and supply current vs capacitive load characteristic curves aid in determining power dissipation calculations. Table 1 lists the maximum safe operating frequency for several power supply voltages when driving a 2500pF load. More accurate power dissipa- tion figures can be obtained by summing the three dissipa- tion sources. Given the power dissipation in the device, and the thermal resistance of the package, junction operating temperature for any ambient is easy to calculate. For example, the thermal resistance of the 8-pin CerDIP package, from the data sheet, is 150C/W. In a 25C ambient, then, using a maximum junction temperature of 150C, this package will dissipate 800mW. Accurate power dissipation numbers can be obtained by summing the three sources of power dissipation in the device: + Load Power Dissipation (PL) * Quiescent power dissipation (Pq) * Transition power dissipation (PT) Calculation of load power dissipation differs depending on whether the load is capacitive, resistive or inductive. Resistive Load Power Dissipation Dissipation caused by a resistive load can be calculated as: P, =|? AGD where: |= the current drawn by the load Ro =_ the output resistance of the driver when the outputis high, at the power supply voltage used. (See data sheet) D = _ fraction of time the load is conducting (duty cycle) Table 1: MIC4429 Maximum ~_Lswima wee Operating Frequency TEK CURRENT Vv. Max PROBE 6302 \ 18V 500kHz 7 Wwe 11000 15V 700kHz e 10V 1.6MHz Conditions: 1. DIP Package (8ya = 130C/W) 2. Ta= 25C 3. Cy = 2500pF Figure 3. Switching Time Degradation Due to Negative Feedback 1997 5-39MIC 4420/4429 Capacitive Load Power Dissipation Dissipation caused by a capacitive load is simply the energy placed in, or removed from, the load capacitance by the driver, The energy stored in a capacitor is described by the equation: E=1/2C0 Ve As this energy is lost in the driver each time the load is charged or discharged, for power dissipation calculations the 1/2 is removed. This equation also shows that it is good practice not to place more voitage on the capacitor than is necessary, as dissipation increases as the square of the voltage applied to the capacitor. For a driver with a capaci- tive load: PL=FC (Vs) where: F = Operating Frequency C = Load Capacitance Vg = Driver Supply Voltage Inductive Load Power Dissipation For inductive loads the situation is more complicated. For the part of the cycle in which the driver is actively forcing current into the inductor, the situation is the same as it is in the resistive case: PLi=l2 Ro D However, in this instance the Ro required may be either the on resistance of the driver when its output is in the high state, or its on resistance when the driver is in the low state, depending on how the inductor is connected, and this is still only half the story. For the part of the cycle when the inductor is forcing current through the driver, dissipation is best described as PL2 =! Vp (1-D) where Vp is the forward drop of the clamp diode in the driver (generally around 0.7V). The two parts of the load dissipa- tion must be summed in to produce PL Pi =Pii+ Pie Quiescent Power Dissipation Quiescent power dissipation (Pa, as described in the input section) depends on whether the input is high or low. A low input will result in a raaximum current drain (per driver} of <0.2mA; a logic high will result in a current drain of <2.0mA. Quiescent power can therefore be found from: Pq = Vs [D Ip, + (1-D) IL] Micrel where: lH = quiescent current with input high IL = quiescent current with input low D= fraction of time input is high (duty cycle) Vs = power supply voltage Transition Power Dissipation Transition power is dissipated in the driver each time its output changes state, because during the transition, for a very brief interval, both the N- and P-channel MOSFETs in the output totem-pole are ON simultaneously, and a current is conducted through them from Vts to ground. The transi- tion power dissipation is approximately: PT = 2 F Vs (Ass) where (Ass) is a time-current factor derived from the typical characteristic curves. Total power (Pp) then, as previously described is: Pp = PL + PQ+PT Definitions Load Capacitance in Farads. D= Duty Cycle expressed as the fraction of time the input to the driver is high. F= Operating Frequency of the driver in Hertz ty = Power supply current drawn by a driver when both inputs are high and neither output is loaded. iL = Power supply current drawn by a driver when both inputs are low and neither output is loaded. Ip = Output current from a driver in Amps. Total power dissipated in a driver in Watts. Power dissipated in the driver due to the driver's load in Watts. Power dissipated in a quiescent driver in Watts. Power dissipated in a driver when the output changes states (shoot-through current) in Watts. NOTE: The shoot-through current from a dual transition (once up, once down) for both drivers is shown by the Typical Characteristic Curve : Crossover Area vs. Supply Voltage and is in ampere-seconds. This figure musi be multiplied by the number of repetitions per second (fre- quency) to find Watts. Output resistance of a driver in Ohms. Vs = Power supply voltage to the IC in Volts. 5-40 1997MIC 4420/4429 Micrel +18V 4q L WIMA MK22 OM 5.0V. 1 TEK CURRENT 18V 3 PROBE 6302 6,7 MiCc4429 OV = w)5 = OV 0.1 pF 4 , i. HF 10,000 pF POLYCARBONATE v Figure 6. Peak Output Current Test Circuit 1997 5-41