ML4428CP

April 1997 PRELIMINARY ML4428* Sensorless Smart-Start™ BLDC PWM Motor Controller GENERAL DESCRIPTION The ML4428 motor controller provides all of the functions necessary for starting and controlling the speed of delta or wye-wound Brushless DC (BLDC) Motors without the need for Hall Effect sensors. Back-EMF voltage is sensed from the motor windings to determine the proper commutation phase sequence using PLL techniques. The patented back-EMF sensing technique used will commutate virtually any 3-phase BLDC motor that has at least a 30% variation in inductance during rotation and is insensitive to PWM noise and motor snubbing circuitry. The ML4428 also utilizes a patented start-up technique which samples the rotor position and applies the proper drive to accelerate the motor. This ensures no reverse rotation at start-up and reduces total start-up time. FEATURES s s Stand-alone operation with forward and reverse On-board start sequence: Sense Position Æ Drive Æ Accelerate Æ Set Speed No backward movement at start-up Patented back-EMF commutation technique Simple variable speed control with on-board reference Single external resistor sets all critical currents PWM control for maximum efficiency or linear control for minimum noise 12V operation provides direct FET drive for 12V motors Drives high voltage motors with high side FET drivers s s s s s s s s Guaranteed no shoot-through when driving external FET gates directly * Some Packages Are End Of Life BLOCK DIAGRAM/TYPICAL APPLICATION 19 RINIT CSC 5 6 CPWM PWM SPEED CONTROL CISC RREF VREF VSPEED 6V REF 16 RVCO VCO 15 CVCO 20 RCVCO 14 VCC 9V POWER FAIL VCO 13 PHI1 22 BACK-EMF SAMPLER PHI2 23 PHI3 24 27 7 8 + – RUN 0.6V HIGH SIDE GATE DRIVE P1 2 P2 3 P3 4 F/R 12 BRAKE 25 CSNS 17 26 START-UP AND COMMUTATION LOGIC PWM CURRENT CONTROL AND ONE SHOT CIOS 1 ISNS N1 LOW SIDE GATE DRIVE N2 N3 11 GND 28 9 10 VFLT 18 21 1 ML4428 PIN CONFIGURATION ML4428 28-Pin Molded Narrow Dip (P28N) 28-Pin SOIC(S28) ISNS P1 P2 P3 CSC CPWM VREF VSPEED N1 N2 N3 F/R VCO VCC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 GND RREF CIOS BRAKE PHI3 PHI2 PHI1 CISC RCVCO RINIT VFLT CSNS RVCO CVCO TOP VIEW 2 ML4428 PIN DESCRIPTION PIN NAME FUNCTION PIN NAME FUNCTION 1 ISNS Motor current sense input. Current limit one-shot is triggered when this pin is approximately 0.5V. Drives the external P-channel transistor driving motor PHI1. Drives the external P-channel transistor driving motor PHI2. Drives the external P-channel transistor driving motor PHI3. The resistor/capacitor combination on this gm amplifier output sets a pole zero of the speed loop in conjunction with a gm of 0.230mmho. A capacitor to ground at this pin sets the PWM oscillator frequency. A 1nF capacitor will set the frequency to approximately 25kHz for PWM speed control. Grounding this pin selects linear speed control. This voltage reference output (6V) can be used to set the speed reference voltage. This voltage input to the amplifier in the speed loop controls the speed target of the motor. Drives the external N-channel MOSFETs for PHI1. Drives the external N-channel MOSFETs for PHI2. Drives the external N-channel MOSFETs for PHI3. The forward/reverse pin controls the sequence of the commutation states and thus the direction of motor rotation. (TTL level) This logic output indicates the commutation frequency of the motor in run mode. (TTL level) 12V power supply. Timing capacitor for VCO 16 RVCO 17 CSNS The resistor on this pin sets a process independent current to generate a repeatable VCO frequency. This capacitor to ground sets the ON time of the 6 sense pulses used for position detection at start-up and at low speeds. A 5.6nF capacitor will set the on time to approximately 200µs. A logic “0” indicates the power supply is under-voltage. (TTL level) This resistor sets the minimum VCO frequency, and thus, the initial on time of the drive energization at start-up. A 2 Mý resistor to ground sets the minimum VCO frequency to approximately 10Hz, resulting in an initial drive energization pulse of 100ms in conjunction with 82nF CVCO and 10k RVCO. VCO loop filter components. A capacitor to ground at this gm amplifier output sets a pole in the current-mode portion of the speed loop in conjunction with a gm of 0.230mmho. Motor Terminal 1 Motor Terminal 2 Motor Terminal 3 A ”0” activates the braking circuit. (TTL level) A 50µA current from this pin will charge a timing capacitor to GND for fixed OFF-time PWM current control This resistor sets constant currents on the device to reduce process dependence and external components. A 120k resistor sets the previously mentioned current levels. Signal and Power Ground 2 3 4 5 P1 P2 P3 CSC 18 VFLT 19 RINIT 6 CPWM 20 RCVCO 21 CISC 7 VREF 8 VSPEED 22 PHI1 23 PHI2 24 PHI3 25 BRAKE 26 CIOS 9 N1 10 N2 11 N3 12 F/R 27 RREF 13 VCO 28 GND 14 VCC 15 CVCO 3 ML4428 ABSOLUTE MAXIMUM RATINGS Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. Supply Voltage (pin 14) ............................................. 14V Output Current (pins 2, 3, 4, 9,10,11) ................... ±50mA Logic Inputs (pins 12, 25) ................................ –0.3 to 7V Junction Temperature ............................................ 150°C Storage Temperature Range ..................... –65°C to 150°C Lead Temperature (Soldering 10 sec.) .................... 260°C Thermal Resistance (qJA) Plastic DIP ....................................................... 52°C/W Plastic SOIC ..................................................... 75°C/W OPERATING CONDITIONS Temperature Range Commercial ............................................... 0°C to 70°C Industrial ................................................ –40°C to 85°C VCC Voltage ..................................................... 12V ±10% ELECTRICAL CHARACTERISTICS Unless otherwise specified, TA = 0°C to 70°C, VCC = 12V, RSNS = 0.3ý, CVCO = 82nF, CIOS = 100pF, RREF = 120ký, CSNS = 5.6nF, RVCO = 10k, RINIT = 2Meg (Notes 1, 2, and 3) SYMBOL Oscillator (VCO) Frequency vs. VPIN 20 Maximum Frequency RCVCO = 2V RCVCO = 6V 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C Sampling Amplifier IRCVCO (Note 4) State A, VPH2 = VCC/3 State A, VPH2 = VCC/2 State A, VPH2 = 2VCC/3 Current Limit ISNS Trip Point One Shot Off Time Power Fail Detection Power Fail Trip Voltage Hysteresis Logic Inputs VIH VIL IIH IIL VOH VOL Voltage High Voltage Low Current High Current Low VIN = 2.7V VIN = 0.4V IOUT = –0.1mA IOUT = 1mA –300 –400 2 0.8 0 0 V V µA µA 8.0 300 500 9.0 700 V mV 0.45 10 0.5 13 0.55 15 µs 80 –25 –150 116 0 –116 150 25 –80 µA µA µA 550 520 1850 1650 600 600 2150 2150 750 750 2350 2350 Hz/V Hz/V Hz Hz PARAMETER CONDITIONS MIN TYP MAX UNITS Logic Outputs Voltage High Voltage Low 3.3 0.4 V V 4 ML4428 ELECTRICAL CHARACTERISTICS SYMBOL Output Drivers VP High VP Low Ip Low VP = 1V 0°C to 70°C –40°C to 85°C P Comparator Threshold VN High VN Low N Comparator Threshold Speed Control fPWM gm Current CSC Positive Clamp CISC Positive Clamp CISC Negative Clamp VREF Supply VCC Current Note 1: Note 2: Note 3: Note 4: Limits are guaranteed by 100% testing, sampling or correlation with worst case test conditions. F/R and BRAKE have internal 17kW pull-up resistors to an internal 5V reference. VFLT and VCO have internal 4.3kW pull-up resistors to an internal 5V reference. For explanation of states, see Figure 6 and Table 1. (Continued) CONDITIONS MIN TYP MAX UNITS PARAMETER IP = –10µA VCC – 1.2 0.7 2.5 1.5 VCC – 3.0 4 4 1.2 6 6 V V mA mA V V 0.7 1.2 3 V V VPIN12 = 0V IN = 1mA VCC – 1.2 COSC = 1nF 20 25 ±160 36 kHz µA 2.9 5.2 1.2 5.5 3.1 5.5 1.7 5.9 3.35 5.6 1.9 6.5 V V V V 18 25 32 mA 5 ML4428 FUNCTIONAL DESCRIPTION The ML4428 provides closed-loop commutation for 3-phase brushless motors. To accomplish this task, a VCO, integrating back-EMF Sampling error amplifier and sequencer form a phase-locked loop, locking the VCO to the back-EMF of the motor. The IC contains circuitry to control motor speed in PWM mode. Braking and power fail detection functions are also provided on the chip. The ML4428 is designed to drive external power transistors (N-channel sinking transistors and P-channel sourcing transistors) directly. The ML4428 limits the motor current with a constant offtime PWM controlled current. The velocity loop is controlled with an on-board amplifier. An accurate, jitterfree VCO output is provided equal to the commutation frequency of the motor. The ML4428 switches the gates of external N-channel power MOSFETs to regulate the motor current and directly drives the P-channel MOSFETs for 12V motors. The ML4428 ensures that there is no shoot through in any state of power drive to the FETs. Higher voltage motors can be driven using buffer transistors or standard “high side” drivers. Speed sensing is accomplished by monitoring the output of the VCO, which will be a signal which is phase-locked to the commutation frequency of the motor. BACK-EMF SENSING AND COMMUTATOR The ML4428 contains a patented back-EMF sensing circuit (Figure 1) which samples the phase which is not energized (Shaded area in Figure 2) to determine whether to increase or decrease the commutator (VCO) frequency. A late commutation causes the error amplifier to charge the filter 0 60 120 180 240 300 0 (RC) on RCVCO, increasing the VCO input while early commutation causes RCVCO to discharge. The analog speed control loop uses RCVCO as a speed feedback voltage. The input impedance of the three PH inputs is about 8.7ký to GND. When operating with a higher voltage motor, the PH inputs should be divided down in voltage with series resistors so that the maximum voltage at any PH input does not exceed VCC. NEUTRAL Figure 2. Typical Motor Phase Waveform with back-EMF Superimposed (Ideal Commutation). PHI1 22 PHI2 23 PHI3 24 5.8K NEUTRAL SIMULATOR ΦA + ΦB + ΦC 9 I(RC) = Va – Vb 4.35K a + RCVCO – R C1 C2 LOOP FILTER SIGN CHANGER MULTIPLEXER b 2.9K COMMUTATION LOGIC VCO VCO Figure 1. Back-EMF Sensing Block Diagram 6 ML4428 COMPONENT SELECTION GUIDE In order to properly select the critical components for the ML4428 you should know the following things: 1. The motor operating voltage, VMOTOR (V). 2. The maximum operating current for the motor, IMAX (A). 3. The number of poles the motor has, N. 4. The back-EMF constant of the motor, Ke (V ¥ s/rad). 5. The torque constant of the motor, Ke (N ¥ m/A). (This is the same as the back-EMF constant, only in different units.) 6. The maximum desired speed of operation, RPMMAX (rpm). 7. Line to line resistance, RL-L (Ohms). 8. Line to line inductance, LL-L (Henries). 9. The motor should have at least 15% line-to-line inductance variation during rotation for proper startup sensing. (Air core motors will not run using the ML4428.) Examine the motor to determine if there is any iron in the core. If the stator coils are not wound around an iron form, the ML4425 or ML4426 may be a better choice. If you do not know one or more of the above values, it is still possible to pick components for the ML4428, but some experimentation may be necessary to determine the optimal value. All quantities are in SI units unless other wise specified. The formulas in the following section are based on linear system models. The following formulas should be considered a starting point from which you can optimize your application. Note: Refer to Application Note 43 for details on loop compensation. RSENSE The function of RSENSE is to provide a voltage proportional to the motor current, for current limit/feedback purposes. The trip voltage across RSENSE is 0.5V so: RSENSE = 0.5 IMAX RES1, RES2 and RES3 Operating motors at greater than 12V requires attenuation resistors in series with the sense inputs (PHI1, PHI2, PHI3) to keep the voltage less than 12V. The phase sense input impedance is 8700ý. This requires the external resistor to be set as follows and results in the given attenuation. RES1 = RES2 = RES3 RESI = 725 (VMOTOR – 10) 2900 RES1+ 8700 A larger value for RES1 may be required if the peak motor phase voltage exceds VMOTOR. Atten = ISENSE FILTER The ISENSE filter consists of an RC lowpass filter in series with the current sense signal. The purpose of this filter is to filter out noise spikes on the current, which may cause false triggering of the one shot circuit. It is important that this filter not slow down the current feedback loop, or destruction of the output stage may result. The recommended values for this circuit are R = 1Ký and C= 300pF. This gives a time constant of 300ns, and will filter out spikes of shorter duration. These values should suffice for most applications. If excessive noise is present on the ISENSE pin, the capacitor may be increased at the expense of speed of current loop response. The filter time constant should not exceed 500ns or it will have a significant impact on the response speed of the one shot current limit. CIOS The one shot capacitor determines the off time after the current limit is activated, i.e. the voltage on the ISENSE pin exceeded 0.5V. The following formula ensures that the motor current is stable in current limit: CIOS(MAX) = 1.11× 10−11 × VMOTOR CIOS is in Farads This is the maximum value that CIOS should be. Higher average torque during the current limit cycle can be achieved by reducing this value experimentally, while monitoring the motor current carefully, to be sure that a runaway condition does not occur. This runaway condition occurs when the current gained during the on time exceeds the current lost during the off time, causing the motor current to increase until damage occurs. For most motors this will not occur, as it is usually a self limiting phenomenon. (See Figure 7) IMAX is the maximum motor current. The power dissipation in the resistor is IMAX squared times RSENSE, so the resistor should be sized appropriately. For very high current motors, a smaller resistor can be used, with an op-amp to increase the gain, so that power dissipation in the sense resistor is minimized. 7 ML4428 CVCO As given in the section on the VCO and phase detector: −6 CVCO = 2931× 10 N × RPMMAX VCO AND PHASE DETECTOR CALCULATIONS The VCO should be set so that at the maximum frequency of operation (the running speed of the motor) the VCO control voltage will be no higher than VREF, or 6V. The VCO maximum frequency will be: Where N is the number of poles in the motor, and RPM is the motor’s maximum operating speed in revolutions per minute. CPWM This capacitor sets the PWM ramp oscillator frequency. This is the PWM “switching frequency”. If this value is too low, 30kHz, then the switching losses in the output drivers may become a problem. 25kHz should be a good compromise for this value, which can be obtained by using a 1nF capacitor. RVCO AND RREF RVCO should be 10k and RREF should be 120k for normal operation. VCO FILTER See the section on the VCO and Phase detector for information on these components. FMAX = 0.05 × N × RPMMAX where N is the number of poles on the motor and RPMMAX is the maximum motor speed in Revolutions Per Minute. The minimum VCO gain derived from the specification table (using the minimum FVCO at VVCO = 6V) is: −5 K VCO(MIN) = 2.665 × 10 CVCO Assuming that the VVCO(MAX) = 5.5V, then −5 CVCO = 5.5 × 2.665 × 10 FMAX or −6 CVCO = 2931× 10 N × RPMMAX Gm = 0.23m + SAMPLED PHASE – FOUT VCO KVCO(Hz/sec/V) A/RADIAN ROTOR PHASE BEMF SAMPLER Ke × ω × Atten 2×π gm = 0.23mA/V LOOP FILTER (R × C2 × s + 1) s × (C2 + R × C1 × s × C2 + C1) PHASE DETECTOR RADIAN/sec/V 2.665 × 10–5 ×2×π CVCO × s VCO Figure 4. Back-EMF Phase Locked Loop Components. 8 Ω RCVCO ZRC R C1 C2 V/A ML4428 3000 The simplified impedance of the loop filter is (s + ωLEAD ) ZRC (s) = 1 C1s (s + ωLAG ) 2500 FREQUENCY (Hz) CVCO = 82nF 2000 Where the lead and lag frequencies are set by: 1500 CVCO = 164nF 1000 ωLEAD = ωLAG = 1 R C2 C1 + C2 R C1 C2 500 0 0 2 4 6 VVCO (VOLTS) 8 10 12 Requiring the loop to settle in 20 PLL cycles with w LAG = 10 ¥ w LEAD produces the following calculations for R, C1 and C2: C1 = 7.508 × 10−4 × Atten × K e N Figure 3. VCO Output Frequency vs. VVCO (Pin 20) Figure 4 shows the linearized transfer function of the Phase Locked Loop with the phase detector formed from the sampled phase through the Gm amplifier with the loop filtered formed by R, C1, and C2. The Phase detector gain is: Ke × ω × Atten × 2.3 × 10−4 A / Radian 2π Where Ke is the motor back-E.M.F. constant in V/Radian/ sec, w is the rotor speed in r/s, and Atten is the backE.M.F. resistive attenuator, nominally 0.3. C2 = 9 ¥ C1 R= 8.89 × 104 Atten × K e × RPMMAX where Ke is the back-EMF constant in volts per radian per second, and RPMMAX is the rotor speed. See Micro Linear application note 35 for derivation of the above formulas. The 80k resistor to GND from the RCVCO pin assists in a smooth transition from sense mode to closed loop operation. IMOTOR ~200µs DRIVE ~100ms SENSE ~3ms t IMOTOR LOOP CLOSED HERE (RUN MODE) SENSE DRIVE SENSE DRIVE SENSE DRIVE DRIVE t Figure 5. Typical Sensed Start-up 9 ML4428 CSNS A capacitor to ground at this pin sets the ON time of the 6 current sense pulses used for position detection at start-up and at low speeds. The ON time is set by: TON = CSNS (35.7k) Referring to Figure 5, each of the 6 current sense pulses is governed by a rise time with a time constant of L/R where L is the inductance of the motor network with 2 windings shorted and R is the total resistance in series with the motor between the supply rails. R includes the ON-resistance of the power-FETs and RSNS. The RDSON of the high side FET should match that of the low side FET. L is a function of rotor position. Each pulse will have a peak value VSENSEPEAK of VSENSEPEAK = RSNS − TON   VMOTOR 1 − e L / R    R   What is important for sensing rotor position is the amplitude difference between each of the three pairs of current sense pulses. This can be seen by triggering on ISNS on an oscilloscope with the RCVCO pin shorted to ground. One should see the current waveform of Figure 5. Allowing the peak current sense pulse to reach an amplitude of 0.5V (by adjusting CSNS, and hence TON) or, allowing the difference between the maximum and minimum of the 6 pulses to be >50mV, should suffice for adequate rotor position sensing. A good starting value for TON is 200µs, requiring CSNS = 5.6nF. RINIT The initial time interval between sample pulses during start-up is set by RINIT. This time interval (tINIT) occurs while the RCVCO pin is less than 0.25 volts. RINIT = 3.43 tINIT CVCO where R = 0.75 × RL −L + 2 × RSDON + RSENSE L = 0.75 × LL −L ( ) DIRECTION STATE REVERSE FORWARD A B C D E F N3 N1 OFF OFF ON ON OFF OFF N2 N2 OFF OFF OFF OFF ON ON OUTPUTS N1 N3 ON ON OFF OFF OFF OFF P3 P1 ON OFF OFF OFF OFF ON P2 P2 OFF ON ON OFF OFF OFF P1 P3 OFF OFF OFF ON ON OFF INPUT SAMPLES FORWARD PH2 PH1 PH3 PH2 PH1 PH3 REVERSE PH2 PH3 PH1 PH2 PH3 PH1 Table 1. Commutation States. 3.75V CVCO 2.0V VCO OUT A B C D E F A Figure 6. Commutation Timing and Sequencing. 10 ML4428 START-UP SEQUENCING When the motor is initially at rest, it is generating no back-EMF. Because a back-EMF signal is required for closed loop commutation, the motor must be started by other means until a velocity sufficient to generate some back-EMF is attained. Start For RCVCO voltages of less than 0.6V the ML4428 will send 6 sample pulses to the motor to determine the rotor position and drive the proper windings to produce desired rotation. This will result in motor acceleration until the RCVCO pin achieves 0.6V and closed loop operation begins. This technique results in zero reverse rotation and minimizes start-up time. The sample time pulses are set by CSNS and the initial sample interval is set by RINIT. This sense technique is not effective for air core motors, since a minimum of 30% inductance difference must occur when the motor moves. Direction The direction of motor rotation is controlled by the commutation states as given in Table 1. The state sequence is controlled by the F/R. TOFF (µs) Speed Control The speed control section of the ML4428 is detailed in Figure 8. The two transconductance amplifiers with outputs at CSC and CISC each have a gm of 0.23mmhos. The bandwidth of the current feedback component of the speed control is set at CISC as follows: −4 −5 f3dB = 2.3 × 10 = 3.66 × 10 2π CISC CISC For f3dB = 50kHz, CISC would be 730pF. The filter components on the CSC pin set the dominant pole in the system and should have a bandwidth of about 10% of the position filter on the RCVCO pin. Typically this is in the 1 to 10Hz range. 60 50 40 Run When the RCVCO pin exceeds 0.6V the device will enter run mode. At this time the motor speed should be about 8% FRPMMAX and be high enough to generate a detectable BEMF and allow closed loop operation to begin. The commutation position compensation has been previously discussed. The motor will continue to accelerate as long as the voltage on the RCVCO is less than the voltage on VSPEED. During this time the motor will receive full N-channel drive limited only by ILIMIT. As the voltage on RCVCO approaches that of VSPEED the CISC capacitor will charge and begin to control the gate drive to the N-channel transistor by setting a level for comparison on the 25kHz PWM saw tooth waveform generated on CPWM. The compensation of the speed loop is accomplished on CSC and on CISC which are outputs of transconductance amplifiers with a gm = 2.3 ¥ 10–4 . ý 30 20 10 0 0 100 200 300 CIOS (pF) 400 500 Note: 100pF gives 10µs, 200pF gives 20µs, etc. Slope = dT = dV = 5V = 100kΩ 50µA C i Figure 7. ILIMIT Output Off-Time vs. COS. CSC 5 0.23mmho VSPEED 8 RCVCO 20 + + – – LEVEL SHIFT +1.4V + CPWM 6 – 0.23mmho CISC 21 LINEAR CONTROL TO LOW-SIDE GATE DRIVE MODE SELECT ISNS 1 PWM CONTROL TO COMMUTATION LOGIC Figure 8. Speed Control Block Diagram. 11 ML4428 OUTPUT DRIVERS The P-channel drivers are emitter follower type with 5mA pull down currents. The N-channel drivers are totem pole with a 1200ý resistor in series with the pull up device. Crossover comparators are employed with each driver pair, eliminating the potential of crossover, and hence, shoot-through currents. BRAKING When BRAKE is pulled low all 3 P-channel drivers will be turned off and all 3 N-channel drivers will be turned on. POWER FAIL In the event of a power fail, i.e. VCC falls below 8.75V all 6 output drivers will be turned off. HIGHER VOLTAGE MOTOR DRIVE The ML4428 can be used to drive higher voltage motors by means of level shifters to the high side drive transistors. This can be accomplished by using dedicated high side drivers for applications greater than 80V or a simple NPN level shift as shown in Figure 9 for applications below 80V. Figure 10 shows how to interface to the IR2118, high side drivers from I.R. This allows driving motors up to 600V. The BRAKE pin can be pulsed prior to startup with an RC circuit. This charges the bootstrap capacitors for three inexpensive high side drivers 12 VMOTOR +24 TO 60V 2kΩ IRFR9120 IRFR9120 Q3 2N6718 MOTOR Q2 2N6718 2kΩ 0.1µF 330µF 2kΩ IRFR9120 +12V Q1 2N6718 0.1µF IRFR120 IRFR120 IRFR120 1kΩ 1kΩ 2kΩ 2kΩ 2kΩ 4 3 2 1 300pF ISNS P1 P2 P3 CSC CPWM VREF 7 8 9 GND 28 ML4428 120kΩ RREF 27 CIOS 26 BRAKE 25 PHI3 24 PHI2 23 PHI1 22 RES1 BRAKE RES1 RES1 80kΩ RUN 100pF 0.1µF 50kΩ 5 6 0.1µF 1nF 20kΩ SPEED CONTROL VOLTAGE 100Ω 100Ω 100Ω 1µF VSPEED N1 10 N2 11 N3 12 F/R CISC 21 RCVCO 20 RINIT 19 VFLT 18 CSNS 17 13 VCO 1µF 2kΩ 10µF PWR FAIL Figure 9. Driving Higher Voltage Motors: 24V to 80V. FWD/REVERSE 1.5kΩ VCO +12V RVCO 16 14 VCC CVCO 15 750pF 0.1µF 0.1µF 0.1µF 10kΩ 5.6nF 2MΩ ML4428 13 ML4428 VMOTOR +12V MUR150 330µF 400V IR2118 1 2 IRF720 IRF720 IRF720 VCC IN COM N/C VB 8 HO 7 VS 6 N/C 5 100Ω 25V 2.2µF 25V 0.1µF 3 4 MOTOR MUR150 PH1 IR2118 1 2 VCC IN COM N/C VB 8 HO 7 VS 6 N/C 5 100Ω 25V 2.2µF Note: Refer to IK2118 data sheet for complete information on using this part with different FETs and IGBTs. PH3 PH2 25V 0.1µF 3 4 MUR150 IR2118 1 2 VCC IN COM N/C VB 8 HO 7 VS 6 N/C 5 100Ω 25V 2.2µF 25V 0.1µF 3 4 IRF720 IRF720 IRF720 100Ω 100Ω 100Ω RSENSE 300MΩ 10W 1kΩ 330pF 1 2 3 ML4428 ISNS P1 P2 P3 CSC CPWM VREF VSPEED N1 GND 28 RREF 27 COS 26 BRAKE 25 PHI3 24 PHI2 23 PHI1 22 CISC 21 RCVCO 20 RINIT 19 VFLT 18 CSNS 17 RVCO 16 CVCO 15 0.01µF 750pF 5.6nF 10kΩ 2MΩ 10µF 2kΩ 1µF PWR FAIL 80kΩ 0.01µF 5.11kΩ 5.11kΩ 5.11kΩ BRAKE RUN 120kΩ 0.01µF 12kΩ 10µF 1nF 4 5 6 7 VSPEED 8 787Ω 0.1µF 10kΩ 9 10 N2 11 N3 12 F/R VCO +12V FWD/REVERSE 25V 1µF 13 VCO 14 VCC 0.1µF Figure 11. ML4428 High Voltage Motor Driver: 12V to 500V 14 ML4428 PHYSICAL DIMENSIONS inches (millimeters) Package: P28N 28-Pin Narrow PDIP 1.355 - 1.365 (34.42 - 34.67) 28 PIN 1 ID 0.280 - 0.296 0.299 - 0.325 (7.11 - 7.52) (7.60 - 8.26) 1 0.045 - 0.055 (1.14 - 1.40) 0.100 BSC (2.54 BSC) 0.020 MIN (0.51 MIN) 0.180 MAX (4.57 MAX) 0.125 - 0.135 (3.18 - 3.43) 0.015 - 0.021 (0.38 - 0.53) SEATING PLANE 0º - 15º 0.008 - 0.012 (0.20 - 0.31) 15 ML4428 PHYSICAL DIMENSIONS inches (millimeters) Package: S28 28-Pin SOIC 0.699 - 0.713 (17.75 - 18.11) 28 0.291 - 0.301 0.398 - 0.412 (7.39 - 7.65) (10.11 - 10.47) PIN 1 ID 1 0.024 - 0.034 (0.61 - 0.86) (4 PLACES) 0.050 BSC (1.27 BSC) 0.095 - 0.107 (2.41 - 2.72) 0º - 8º 0.090 - 0.094 (2.28 - 2.39) 0.012 - 0.020 (0.30 - 0.51) SEATING PLANE 0.005 - 0.013 (0.13 - 0.33) 0.022 - 0.042 (0.56 - 1.07) 0.009 - 0.013 (0.22 - 0.33) ORDERING INFORMATION PART NUMBER ML4428CP (EOL) ML4428CS (EOL) ML4428IP ML4428IS TEMPERATURE RANGE 0°C to 70°C 0°C to 70°C –40°C to 85°C –40°C to 85°C PACKAGE 28-Pin DIP (P28N) 28-Pin SOIC (S28) 28-Pin DIP (P28N) 28-Pin SOIC (S28) © Micro Linear 1997 is a registered trademark of Micro Linear Corporation Products described in this document may be covered by one or more of the following patents, U.S.: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940; 5,546,017; 5,559,470; 5,565,761; 5,592,128; 5,594,376; Japan: 2598946; 2619299. Other patents are pending. Micro Linear reserves the right to make changes to any product herein to improve reliability, function or design. Micro Linear does not assume any liability arising out of the application or use of any product described herein, neither does it convey any license under its patent right nor the rights of others. The circuits contained in this data sheet are offered as possible applications only. Micro Linear makes no warranties or representations as to whether the illustrated circuits infringe any intellectual property rights of others, and will accept no responsibility or liability for use of any application herein. The customer is urged to consult with appropriate legal counsel before deciding on a particular application. 2092 Concourse Drive San Jose, CA 95131 Tel: 408/433-5200 Fax: 408/432-0295 DS4428-01 16