April 1997 PRELIMINARY ML4428* Sensorless Smart-Start™ BLDC PWM Motor Controller GENERAL DESCRIPTION FEATURES 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. ■ 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 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. Guaranteed no shoot-through when driving external FET gates directly * Some Packages Are End Of Life ■ BLOCK DIAGRAM/TYPICAL APPLICATION 19 16 RINIT 6 21 14 20 CVCO RCVCO VCC VFLT 9V POWER FAIL VCO CSC 5 15 RVCO 18 VCO 13 CPWM PHI1 PWM SPEED CONTROL 22 BACK-EMF SAMPLER CISC PHI2 23 PHI3 24 27 7 8 RREF VREF + 6V REF – RUN P1 0.6V VSPEED 2 HIGH SIDE GATE DRIVE P2 3 P3 4 F/R 12 START-UP AND COMMUTATION LOGIC BRAKE N1 LOW SIDE GATE DRIVE PWM CURRENT CONTROL AND ONE SHOT 25 CSNS 17 9 10 N3 11 CIOS 26 N2 ISNS 1 GND 28 1 ML4428 PIN CONFIGURATION ML4428 28-Pin Molded Narrow Dip (P28N) 28-Pin SOIC(S28) ISNS 1 28 GND P1 2 27 RREF P2 3 26 CIOS P3 4 25 BRAKE CSC 5 24 PHI3 CPWM 6 23 PHI2 VREF 7 22 PHI1 VSPEED 8 21 CISC N1 9 20 RCVCO N2 10 19 RINIT N3 11 18 VFLT F/R 12 17 CSNS VCO 13 16 RVCO VCC 14 15 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. 16 RVCO The resistor on this pin sets a process independent current to generate a repeatable VCO frequency. 2 P1 Drives the external P-channel transistor driving motor PHI1. 17 CSNS 3 P2 Drives the external P-channel transistor driving motor PHI2. 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. 4 P3 Drives the external P-channel transistor driving motor PHI3. 18 VFLT A logic “0” indicates the power supply is under-voltage. (TTL level) 5 CSC 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. 19 RINIT 6 CPWM 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 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. 20 RCVCO VCO loop filter components. 21 CISC 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. 22 PHI1 Motor Terminal 1 23 PHI2 Motor Terminal 2 7 VREF This voltage reference output (6V) can be used to set the speed reference voltage. 8 VSPEED This voltage input to the amplifier in the speed loop controls the speed target of the motor. 9 N1 Drives the external N-channel MOSFETs for PHI1. 24 PHI3 Motor Terminal 3 10 N2 Drives the external N-channel MOSFETs for PHI2. 25 BRAKE A ”0” activates the braking circuit. (TTL level) 11 N3 Drives the external N-channel MOSFETs for PHI3. 26 CIOS 12 F/R The forward/reverse pin controls the sequence of the commutation states and thus the direction of motor rotation. (TTL level) A 50µA current from this pin will charge a timing capacitor to GND for fixed OFF-time PWM current control 27 RREF This resistor sets constant currents on the device to reduce process dependence and external components. A 120k resistor sets the previously mentioned current levels. 28 GND Signal and Power Ground 13 VCO This logic output indicates the commutation frequency of the motor in run mode. (TTL level) 14 VCC 12V power supply. 15 CVCO Timing capacitor for VCO 3 ML4428 ABSOLUTE MAXIMUM RATINGS OPERATING CONDITIONS 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. Temperature Range Commercial ............................................... 0°C to 70°C Industrial ................................................ –40°C to 85°C VCC Voltage ..................................................... 12V ±10% 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 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 PARAMETER CONDITIONS MIN TYP MAX UNITS 0°C to 70°C 550 600 750 Hz/V –40°C to 85°C 520 600 750 Hz/V 0°C to 70°C 1850 2150 2350 Hz –40°C to 85°C 1650 2150 2350 Hz State A, VPH2 = VCC/3 80 116 150 µA State A, VPH2 = VCC/2 –25 0 25 µA State A, VPH2 = 2VCC/3 –150 –116 –80 µA 0.45 0.5 0.55 10 13 15 µs 9.0 V 700 mV Oscillator (VCO) Frequency vs. VPIN 20 Maximum Frequency RCVCO = 2V RCVCO = 6V Sampling Amplifier IRCVCO (Note 4) Current Limit ISNS Trip Point One Shot Off Time Power Fail Detection Power Fail Trip Voltage 8.0 Hysteresis 300 500 Logic Inputs VIH Voltage High 2 VIL Voltage Low IIH Current High VIN = 2.7V IIL Current Low VIN = 0.4V V 0.8 V –300 0 µA –400 0 µA Logic Outputs 4 VOH Voltage High IOUT = –0.1mA 3.3 V VOL Voltage Low IOUT = 1mA 0.4 V ML4428 ELECTRICAL CHARACTERISTICS SYMBOL (Continued) PARAMETER CONDITIONS MIN TYP MAX UNITS Output Drivers VP High IP = –10µA VCC – 1.2 VP Low Ip Low VP = 1V VPIN12 = 0V VN Low IN = 1mA 0.7 1.2 V 0°C to 70°C 2.5 4 6 mA –40°C to 85°C 1.5 4 6 mA P Comparator Threshold VN High V VCC – 3.0 V VCC – 1.2 V 0.7 N Comparator Threshold 1.2 V 3 V 36 kHz Speed Control fPWM COSC = 1nF 20 25 ±160 gm Current µA CSC Positive Clamp 2.9 3.1 3.35 V CISC Positive Clamp 5.2 5.5 5.6 V CISC Negative Clamp 1.2 1.7 1.9 V VREF 5.5 5.9 6.5 V VCC Current 18 25 32 mA Supply 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. 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. (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. 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. NEUTRAL 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 PHI1 22 PHI2 23 PHI3 24 NEUTRAL SIMULATOR ΦA + ΦB + ΦC 9 I(RC) = 0 120 180 240 Va – Vb 4.35K a b + LOOP FILTER RCVCO – R MULTIPLEXER C1 C2 2.9K COMMUTATION LOGIC VCO VCO Figure 1. Back-EMF Sensing Block Diagram 6 300 0 Figure 2. Typical Motor Phase Waveform with back-EMF Superimposed (Ideal Commutation). SIGN CHANGER 5.8K 60 ML4428 COMPONENT SELECTION GUIDE RES1, RES2 and RES3 In order to properly select the critical components for the ML4428 you should know the following things: 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. 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 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. 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) 7 ML4428 CVCO VCO AND PHASE DETECTOR CALCULATIONS As given in the section on the VCO and phase detector: 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: −6 CVCO = 2931× 10 N × RPMMAX FMAX = 0.05 × N × RPMMAX Where N is the number of poles in the motor, and RPM is the motor’s maximum operating speed in revolutions per minute. where N is the number of poles on the motor and RPMMAX is the maximum motor speed in Revolutions Per Minute. CPWM The minimum VCO gain derived from the specification table (using the minimum FVCO at VVCO = 6V) is: This capacitor sets the PWM ramp oscillator frequency. This is the PWM “switching frequency”. If this value is too low, <20kHz, then magnetostriction effects in the motor may cause audible noise. If this frequency is too high, >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. −5 K VCO(MIN) = 2.665 × 10 CVCO Assuming that the VVCO(MAX) = 5.5V, then −5 CVCO = 5.5 × 2.665 × 10 FMAX RVCO AND RREF RVCO should be 10k and RREF should be 120k for normal operation. or −6 CVCO = 2931× 10 N × RPMMAX VCO FILTER See the section on the VCO and Phase detector for information on these components. Ω Gm = 0.23m + SAMPLED PHASE RCVCO ZRC – R C1 FOUT C2 VCO KVCO(Hz/sec/V) A/RADIAN ROTOR PHASE (R × C2 × s + 1) s × (C2 + R × C1 × s × C2 + C1) BEMF SAMPLER Ke × ω × Atten 2×π V/A gm = 0.23mA/V LOOP FILTER PHASE DETECTOR RADIAN/sec/V 2.665 × 10–5 ×2×π CVCO × s VCO Figure 4. Back-EMF Phase Locked Loop Components. 8 ML4428 The simplified impedance of the loop filter is 3000 (s + ωLEAD ) ZRC (s) = 1 C1s (s + ωLAG ) FREQUENCY (Hz) 2500 CVCO = 82nF Where the lead and lag frequencies are set by: 2000 ωLEAD = 1500 CVCO = 164nF ωLAG = 1000 500 1 R C2 C1 + C2 R C1 C2 Requiring the loop to settle in 20 PLL cycles with w LAG = 10 ¥ w LEAD produces the following calculations for R, C1 and C2: 0 0 2 4 6 8 10 12 C1 = VVCO (VOLTS) Figure 3. VCO Output Frequency vs. VVCO (Pin 20) 7.508 × 10−4 × Atten × K e N C2 = 9 ¥ C1 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 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. 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. IMOTOR ~200µs DRIVE ~100ms t SENSE ~3ms 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 = where ( 3.43 tINIT CVCO ) R = 0.75 × RL −L + 2 × RSDON + RSENSE L = 0.75 × LL −L DIRECTION STATE OUTPUTS INPUT SAMPLES REVERSE N3 N2 N1 P3 P2 P1 FORWARD N1 N2 N3 P1 P2 P3 FORWARD REVERSE A OFF OFF ON ON OFF OFF PH2 PH2 B OFF OFF ON OFF ON OFF PH1 PH3 C ON OFF OFF OFF ON OFF PH3 PH1 D ON OFF OFF OFF OFF ON PH2 PH2 E OFF ON OFF OFF OFF ON PH1 PH3 F OFF ON OFF ON OFF OFF PH3 PH1 Table 1. Commutation States. 3.75V CVCO 2.0V VCO OUT A B C D E Figure 6. Commutation Timing and Sequencing. 10 F A ML4428 START-UP SEQUENCING Speed Control 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. 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: 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. −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 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. 50 40 TOFF (µs) 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. 30 20 10 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 ýtransconductance amplifiers with a gm = 2.3 ¥ 10–4 . 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 CISC 5 21 0.23mmho VSPEED 8 + 0.23mmho + RCVCO 20 LINEAR CONTROL TO LOW-SIDE GATE DRIVE – – ISNS 1 LEVEL SHIFT +1.4V MODE SELECT + CPWM 6 – 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 330µF VMOTOR +24 TO 60V 0.1µF +12V 0.1µF Q1 2N6718 2kΩ 1kΩ IRFR120 Q2 2N6718 2kΩ FWD/REVERSE IRFR9120 0.1µF IRFR120 IRFR9120 IRFR9120 1µF 1nF 50kΩ 300pF 0.1µF VCO 100Ω 100Ω 100Ω +12V SPEED CONTROL VOLTAGE 0.1µF 2kΩ 2kΩ 2kΩ 1kΩ IRFR120 1.5kΩ 20kΩ Q3 2N6718 2kΩ PHI1 22 VREF 7 12 F/R 0.1µF CVCO 15 CSNS 17 11 N3 14 VCC VFLT 18 10 N2 RVCO 16 RINIT 19 N1 9 13 VCO RCVCO 20 VSPEED 8 CISC 21 PHI2 23 CPWM 6 P3 PHI3 24 BRAKE 25 CSC CIOS 26 RREF 27 GND 28 5 4 ML4428 P2 P1 2 3 ISNS 1 750pF 100pF 120kΩ 10µF 80kΩ 0.1µF PWR FAIL 2kΩ 1µF RES1 RES1 RES1 MOTOR 10kΩ 5.6nF BRAKE RUN 2MΩ ML4428 Figure 9. Driving Higher Voltage Motors: 24V to 80V. 13 ML4428 VMOTOR +12V MUR150 IR2118 1 VCC 2 IN 3 COM 4 N/C IRF720 IRF720 IRF720 330µF 400V VB 8 HO 7 100Ω 25V 0.1µF VS 6 25V 2.2µF N/C 5 MOTOR PH1 MUR150 IR2118 25V 0.1µF 1 VCC 2 IN 3 COM 4 N/C VB 8 HO 7 PH3 100Ω VS 6 PH2 25V 2.2µF N/C 5 Note: Refer to IK2118 data sheet for complete information on using this part with different FETs and IGBTs. MUR150 IR2118 25V 0.1µF 1 VCC 2 IN 3 COM 4 N/C VB 8 HO 7 100Ω VS 6 25V 2.2µF N/C 5 IRF720 IRF720 IRF720 100Ω 100Ω RSENSE 300MΩ 10W 100Ω 1kΩ 330pF 0.01µF 12kΩ 10µF VSPEED 1nF 787Ω 10kΩ ML4428 1 ISNS 2 P1 3 P2 COS 26 4 P3 BRAKE 25 5 CSC VCO FWD/REVERSE 25V 1µF CPWM PHI2 23 VREF PHI1 22 8 VSPEED CISC 21 9 N1 RCVCO 20 10 N2 RINIT 19 VFLT 18 12 F/R CSNS 17 14 VCC 5.11kΩ RVCO 16 BRAKE PWR FAIL 2kΩ 750pF CVCO 15 5.6nF 10kΩ 2MΩ 0.01µF 80kΩ 1µF 10µF Figure 11. ML4428 High Voltage Motor Driver: 12V to 500V 14 RUN 5.11kΩ 5.11kΩ 11 N3 0.1µF 0.01µF PHI3 24 7 13 VCO 120kΩ RREF 27 6 0.1µF +12V GND 28 ML4428 PHYSICAL DIMENSIONS inches (millimeters) Package: P28N 28-Pin Narrow PDIP 1.355 - 1.365 (34.42 - 34.67) 28 0.280 - 0.296 0.299 - 0.325 (7.11 - 7.52) (7.60 - 8.26) PIN 1 ID 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 0.012 - 0.020 (0.30 - 0.51) 0.090 - 0.094 (2.28 - 2.39) 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 PACKAGE 0°C to 70°C 0°C to 70°C 28-Pin DIP (P28N) 28-Pin SOIC (S28) –40°C to 85°C –40°C to 85°C 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. 16 2092 Concourse Drive San Jose, CA 95131 Tel: 408/433-5200 Fax: 408/432-0295 DS4428-01