 |
|
| 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: |
| Order this document by MC33033/D MC33033 Brushless DC Motor Controller The MC33033 is a high performance second generation, limited feature, monolithic brushless dc motor controller which has evolved from Motorolas full featured MC33034 and MC33035 controllers. It contains all of the active functions required for the implementation of open loop, three or four phase motor control. The device consists of a rotor position decoder for proper commutation sequencing, temperature compensated reference capable of supplying sensor power, frequency programmable sawtooth oscillator, fully accessible error amplifier, pulse width modulator comparator, three open collector top drivers, and three high current totem pole bottom drivers ideally suited for driving power MOSFETs. Unlike its predessors, it does not feature separate drive circuit supply and ground pins, brake input, or fault output signal. Included in the MC33033 are protective features consisting of undervoltage lockout, cycle-by-cycle current limiting with a selectable time delayed latched shutdown mode, and internal thermal shutdown. Typical motor control functions include open loop speed, forward or reverse direction, and run enable.The MC33033 is designed to operate brushless motors with electrical sensor phasings of 60/300 or 120/240, and can also efficiently control brush dc motors. BRUSHLESS DC MOTOR CONTROLLER SEMICONDUCTOR TECHNICAL DATA 20 1 P SUFFIX PLASTIC PACKAGE CASE 738 * * * * * * * * * 10 to 30 V Operation Undervoltage Lockout 6.25 V Reference Capable of Supplying Sensor Power Fully Accessible Error Amplifier for Closed Loop Servo Applications High Current Drivers Can Control External 3-Phase MOSFET Bridge Cycle-By-Cycle Current Limiting Internal Thermal Shutdown Selectable 60/300 or 120/240 Sensor Phasings Also Efficiently Control Brush DC Motors with External MOSFET H-Bridge Top Drive Output BT 1 AT 2 Fwd/Rev SA Sensor Inputs SB SC Reference Output Package SO-20L TA = - 40 to + 85C Plastic DIP Oscillator 8 Error Amp 9 Non Inverting Input Error Amp 10 Inverting Input (Top View) 3 4 5 6 7 20 CT 19 Output Enable 18 60/120 Select 17 AB 16 BB 15 CB 14 VCC 13 Gnd 12 Current Sense Non Inverting Input 11 Error Amp Out/ PWM Input Bottom Drive Outputs 20 1 DW SUFFIX PLASTIC PACKAGE CASE 751D (SO-20L) PIN CONNECTIONS ORDERING INFORMATION Device MC33033DW MC33033P Operating Temperature Range (c) Motorola, Inc. 1996 Rev 3 MOTOROLA ANALOG IC DEVICE DATA 1 MC33033 Representative Schematic Diagram VM N S N S Rotor Position Decoder FWR/REV 60/120 Motor Enable VCC Reference Regulator Speed Set Faster RT PWM R S Oscillator CT S R Q Q Undervoltage Lockout Output Buffers Error Amp Thermal Shutdown Current Sense This device contains 266 active transistors. 2 MOTOROLA ANALOG IC DEVICE DATA MC33033 MAXIMUM RATINGS Rating Power Supply Voltage Digital Inputs (Pins 3, 4, 5, 6, 18, 19) Oscillator Input Current (Source or Sink) Error Amp Input Voltage Range (Pins 9, 10, Note 1) Error Amp Output Current (Source or Sink, Note 2) Current Sense Input Voltage Range Top Drive Voltage (Pins 1, 2, 20) Top Drive Sink Current (Pins 1, 2, 20) Bottom Drive Output Current (Source or Sink, Pins 15,16, 17) Power Dissipation and Thermal Characteristics P Suffix, Dual-In-Line, Case 738 Maximum Power Dissipation @ TA = 85C Thermal Resistance, Junction-to-Air DW Suffix, Surface Mount, Case 751D Maximum Power Dissipation @ TA = 85C Thermal Resistance, Junction-to-Air Operating Junction Temperature Operating Ambient Temperature Range Storage Temperature Range Symbol VCC - IOSC VIR IOut VSense VCE(top) ISink(top) IDRV Value 30 Vref 30 - 0.3 to Vref 10 - 0.3 to 5.0 40 50 100 Unit V V mA V mA V V mA mA PD RJA PD RJA TJ TA Tstg 867 75 619 105 150 - 40 to + 85 - 65 to +150 mW C/W mW C/W C C C ELECTRICAL CHARACTERISTICS (VCC = 20 V, RT = 4.7 k, CT = 10 nF, TA = 25C, unless otherwise noted.) Characteristic REFERENCE SECTION Reference Output Voltage (Iref = 1.0 mA) TA = 25C TA = - 40 to + 85C Line Regulation (VCC = 10 V to 30 V, Iref = 1.0 mA) Load Regulation (Iref = 1.0 mA to 20 mA) Output Short-Circuit Current (Note 3) Reference Under Voltage Lockout Threshold ERROR AMPLIFIER Input Offset Voltage (TA = - 40 to + 85C) Input Offset Current (TA = - 40 to + 85C) Input Bias Current (TA = - 40 to + 85C) Input Common Mode Voltage Range Open Loop Voltage Gain (VO = 3.0 V, RL = 15 k) Input Common Mode Rejection Ratio Power Supply Rejection Ratio (VCC = 10 V to 30 V) Output Voltage Swing High State (RL = 15 k to Gnd) Low State (RL = 17 k to Vref) VIO IIO IIB VICR AVOL CMRR PSRR VOH VOL 70 55 65 4.6 - - - - 0.4 8.0 - 46 (0 V to Vref) 80 86 105 5.3 0.5 - - - - 1.0 10 500 -1000 mV nA nA V dB dB dB V Vref 5.9 5.82 Regline Regload ISC Vth - - 40 4.0 6.24 - 1.5 16 75 4.5 6.5 6.57 30 30 - 5.0 mV mV mA V V Symbol Min Typ Max Unit NOTES: 1. The input common mode voltage or input signal voltage should not be allowed to go negative by more than 0.3 V. 2. The compliance voltage must not exceed the range of - 0.3 to Vref. 3. Maximum package power dissipation limits must be observed. MOTOROLA ANALOG IC DEVICE DATA 3 MC33033 ELECTRICAL CHARACTERISTICS (continued) (VCC = 20 V, RT = 4.7 k, CT = 10 nF, TA = 25C, unless otherwise noted.) Characteristic OSCILLATOR SECTION Oscillator Frequency Frequency Change with Voltage (VCC = 10 V to 30 V) Sawtooth Peak Voltage Sawtooth Valley Voltage LOGIC INPUTS Input Threshold Voltage (Pins 3, 4, 5, 6, 18, 19) High State Low State Sensor Inputs (Pins 4, 5, 6) High State Input Current (VIH = 5.0 V) Low State Input Current (VIL = 0 V) Forward/Reverse, 60/120 Select and Output Enable (Pins 3, 18, 19) High State Input Current (VIH = 5.0 V) Low State Input Current (VIL = 0 V) CURRENT-LIMIT COMPARATOR Threshold Voltage Input Common Mode Voltage Range Input Bias Current OUTPUTS AND POWER SECTIONS Top Drive Output Sink Saturation (ISink = 25 mA) Top Drive Output Off-State Leakage (VCE = 30 V) Top Drive Output Switching Time (CL = 47 pF, RL = 1.0 k) Rise Time Fall Time Bottom Drive Output Voltage High State (VCC = 30 V, Isource = 50 mA) Low State (VCC = 30 V, Isink = 50 mA) Bottom Drive Output Switching Time (CL = 1000 pF) Rise Time Fall Time Under Voltage Lockout Drive Output Enabled (VCC Increasing) Hysteresis Power Supply Current VCE(sat) IDRV(leak) tr tf VOH VOL tr tf Vth(on) VH ICC - - - - (VCC - 2.0) - - - 8.2 0.1 - 0.5 0.06 107 26 (VCC - 1.1) 1.5 38 30 8.9 0.2 15 1.5 100 300 300 V - 2.0 ns 200 200 V 10 0.3 22 mA V A ns Vth VICR IIB 85 - - 101 3.0 - 0.9 115 - - 5.0 mV V A V VIH VIL IIH IIL 3.0 - -150 - 600 2.2 1.7 -70 - 337 - 0.8 A - 20 -150 A IIH IIL -75 - 300 - 36 -175 -10 -75 fOSC fOSC/V VOSC(P) VOSC(V) 22 - - 1.2 25 0.01 4.1 1.5 28 5.0 4.5 - kHz % V V Symbol Min Typ Max Unit 4 MOTOROLA ANALOG IC DEVICE DATA MC33033 Figure 1. Oscillator Frequency versus Timing Resistor 100 f OSC, OSCILLATOR FREQUENCY (kHz) VCC = 20 V TA = 25C f OSC, OSCILLATOR FREQUENCY CHANGE (%) Figure 2. Oscillator Frequency Change versus Temperature 4.0 VCC = 20 V RT = 4.7 k CT = 10 nF 2.0 10 0 CT = 100 nF 0 1.0 CT = 10 nF CT = 1.0 nF - 2.0 10 100 1000 - 4.0 - 55 - 25 0 25 50 75 100 125 RT, TIMING RESISTOR (k) TA, AMBIENT TEMPERATURE (C) Figure 3. Error Amp Open Loop Gain and Phase versus Frequency Vsat , OUTPUT SATURATION VOLTAGE (V) AVOL , OPEN-LOOP VOLTAGE GAIN (dB) 56 48 40 32 24 16 VCC = 20 V VO = 3.0 V 0 RL = 15 k C = 100 pF - 8.0 TL = 25C A -16 - 24 10 k 1.0 k 8.0 Gain Phase 40 , EXCESS PHASE (DEGREES) 60 80 0 Figure 4. Error Amp Output Saturation Voltage versus Load Current Vref Source Saturation (Load to Ground) VCC = 20 V TA = 25C - 0.8 -1.6 1.6 0.8 0 0 100 120 140 160 180 200 220 100 k f, FREQUENCY (Hz) 1.0 M 240 10M Gnd Sink Saturation (Load to Vref) 5.0 1.0 2.0 3.0 4.0 IO, OUTPUT LOAD CURRENT (mA) Figure 5. Error Amp Small-Signal Transient Response AV = +1.0 No Load TA = 25C Figure 6. Error Amp Large-Signal Transient Response AV = +1.0 No Load TA = 25C VO, OUTPUT VOLTAGE (V) 3.0 VO, OUTPUT VOLTAGE (V) 3.05 4.5 3.0 2.95 1.5 1.0 s/DIV 5.0 s/DIV MOTOROLA ANALOG IC DEVICE DATA 5 MC33033 Vref, REFERENCE OUTPUT VOLTAGE CHANGE (mV) Figure 7. Reference Output Voltage Change versus Output Source Current Vref, REFERENCE OUTPUT VOLTAGE (V) 0 - 4.0 - 8.0 - 12 - 16 - 20 - 24 0 10 20 30 40 50 60 Iref, REFERENCE OUTPUT SOURCE CURRENT (mA) VCC = 20 V TA = 25C 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0 0 Figure 8. Reference Output Voltage versus Supply Voltage No Load TA = 25C 10 20 VCC, SUPPLY VOLTAGE (V) 30 40 Vref, NORMALIZED REFERENCE VOLTAGE CHANGE (mV) Figure 9. Reference Output Voltage versus Temperature 100 40 20 0 - 20 VCC = 20 V No Load - 40 0 - 55 - 25 0 25 50 75 100 125 0 OUTPUT DUTY CYCLE (%) 80 60 40 20 Figure 10. Output Duty Cycle versus PWM Input Voltage VCC = 20 V RT = 4.7 k CT = 10 nF TA = 25C 1.0 2.0 3.0 4.0 5.0 TA, AMBIENT TEMPERATURE (C) PWM INPUT VOLTAGE (V) Figure 11. Bottom Drive Response Time versus Current Sense Input Voltage t HL , BOTTOM DRIVE RESPONSE TIME (ns) Vsat , OUTPUT SATURATION VOLTAGE (V) 250 VCC = 20 V RL = CL = 1.0 nF TA = 25C 1.2 Figure 12. Top Drive Output Saturation Voltage versus Sink Current VCC = 20 V TA = 25C 0.8 200 150 100 50 0 1.0 1 0.4 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10 0 0 10 VSense, CURRENT SENSE INPUT VOLTAGE (NORMALIZED TO Vth) 20 30 ISink, SINK CURRENT (mA) 40 6 MOTOROLA ANALOG IC DEVICE DATA MC33033 Figure 13. Top Drive Output Waveform Figure 14. Bottom Drive Output Waveform VCC = 20 V CL = 1.0 nF TA = 25C 100 OUTPUT VOLTAGE (%) OUTPUT VOLTAGE (%) 50 ns/DIV 100 0 VCC = 20 V RL = 1.0 k CL = 15 pF TA = 25C 0 50 ns/DIV Figure 15. Bottom Drive Output Waveform VCC = 20 V CL = 15 pF 100 TA = 25C Vsat, OUTPUT SATURATION VOLTAGE (V) 0 -1.0 Figure 16. Bottom Drive Output Saturation Voltage versus Load Current VCC Source Saturation (Load to Ground) OUTPUT VOLTAGE (%) - 2.0 VCC = 20 V TA = 25C 2.0 1.0 0 0 20 40 Gnd Sink Saturation (Load to VCC) 0 50 ns/DIV 60 80 IO, OUTPUT LOAD CURRENT (mA) Figure 17. Supply Current versus Voltage 20 I CC, POWER SUPPLY CURRENT (mA) 18 16 14 12 10 8.0 6.0 4.0 2.0 0 0 5.0 10 15 RT = 4.7 k CT = 10 nF Pins 3-6, 12, 13 = Gnd Pins 18, 19 = Open TA = 25C 20 25 30 VCC, SUPPLY VOLTAGE (V) MOTOROLA ANALOG IC DEVICE DATA 7 MC33033 PIN FUNCTION DESCRIPTION Pin 1, 2, 20 3 4, 5, 6 7 8 9 10 11 12 BT, AT, CT Fwd//Rev SA, SB, SC Reference Output Oscillator Error Amp Noninverting Input Error Amp Inverting Input Error Amp Out/PWM Input Current Sense Noninverting Input Symbol Description These three open collector Top Drive Outputs are designed to drive the external upper power switch transistors. The Forward/Reverse Input is used to change the direction of motor rotation. These three Sensor Inputs control the commutation sequence. This output provides charging current for the oscillator timing capacitor CT and a reference for the Error Amplifier. It may also serve to furnish sensor power. The Oscillator frequency is programmed by the values selected for the timing components, RT and CT. This input is normally connected to the speed set potentiometer. This input is normally connected to the Error Amp Output in open loop applications. This pin is available for compensation in closed loop applications. A 100 mV signal, with respect to Pin 13, at this input terminates output switch conduction during a given oscillator cycle. This pin normally connects to the top side of the current sense resistor. This pin supplies a separate ground return for the control circuit and should be referenced back to the power source ground. This pin is the positive supply of the control IC. The controller is functional over a VCC range of 10 to 30 V. These three totem pole Bottom Drive Outputs are designed for direct drive of the external bottom power switch transistors. The electrical state of this pin configures the control circuit operation for either 60 (high state) or 120 (low state) sensor electrical phasing inputs. A logic high at this input causes the motor to run, while a low causes it to coast. 13 14 15, 16, 17 18 19 Gnd VCC CB, BB, AB 60/120 Select Output Enable 8 MOTOROLA ANALOG IC DEVICE DATA MC33033 INTRODUCTION The MC33033 is one of a series of high performance monolithic dc brushless motor controllers produced by Motorola. It contains all of the functions required to implement a limited-feature, open loop, three or four phase motor control system. Constructed with Bipolar Analog technology, it offers a high degree of performance and ruggedness in hostile industrial environments.The MC33033 contains a rotor position decoder for proper commutation sequencing, a temperature compensated reference capable of supplying sensor power, a frequency programmable sawtooth oscillator, a fully accessible error amplifier, a pulse width modulator comparator, three open collector top drive outputs, and three high current totem pole bottom driver outputs ideally suited for driving power MOSFETs. Included in the MC33033 are protective features consisting of undervoltage lockout, cycle-by-cycle current limiting with a latched shutdown mode, and internal thermal shutdown. Typical motor control functions include open loop speed control, forward or reverse rotation, and run enable. In addition, the MC33033 has a 60/120 select pin which configures the rotor position decoder for either 60 or 120 sensor electrical phasing inputs. effect the commutation sequence is reversed and the motor changes directional rotation. Motor on/off control is accomplished by the Output Enable (Pin19). When left disconnected, an internal pull-up resistor to a positive source enables sequencing of the top and bottom drive outputs. When grounded, the Top Drive Outputs turn off and the bottom drives are forced low, causing the motor to coast. The commutation logic truth table is shown in Figure 19. In half wave motor drive applications, the Top Drive Outputs are not required and are typically left disconnected. Error Amplifier A high performance, fully compensated Error Amplifier with access to both inputs and output (Pins 9, 10, 11) is provided to facilitate the implementation of closed loop motor speed control. The amplifier features a typical dc voltage gain of 80 dB, 0.6 MHz gain bandwidth, and a wide input common mode voltage range that extends from ground to Vref. In most open loop speed control applications, the amplifier is configured as a unity gain voltage follower with the Noninverting Input connected to the speed set voltage source. Additional configurations are shown in Figures 29 through 33. Oscillator The frequency of the internal ramp oscillator is programmed by the values selected for timing components RT and CT. Capacitor CT is charged from the Reference Output (Pin 7) through resistor RT and discharged by an internal discharge transistor. The ramp peak and valley voltages are typically 4.1 V and 1.5 V respectively. To provide a good compromise between audible noise and output switching efficiency, an oscillator frequency in the range of 20 to 30 kHz is recommended. Refer to Figure 1 for component selection. Pulse Width Modulator The use of pulse width modulation provides an energy efficient method of controlling the motor speed by varying the average voltage applied to each stator winding during the commutation sequence. As CT discharges, the oscillator sets both latches, allowing conduction of the Top and Bottom Drive Outputs. The PWM comparator resets the upper latch, terminating the Bottom Drive Output conduction when the positive-going ramp of CT becomes greater than the Error Amplifier output. The pulse width modulator timing diagram is shown in Figure 20. Pulse width modulation for speed control appears only at the Bottom Drive Outputs. Current Limit Continuous operation of a motor that is severely over-loaded results in overheating and eventual failure. This destructive condition can best be prevented with the use of cycle-by-cycle current limiting. That is, each on-cycle is treated as a separate event. Cycle-by-cycle current limiting is accomplished by monitoring the stator current build-up each time an output switch conducts, and upon sensing an over current condition, immediately turning off the switch and holding it off for the remaining duration of FUNCTIONAL DESCRIPTION A representative internal block diagram is shown in Figure 18, with various applications shown in Figures 34, 36, 37, 41, 43, and 44. A discussion of the features and function of each of the internal blocks given below and referenced to Figures 18 and 36. Rotor Position Decoder An internal rotor position decoder monitors the three sensor inputs (Pins 4, 5, 6) to provide the proper sequencing of the top and bottom drive outputs. The Sensor Inputs are designed to interface directly with open collector type Hall Effect switches or opto slotted couplers. Internal pull-up resistors are included to minimize the required number of external components. The inputs are TTL compatible, with their thresholds typically at 2.2 V. The MC33033 series is designed to control three phase motors and operate with four of the most common conventions of sensor phasing. A 60/120 Select (Pin 18) is conveniently provided which affords the MC33033 to configure itself to control motors having either 60, 120, 240 or 300 electrical sensor phasing. With three Sensor Inputs there are eight possible input code combinations, six of which are valid rotor positions. The remaining two codes are invalid and are usually caused by an open or shorted sensor line. With six valid input codes, the decoder can resolve the motor rotor position to within a window of 60 electrical degrees. The Forward/Reverse input (Pin 3) is used to change the direction of motor rotation by reversing the voltage across the stator winding. When the input changes state, from high to low with a given sensor input code (for example 100), the enabled top and bottom drive outputs with the same alpha designation are exchanged (AT to AB, BT to BB, CT to CB). In MOTOROLA ANALOG IC DEVICE DATA 9 MC33033 Figure 18. Representative Block Diagram VM SA Sensor Inputs SB SC Foward/Reverse 60/120 Select Output Enable VCC 4 5 6 3 18 20 k 20 k 20 k 40 k 40 k 2 AT Rotor Position Decoder 1 BT Top Drive Outputs 20 19 14 40 k Undervoltage Lockout Reference Regulator 8.9 V CT Reference Output 7 4.5 V 17 AB Noninv. Input Faster RT Error Amp Out PWM Input 9 10 11 Error Amp Thermal Shutdown PWM Latch R Q S Latch S Q R 16 BB Bottom Drive Outputs 15 CB 8 CT Sink Only Positive True = Logic With Hysteresis Oscillator ILimit 100 mV 12 Current Sense Input 13 Gnd 10 MOTOROLA ANALOG IC DEVICE DATA MC33033 Figure 19. Three Phase, Six Step Commutation Truth Table (Note 1) Inputs (Note 2) Sensor Electrical Phasing (Note 4) 60 SA 1 1 1 0 0 0 1 1 1 0 0 0 1 0 V V SB 0 1 1 1 0 0 0 1 1 1 0 0 0 1 V V SC 0 0 1 1 1 0 0 0 1 1 1 0 1 0 V V SA 1 1 0 0 0 1 1 1 0 0 0 1 1 0 V V 120 SB 0 1 1 1 0 0 0 1 1 1 0 0 1 0 V V Current SC 0 0 0 1 1 1 0 0 0 1 1 1 1 0 V V F/R 1 1 1 1 1 1 0 0 0 0 0 0 X X X X Enable 1 1 1 1 1 1 1 1 1 1 1 1 X X 0 1 Sense 0 0 0 0 0 0 0 0 0 0 0 0 X X X 1 AT 0 1 1 1 1 0 1 1 0 0 1 1 1 1 1 1 BT 1 0 0 1 1 1 1 1 1 1 0 0 1 1 1 1 CT 1 1 1 0 0 1 0 0 1 1 1 1 1 1 1 1 AB 0 0 1 1 0 0 1 0 0 0 0 1 0 0 0 0 BB 0 0 0 0 1 1 0 1 1 0 0 0 0 0 0 0 CB 1 1 0 0 0 0 0 0 0 1 1 0 0 0 0 0 (Note 5) F/R = 1 Outputs (Note 3) Top Drives Bottom Drives (Note 5) F/R = 0 (Note 6) (Note 7) (Note 8) NOTES: 1. V = Any one of six valid sensor or drive combinations. X = Don't care. 2. The digital inputs (Pins 3, 4, 5, 6, 18, 19) are all TTL compatible. The current sense input (Pin 12) has a 100 mV threshold with respect to Pin 13. A logic 0 for this input is defined as < 85 mV, and a logic 1 is > 115 mV. 3. The top drive outputs are open collector design and active in the low (0) state. 4. With 60/120 (Pin 18) in the high (1) state, configuration is for 60 sensor electrical phasing inputs. With Pin 18 in the low (0) state, configuration is for 120 sensor electrical phasing inputs. 5. Valid 60 or 120 sensor combinations for corresponding valid top and bottom drive outputs. 6. Invalid sensor inputs; All top and bottom drives are off. 7. Valid sensor inputs with enable = 0; All top and bottom drives are off. 8. Valid sensor inputs with enable and current sense = 1; All top and bottom drives are off. oscillator ramp-up period. The stator current is converted to a voltage by inserting a ground-referenced sense resistor RS (Figure 34) in series with the three bottom switch transistors (Q4, Q5, Q6). The voltage developed across the sense resistor is monitored by the current sense input (Pin 12), and compared to the internal 100 mV reference. If the current sense threshold is exceeded, the comparator resets the lower latch and terminates output switch conduction. The value for the sense resistor is: R S transistor as shown in Figure 21. A 6.25 V reference level was chosen to allow implementation of the simpler NPN circuit, where Vref - VBE exceeds the minimum voltage required by Hall Effect sensors over temperature. With proper transistor selection, and adequate heatsinking, up to one amp of load current can be obtained. Undervoltage Lockout A dual Undervoltage Lockout has been incorporated to prevent damage to the IC and the external power switch transistors. Under low power supply conditions, it guarantees that the IC and sensors are fully functional, and that there is sufficient Bottom Drive Output voltage. The positive power supply to the IC (VCC) is monitored to a threshold of 8.9 V. This level ensures sufficient gate drive necessary to attain low RDS(on) when interfacing with standard power MOSFET devices. When directly powering the Hall sensors from the reference, improper sensor operation can result if the reference output voltage should fall below 4.5 V. If one or both of the comparators detects an undervoltage condition, the top drives are turned off and the Bottom Drive Outputs are held in a low state. Each of the comparators contain hysteresis to prevent oscillations when crossing their respective thresholds. +I 0.1 stator(max) The dual-latch PWM configuration ensures that only one single output conduction pulse occurs during any given oscillator cycle, whether terminated by the output of the Error Amplifier or the current limit comparator. Reference The on-chip 6.25 V regulator (Pin 7) provides charging current for the oscillator timing capacitor, a reference for the Error Amplifier, and can supply 20 mA of current suitable for directly powering sensors in low voltage applications. In higher voltage applications it may become necessary to transfer the power dissipated by the regulator off the IC. This is easily accomplished with the addition of an external pass MOTOROLA ANALOG IC DEVICE DATA 11 MC33033 Figure 20. PWM Timing Diagram Figure 21. Reference Output Buffers Vin MPS U01A 14 REF 7 UVLO Capacitor CT Error Amp Out/ PWM Input Current Sense Input Latch "Set" Inputs To Sensor Control Power Circuitry 5.6 V 6.25 V Vin 36 14 REF 7 0.1 To Control Circuitry and Sensor Power 6.25 V The NPN circuit is recommended for powering Hall or opto sensors, where the output voltage temperature coefficient is not critical. The PNP circuit is slightly more complex, but also more accurate. Neither circuit has current limiting. UVLO Top Drive Outputs Bottom Drive Outputs MPS U51A Figure 22. High Voltage Interface with NPN Power Transistors 2 Rotor Position Decoder AT 1 BT 20 CT VCC Q1 Q2 Q3 VM Figure 23. High Voltage Interface with N-Channel Power MOSFETs VCC = 12 V 2 Rotor Position Decoder AT 1 BT 20 CT 1.0 k 1 2 4.7 k 1N4744 MOC8204 Optocoupler VBoost VM = 170 V 5 4 6 1.0 M Load 17 17 Load 16 Q4 16 15 15 Transistor Q1 is a common base stage used to level shift from VCC to the high motor voltage, VM. The collector diode is required if VCC is present while VM is low. 12 MOTOROLA ANALOG IC DEVICE DATA MC33033 Figure 24. Current Waveform Spike Suppression Figure 25. MOSFET Drive Precautions Rg D Rg D Rg D 12 100 mV C R RS 100 mV D = 1N5819 Series gate resistor Rg will damp any high frequency oscillations caused by the MOSFET input capacitance and any series wiring induction in the gate-source circuit. Diode D is required if the negative current into the Bottom Drive Outputs exceeds 50 mA. 17 17 16 16 15 15 12 The addition of the RC filter will eliminate current-limit instability caused by the leading edge spike on the current waveform. Resistor RS should be a low inductance type. Figure 26. Bipolar Transistor Drive C 17 Figure 27. Current Sensing Power MOSFETs D 17 G M SENSEFET S K C 16 16 C 15 12 100 mV IB + 0 - Base Charge Removal t 100 mV RS 13 Gnd 12 15 Power Ground: To Input Source Return V Pin 9 [ R S @Ipk @RDS(on) r )RS DM(on) If : SENSEFET = MPT10N10M RS = 200 , 1/4 W Then : V Pin 9 0.75 I pk [ The totem pole output can furnish negative base current for enhanced transistor turn-off, with the addition of capacitor C. Virtually lossless current sensing can be achieved with the implementation of SENSEFET power switches. Figure 28. High Voltage Boost Supply VBoost Voltage (V) VM + 12 Figure 29. Differential Input Speed Controller REF 7 VC = 12 V 8 6 R 5 S 2 1 0.001 MC1455 18 k Q 3 4 7 VM + 8.0 19 VM + 4.0 1.0 /200 V 1N5352A 20 40 60 Boost Current (mA) * * 22 VBoost VA VB R1 R3 R4 9 R2 10 11 EA PWM 40 k VM = 170 V * = MUR115 V This circuit generates VBoost for Figure 23. Pin 11 + VA )R4 R 1 )R 2 R3 R2 R3 - R4 R3 V B MOTOROLA ANALOG IC DEVICE DATA 13 MC33033 Figure 30. Controlled Acceleration/Deceleration Figure 31. Digital Speed Controller 5.0 V 16 REF 7 Enable R1 Increase Speed R2 C 40 k BCD Inputs EA 10 11 PWM Gnd 8 Resistor R1 with capacitor C sets the acceleration time constant while R2 controls the deceleration. The values of R1 and R2 should be at least ten times greater than the speed set potentiometer to minimize time constant variations with different speed settings. The SN74LS145 is an open collector BCD to One of Ten decoder. When connected as shown, input codes 0000 through 1001 steps the PWM in increments of approximately 10% from 0 to 90% on-time. Input codes 1010 through 1111 will produce 100% on-time or full motor speed. VCC Q9 11 10 166 k 145 k 126 k 108 k 92.3 k 77.6 k 63.6 k 51.3 k 40.4 k 10 11 19 9 100 k 7 REF 13 9 14 15 P2 P1 P0 SN74LS145 19 12 P3 Q8 9 Q7 7 Q6 6 Q5 5 Q4 4 Q3 3 Q2 2 Q1 1 Q 0 40 k EA PWM Figure 32. Closed Loop Speed Control REF 7 To Sensor Input (Pin 4) 0.01 10 k 100 k 10 k 0.1 1.0 M 0.22 19 9 Increase Speed 10 10 M 11 EA PWM 40 k V Pin 11 Figure 33. Closed Loop Temperature Control + Vref V R5 R6 ref R3 R1 )R4 )R2 R2 R3 - R4 R3 V B 7 19 9 REF V B + )1 R1 R5 R3 R6 T R2 R4 40 k EA 10 11 PWM R3 R6 o R6 The rotor position sensors can be used as a tachometer. By differentiating the positive-going edges and then integrating them over time, a voltage proportional to speed can be generated. The error amp compares this voltage to that of the speed set to control the PWM. This circuit can control the speed of a cooling fan proportional to the difference between the sensor and set temperatures. The control loop is closed as the forced air cools the NTC thermistor. For controlled heating applications, exchange the positions of R1 and R2. Drive Outputs The three Top Drive Outputs (Pins 1, 2, 20) are open collector NPN transistors capable of sinking 50 mA with a minimum breakdown of 30 V. Interfacing into higher voltage applications is easily accomplished with the circuits shown in Figures 22 and 23. The three totem pole Bottom Drive Outputs (Pins 15, 16, 17) are particularly suited for direct drive of N-Channel MOSFETs or NPN bipolar transistors (Figures 24, 25, 26, and 27). Each output is capable of sourcing and sinking up to 100 mA. Thermal Shutdown Internal thermal shutdown circuity is provided to protect the IC in the event the maximum junction temperature is exceeded. When activated, typically at 170C, the IC acts as though the regulator was disabled, in turn shutting down the IC. SYSTEM APPLICATIONS Three Phase Motor Commutation The three phase application shown in Figure 34 is an open loop motor controller with full wave, six step drive. The upper power switch transistors are Darlington PNPs while the lower switches are N-Channel power MOSFETs. Each of these devices contains an internal parasitic catch diode that is used to return the stator inductive energy back to the power supply. The outputs are capable of driving a delta or wye connected stator, and a grounded neutral wye if split supplies are used. At any given rotor position, only one top and one bottom power switch (of different totem poles) is enabled. This configuration switches both ends of the stator winding from supply to ground which causes the current flow to be bidirectional or full wave. A leading edge spike is usually present on the current waveform and can cause a current-limit error. The spike can be eliminated by adding an RC filter in series with the Current Sense Input. Using a low inductance type resistor for RS will also aid in spike reduction. Figure 35 shows the commutation waveforms over two electrical cycles. The first cycle (0 to 360) depicts motor operation at full speed while the second cycle (360 to 720) shows a reduced speed with about 50% pulse width modulation. The current waveforms reflect a constant torque load and are shown synchronous to the commutation frequency for clarity. 14 MOTOROLA ANALOG IC DEVICE DATA MC33033 Figure 34. Three Phase, Six Step, Full Wave Motor Controller VM 4 5 6 3 18 2 Q1 A S N S N Rotor Position Decoder 1 Q2 B FWR/REV 60/120 Enable VM 20 19 14 Q3 C Motor Undervoltage Lockout Reference Regulator 7 Speed Set Faster RT Error Amp Thermal Shutdown PWM R Q S 8 CT R Oscillator S Q ILimit 17 Q4 9 10 11 16 Q5 15 Q6 12 C R RS 13 Gnd MOTOROLA ANALOG IC DEVICE DATA 15 MC33033 Figure 35. Three Phase, Six Step, Full Wave Commutation Waveforms Rotor Electrical Position (Degrees) 0 SA Sensor Inputs 60/120 Select Pin Open SB SC Code 100 110 111 011 001 000 100 110 111 011 001 000 60 120 180 240 300 360 420 480 540 600 660 720 SA Sensor Inputs 60/120 Select Pin Grounded SB SC Code 100 110 010 011 001 101 100 110 010 011 001 101 AT Top Drive Outputs BT CT AB Bottom Drive Outputs BB CB Conducting Power Switch Transistors + A O - + Motor Drive Current B O - + CO - Full Speed (No PWM) FWD/REV = 1 Reduced Speed ( 50% PWM) Q1 + Q6 Q2 + Q6 Q2 + Q4 Q3 + Q4 Q3 + Q5 Q1 + Q5 Q1 + Q6 Q2 + Q6 Q2 + Q4 Q3 + Q4 Q3 + Q5 Q1 + Q5 16 MOTOROLA ANALOG IC DEVICE DATA MC33033 Figure 36 shows a three phase, three step, half wave motor controller. This configuration is ideally suited for automobile and other low voltage applications since there is only one power switch voltage drop in series with a given stator winding. Current flow is unidirectional or half wave because only one end of each winding is switched. The stator flyback voltage is clamped by a single zener and three diodes. Figure 36. Three Phase, Three Step, Half Wave Motor Controller Motor 4 5 2 N S S N VM 6 3 18 Rotor Position Decoder 1 FWR/REV 60/120 Enable VM 20 19 14 Undervoltage Lockout Reference Regulator 7 Speed Set Faster RT 17 9 10 11 Error Amp Thermal Shutdown R Q S 16 PWM 15 8 CT Oscillator S Q R ILimit 12 13 Gnd MOTOROLA ANALOG IC DEVICE DATA 17 MC33033 Three Phase Closed Loop Controller The MC33033, by itself, is capable of open loop motor speed control. For closed loop speed control, the MC33033 requires an input voltage proportional to the motor speed. Traditionally this has been accomplished by means of a tachometer to generate the motor speed feedback voltage. Figure 37 shows an application whereby an MC33039, powered from the 6.25 V reference (Pin 7) of the MC33033, is used to generate the required feedback voltage without the need of a costly tachometer. The same Hall sensor signals used by the MC33033 for rotor position decoding are utilized by the MC33039. Every positive or negative going transition of the Hall sensor signals on any of the sensor lines causes the MC33039 to produce an output pulse of defined amplitude and time duration, as determined by the external resistor R1 and capacitor C1. The resulting output train of pulses present at Pin 5 of the MC33039 are integrated by the Error Amplifier of the MC33033 configured as an integrator, to produce a dc voltage level which is proportional to the motor speed. This speed proportional voltage establishes the PWM reference level at Pin 11 of the MC33033 motor controller and completes or closes the feedback loop. The MC33033 ouputs drive a TMOS power MOSFET 3-phase bridge. High current can be expected during conditions of start-up and when changing direction of the motor. The system shown in Figure 37 is designed for a motor having 120/240 degrees Hall sensor electrical phasing. The system can easily be modified to accommodate 60/300 degree Hall sensor electrical phasing by removing the jumper (J1) at Pin 18 of the MC33033. Figure 37. Closed Loop Brushless DC Motor Control With the MC33033 Using the MC33039 1 2 3 4 MC33039 8 7 6 5 1.0 M R1 750 pF C1 1.1 k TP1 1.0 k 1.1 k 330 VM (18 to 30 V) 1.1 k 0.1 1000 1 2 F/R 3 4 5 6 7 0.01 Speed Faster 10 k 5.1 k 8 9 10 1.0 M 0.1 100 k Close Loop MC33033 1.0 k 20 19 18 17 16 15 14 13 12 11 4.7 k J1 1.0 k Enable S N S N 470 470 470 Motor 1N5819 1N4742 0.1 0.1 33 100 TP2 0.05/1.0 W 18 MOTOROLA ANALOG IC DEVICE DATA MC33033 Sensor Phasing Comparison There are four conventions used to establish the relative phasing of the sensor signals in three phase motors. With six step drive, an input signal change must occur every 60 electrical degrees, however, the relative signal phasing is dependent upon the mechanical sensor placement. A comparison of the conventions in electrical degrees is shown in Figure 38. From the sensor phasing table (Figure 39), note that the order of input codes for 60 phasing is the reverse of 300. This means the MC33033, when the 60/120 select (Pin 18) and the FWD/REV (Pin 3) both in the high state (open), is configured to operate a 60 sensor phasing motor in the forward direction. Under the same conditions a 300 sensor phasing motor would operate equally well but in the reverse direction. One would simply have to reverse the FWD/REV switch (FWD/REV closed) in order to cause the 300 motor to also operate in the same direction. The same difference exists between the 120 and 240 conventions. In this data sheet, the rotor position has always been given in electrical degrees since the mechanical position is a function of the number of rotating magnetic poles. The relationship between the electrical and mechanical position is: Electrical Degrees + Mechanical Degrees #Rotor2 Poles An increase in the number of magnetic poles causes more electrical revolutions for a given mechanical revolution. General purpose three phase motors typically contain a four pole rotor which yields two electrical revolutions for one mechanical. Two and Four Phase Motor Commutation The MC33033 configured for 60 sensor inputs is capable of providing a four step output that can be used to drive two or four phase motors. The truth table in Figure 40 shows that by connecting sensor inputs SB and SC together, it is possible to truncate the number of drive output states from six to four. The output power switches are connected to BT, CT, BB, and CB. Figure 41 shows a four phase, four step, full wave motor control application. Power switch transistors Q1 through Q8 are Darlington type, each with an internal parasitic catch diode. With four step drive, only two rotor position sensors spaced at 90 electrical degrees are required. The commutation waveforms are shown in Figure 42. Figure 43 shows a four phase, four step, half wave motor controller. It has the same features as the circuit in Figure 36, except for the deletion of speed adjust. Figure 40. Two and Four Phase, Four Step, Commutation Truth Table MC33033 (60/120 Select Pin Open) Inputs Sensor Electrical Spacing* = 90 SA SB 1 1 0 0 1 1 0 0 0 1 1 0 0 1 1 0 Outputs Top Drives F/R 1 1 1 1 0 0 0 0 BT 1 0 1 1 1 1 1 0 CT 1 1 0 1 0 1 1 1 Bottom Drives BB 0 0 0 1 0 1 0 0 CB 1 0 0 0 0 0 1 0 Figure 38. Sensor Phasing Comparison Rotor Electrical Position (Degrees) 0 SA 60 Sensor Electrical Phasing SB SC SA 120 SB SC SA 240 SB SC SA 300 SB SC 60 120 180 240 300 360 420 480 540 600 660 720 Figure 39. Sensor Phasing Table Sensor Electrical Phasing (Degrees) 60 SA 1 1 1 0 0 0 SB 0 1 1 1 0 0 SC 0 0 1 1 1 0 SA 1 1 1 0 0 0 120 SB 0 0 1 1 1 0 SC 1 0 0 0 1 1 SA 1 1 1 0 0 0 240 SB 1 0 0 0 1 1 SC 0 0 1 1 1 0 SA 1 1 1 0 0 0 300 SB 1 1 0 0 0 1 SC 1 0 0 0 1 1 *With MC33033 sensor input SB connected to SC MOTOROLA ANALOG IC DEVICE DATA 19 Figure 41. Four Phase, Four Step, Full Wave Controller 20 4 2 VM 5 6 1 Q4 3 Rotor Position Decoder Q3 Q2 18 20 19 14 Lockout Reference Regulator 7 17 A B C 9 Error Amp PWM R Q S 8 Oscillator S Q R Thermal Shutdown 10 11 16 Q8 15 Q5 Q7 Q6 D Motor Undervoltage N S S N FWR/REV Q1 Enable VM MC33033 RT CT ILimit 12 C R RS MOTOROLA ANALOG IC DEVICE DATA 13 Gnd MC33033 Figure 42. Four Phase, Four Step, Full Wave Commutation Waveforms Rotor Electrical Position (Degrees) 0 SA Sensor Inputs 60/120 Select Pin Open SB Code 10 10 01 00 10 11 01 00 90 180 270 360 450 540 630 720 Top Drive Outputs BT CT BB Bottom Drive Outputs CB Conducting Power Switch Transistors + A O - + B Motor Drive Current C O - + O - + D O - Full Speed (No PWM) FWD/REV = 1 Q3 + Q5 Q4 + Q6 Q1 + Q 7 Q2 + Q8 Q3 + Q5 Q4 + Q 6 Q1 + Q7 Q2 + Q8 MOTOROLA ANALOG IC DEVICE DATA 21 Figure 43. Four Phase, Four Step, Half Wave Motor Controller 22 4 2 VM 5 6 1 3 Rotor Position Decoder FWR/REV 18 20 19 14 Lockout Reference Regulator 7 17 Motor Error Amp PWM R S 8 Oscillator CT S Q R Q Thermal Shutdown 16 Undervoltage Enable VM N S S N MC33033 9 10 11 RT 15 ILimit 12 C R RS 13 Gnd MOTOROLA ANALOG IC DEVICE DATA MC33033 Brush Motor Control Though the MC33033 was designed to control brushless dc motors, it may also be used to control dc brush-type motors. Figure 44 shows an application of the MC33033 driving a H-bridge affording minimal parts count to operate a brush-type motor. Key to the operation is the input sensor code [100] which produces a top-left (Q1) and a bottom-right (Q3) drive when the controller's Forward/Reverse pin is at logic [1]; top-right (Q4), bottom-left (Q2) drive is realized when the Forward/Reverse pin is at logic [0]. This code supports the requirements necessary for H-bridge drive accomplishing both direction and speed control. The controller functions in a normal manner with a pulse width modulated frequency of approximately 25 kHz. Motor speed is controlled by adjusting the voltage presented to the noninverting input of the Error Amplifier establishing the PWMs slice or reference level. Cycle-by-cycle current limiting of the motor current is accomplished by sensing the voltage (100 mV threshold) across the RS resistor to ground of the H-bridge motor current. The over current sense circuit makes it possible to reverse the direction of the motor, on the fly, using the normal Forward/Reverse switch, and not have to completely stop before reversing. LAYOUT CONSIDERATIONS Do not attempt to construct any of the motor control circuits on wire-wrap or plug-in prototype boards. High frequency printed circuit layout techniques are imperative to prevent pulse jitter. This is usually caused by excessive noise pick-up imposed on the current sense or error amp inputs. The printed circuit layout should contain a ground plane with low current signal and high drive and output buffer grounds returning on separate paths back to the power supply input filter capacitor VM. Ceramic bypass capacitors (0.01 F) connected close to the integrated circuit at VCC, Vref and error ampliflier noninverting input may be required depending upon circuit layout. This provides a low impedance path for filtering any high frequency noise. All high current loops should be kept as short as possible using heavy copper runs to minimize radiated EMI. Figure 44. H-Bridge Brush-Type Controller 4 5 6 3 18 Rotor Position Decoder 2 +12 V 1.0 k 1 Q1* 1.0 k FWR/REV 20 Enable +12 V 0.1 Reference Regulator 7 17 22 10 k Faster 10 k 9 10 11 PWM Error Amp Thermal Shutdown R S 8 0.005 R Oscillator S Q ILimit 12 0.001 1.0 k RS 16 19 14 Undervoltage Lockout DC Brush Motor Q2* M Q4* Q 15 22 Q3* 13 Gnd MOTOROLA ANALOG IC DEVICE DATA 23 MC33033 OUTLINE DIMENSIONS P SUFFIX PLASTIC PACKAGE CASE 738-03 ISSUE E 11 -A- 20 B 1 10 C L NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION L TO CENTER OF LEAD WHEN FORMED PARALLEL. 4. DIMENSION B DOES NOT INCLUDE MOLD FLASH. DIM A B C D E F G J K L M N INCHES MIN MAX 1.010 1.070 0.240 0.260 0.150 0.180 0.015 0.022 0.050 BSC 0.050 0.070 0.100 BSC 0.008 0.015 0.110 0.140 0.300 BSC 15 0 0.020 0.040 MILLIMETERS MIN MAX 25.66 27.17 6.10 6.60 3.81 4.57 0.39 0.55 1.27 BSC 1.27 1.77 2.54 BSC 0.21 0.38 2.80 3.55 7.62 BSC 0 15 1.01 0.51 -T- SEATING PLANE K M E G F D 20 PL 0.25 (0.010) M N J 20 PL 0.25 (0.010) TA M M T B M -A- 20 11 DW SUFFIX PLASTIC PACKAGE CASE 751D-04 (SO-20L) ISSUE E -B- P 10 PL 0.010 (0.25) M B M 1 10 NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: MILLIMETER. 3. DIMENSIONS A AND B DO NOT INCLUDE MOLD PROTRUSION. 4. MAXIMUM MOLD PROTRUSION 0.150 (0.006) PER SIDE. 5. DIMENSION D DOES NOT INCLUDE DAMBAR PROTRUSION. ALLOWABLE DAMBAR PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN EXCESS OF D DIMENSION AT MAXIMUM MATERIAL CONDITION. DIM A B C D F G J K M P R MILLIMETERS MIN MAX 12.65 12.95 7.40 7.60 2.35 2.65 0.35 0.49 0.50 0.90 1.27 BSC 0.25 0.32 0.10 0.25 0 7 10.05 10.55 0.25 0.75 INCHES MIN MAX 0.499 0.510 0.292 0.299 0.093 0.104 0.014 0.019 0.020 0.035 0.050 BSC 0.010 0.012 0.004 0.009 0 7 0.395 0.415 0.010 0.029 D 20 PL J M 0.010 (0.25) T A S B S F R X 45 C -T- G 18 PL SEATING PLANE K M Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. "Typical" parameters which may be provided in Motorola data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including "Typicals" must be validated for each customer application by customer's technical experts. Motorola does not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. How to reach us: USA / EUROPE / Locations Not Listed: Motorola Literature Distribution; P.O. Box 20912; Phoenix, Arizona 85036. 1-800-441-2447 or 602-303-5454 MFAX: RMFAX0@email.sps.mot.com - TOUCHTONE 602-244-6609 INTERNET: http://Design-NET.com JAPAN: Nippon Motorola Ltd.; Tatsumi-SPD-JLDC, 6F Seibu-Butsuryu-Center, 3-14-2 Tatsumi Koto-Ku, Tokyo 135, Japan. 03-81-3521-8315 ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park, 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852-26629298 24 *MC33033/D* MOTOROLA ANALOG IC DEVICE DATA MC33033/D |
Price & Availability of MC33033
 |
|
|
|
|
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] |