偉詮電子股份有限公司 Weltrend Semiconductor, Inc. WT7062 3-Phase Sensorless Motor Driver Data Sheet REV. 0.05 March 4, 2011 Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page i WT7062 3-Phase Brushless Sensorless DC Motor Driver Revision History Version 0.01 0.02 Content First released Date August 3, 2010 1. Added pin description and DFN-10 outline drawing 2. Modified Supply current August 24, 2010 1. Added DFN10 Theta Ja, Jc, Tjmax, Pdmax 0.03 2. Modified MSOP10 Theta Ja, Jc, Tjmax, Pdmax 3. Modified PWM VPWML, VPWMH September 16, 2010 4. Modified LDT, LRT 0.04 0.05 1. Described FR function and Added LHT, LRT 2. Modified LDT, LRT 1. Added FIL Pin and modify Application circuit Weltrend Semiconductor, Inc. Proprietary & Confidential December 14, 2010 March 4, 2011 Mar. 4, 2010 Rev. 0.05 Page ii WT7062 3-Phase Brushless Sensorless DC Motor Driver Generation Description The WT7062 is 3-phase full-wave drivers for brushless sensorless DC motors. It features 150° square drive, high torque output, and silent drive. Speed control can be achieved through either power supply modulation or pulse-width-modulation (using the PWM digital input pin). Due to the compact packaging and minimum bill-of-material (power transistors incorporated, no Hall sensor, no external tuning), they are best suited for low-cost fan applications requiring high efficiency and low acoustic noise, such as notebook cooling fans. Frequency generator output is also included (FG). The WT7062 driver includes a lockup protection mode, which turns-off the output current when the motor is under lock condition, and an automatic recovery that enables the fan to release when the lock condition is removed. Thermal-shutdown protection is also included. They are available in a compact thermally-enhanced MSOP10 package. Features Position sensorless BLDC drivers (no Hall sensor required) 150° square drive, for high efficiency and low acoustic noise Support 2.0V to 5.5V power supplies Speed control through PAM or PWM Built-in frequency generator (FG output signal) Built-in lockup protection and automatic recovery circuit (external capacitors not necessary) Built-in thermal shutdown protection MSOP-10 & DFN-10 package No external tuning required Weltrend reserves the right to change this documentation without prior notice. Information provided by Weltrend is believed to be accurate and reliable. However, Weltrend makes no warranty for any errors which may appear in this document. Contact Weltrend to obtain the latest version of device specifications before placing your order. No responsibility is assumed by Weltrend for any infringement of patent or other rights of third parties which may result from its use. In addition, Weltrend products are not authorized for use as critical components in life support devices/ systems or aviation devices/systems, where a malfunction or failure of the product may reasonably be expected to result in significant injury to the user, without the express written approval of Weltrend Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page i Block Diagram PWM FG UV W 10 MUX 1 FIL COM 9 2 VREF CMP OSC Controller Logic FR 3 TSD VSS 8 Pre-Driver VCC V 4 7 U W 5 6 Figure 1: block diagram Pin Assignments FG 1 10 PWM FG 1 10 PWM COM 2 9 FIL COM 2 9 FIL FR 3 8 VSS FR 3 8 VSS VCC 4 7 V VCC 4 7 V U 5 6 W U 5 6 W Figure 2: DFN-10 & MSOP-10 pin assignments Pin Description Pin No. Pin name Function Equivalent circuit Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 2 1 FG 2 VCOM 3 FR VCC FG pulse output. VCC Motor middle point connection. VCC Motor rotation direction switching. A low level input (0~0.3Vcc) causes forward 500Ω rotation. A middle level input (0.3Vcc~0.7cc) makes the 20kΩ motor locked. And a high level input (0.7Vcc~Vcc) causes reverse rotation. 4 VCC 5 U Power supply VCC Output pin. Connect the motor coil. 6 W V U 7 V 8 GND 9 FIL Ground for IC Motor position detection filter VCC pin. Connect a capacitor between this pin and the VCOM pin. Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 3 W 10 PWM VCC PWM signal input. The motor speed is controlled by the input 8kΩ PWM duty cycle setting. 500Ω Pin Functions Pin # 1 2 3 4 5 6 7 8 9 10 Pin Name FG COM FR VCC U W V VSS FIL PWM Pin Description Motor speed indication output (open drain) Motor middle point terminal Motor rotation direction switching Power Supply for the IC and motor U phase output terminal W phase output terminal V phase output terminal Ground terminal Motor position detection filter pin PWM input signal for speed control Figure 4: MSOP-10/DFN-10 pin assignments Functional Description The WT7062 generates signals to drive a 3-phase sensorless BLDC motor. High efficiency and low-power consumption are achieved due to synchronous rectification drive type. The current carrying order of the outputs is as follows: U phase -> V phase -> W phase. Speed Control The rotational speed of the motor can be controlled either through the PWM digital input signal or by acting directly on the power supply (VCC). When the PWM signal is “High” (or Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 4 left open) the motor rotates at full speed. When the PWM signal is “Low” the motor is stopped (and the IC outputs are set to high-impedance). By changing the PWM duty cycle, the speed can be adjusted. Notice that the PWM frequency has no special meaning for the motor speed and is asynchronous with the activation of the output transistors. Thus the user has maximum freedom to choose the PWM system frequency within a wide range (from 20KHz to 50kHz) Frequency Generator Function The Frequency Generator output (FG) is a “Hall-sensor equivalent” digital output, giving information to an external controller about the speed and phase of the motor. When a lock (or out-of-sync) situation is detected by the driver, this output is set to “Low” until the motor is restarted. The FG pin is an open collector output, connecting to a logical voltage level through an external pull-up resistor. Leave the pin open when not used. Lockup Protection and Automatic Restart If the motor is stopped (blocked) or if it loses synchronization with the driver, a lock-up protection circuit detects this situation and disables the driver (by setting its outputs to high-impedance) in order to prevent the motor coil from burnout. After a "release time" (LRT), the lock-up protection is released and normal operation resumes for a given time (LDT). In case of the motor is still blocked, a new period of waiting time is started. LRT and LDT timings are fixed internally, so that no external capacitor is needed. Figure 4 Lock and FG timing charts Thermal Shutdown The WT7062 has a thermal protection function which detects when the die temperature exceeds Tj=150°C. When this temperature is reached, the circuit enters the thermal shutdown mode and the outputs U phase, V phase and W phase are disabled (high impedance), avoiding IC destruction and allowing the circuit to cool down. Once the junction temperature (TJ) has dropped below 120°C, the normal operation resumes (thermal detection circuit has 30°C hysteresis function). Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 5 Figure 5 Thermal protection hysteresis Positional Detection Filter The positional detection problems caused by a comparator input noise is improvable by connecting a capacitor (0.1uF) between the VCOM and the FIL pin. U,V,W phase and FG output signals The timing charts of the output signals from the U, V and W phases as well as the FG terminal are shown as below. Assuming that a three-slot tetrode motor is used, two pulse outputs of FG are produced for one motor cycle. The three phases are excited in the order of U, V and W phases. U phase voltage V phase voltage W phase voltage FG Figure 6: U, V, W and FG timing charts FR function FR pin is the motor rotational direction switching pin. Low level voltage input ： U → V → W, High level voltage input ： U → W → V Perform a current – carrying to the motor in above order. The motor is revolving in the other direction by exchanging the current – carrying order. Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 6 Forward Induced electromotive voltage detection Stop Float FHT FRT Backward FR FG Figure 7: FR and FG timing charts FR 3 FR1 0.7Vcc 5KO FR2 0.3Vcc 0.7VCC 0.3VCC FR FR1 FR2 Forward Stop (V-PMOS, W-NMOS Turn-on) LHT Floating Reverse FRT Stop (V-PMOS, U-NMOS Turn-on) LHT Floating Reverse FRT When the motor is running Forward (FR<0.3Vcc) or Reverse (FR>0.7Vcc) , if FR goes to the voltage between 0.3Vcc to 0.7Vcc, WT7062 will deliver a stop signal to hold the motor. When the motor is hold (0.3Vcc < FR < 0.7Vcc), if FR goes to the voltage less than 0.3Vcc or larger than 0.7Vcc, WT7062 will let the motor float for 1 Sec and then back to the forward or reverse mode. Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 7 ELECTRICAL SPECIFICATIONS Absolute maximum ratings at Ta= 25℃ ℃ Parameter Power Supply Voltage Output pin current PWM input pin voltage FG output pin voltage FG output pin current Allowable Power Dissipation 1 Allowable Power Dissipation 2 Operating Temperature Storage Temperature Symbol Vcc max Iout max VPWM max VFG max IFG max Pd max 1 Pd max 2 Topr Tstg Ratings 6.5 600* 6.5 6.5 5 600 683 -30 ~ +95 -40 ~ +150 Unit V mA V V mA mW mW ℃ ℃ Conditions MSOP10 DFN10 * This value is not to exceed Pd Recommended operating conditions Parameter Symbol Limit Unit Operating supply voltage range VCC 2 ~ 5.5 V Electrical Characteristic(Vcc=5V,Ta=25℃unless otherwise noted) Parameter Supply current (standby current) Source + Sink Output voltage PWM pin high-level input voltage PWM pin low-level input voltage PWM input frequency FG low voltage Lock protection detection time Lock protection release time Thermal protection temperature Thermal protection hysteresis FR pin high-level input voltage FR pin low-level input voltage FR hold time FR release time Symbol Icc Ron(H+L) VO VPWMH VPWML Fpwm VFGL LDT LRT TSD ∆TSD VFRH VFRL FHT FRT Weltrend Semiconductor, Inc. Proprietary & Confidential Min 1 1.2 0.5 2.5 0 20 0.2 0.64 3.2 3.5 0 0.64 0.64 Ratings Typ - 1 5 150 30 1 1 Unit Max 1.5 1.5 0.75 Vcc 0.6 50 0.4 1.42 7.11 5 1.5 1.42 mA V V V kHz V s s ℃ ℃ V V s s Conditions PWM=GND Iout =0.5A, Iout =0.5A, IFG=5mA VDD=5V Reverse Forward Stop Float Mar. 4, 2011 Rev. 0.05 Page 8 Application Notes PWM FG 10 FIL COM 9 2 VREF CMP C3 C4 330pF FR 3 FR PWM MUX 1 FG UV W Controller Logic OSC TSD 330pF C2 0.1uF VSS 8 Pre-Driver VCC V 4 VCC C1 7 1uF U W 5 6 Package Outlines Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 9 Package: 10-Lead MSOP (3x5x1.1mm) Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 10 Package: 10-pin DFN (3x3x0.5mm) Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 11 Carrier Tape & Reel Dimensions Package: 10-Lead MSOP Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 12 Package: 10-pin DFN Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 13 Ordering Information Part Number Package Type 10-Pin MSOP, Green Package 10-Pin DFN, Green Package WT7062-MG100 WT7062-VG100 Transport Media Tape & Reel Tape & Reel Quantity 2,500 2,500 Allowable Power Dissipation , Pd max - mW Thermal De-rating Curve MSOP10 700 600 500 400 300 200 100 0 25 50 75 95 125 150 Ambient Temperature, Ta –°C Allowable Power Dissipation , Pd max - mW *70mm × 70mm × 1.6mm single layer board. *ΘJa=208 ℃/W, ΘJc= 48 ℃/W, Tj max= 150℃, Pd max 600mW. DFN10 683 600 500 400 300 200 100 0 25 50 75 95 125 150 Ambient Temperature, Ta –°C *70mm x 70mm x 1.6mm single layer board. *ΘJa=182.9 ℃/W, ΘJc= 33.6 ℃/W, Tj max= 150℃, Pd max 683mW. Weltrend Semiconductor, Inc. Proprietary & Confidential Mar. 4, 2011 Rev. 0.05 Page 14