11-MD215 Version Issue Date File Name Total Page : A.001 : 2007-12-07 : SP-MD215-A.001.doc : 10 VCM Driver for Mobile Phone 新竹市展業一路 9 號 7 樓之 1 SILICON TOUCH TECHNOLOGY INC. 9-4F-3, Prosperity Rd I, Science-Based Industrial Park Hsinchu, Taiwan, R.O.C. Tel：886-3-5727171 Fax：886-3-5727390 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. 11-MD215 VCM Driver for Mobile Phone General Specifications The 11-MD215 is a 1ch voice coil motor driver which provides a controllable constant current via external PWM input signal control. With miniature package, it is suitable for reduced -space mounting in camera module application and other portable device. Features and Benefits z z z z z z z z z Low supply voltage operation Low saturation voltage Low operating current Zero standby current Low digital pin (PD) control voltage (i.e., VIH = 1.6V @ VDD = 2.8V) Built-in a freewheeling diode Constant current control PWM input control with low input current Ultra-small package (WLCSP, 0.79*1.19*0.5 mm) SP-MD215-A.001 Version：A.001 Page：1 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Pin Assignment Pin Assignment of WLCSP (0.79*1.19*0.5mm) TOP View Pin NO. Pin Name 1 VDD 2 IN 3 OUT Motor output pin 4 AGND Analog ground 5 GND 6 PD SP-MD215-A.001 Description Power supply pin for controller. Constant current setting pin Controller ground Power down. Asynchronous power down signal Version：A.001 Page：2 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Absolute Maximum Ratings (Unless otherwise noted, TA= 25℃) Characteristic Symbol Rating Unit Supply Voltage VDD 5.5 V Input Voltage VIN VDD+0.4 V Maximum output current IOUT 250 mA Power Dissipation PD 300 mW Operating Temperature Range TOPR -40 ~ 125 °C Storage Temperature Range TSTG -65 ~ 150 °C Electrical Characteristic (Unless otherwise noted, TA= 25℃ & VDD = 2.8V, VCM= 28.5 Ω, 460μ H ) Item Sym. Condition Limit Unit Min. Typ. Max. 2.0 2.8 5.5 V Whole circuits Supply Voltage VDD Supply Current ISTB PD = L (Standby mode) 0.1 1 μA ( IDD ) IDD1 PD = H (Operation mode) 0.6 1 mA Power down Input Voltage ‘H’ VPDH - 0.57*VDD - VDD+0.4 V Input Voltage ‘L’ VPDL - -0.4 - 0.2*VDD V Input Current ‘H’ IPDH - 10 20 μA Input Current ‘L’ IPDL - - ±1 μA - - 200 mA PD = L - - 1 μA IOUT = 80 mA - 0.3 0.35 V 20 50 μs VPD = 2.8V(built-in pull low resistor 300k) VPD = 0 V Constant Current Output Terminal Output constant current IOUT Output current during PD IOUT,PD Saturation Voltage (VOUT->AGND) VSAT Output Current Settling Time ts SP-MD215-A.001 VDD = 2.8V, CL=0.1 μ F , IOUT = 0 -> 100mA Version：A.001 Page：3 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Block Diagram IN VDD PD 1 6 Output Driver Level Shift & Pre Driver 2 5 3 OUT 4 GND AGND Application Circuit 1. PWM control V PW M D % × V PW M SP-MD215-A.001 Version：A.001 Page：4 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Application Notes z The 11-MD215 is constant current control for use in Auto-Focus. The range of supply voltage of 11-MD215, VDD is from 2.0V to 5.5V. The 11-MD215 digital control pin, PD, its input range is defined that logic “H” is from 0.57*VDD to VDD+0.4V and logic “L” is from –0.4V to 0.2*VDD. So the digital PD pin is suitable to be controlled by 1.8V ISP. z The power down pin (PD) is the enable pin of 11-MD215, which logic high level (PD = H) is for IC operation. On the other hand, its logic low level (PD = L) puts the chip into standby mode for power saving. Internal pull low resistor, 300k, prevents IC from abnormal operation when PD is open. Therefore, it is easy to switch the working status by controlling PD pin, and it is recommended that keeps PD at low level (PD = L) before operation to reach the maximum efficiency of power saving, especially in the application of portable device. z Constant current operation of 11-MD215 provides the current, which can be evaluated by the formula I = VIN 15 (A) . It is convenient to get constant output current by controlling input dc voltage, VIN. Therefore, by adjusting the resistance of RA, RB, and the capacitance CIN, with appropriately PWM frequency will get the suitable and stable input voltage level, VIN, for setting constant current in the output. z In the application circuit diagram, the signal PWM, VPWM, is filtered by a low pass filter which consists of RA, RB, and CIN. The -3dB frequency ω3dB and VIN are given by ω3dB = VIN = 1 ( RA // RB ) CIN RB D% × VPWM RA + RB (1) (V) , , which D% is the duty ratio of PWM frequency. The corresponding of constant current at the output could be changed by setting different duty ratio of PWM, In order to confirm the accuracy and stable value of constant current, the amount of SP-MD215-A.001 Version：A.001 Page：5 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. -3dB frequency ω3dB is suggested lower than the 1/1000 of the PWM frequency. It is shown as follows, ω3dB = z 1 ωPWM 1000 (2) The following example explains how to design the low pass filter. For PWM frequency f PWM = 92.8kHz , and desired maximum output constant current, I MAX , is 80mA and VPWM = 2.8V. Please determine CIN, RA and RB. According to equation (1) & (2), we have f3dB = 1 1 = f PWM = 92.8 Hz 2π ( RA // RB ) CIN 1000 By choosing CIN = 0.1uF , we can get ( RA // RB ) = 17.1k Ω . Owing to I MAX = VIN , MAX 15 (A) = RB VDD ( A ) , 15 ( RA + RB ) Then RA = 40k Ω , RB = 30k Ω z In order to ensure the stabilization of output current, the compensation capacitance CL is suggested placing in parallel with VCM. The suggestion value of CL is about 0.1~1uF and maybe fine tune depending on the different VCM. It is the sense of frequency response compensation to confirm stability while VCM operating. SP-MD215-A.001 Version：A.001 Page：6 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. z LPF Design Look Up Table 1. PWM = 24 KHz VPWM = 2.8V Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 70 0.1 177 106 80 0.1 155 116 Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 70 0.1 92 55 80 0.1 80 60 Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 70 0.1 46 28 80 0.1 40 30 2. PWM = 46 KHz VPWM = 2.8V 3. PWM = 92.8 KHz VPWM = 2.8 V SP-MD215-A.001 Version：A.001 Page：7 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Package Specifications (WLCSP) (size: 0.79*1.19*0.5 mm) E A1 A S L1 D e1 b L2 e2 DIMENSION (mm) SYMBOL A A1 S b D E e1 e2 L1 L2 SP-MD215-A.001 MIN. 0.445 0.17 0.275 0.24 1.14 0.74 0.170 0.170 Version：A.001 NOM. 0.50 0.20 0.30 0.26 1.19 0.79 0.4 0.4 0.195 0.195 MAX. 0.555 0.23 0.325 0.28 1.24 0.84 0.220 0.220 Page：8 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. The products listed herein are designed for ordinary electronic applications, such as electrical appliances, audio-visual equipment, communications devices and so on. Hence, it is advisable that the devices should not be used in medical instruments, surgical implants, aerospace machinery, nuclear power control systems, disaster/crime-prevention equipment and the like. Misusing those products may directly or indirectly endanger human life, or cause injury and property loss. Silicon Touch Technology, Inc. will not take any responsibilities regarding the misusage of the products mentioned above. Anyone who purchases any products described herein with the above-mentioned intention or with such misused applications should accept full responsibility and indemnify. Silicon Touch Technology, Inc. and its distributors and all their officers and employees shall defend jointly and severally against any and all claims and litigation and all damages, cost and expenses associated with such intention and manipulation. SP-MD215-A.001 Version：A.001 Page：9