11-MD115 Version Issue Date File Name Total Page : A.005 : 2006-06-18 : SP-MD115-A.005.doc : 17 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-MD115 VCM Driver for Mobile Phone General Specifications The 11-MD115 is a 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 voltage operation Low saturation voltage Low operating current Zero standby current Built-in pull down resistor for PD pin Built-in a freewheeling diode Constant current control PWM input control with low input current Ultra-small package (LFCSP6, 1.6mm*1.4mm*0.425mm) and (WLCSP, 1.5mm*1.0mm*0.5mm) Pin Assignment Pin Assignment of LFCSP6 Bottom view TOP view VDD 1 IN 2 OUT 3 11-MD115 SP-MD115-A.005.doc 6 PD PD 6 5 GND GND 5 4 IM IM 4 Version：A.005 11-MD115 Page：1 1 VDD 2 IN 3 OUT 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Pin Descriptions (LFCSP6) Pin NO. Pin Name 1 VDD 2 IN 3 OUT 4 IM 5 GND 6 PD Description Power supply pin for controller. Constant current setting pin Motor output pin Current sense resistor Controller ground Power down. Asynchronous power down signal Pin Assignment of WLCSP Top View WL1 WL6 WL2 WL5 WL3 WL4 Pin Descriptions (WLCSP) Pin NO. Pin Name WL1 OUT WL2 IN WL3 VDD WL4 PD WL5 VSS WL6 IM SP-MD115-A.005.doc Description Motor output pin Constant current setting pin Power supply pin for controller. Power down. Asynchronous power down signal Controller ground Current sense resistor Version：A.005 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 200 mA Power Dissipation PD 400 mW Operating Temperature Range TOPR -40 ~ 125 °C Storage Temperature Range TSTG -65 ~ 150 °C SP-MD115-A.005.doc Version：A.005 Page：3 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Electrical Characteristic (Unless otherwise noted, TA= 25℃ & VDD = 2.8V) Item Sym. Limit Condition 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 5 μA ( IDD ) IDD1 PD = H (Operation mode) 0.8 1.6 mA Input Voltage “H” VPDH - 0.8*VDD - VDD+0.4 V Input Voltage “L” VPDL - -0.4 - 0.15*VDD V Input Current “H” IPDH VPD = VDD=3V - 10 20 μA Input Current “L” IPDL VPD = 0 V - - ±5 μA 10 - 120 mA PD = L - - 5 μA IOUT = 120 mA - 0.1 0.15 V 200 250 μs Power down Constant Current Output Terminal Output constant current IOUT Output current during PD IOUT,PD Saturation Voltage VSAT RS =1.5 Ω ,PWM input control VDD = 2.8V, CL=1 μ F , Output Current Settling Time ts RS =1.5 Ω , VCM( 28.5 SP-MD115-A.005.doc Ω, 460μ H ) Version：A.005 Page：4 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Block Diagram Application Circuit 1. PWM control VPWM D % × VPWM SP-MD115-A.005.doc Version：A.005 Page：5 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. 2. PDM control SP-MD115-A.005.doc Version：A.005 Page：6 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Application Notes z The 11-MD115 is constant current control for use in Auto-Focus. The range of supply voltage of 11-MD115, VDD is from 2.0V to 5.5V. The 11-MD115 digital control pin, PD, its input range is defined that logic “H” is from 0.8*VDD to VDD+0.4V and logic “L” is from –0.4V to 0.2*VDD. The input pin, IN, is VCM constant current setting pin. z The power down pin (PD) is the enable pin of 11-MD115, 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. 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-MD115 provides the current, which can be VIN evaluated by the formula I = ( A ) . It is obviously that constant current 10* RS ( Ω ) not only depends on the resistance load on the current sense terminal, IM, but the amount of input voltage level, 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 (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-MD115-A.005.doc Version：A.005 Page：7 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. -3dB frequency ω3dB is suggested lower than the 1/100 of the PWM frequency. It is shown as follows, ω3dB = z 1 ωPWM 100 The following example explains how to design the low pass filter. For PWM frequency f PWM = 20kHz , the sense resistance RS = 1.5 Ω , the desired maximum output constant current is 100mA and VPWM = 3V, determine CIN, RA and RB. f3dB = 1 1 = f PWM = 0.2kHz 2π ( RA // RB ) CIN 100 By choosing CIN = 0.1uF , we can get ( RA // RB ) = 7.96k Ω . Because to I max = VIN ,max (A) , 10* RS ( Ω ) Then RA = ( RA // RB ) 10 × I max × RS VPWM = 15.9k Ω RB = 15.9k Ω z The accuracy of output constant current is closely dependent on the PWM frequency. The higher PWM frequency, there will be less voltage variation in IM pin within the desired constant current. The output sense resistor RS 1 = 1.5 or 1.8 Ω is recommended to have a better accuracy of output constant current. SP-MD115-A.005.doc Version：A.005 Page：8 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. z In order to ensure the stabilization of output current, the compensation capacitance CL is suggested to reserve between the both terminals of VCM. The suggestion value of CL is about 1uF and maybe fine tune depending on the different VCM. It is the sense of frequency response compensation to confirm stability while VCM operating. z Suggestion Look Up Table (PWM control) : Condition I: PWM freq. = 16 KHz, RIM =1.5Ω VPWM = 2.8V Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 18.6 21.4 120 0.1 15.5 27.9 Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 20 20 120 0.1 16.6 24.9 VPWM = 3 V Condition II: PWM freq. = 20 KHz, RIM =1.5Ω VPWM = 2.8V Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 14.9 17.1 120 0.1 12.4 22.3 SP-MD115-A.005.doc Version：A.005 Page：9 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. VPWM = 3 V Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 15.9 15.9 120 0.1 13.3 20 Condition III: PWM freq. = 24 KHz, RIM =1.5Ω VPWM = 2.8 V Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 12.4 14.3 120 0.1 10.3 18.6 Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 13.3 13.3 120 0.1 11 16.6 VPWM = 3 V SP-MD115-A.005.doc Version：A.005 Page：10 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. z With PDM signal as input, passed through a low pass filter made up by RA, RB, and CIN, will essentially get the averaged dc value. For the overall 256 steps with duty ratio 50% and PDM base frequency f PDM = 4.8MHz , the effectively PWM frequency is 18.75 KHz. Therefore, the parameters, RA, RB, and CIN, of LPF corresponding to the effectively PWM frequency will suggest in the following look up table. V pp = 2.6 ( V ) , f PDM =4.8MHz, and 256 steps with 50% duty 18.75kHz PWM frequency effectively RIM =1.5Ω Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 14.7 20 100 0.01 147 200 120 0.1 12.3 27.6 120 0.01 123 276 Max. output current I (mA) CIN ( μ F ) RA ( kΩ ) RB ( kΩ ) 100 0.1 12.3 27.6 100 0.01 123 276 120 0.1 10.2 50.2 120 0.01 102 502 RIM =1.8Ω SP-MD115-A.005.doc Version：A.005 Page：11 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Measurement Result In the following, we take some measured data as examples to explain the linear relationship between PWM duty and output current. From the measurement result, it appears that the output constant current is highly linear to the PWM duty ratio. 1. PWM freq. = 16 KHz, VPWM = 2.8V, CIN = 0.1 μ F , IMAX = 100mA. @25 ℃ RA = 17.9 kΩ , RB = 21.8 kΩ , RS = 1.55 Ω PWM duty v.s output constant current (mA) 80 RA = 17.9k, RB = 21.8k, RIM = 1.55 ohm 70 60 Iim (mA) 50 40 30 20 10 20 30 40 50 PWM duty ratio (%) 60 70 80 . SP-MD115-A.005.doc Version：A.005 Page：12 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. 2. PWM freq. = 24 KHz, VPWM = 2.8V, CIN = 0.1 μ F , IMAX = 100mA. @25 ℃ RA = 12.34 kΩ , RB = 14.28 kΩ , RS = 1.55 Ω PWM duty v.s output constant current (mA) 80 RA = 12.34k, RB = 14.28k, RIM = 1.55 ohm 70 60 Iim (mA) 50 40 30 20 10 20 30 40 50 PWM duty ratio (%) 60 70 80 3. PWM freq. = 24 KHz, VPWM =3V, CIN = 0.1 μ F , IMAX = 100mA. @25 ℃ RA = 12.23 kΩ , RB = 13.25 kΩ , RS = 1.55 Ω PWM duty v.s output constant current (mA) 80 RA = 13.23k, RB = 13.25k, RIM = 1.55 ohm 70 60 Iim (mA) 50 40 30 20 10 20 SP-MD115-A.005.doc 30 40 50 PWM duty ratio (%) Version：A.005 60 70 80 Page：13 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. Package Specifications (LFCSP6) 6 4 Top View 1 3 b Bottom View 0.20typ 6 4 E1 1.25 D D1 0.20 0.715 typ. A L 1 3 e L1 A3 A1 e1 E2 E DIMENSION (mm) SYMBOL A A1 A3 b D D1 E E1 E2 L L1 e e1 y MIN. 0.00 0.22 1.50 0.5 1.30 1.00 0.25 - SP-MD115-A.005.doc NOM. 0.02 0.127 REF 0.30 1.60 0.6 1.40 1.10 1.30 BASIC 0.30 0.05 BASIC 0.50 BASIC 1.00 BASIC - DIMENSION (mil) MAX. 0.425 0.05 MIN. 0 0.38 1.70 0.7 1.50 1.20 8.7 59.1 19.7 51.1 39.4 0.35 9.8 0.08 - Version：A.005 NOM. 0.8 5 REF 11.8 63.0 23.6 55.1 43.3 51.2 BASIC 11.8 2.00 BASIC 20.0 BASIC 39.4 BASIC - MAX. 16.7 2 Page：14 15 66.9 27.6 59.1 47.2 13.8 3 點晶科技股份有限公司 SILICON TOUCH TECHNOLOGY INC. A A1 A2 L1 D e1 Package Specifications (WLCSP) DIMENSION (mm) SYMBOL A A1 A2 b D E e1 e2 L1 L2 SP-MD115-A.005.doc MIN. 0.45 0.08 0.37 0.26 1.45 0.95 0.48 0.48 0.22 0.22 Version：A.005 NOM. 0.50 0.10 0.40 0.28 1.50 1.00 0.50 0.50 0.25 0.25 MAX. 0.55 0.12 0.43 0.30 1.55 1.05 0.52 0.52 0.28 0.28 Page：15 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-MD115-A.005.doc Version：A.005 Page：16