ZSP4422A Electroluminescent Lamp Driver Zywyn ZSP4422A Electroluminescent Lamp Driver Features General Description • • • • The ZSP4422A is a high voltage output DC-AC converter that can operate from a +2.2V to +5.0V power supply. The ZSP4422A is designed with our proprietary high voltage BiCMOS technology and is capable of supplying up to 160VPP signals, making it ideal for driving small electroluminescent lamps. The device features 50nA (typical) standby current, for use in low power portable products. One external inductor is required to generate the high voltage, and an external capacitor is used to select the oscillator frequency. The ZSP4422A is offered in an 8-pin narrow SOIC package or an 8-pin MSOP package. For delivery in die form, please consult the factory. +2.2V to +5.0V battery operation 50nA typical standby current High voltage output typical 160VPP Internal oscillator Applications • • • • PDAs Cellular phones Remote controls Handheld computers Ordering Information Pin Configuration 8 HON 1 CAP2 VSS 2 Zywyn 7 CAP1 COIL 3 ZSP4422A 6 VDD 5 EL1 EL2 4 Part Number Temperature Range Package Type ZSP4422ACN –40°C to +85°C 8-Pin nSOIC ZSP4422ACU –40°C to +85°C 8-Pin MSOP ZSP4422ACX 0°C to +70°C Die in Wafflepack ZSP4422ANEB n/a nSOIC Eval. Board ZSP4422AUEB n/a MSOP Eval. Board Please contact the factory for pricing and availabiliy on a Tape-on-Reel option. 8-Pin nSOIC/MSOP Please contact the factory for EL driver design support and availability of custom-made evaluation demo boards. Zywyn Corporation • Tel (408) 733-3225 • Fax (408) 733-3206 • Email [email protected] • www.zywyn.com specifications subject to change without notice March 2004 rev. 01 Zywyn Corporation ZSP4422A Absolute Maximum Ratings Storage Considerations These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. VDD ................................................................................................. +7.0V Input Voltages/Currents HON (pin 1) ................................... –0.5V to (VDD +0.5V) COIL (pin3)..............................................................60mA Lamp Output .......................................................... 230VPP Storage Temperature .............................. –65°C to +150°C Operating Temperature ............................. –40°C to +85°C Power Dissipation Per Package 8-pin NSOIC (derate 6.14mW/°C above +70°C) ... 500mW 8-pin µSOIC (derate 4.85mW/°C above +70°C) ... 390mW Storage in a low humidity environment is preferred. Large high density plastic packages are moisture sensitive and should be stored in Dry Vapor Barrier Bags. Prior to usage, the parts should remain bagged and stored below 40°C and 60%RH. If the parts are removed from the bag, they should be used within 48 hours or stored in an environment at or below 20%RH. If the above conditions cannot be followed, the parts should be baked for four hours at 125°C in order remove moisture prior to soldering. Zywyn ships product in Dry Vapor Barrier Bags with a humidity indicator card and desiccant pack. The humidity indicator should be below 30%RH. The information furnished by Zywyn has been carefully reviewed for accuracy and reliability. Its application or use, however,is solely the responsibility of the user. No responsibility of the use of this information become part of the terms and conditions of any subsequent sales agreement with Zywyn. Specifications are subject to change without the responsibility for any infringement of patents or other rights of third parties which may result from its use. No license or proprietary rights are granted by implication or otherwise under any patent or patent rights of Zywyn Corporation. Electrical Characteristics TA = +25°C, VDD = +3.0V, CLAMP = 17nF with 100Ω series resistor, Coil = 5mH (RS = 18Ω); COSC = 100pF, unless otherwise noted. Symbol Parameter VDD Supply Voltage ICOIL + IDD Supply Current VCOIL Coil Voltage VHON HON Input Voltage LOW: EL off HIGH: EL on Condition Min Typ Max Units 2.2 3.0 5.0 V 20 40 30 60 mA 5.0 V 0 VDD 0.25 VDD + 0.25 V µA VDD = +3.0V, VHON = +3.0V VDD = +5.0V, VHON = +5.0V VDD –0.25 VDD – 0.25 IHON HON Current VDD - VHON - +3.0V 25 60 ISD = ICOIL + IDD Shutdown Current VDD = +3.0V, VHON = LOW VDD = +5.0V, VHON = LOW 50 500 0.3 µA Coil Frequency 11.2 kHz Coil Duty Cycle 94 % nA INDUCTOR DRIVE fCOIL = fLAMP x 32 IPK-COIL Peak Coil Current Guaranteed by design fLAMP EL Lamp Frequency TA = +25°C, VDD = +3.0V VPP Peak-to-Peak Output Voltage TA = +25°C, VDD = +2.2V 60 80 TA = +25°C, VDD = +3.0V TA = +25°C, VDD = +5.0V 110 140 180 200 60 mA 500 600 Hz EL LAMP OUTPUT 250 200 350 V Zywyn 2 March 2004 rev. 01 Zywyn Corporation ZSP4422A Block Diagram VDD VBATTERY 5mH/18Ω 0.1µF 6 1 VDD 3 HON Coil OSC 7 fCOIL Cap1 COSC = 100pF HV1 HV2 Cap2 8 fLAMP Q FF1 FF2 Q fLAMP VSS EL1 EL2 2 4 5 EL Lamp Figure 1. Block Diagram Pin Description Pin Number Pin Name Pin Function 1 HON Enable for driver operation: high = active; low = inactive. 2 VSS Power supply common: connect to ground. 3 COIL 4 EL2 Coil input: connect coil from VDD to this pin. Lamp driver output 2: connect to EL lamp. 5 EL1 Lamp driver output 1: connect to EL lamp. 6 VDD 7 CAP1 Power supply for driver: connect to system VDD. Capacitor Input 1: connect to COSC. 8 CAP2 Capacitor Input 2: connect to COSC. Die Photo Bonding Diagram VD D PAD X EL1 5 5 6 .5 1 7 9 .0 EL2 5 5 6 .2 -1 5 1 .0 -1 9 .5 -5 6 8 .0 -5 1 7 .0 -5 1 7 .0 HO N -5 4 9 .0 -2 5 6 .5 CAP2 -5 4 9 .0 9 3 .5 CAP1 -5 6 8 .0 -5 1 6 .5 VD D -3 4 9 .0 5 1 7 .0 C O IL VS S CAP1 E L1 CAP 2 E L2 HON ZSP4422A VS S C O IL N 1. 2. 3. 4. 5. 6. 7. 8. Y O TES: Dimensions a re in microns unless othe rwise no ted. Bonding pads a re 125x125 typical Outside dimensions a re maximum , including sc ribe area . Die thickness is 11 mils +/- 1. Pad center coordinates are relative to die center. Die subst rate down-bonds to Vss (GND). Die mask num ber is MS129. Die size 1346 x 1447 ( 53 x 57 mils). Zywyn 3 March 2004 rev. 01 Zywyn Corporation ZSP4422A The supply VDD can range from +2.2V to +5.0V. It is not necessary that VDD = V BATTERY. VBATTERY should not exceed max coil current specification. The majority of the current goes through the coil and is typically much greater than IDD. The fCOIL signal controls a switch that connects the end of the coil at pin 3 to ground or to open circuit. The f COIL signal is a 94% duty cycle signal switching at 1/8 the oscillator frequency. For a 64kHz oscillator f COIL is 8kHz. During the time when the fCOIL signal is high, the coil is connected from VBATTERY to ground and a charged magnetic field is created in the coil. During the low part of fCOIL, the ground connection is switched open, the field collapses and the energy in the inductor is forced to flow toward the high voltage H-bridge switches. f COIL will send 16 of these charge pulses (see Figure 5) to the lamp, each pulse increases the voltage drop across the lamp in discrete steps. As the voltage potential approaches its maximum, the steps become smaller (see Figure 4). The H-bridge consists of two proprietary low on-resistance high-voltage switches. These two switches control the polarity of how the lamp is charged. The high-voltage switches are controlled by the fLAMP signal which is the oscillator frequency divided by 256. For a 64kHz oscillator, fLAMP = 256Hz. The direction of current flow is determined by which high-voltage switch is enabled. One full cycle of the H-bridge will create 16 voltage steps from ground to 80V (typical) on pins 4 and 5 which are 180 degrees out of phase from each other (see Figure 6). A differential representation of the outputs is shown in Figure 7. Circuit Description The ZSP4422A is made up of three basic circuit elements, an oscillator, coil,and switched H-bridge network. The oscillator provides the device with an on-chip clock source used to control the charge and discharge phases for the coil and lamp. An external capacitor connected between pins 7 and 8 allows the user to vary the oscillator frequency from 32kHz to 400kHz. In general, increasing the C OSC capacitor will increase the lamp output. The suggested oscillator frequency is 90kHz (COSC =100pF). The oscillator output is internally divided to create two internal control signals, fCOIL and fLAMP. The oscillator output is internally divided down by 8 flip-flops, a 90kHz signal will be divided into 8 frequencies; 45kHz, 22.5kHz, 11.2kHz, 5.6kHz, 2.8kHz, 1.4kHz, 703Hz, and 352Hz. The third flip-flop output (8kHz) is used to drive the coil (see Figure 1) and the eighth flip-flop output (250Hz) is used to drive the lamp. Although the oscillator frequency can be varied to optimize the lamp output, the ratio of fCOIL/fLAMP will always equal 32. The on-chip oscillator of the ZSP4422A can be overdriven with an external clock source by removing the C OSC capacitor and connecting a clock source to pin 8. The clock should have a 50% duty cycle and range from VDD to ground. An external clock signal may be desirable in order to synchronize any parasitic switching noise with the system clock. The maximum external clock frequency that can be supplied is 400kHz. The coil is an external component connected from VBATTERY to pin 3 of the ZSP4422A. Energy is stored in the coil according to the equation EL =1/2LI2, where I is the peak current flowing in the inductor. The current in the inductor is time dependent and is set by the “ON” time of the coil switch: I = (VL/L)t ON, where VL is the voltage across the inductor. At the moment the switch closes, the current in the inductor is zero and the entire supply voltage (minus the VSAT of the switch) is across the inductor. The current in the inductor will then ramp up at a linear rate. As the current in the inductor builds up, the voltage across the inductor will decrease due to the resistance of the coil and the “ON” resistance of the switch: VL = VBATTERY – IRL – VSAT . Since the voltage across the inductor is decreasing, the current ramp-rate also decreases which reduces the current in the coil at the end of tON the energy stored in the inductor per coil cycle and therefore the light output. The other important issue is that maximum current (saturation current) in the coil is set by the design and manufacturer of the coil. If the parameters of the application such as VBATTERY, L, RL or tON cause the current in the coil to increase beyond its rated ISAT, excessive heat will be generated and the power efficiency will decrease with no additional light output. The Zywyn ZSP4422A is final tested using a 5mH/18Ω coil from Hitachi Metals. For suggested coil sources see, “Coil Manfacturers.” Layout Considerations The ZSP4422A circuit board layout must observe careful analog precautions. For applications with noisy voltage power supplies a 0.1µF low ESR decoupling capacitor must be connected from V DD to ground. Any high voltage traces should be isolated from any digital clock traces or enable lines. A solid ground plane connection is strongly recommended. All traces to the coil or to the high voltage outputs should be kept as short as possible to minimize capacitive coupling to digital clock lines and to reduce EMI emissions. Electroluminescent Technology What is Electroluminescence? An EL lamp is basically a strip of plastic that is coated with a phosphorous material which emits light (fluoresces) when a high voltage (>40V) which was first applied across it, is removed or reversed. Long periods of DC voltages applied to the material tend to breakdown the material and reduce its lifetime. With these considerations in mind, the ideal signal to drive an EL lamp is a high voltage sine wave. Traditional approaches to achieving this type of waveform included discrete circuits incorporating a transformer, transistors, and several resistors and capacitors. Zywyn 4 March 2004 rev. 01 Zywyn Corporation ZSP4422A This approach is large and bulky, and cannot be implemented in most hand held equipment. Zywyn now offers low power single chip driver circuits specifically designed to drive small to medium sized electroluminescent panels. All that is required is one external inductor and capacitor. Electroluminescent backlighting is ideal when used with LCD displays, keypads, or other backlit readouts. Its main use is to illuminate displays in dim to dark conditions for momentary periods of time. EL lamps typically consume less than LEDs or bulbs making them ideal for battery powered products. Also, EL lamps are able to evenly light an area without creating “hot spots” in the display. The amount of light emitted is a function of the voltage applied to the lamp, the frequency at which it is applied, the lamp material used and its size, and lastly, the inductor used. There are many variables which can be optimized for specific applications. Typical Application Figure 2. Typical Application Circuit Contact the factory for any technical and application support. 5mH/18Ω Test Circuit HON=VDD=ON HON=0V=OFF VIN=3V COSC=100pF + HON Cap2 - VSS Cap1 Coil VDD EL2 EL1 NOTE: Keep coil as close to the ZSP4422A as possible ZSP4422A 0.1µF Low ESR Decoupling Capacitor 100Ω 17nF NOTE: Keep high voltage traces short and away from VDD and clock lines Zywyn Figure 3. Typical Test Circuit 5 March 2004 rev. 01 Zywyn Corporation ZSP4422A Waveforms VPEAK=80V (typical) EL1 output; 16 charge steps per half cycle Figure 4. EL Output Voltage in Discrete Steps at EL1 Output 16 coil pulses per half cycle; 94% duty cycle. Figure 5. Voltage Pulses Released from the Coil to the EL Driver Circuitry EL1 Output - EL2 Output Figure 6. EL Voltage Waveforms from the EL1 and EL2 Outputs EL1 Output VPP=160V (typical) - EL2 Output Differential Representation E12. Figure 7. EL Differential Output Waveform of the EL1 and EL2 Outputs Zywyn 6 March 2004 rev. 01 Zywyn Corporation Coil Manufacturers Hitachi Metals Material Trading Division 2101 S. Arlington Heights Road, Suite 116 Arlington Heights, IL 60005-4142 Phone: 1-800-777-8343 Ext. 12 (847) 364-7200 Ext. 12 Fax: (847) 364-7279 Hitachi Metals Ltd. Europe Immernannstrasse 14-16, 40210 Dusseldorf, Germany Contact: Gary Loos Phone: 49-211-16009-0 Fax: 49-211-16009-29 Hitachi Metals Ltd. Kishimoto Bldg. 2-1, Marunouchi 2-chome, Chiyoda-Ku, Tokyo, Japan Contact: Mr. Noboru Abe Phone: 3-3284-4936 Fax: 3-3287-1945 Hitachi Metals Ltd. Singapore 78 Shenton Way #12-01, Singapore 079120 Contact: Mr. Stan Kaiko Phone: 222-8077 Fax: 222-5232 ZSP4422A Murata Electronics Singapore Transflector Material 200 Yishun Ave. 7, Singapore 2776, Republic of Singapore Phone: 011 657584233 Fax: 011 657536181 Astra Products Mark Bogin P.O. Box 479 Baldwin, NJ 11510 Phone (516)-223-7500 Fax (516)-868-2371 Murata Hong Kong Room 709-712 Miramar Tower, 1 Kimberly Road, Tsimshatsui, Kowloon, Hong Kong Phone: 011-85223763898 Fax: 011-85223755655 Panasonic. 6550 Katella Ave Cypress, CA 90630-5102 Phone: (714) 373-7366 Fax: (714) 373-7323 Murata 2200 Lake Park Drive, Smyrna Georgia 30080 U.S.A. Phone: (770) 436-1300 Fax: (770) 436-3030 Leading Edge Ind. Inc. 11578 Encore Circle Minnetonka, MN 55343 Phone 1-800-845-6992 Midori Mark Ltd. 1-5 Komagata 2-Chome Taita-Ku 111-0043 Japan Phone: 81-03-3848-2011 Sumida Electric Co., LTD. 5999, New Wilke Road, Suite #110 Rolling Meadows, IL,60008 U.S.A. Phone: (847) 956-0666 Fax: (847) 956-0702 NEC Corporation Yumi Saskai 7-1, Shiba 5 Chome, Minato-ku, Tokyo 108-01, Japan Phone: (03) 3798-9572 Fax: (03) 3798-6134 Sumida Electric Co., LTD. 4-8, Kanamachi 2-Chrome, Katsushika-ku, Tokyo 125 Japan Phone: 03-3607-5111 Fax: 03-3607-5144 Hitachi Metals Ltd. Hong Kong Room 1107, 11/F., West Wing, Tsim Sha. Tsui Center 66 Mody Road,Tsimshatsui East, Kowloon, Hong Kong Phone: 2724-4188 Fax: 2311-2095 EL Lamp Manufacturers Sumida Electric Co., LTD. Block 15, 996, Bendemeer Road #04-05 to 06, Singapore 339944 Republic of Singapore Phone: 2963388 Fax: 2963390 Seiko Precision Shuzo Abe 1-1, Taihei 4-Chome, Sumida-ku, Tokyo, 139 Japan Phone: (03) 5610-7089 Fax: (03) 5610-7177 Gunze Electronics 2113 Wells Branch Parkway Austin, TX 78728 Phone: (512) 752-1299 Fax: (512) 252-1181 Sumida Electric Co., LTD. Murata European 14 Floor, Eastern Center, 1065 King’s Road, Quarry Bay, Hong Kong Phone: 28806688 Fax: 25659600 Holbeinstrasse 21-23, 90441 Numberg, Postfachanschrift 90015 Phone: 011-4991166870 Fax: 011-49116687225 Polarizers/Transflector Manufacturers Nitto Denko Murata Taiwan Electronics 225 Chung-Chin Road, Taichung, Taiwan, R.O.C. Phone: 011 88642914151 Fax: 011 88644252929 Yoshi Shinozuka Bayside Business Park 48500 Fremont, CA. 94538 Phone: 510 445 5400 Fax: 510 445-5480 Top Polarizer- NPF F1205DU Bottom - NPF F4225 or (F4205) P3 w/transflector Zywyn 7 March 2004 rev. 01 Zywyn Corporation ZSP4422A Package Information All package dimensions in inches 8-pin MSOP 8-pin nSOIC 0.0256 BSC 12.0˚ ±4˚ 0.012 ±0.003 0.0965 ±0.003 ZSP4422ACU ZSP4422ACN 0.228/0.244 0.053/0.069 0˚ - 6˚ 0.006 ±0.006 0.006 ±0.006 R .003 0.189/0.197 0.150/0.157 0.008 0.118 ±0.002 0.16 ±0.003 12.0˚ ±4˚ 0.01 0.020 0.020 1 3.0˚ ±3˚ 0.0215 ±0.006 0.037 Ref 2 0.014/0.019 0.050 BSC 0.116 ±0.004 1 0.034 ±0.002 0.116 ±0.004 0.040 ± 0.002 0.013 ±0.005 0.118 ±0.002 95 ZSP4422ACN per tube 0.118 ±0.004 0.004 ±0.002 50 ZSP4422ACU per tube P W nSOIC-8 13" reels: P=8mm, W=12mm MSOP-8 13" reels: P=8mm, W=12mm Pkg. ACN and ACU Minimum qty per reel Standard qty per reel 500 2500 Maximum qty per reel 3000 400 ZSP4422ACX die per wafflepack Waffle tray size = 1996 x 1996 mils Waffle pocket size cavity = 60 x 70 mils Waffle depth size cavity = 22 mils Zywyn Corporation Headquarters and Sales Office 1270 Oakmead Parkway, Suite 201 • Sunnyvale, CA 94085 • Tel: (408) 733-3225 • Fax: (408) 733-3206 Email: [email protected] • www.zywyn.com Zywyn Corporation reserves the right to make changes to any products described herein. Zywyn does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. © 2003 Zywyn Corporation Zywyn 8 March 2004 rev. 01