Data Sheet D371A Electroluminescent Lamp Driver IC General Description: The Durel® D371A Lamp Driver is part of a family of switch-mode IC drivers intended to reduce EL system cost, improve performance and to simplify the design, specification, and manufacture of EL backlighting systems. This driver is optimized for cellular phone and databank backlighting applications. MSOP-10 Features • • • • • • A pplications Applications Flexible Wave shaping Capability High Efficiency Small Package Size Adjustable Output Frequency High AC Voltage Output External Clock Compatible • • • Cellular / PHS Phones Data Banks LCD Backlighting Lamp D er SSpecifications: pecifications: Drriv iver (V+=3.0V, CLF=3.9nF, CHF=68pF, L=2.2mH/4Ω, E=V+, Renable=0Ω, DCH open, Load 2*, Ta=25°C, unless otherwise specified) Parameter Symbol Supply Current Standby Current Enable Current Enable Voltage On Off Inductor Frequency Lamp Frequency Output Voltage Minimum Typical I 15 5 15 E 2.6 HF LF VOUT 190 160 23 260 188 Maximum 18 1000 0.4 330 215 Typical Wav efor m avefor eform * Load 2 100Ω 10 nF 1 Unit Conditions mA nA µA E = GND E = 3.0V V V kHz Hz Vpp CHF=68pF CLF=3.9nF Absolute Maximum Ratings: Parameter Symbol Supply voltage Operating range Withstand range Output Voltage Enable voltage Operating temperature Storage temperature Solder temperature CHF (Pin 1) Voltage CLF (Pin 2) Voltage Minimum Maximum Unit Comments V V+ 2.0 -0.5 Vout E Ta Ts 6.5 9.0 220 (V+) +0.5 85 150 300 (V+)+0.3V (V+)+0.3V -0.5 -40 -65 245 GND GND VCHF VCLF Vpp V °C °C °C V V Peak to peak voltage 5 second soak Note: The absolute maximum ratings are stress ratings only. Functional operation of the device at these ratings or any other conditions above those indicated in the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect life of lamp or driver. Physical D ata: Data: Pad C enter Locations Center Xµm Yµm Name N ame CHF CLF E DCH GND N/C LV-out L+ V+ -427 -427 -426 -445 -459 467 473 473 475 728 463 -413 -583 -776 -345 -78 190 786 MSOP Pin-outs 1 2 3 4 5 6 7 8 9 10 Function V+ CHF Capacitor input to high frequency oscillator Capacitor input to low frequency oscillator System Enable Wave shaping input Power ground Not connected Negative power connection to inductor Output voltage to EL lamp Positive power connection to inductor System power input CLF L+ 0 VOUT 0 L- E DCH GND Notes: 1. Dimensions are in microns, unless otherwise noted. 2. Bond pads are typically 100 x 100. 3. Die thickness is 330 +/- 25 (13 +/- 1 mil). 4. Pad center coordinates are relative to origin on center of die. 5. Die size is 1170 x 1760. 6. Base of die should be grounded. Block D iagram of the IInv nv er ter C ir cuitr y: Diagram nver erter Cir ircuitr cuitry: 1.0µF Renable V BAT DCH E V+ L+ CLF Low Frequency Oscillator Constant current discharge Discharge logic CHF High Frequency Oscillator L- VOUT EL Lamp 2 GND Typical D371A EL D er Configuration: Drriv iver 3.0V Cellular LCD Typical O utput Output Brightness = 6.75 fL (23.1 Cd/m2) Lamp Frequency = 460 Hz Supply Current = 16mA Vpp = 190 Load = 1.5in2 3.3 V C ellular Display and K Cellular Keeypad Typical O utput Output Brightness = 4.45 fL (15.2 Cd/m2) Lamp Frequency = 275 Hz Supply Current = 12mA Vpp = 185 Load = 2.25in2 5.0 V PDA Typical O utput Output Brightness = 5.5fL (18.8 Cd/m2) Lamp Frequency = 285 Hz Supply Current = 15mA Vpp = 200 Load = 4in2 3 DESIGNING WITH D371 The Durel® D371A Lamp Driver is part of a family of switch-mode IC drivers intended to reduce EL system cost, improve performance and to simplify the design, specification, and manufacture of EL backlighting systems. This driver is optimized for cellular phone and databank backlighting applications. A typical D371 circuit is represented in Figure 1. This application guideline is furnished to help you optimize your EL driver circuit design. It provides typical system outputs, such as lamp luminance and supply current draw, for various circuit configurations. Durel also provides a Designer’s Kit, which includes a printed circuit board to aid you in developing an EL lamp driver configuration that meets your requirements. Figur ir cuit D esign iguree 1: Typical D371 C Cir ircuit Design I. Lamp Frequency Selecting the appropriate value of capacitor (CLF) for the low frequency oscillator will set the output frequency of the D371 inverter. Figure 2 graphically represents the effect of the CLF capacitor value on the oscillator frequency at V+ = 3.0V. 900 Lamp Frequency (Hz) 800 700 600 500 400 300 200 100 0 1 2 3 4 5 6 7 8 9 10 CLF (nF) Figur equency vs. CLF capacitor iguree 2: Typical Lamp fr frequency 4 The lamp frequency may also be controlled with an external clock signal. The resulting lamp frequency will be half of the clock signal frequency. The output voltage (pin 8) will increase in magnitude during the low portion of the clock signal and linearly decrease during the high portion of the clock signal. Lamp frequencies of 200-500Hz are typically used. The lamp frequency should always be set so that the output voltage does not exceed 200Vpp. II. Inductor Switching Frequency Selecting the appropriate value of capacitor (CHF) for the high frequency oscillator will set the inductor switching frequency of the D371 inverter. Figure 2 graphically represents the effect of the CHF capacitor value on the oscillator frequency at V+ = 3.0V. Inductor Frequency (kHz) 25 20 15 10 50 75 100 125 150 175 200 225 CHF (pF) Figur equency vs. CHF capacitor iguree 3: Typical inductor fr frequency The inductor switching frequency may also be controlled with an external clock signal. The inductor will charge during the low portion of the clock signal and discharge into the EL lamp during the high portion of the clock signal. III. Inductor Selection The inductor value and inductor switching frequency have the greatest impact on the output brightness and current consumption of the driver. Figures 4 and 5 show typical brightness and current draw of a D371 circuit with several different inductor and CHF values. The CLF value was modified in each case such that the output voltage was approximately 190Vpp. Please note that the DC resistance (DCR) and current rating of inductors with the same inductance value may vary with manufacturer and inductor type. Thus, inductors made by a different manufacturer may yield different outputs, but the trend of the different curves should be similar. 5 50.0 9.00 45.0 8.00 40.0 7.00 35.0 6.00 30.0 5.00 25.0 4.00 20.0 3.00 Current (mA) Brightness (Ft-L) 10.00 15.0 68 pF Brightness 100 pF Brightness 2.00 10.0 68 pF Current 100 pF Current 1.00 5.0 0.00 0.0 0.39 0.47 0.56 0.68 0.82 1.00 1.20 1.50 1.80 2.20 2.70 3.30 3.90 Inductor (mH) Figure 4: Brightness and current vs. inductor and CHF value. Conditions: V+=3.0V, Lamp=2.0in2 12.00 70.0 60.0 10.00 50.0 40.0 6.00 30.0 4.00 20.0 68 pF Brightness 100 pF Brightness 2.00 68 pF Current 10.0 100 pF Current 0.00 0.0 0.39 0.47 0.56 0.68 0.82 1.00 1.20 1.50 1.80 2.20 2.70 3.30 Inductor (mH) Figure 5: Brightness and current vs. inductor and CHF value. Conditions: V+=5.0V, Lamp=4.0in2 6 3.90 Current (mA) Brightness (Ft-L) 8.00 IV. Wave-Shaping The D371 inverter uses a patented wave-shaping technique for reducing audible noise from an EL lamp. The linear discharge of the output waveform may be adjusted by selecting one of 4 lamp discharge levels. The optimal discharge level for an application depends on the lamp size, lamp brightness, etc. To ensure that the D371 is configured optimally, each level should be evaluated. In many cases, the lower discharge levels result in lower audible noise from the EL lamp. Discharge level Renable DCH pin Typical Lamp SSiz iz izee 1 (slowest) 2 3 4 (fastest) 80kΩ 0Ω 80kΩ 0Ω Open Open GND GND 0.5-1.5 in2 1.0-2.5 in2 1.5-3.5 in2 >3.5 in2 V. Output Voltage The inductor and CLF capacitor should be set such that the output voltage of the D371A inverter does not exceed 200Vpp. In some cases, a pair of zener diodes connected to the output (as shown below) is recommended to prevent over-voltage on pin 8. Durel can provide assistance in optimizing circuit components for your application. 7 Ordering Information: The D371A inverter is available as bare die in probed wafer form or in die trays, and in a standard MSOP-10 plastic package per tube or per tape and reel. A Durel D371A Designer’s Kit is available for evaluating and identifying the optimum component values for your application. MSOP-10 Min. Description A B C D E F G H J mm. 0.92 0.05 0.15 0.40 0.13 2.90 0.35 4.75 2.90 F Typical in. 0.036 0.002 0.006 0.016 0.005 0.114 0.014 0.187 0.114 mm. 1.00 0.10 0.23 0.55 0.18 3.00 0.50 4.90 3.00 Max. in. mm. in. 0.039 0.004 0.009 0.022 0.007 0.118 0.020 0.193 0.118 1.08 0.15 0.31 0.70 0.23 3.10 0.65 5.05 3.10 0.043 0.006 0.012 0.028 0.009 0.122 0.026 0.199 0.122 I D E C A G MSOPs are marked with direct logo part number (371A) and wafer lot number. Marking orientation is bottom closest to pin 1 side. H B MSOPs in Tubes: 1DDD371AA-M03 MSOPs in Tape & Reel: 1DDD371AA-M04 Tube-length = 320 mm (12.6 in). 100 units per tube. Embossed tape on 360 mm diameter reel per EIA-481-2. 2500 units per reel. Quantity marked on reel label. Die in Trays: 1DDD371AA-B02 ! ! ! ! Tape Orientation Die tray size is 2 inches square Total number of pockets is 100 Pocket depth is 890µm (0.035”) Pocket area is 2030µm x 2030µm (0.080” x 0.080”) ISO 9001 Certified DUREL Corporation 2225 W. Chandler Blvd. Chandler, AZ 85224-6155 Tel: (480) 917-6000 FAX: (480) 917-6049 Website: http://www.durel.com The DUREL name and logo are registered trademarks of DUREL CORPORATION. This information is not intended to and does not create any warranties, express or implied, including any warranty of merchantability or fitness for a particular purpose. The relative merits of materials for a specific application should be determined by your evaluation. This inverter is covered by the following U.S. patents: #5,313,141, #5,789,870. Corresponding foreign patents are issued and pending. © 2000, Durel Corporation Printed in U.S.A. LIT-I 9028 Rev. A07