Typical Output Waveform Load B* 47 nF 22 nF 100Ω 10kΩ * Load B approximates a 5in2 EL lamp. Absolute Maximum Ratings Parameter Supply voltage Operating range Withstand range Enable Voltage Output Voltage CLF Voltage Operating temperature Storage temperature Symbol Minimum V+ 1.0 -0.5 -0.5 E’ Vout VCLF Ta Ts Maximum 7.0 10.0 (V+) +0.5 220 (V+)+0.3 85 150 0 -40 -65 Unit V V Vpp V °C °C Comments E’ = GND E’ = V+ Peak to peak voltage External clock input Note: The above are stress ratings only. Functional operation of the device at these ratings or any other above those indicated in the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. Physical Data PIN # NAME 1 8 2 7 3 6 4 5 1 2 3 4 5 6 7 8 GND LVout L+ V+ CLF1 CLF2 E’ FUNCTION System ground connection Negative input to inductor High voltage AC output to lamp Positive input to inductor DC power supply input Lamp frequency capacitor/clock input Lamp frequency capacitor/clock input System enable; Power Down Control Note: Please consult factory for bare die physical data and bond pad locations 2 Typical Performance Characteristics Using Standard Test Circuit 450 400 350 300 250 450 200 150 100 50 0 200 400 350 300 250 150 100 50 0 1 2 3 4 5 6 7 -40 -20 DC Input Voltage 240 200 200 160 160 120 120 80 80 40 40 0 0 3 4 5 40 60 80 Output Frequency vs. Ambient Temperature 240 2 20 Temperature (oC) Output Frequency vs. DC Supply Voltage 1 0 6 -40 7 -20 0 20 40 60 80 o Temperature ( C) DC Input Voltage Output Voltage vs. Ambient Temperature Output Voltage vs. DC Supply Voltage 50 50 40 40 30 30 20 20 10 10 0 0 1 2 3 4 5 6 7 -40 DC Input Voltage -20 0 20 40 60 Temperature (oC) Supply Current vs. Ambient Temperature Supply Current vs. DC Supply Voltage 3 80 Block Diagram of the Driver Circuitry 1.0 µ F E’ V+ L+ CLF1 CLF2 Low Frequency Oscillator High Frequency Oscillator L- VOUT GND EL Lamp Theory of Operation Electroluminescent (EL) lamps are essentially capacitors with one transparent electrode and a special phosphor material in the dielectric. When a strong AC voltage is applied across the EL lamp electrodes, the phosphor glows. The required AC voltage is typically not present in most systems and must be generated from a low voltage DC source. Thus, Durel developed its patented Three-Port (3P) switch-mode inverter circuit to convert the available DC supply to an optimal drive signal for high brightness and low-noise EL lamp applications. The Durel 3P topology offers the simplicity of a single DC input, single AC output, and a shared common ground that provides an integrated EMI shielding. The D355B drives the EL lamp by repeatedly pumping charge through an external inductor with current from a DC source and discharging into the capacitance of the EL lamp load. With each high frequency (HF) cycle the voltage on the lamp is increased. At a period specified by the lamp frequency (LF) oscillator, the voltage on the lamp is discharged to ground and the polarity of the inductive charging is reversed. By this means, an alternating positive and negative voltage is developed at the single output lead of the device to one of the electrodes of the EL lamp. The other lamp electrode is commonly connected to a ground plane, which can then be considered as electrical shielding for any underlying circuitry on the application. The EL driving system is divided into several parts: on-chip logic and control, on-chip high voltage output circuitry, discharge logic circuitry, and off-chip components. The on-chip logic controls the output frequency (LF), as well as the inductor switching frequency (HF), and HF and LF duty cycles. These signals are combined and buffered to regulate the high voltage output circuitry. The output circuitry handles the power through the inductor and delivers the high voltage to the lamp. The selection of off-chip components provides a degree of flexibility to accommodate various lamp sizes, system voltages, and brightness levels. Since a key objective for EL driver systems is to save space and cost, required off-chip components were kept to a minimum. Durel provides a D355B Designer’s Kit, which includes a printed circuit evaluation board intended to aid you in developing an EL lamp driver configuration using the D355B that meets your requirements. A section on designing with the D355B is included in this datasheet to serve as a guide to help you select the appropriate external components to complete your D355B EL driver system. Typical D355B configurations for driving EL lamps in various applications are shown on the following page. The expected system outputs, such as lamp luminance, lamp output frequency and voltage and average supply current draw, for the various sample configurations are also shown with each respective figure. 4 Typical D355B EL Driver Configurations 1.5V Analog Watch 1 GND Typical Output Luminance = 3.5 fL (12 cd/m2) Lamp Frequency = 220 Hz Supply Current = 10 mA Vout = 178 Vpp Load = 1 in2 Durel ®3 Green EL OFF 1.5V E’ 8 2 L- ON GND CLF2 7 6.8 nF 2.2 mH Sumida CLS62-222 3 VOUT 4 L+ CLF1 6 V+ 5 D355 1.5 V 1.0 µF 1 in2 EL Lamp 3.0V Handset LCD or Digital Watch 1MΩ Typical Output Luminance = 8.6 fL (29.5 cd/m2) Lamp Frequency = 475 Hz Supply Current = 14 mA Vout = 208 Vpp Load = 1 in2 Durel ®3 Green EL 1 GND 4.7 mH Coilcraft DS1608BL-475 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ 1MΩ E’ 8 OFF GND 3.3 nF 3.0 V 1.0µF 5.0V PDA 1 GND Luminance = 7.7 fL (26.4 cd/m2) Lamp Frequency = 360 Hz Supply Current = 19 mA Vout = 220 Vpp Load = 4 in2 Durel ®3 Green EL 5.0 mH Hitachi Metals MD735L-502A OFF ON 5.0V GND E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ D355 4 in2 EL Lamp 5 ON 3.0V V+ 5 D355 1 in2 EL Lamp Typical Output E MMBTA06 4.7 nF V+ 5 1.0µF 5.0 V Designing With D355B I. Lamp Frequency Capacitor (CLF) Selection Selecting the appropriate value of capacitor for the low frequency oscillator (CLF) will set the output frequency of the D355 inverter. Figure 1 graphically represents the inversely proportional relationship between the CLF capacitor value and the oscillator frequency. In this example at V+=3.0V, LF = 1600 nF-Hz/CLF. 900 800 700 600 500 400 300 200 100 0 0 1 2 3 4 5 6 CLF (nF) 7 8 9 10 Figure 1: Typical Lamp Frequency vs. CLF Capacitor Alternatively, the lamp frequency may also be controlled with an external clock signal with a 50% duty cycle. The output lamp frequency will be the same frequency as the input clock signal. For example, if a 250Hz input clock signal is used, the resulting lamp frequency will be 250Hz. The clock signal input voltage should not exceed V+. The selection of the CLF value can also affect the brightness of the EL lamp because of its control of the lamp frequency (LF). Although input voltage and lamp size can change EL lamp frequency as well, LF mainly depends on the CLF value selected or the frequency of the input clock signal to CLF. The luminance of various sizes of Durel 3 Blue-green EL lamp driven by a D355B at V+ = 3.0V using the same inductor value is shown in Figure 2 with respect to lamp frequency. 8 7 6 2 2in EL Lamp 5 2 4 4in EL Lamp 3 2 6in EL Lamp 2 1 0 0 200 400 600 800 1000 Lamp Frequency (Hz) Figure 2: Typical Lamp Luminance vs. Lamp Frequency 6 II. Inductor (L) Selection 10 48 12 48 40 10 40 8 32 6 24 4 16 Lamp Luminance (fL) Brightness Current Current (mA) Lamp Luminance (fL) 12 8 32 6 24 4 16 2 8 0 0 0 1 2 3 4 Figure 3: V+ = 1.5V, 1 in2 EL Lamp Current (mA) Lamp Luminance (fL) 40 8 32 6 24 4 16 2 8 0 0 2 4 6 8 1 2 3 Inductor (m H) 4 5 Figure 4: V+ = 3.0V, 1 in2 EL Lamp 48 Brightness Current 0 0 0 12 8 0 5 Inductor (mH) 10 Brightness Current 2 10 Inductor (mH) Figure 5: V+ = 5.0V, 4 in2 EL Lamp 7 Current (mA) The external inductor (L) selection for a D355B circuit greatly affects the output capability and current draw of the driver. A careful designer will balance current draw considerations with output performance in the choice of an ideal inductor for a particular application. Figures 3, 4, and 5 show typical brightness and current draw of a D355B circuit with different inductor values, lamp sizes, and supply voltages while keeping the LF constant. Please note that the DC resistance (DCR) of inductors with the same nominal 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. Lamp luminance is also a function of lamp size. In each example, a larger lamp will have less luminance with approximately the same current draw. D355B Design Ideas I. Driving Multi-Segment Lamps The D355B may be used to drive two or more EL lamps or EL lamp areas independently. An external switching circuit can be used to turn each lamp segment on or off. A high signal at the E input for the corresponding EL lamp will power the segment when the IC is enabled. In this example, Segment 1 is always on when the Durel D355B is enabled. Otherwise, always make sure that at least one segment is switched on when the driver IC is activated. OFF 1 GND E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 ON CLF L 4 L+ D355 V+ 5 Vbat 1.0µF EL Lamp Segment 1 EL Lamp Segment 2 BAS21LT1 BAS21LT1 ON BAS21LT1 E2 OFF 2.2K EL Lamp Segment 3 4.7K ON OFF 2.2K MMBT5551LT1 MMBT5401LT1 BAS21LT1 E3 4.7K MMBT5551LT1 MMBT5401LT1 100 nF 1K 1K 100 nF II. Enabling the D355B with a High Logic Signal A low logic signal at the E’ pin will enable the D355B. Adding a transistor and two resistors will allow the D355B to be enabled with a high voltage signal. Vbat 1MΩ E’ 8 1 GND ON 1MΩ CLF2 7 2 LL 3 E VOUT CLF1 6 4 L+ OFF CLF V+ 5 D355 1.0µF EL Lamp 8 Vbat III. Two-Level Dimming Toggle switching between two different EL lamp brightness levels may be achieved with the following circuit. When DIM is low, the external pnp transistor is saturated and the EL lamp runs at full brightness. When DIM is high, the external pnp turns off and the 47Ω resistor reduces the voltage at (V+) and dims the EL lamp. OFF 1 GND L ON E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 E’ Low B DIM High B CLF 1kΩ 2N3906 4 L+ V+ 5 D355 47Ω Vbat 1.0µF EL Lamp IV. Lamp Frequency Control with an External Clock Signal An external clock signal with a 50% duty cycle may be used to control the EL lamp frequency (LF). This technique allows the designer flexibility to synchronize the El driver IC with other elements in the application. The output lamp frequency will be the same frequency as the input clock signal. For example, if a 250Hz input clock signal is used, the resulting lamp frequency will be 250Hz. The clock signal voltage should not exceed V+. 1 GND L E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ D355 OFF ON Lamp Frequency CLK 1.0V Min 150kΩ 0.2V Max V+ 5 1.0µF EL Lamp 9 Vbat V. Automatic Turn-Off After Short Time Delay It is sometimes desirable for the EL lamp to turn off automatically after a few seconds of operation. Typically, a mechanical switch pulls E’ low to initially turn on the device. When the switch is released, Cdelay keeps the D355B operating for a short period before turning off. The following table shows typical delay ontimes. Cdelay (µF) 5 7 10 15 20 Vbat 3.0V 4.0 s 5.5 s 8.6 s 12.7 s 17.2 s 1.5V 2.4 s 3.3 s 5.1 s 7.2 s 9.9 s 5.0V 6.0 s 7.8 s 12.5 s 19.3 s 27.0 s E’ 8 1 GND 2 L- CLF2 7 3 VOUT CLF1 6 Cdelay CLF L 4 L+ 1MΩ V+ 5 D355 Vbat 1.0µF EL Lamp VI. Automatic Turn-Off After Long Time Delay Longer on-times can be achieved with the addition of an external transistor. Typically, a mechanical switch pulls E’ low to initially turn on the device. When the switch is released, Cdelay keeps the D355B operating for a period before turning off. The following table shows typical delay on-times using the following circuit with smaller capacitor values. Vbat 1.5V 3.0V 5.0V Cdelay (µF) 1 9.5 s 13.0 s 15.6 s 2 17.8 s 24.0 s 29.0 s 3 26.5 s 36.0 s 42.0 s Vbat 470kΩ L 1 GND 2 L- E’ 8 CLF2 7 3 VOUT 4 L+ 3.3MΩ 2N3904 Cdelay CLF CLF1 6 D355 V+ 5 1.0µF EL Lamp 10 Vbat VII. High EL Brightness Through Supply Voltage Doubling (Option 1) Maximum brightness from a D355 is achieved at relatively high supply voltages (>3.0V). An external voltage boost circuit may be used to increase the voltage supplied to the D355. In the following circuit, the National Semiconductor LM2665 is used to double the voltage supplied to the D355. This can produce about twice the brightness of the D355 alone. NOTE: It is important not to exceed the maximum ratings of either device in this circuit. 3.3µF Vbat 1 VBAT CAP+ 6 1N914 2 GND OUT 5 SD 4 3 CAP- Vbat OFF LM2665 1 GND ON E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 CLF L 4 L+ V+ 5 D355 3.3µF EL Lamp VIII. High EL Brightness Through Supply Voltage Doubling (Option 2) In many cases, a resistor may replace the diode in the previous circuit. The diode is used by the LM2665 during startup (see LM2665 datasheet). The circuit below ensures that the LM2665 starts properly before the D355 is turned on. NOTE: It is important not to exceed the maximum ratings of either device in this circuit. 3.3µF Vbat 1 VBAT CAP+ 6 270KΩ 2 GND OUT 5 3 CAP- Vbat LM2665 OFF SD 4 ON 1 GND E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 Vbat CLF L 4 L+ D355 V+ 5 3.3µF EL Lamp 11 IX. High EL Brightness Through Supply Voltage Doubling (Option 3) In the following circuit, the Analog Devices ADM8828 produces a negative Vbat voltage. This voltage may be connected to the GND pin on the D355 to double the differential voltage supplied to the D355. This can produce about twice the brightness of the D355 alone. *NOTE: It is important not to exceed the maximum ratings of either device in this circuit. 1.0µF 1 OUT CAP+ 6 Vbat 2 IN OFF SHDN 5 3 CAP- ON GND 4 ADM8828 1 GND E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ V+ 5 CLF L D355 Vbat 1.0µF EL Lamp X. EL Lamp Brightness Regulation Regulating the DC supply input voltage to the D355 will result in a constant brightness level from the EL lamp, regardless of battery voltage. In this example, a Micrel voltage regulator is used. 1 GND OUT 4 E ON 2 E MIC5203 IN 3 Vbat OFF 1 GND E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 CLF L 4 L+ D355 V+ 5 1.0µF EL Lamp 12 XI. High EL Brightness with Parallel D355 Drivers (Option 1) Two or more D355 EL drivers may be operated in parallel to increase the brightness of the EL lamp by 50100%. In this circuit, an external clock signal with a 50% duty cycle is needed to synchronously drive both D355 ICs. The clock signal voltage should not exceed V+. OFF E’ 8 1 GND ON L 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ 150kΩ V+ 5 D355 Lamp Frequency CLK 1.0V Min 1 GND L E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ 0.2V Max 150kΩ V+ 5 D355 Vbat 1.0µF EL Lamp XII. High EL Brightness with Parallel D355 Drivers (Option 2) Two or more D355 EL drivers may be operated in parallel to increase the brightness of the EL lamp by 50100%. In this circuit, two D355 ICs are operating synchronously using their internal oscillators. The lamp frequency is controlled by a shared CLF capacitor. 1 GND L E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ V+ 5 D355 1 GND L 100Ω ON E’ 8 2 L- CLF2 7 3 VOUT CLF1 6 4 L+ OFF D355 CLF V+ 5 100Ω 1.0µF EL Lamp 13 Vbat Ordering Information: The D355B IC is available as bare die in probed wafer form or in die tray, and in standard MSOP-8 plastic package per tape and reel. A Durel D355B Designer’s Kit (1DDD355BB-K01) provides a vehicle for evaluating and identifying the optimum component values for any particular application using D355B. Durel engineers also provide full support to customers, including specialized circuit optimization and application retrofits. MSOP-8 F Min. Description I H D E C A G B RECOMMENDED PAD LAYOUT A B C D E F G H I mm. 0.94 0.05 0.20 0.41 0.13 2.84 0.43 4.70 2.84 Typical in. 0.037 0.002 0.008 0.016 0.005 0.112 0.017 0.185 0.112 mm. 1.02 0.10 0.33 0.53 0.18 3.00 0.65 4.90 3.00 Max. in. mm. in. 0.040 0.004 0.013 0.021 0.007 0.118 0.026 0.193 0.118 1.09 0.15 0.46 0.65 0.23 3.15 0.83 5.11 3.25 0.043 0.006 0.018 0.026 0.009 0.124 0.033 0.201 0.128 MSOPs are marked with part number (355B) and 3-digit wafer lot code. Bottom of marking is on the Pin 1 side. b MSOP-8 PAD LAYOUT a Min. mm. c e d f a b c d e f 0.60 1.90 3.3 0.89 5.26 0.41 Typical Max. in. mm. in. 0.0236 0.0748 0.130 0.035 0.207 0.016 0.6 1.9 0.0256 0.0768 0.9 0.038 0.4 0.018 mm. 0.70 2.00 3.45 1.05 5.41 0.51 in. 0.0276 0.0788 0.136 0.041 0.213 0.020 MSOPs in Tape and Reel: 1DDD355BB-M02 Tape Orientation Embossed tape on 360 mm diameter reel per EIA-481-2. 2500 units per reel. Quantity marked on reel label. 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. The EL driver circuits herein are covered by one or more of the following U.S. patents: #5,313,141, #5,347,198, #6,043,610. Corresponding foreign patents are issued and pending. © 2000, 2001, 2002 Durel Corporation Printed in U.S.A. LIT-I 9034 Rev. A04 WWW.ALLDATASHEET.COM Copyright © Each Manufacturing Company. All Datasheets cannot be modified without permission. This datasheet has been download from : www.AllDataSheet.com 100% Free DataSheet Search Site. Free Download. No Register. Fast Search System. www.AllDataSheet.com