Data Sheet D340B Electroluminescent Lamp Driver IC General Description: The Durel D340B is part of a family of highly integrated EL drivers based on Durel’s patented three-port (3P) topology, which offers built-in EMI shielding. This low-cost, regulated device is well suited for backlighting timepieces and small liquid crystal displays for portable electronic applications. D 1 34 B MSOP-8 Features • • • • Applications Small System Footprint Regulated AC output voltage Low Standby Current High Efficiency • • • • Timepieces Pagers Calculators Handsets Lamp Driver Specifications: (Using Standard Test Circuit at Ta=25 °C unless otherwise specified.) Parameter Symbol Standby Current Supply Current Output Voltage Lamp Frequency Minimum I Vout LF 110 100 Typical 5 12 144 140 Maximum 1000 20 160 200 Unit Conditions nA mA Vpp Hz E’ = V+ E’ = GND E’ = GND E’ = GND Standard Test Circuit 3.3 V 1 V+ 2 E’ L+ 8 VOUT 7 4.7 uF OFF (3.0 V) 4.7 mH (59 Ohm DCR) ON 3 GND 4 N/C D340B LOAD B 1 L- 6 N/C 5 Typical Output Waveform Load A* 47 nF 100 Ω 22 nF 10kΩ * Load B approximates a 5in2 (32 cm2 ) EL lamp. Absolute Maximum Ratings: Parameter Supply voltage Operating Range Withstand Range Enable Voltage Output Voltage Operating Temperature Storage Temperature Symbol Minimum V+ 1.0 - 0.5 - 0.5 E VOUT Ta Ts Maximum 7.0 10.0 (V+) +0.5 160 70 150 - 40 - 40 Unit V V Vpp °C °C Comments E = GND E = V+ Peak-to-Peak Voltage 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 V+ E’ GND N/C N/C LVOUT L+ FUNCTION DC power supply input System enable; Power Down Control System ground connection No connection No connection Negative input to inductor High voltage AC output to lamp Positive input to inductor Note: Please consult factory for bare die dimensions and bond pad locations. 2 Typical Performance Characteristics Using Standard Test Circuit 400 400 350 350 300 300 250 250 200 200 150 150 100 100 50 50 0 1 2 3 4 5 6 0 7 -40 -20 DC Input Voltage 20 40 60 80 Temperature ( C) Output Frequency vs. DC Supply Voltage Output Frequency vs. Ambient Temperature 200 Output Voltage (Vpp) 200 Output Voltage (Vpp) 0 160 120 80 40 160 120 80 40 0 0 1 2 3 4 5 6 7 -40 -20 DC Input Voltage 0 20 40 60 80 Temperature ( C) Output Voltage vs. DC Supply Voltage Output Voltage vs. Ambient Temperature 30 30 25 25 20 20 15 15 10 10 5 5 0 0 1 2 3 4 5 6 7 -40 DC Input Voltage -20 0 20 40 60 Temperature ( C) Supply Current vs. Ambient Temperature Supply Current vs. DC Supply Voltage 3 80 Block Diagram of the Driver Circuitry 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 D340B 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. When the voltage on the lamp reaches the set voltage on the comparator, 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, and off-chip components. The on-chip logic controls the inductor switching frequency (HF) and change in lamp charging polarity at a frequency (LF) that is dependent on the lamp load size and DC voltage source. 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 D340B Designer’s Kit, which includes a printed circuit evaluation board intended to aid you in developing an EL lamp driver configuration using the D340B that meets your requirements. A section on designing with the D340B is included in this datasheet to serve as a guide to help you select the appropriate external components to complete your D340B EL driver system. Typical D340B 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 D340B EL Driver Configurations 1.5V Analog Watch 1.5 V 1 V+ 2 E' 3 GND 4 N/C L+ 8 VOUT 7 L- 6 N/C 5 4.7 uF Typical Output OFF (3.0 V) Luminance= 2.9 fL (10 cd/m2) Lamp Frequency = 214 Hz Supply Current = 10 mA Vout = 144 Vpp Load = 645 mm2 (1 in2 ) Durel ®3 Green EL ON D340B 2.2 mH Murata LQS33C 1 in2 EL Lamp 3.0V Pager or Digital Watch Typical Output 3.0 V Luminance = 4.7 fL (16 cd/m2) Lamp Frequency = 600 Hz Supply Current = 11 mA Vout = 140 Vpp Load = 645 mm2 (1 in2 ) Durel ®3 Blue-Green EL 1 V+ 2 E' 3 GND 4 N/C L+ 8 VOUT 7 L- 6 N/C 5 4.7 uF OFF (3.0 V) 6.0 mH Hitachi Metals #MD520L-602A ON D340B 1 in2 EL Lamp 6.0 V Remote Control 6.0 V Typical Output Luminance = 5.8 fL (20 cd/m2) Lamp Frequency = 530 Hz Supply Current = 16 mA Vout = 145 Vpp Load = 2580 mm2 (4 in2) Durel ® 3 Green EL 1 V+ 2 E' 3 GND 4 N/C L+ 8 VOUT 7 L- 6 N/C 5 4.7 uF OFF (3.0 V) ON D340B 4 in2 EL Lamp 5 10 mH Coilcraft DT1608C D340B Design Ideas I. Driving Multi-Segment Lamps The D340B may be used to drive two or more EL lamps or EL lamp segments 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 D340B is enabled. Otherwise, always make sure that at least one segment is switched on when the driver IC is activated. II. Enabling the D340B with a High Logic Signal A low logic signal at the E’ pin will enable the D340B. Adding a transistor and two resistors will allow the D340B to be enabled with a high voltage signal. 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 47W resistor reduces the voltage at (V+) and dims the EL lamp. IV. 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 D340B operating for a short period before turning off. The following table shows typical delay on-times. Vbat C delay (uF) 5 7 10 15 20 Vbat 1.0uF 1MOhm 1.5V 1.8 sec 2.3 sec 5.6 sec 5.9 sec 7.7 sec 1 V+ 2 E’ 3 GND 4 N/C 3.0V 2.4 sec 3.1 sec 7.8 sec 9.0 sec 11.2 sec L+ 8 VOUT 7 L- 6 N/C 5 Cdelay D340B EL EL Lamp Lamp 7 5.6 mH V. 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 D340B operating for a period before turning off. The following table shows typical delay on-times using the following circuit with smaller capacitor values. Vbat C delay (uF) 1 2 3 1.5V 8 sec 16 sec 25 sec 8 3.0V 11 sec 21 sec 31 sec Ordering Information The D340B IC is available as bare die in probed wafer form or in die tray, and in standard MSOP-8 plastic package in tape and reel. A Durel D340B Designer’s Kit (1DDD340BB-K01) provides a vehicle for evaluating and identifying the optimum component values for any particular application using D340B. 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 (340B) 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: 1DDD340BB-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 US patent #5,313,141. Corresponding foreign patents are issued and pending. © 1998, 2001, 2002 Durel Corporation Printed in U.S.A. LIT-I9011 Rev. A06