® SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature ■ 4-Level, Software Selectable Light Intensity Function ■ 75%-80%-85%-100% Intensity Level Options ■ Extends Standby Time & Battery Life when used in Conjunction with Power Management Devices ■ Requires only 2 External Components: Oscillator Setting Capacitor and Inductor ■ Low Power +3.3V Operation ■ 100nA Standby Current ■ Space-Saving 10-pin µSOIC Package APPLICATIONS ■ Cellular Phones ■ LCD Displays & Keypads ■ PDAs ■ Handheld Portable Electronic Devices DESCRIPTION The SP4416 is a high voltage output DC-AC converter that operates from a 3.3V battery and generates up to 220VPP AC output. As with Sipex's other electroluminescent driver products, the AC output is used to generate light in an electroluminescent lamp. The SP4416 incorporates an intensity select feature within the enable circuit so that the user can program the desired light intensity. The SP4416 uses only two external components to generate light; the oscillator capacitor and inductor. The ENLI pin is used for either an enable function or a step-up intensity function. Four light intensities can be set by strobing the ENLI pin in a defined time period. The SP4416 with the intensity function can be used in cellular phone applications, PDA's, and other hand-held CPU controlled equipment. SP4416DS/06 COSC2 1 10 COSC1 2 9 VDD VSS 3 8 VEE EL1 4 7 EL2 CS 5 6 COIL SP4416EU ENLI SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 1 © Copyright 1999 Sipex Corporation The information furnished herein by Sipex has been carefully reviewed for accuracy and reliability. Its application or use, however, is solely the responsibility of the user. No responsibility for the use of this information is assumed by Sipex, and this information shall not explicitly or implicitly become part of the terms and conditions of any subsequent sales agreement with Sipex. Specifications are subject to change without prior notice. By the sale or transfer of this information, Sipex assumes no responsibility for any infringement of patents or other rights of third parties which may result from its use. No license or other proprietary rights are granted by implication or otherwise under any patent or patent rights of Sipex Corporation. ABSOLUTE MAXIMUM RATINGS 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 below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. Supply Voltage (VOUT to GND)....................-0.3V, +7V Operating Temperature.......................-40˚C to +85˚C Storage Temperature........................-65˚C to +150˚C Power Dissipation Per Package 10-pin µSOIC (derate 8.84mW/OC above +70OC).......720mW ELECTRICAL CHARACTERISTICS TA= -40°C to +85°C and VDD = +3.0V, unless otherwise noted. L1 = 2.7mH/45Ω, COSC = 330pF, CLOAD = 8nF PARAMETER Supply Voltage, VDD MIN. TYP. MAX. UNITS 2.3 3.0 4.5 V 25 40 mA 6.0 V 0 VDD 0.25V VDD+0.25 V 0.1 1.0 µA Supply Current, ICOIL+IDD Coil Voltage, VCOIL ELEN Input Voltage, VELEN LOW: EL off HIGH: EL on 3.0 -0.25 VDD-0.25 Shutdown Current, ISD=ICOIL+IDD Input Impedance 1 3 MΩ Coil Frequency, fCOIL 8 kHz Coil Duty Cycle 75 % Peak Coil Current, IPK-COIL 45 Intensity Level 1 Intensity Level 2 Intensity Level 3 Intensity Level 4 7 9 12 16 CONDITIONS EN=VDD EN=LOW,VDD=typical value, TAMB = 25oC INDUCTOR DRIVE 100 mA pulses EL LAMP OUTPUT EL Lamp Frequency, fLAMP 125 250 Peak to Peak Output Voltage, VPK-PK 140 186 563 Hz V AC CHARACTERISTICS ENLI - Maximum Interval Between Pulses (tF to tR) 0.8 8 ms ENLI - Minimum Pulse Width 10 800 µs Guaranteed by design 1 ms refer to Figures 6 to 8 for tDELAY 10 µs Guaranteed by design ENLI - On Delay ENLI - Increment Delay SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 2 © Copyright 1999 Sipex Corporation VDD VBATT L1 2.7mH/45Ω VDD COIL VDD ENLI SP4416 * IN4148 CS COSC1 1.8nF * 330pF COSC2 VSS EL1 EL2 EL Lamp 50Ω 8nF 50Ω 1MΩ * Optional Components Figure 1. Typical Operating Circuit of the SP4416 FUNCTION PIN NAME 1 COSC2 Oscillator capacitor input 2 2 COSC1 Oscillator capacitor input 2 3 VSS Logic Supply Common - typically connected to ground 4 EL1 EL Driver Output; connected to EL lamp 5 CS Optional Integrating Capacitor Input. Connect a 1.8nF capacitor from this input pin to ground to filter out any coil switching spikes or ripple present in the output waveform to the EL lamp. Connecting an optional fast recovery diode, 1N4148, from COIL to this input pin increases the light output of the EL lamp. 6 COIL 7 EL2 EL Driver Output; connected to EL lamp 8 VEE High Voltage Supply Common; typically connected to ground 9 VDD 10 ENLI SP4416DS/06 Inductor input; Other end of inductor is connected to the battery Power Supply Pin; connected to voltage source or positive battery terminal Enable and Lamp output intensity select SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 3 © Copyright 1999 Sipex Corporation FUNCTIONAL DESCRIPTIONS Oscillator Section The SP4416 uses an internal oscillator circuit that has the frequency set by COSC. The oscillator produces a 32kHz clock signal used internally and is divided down to create fCOIL and fLAMP. The ratio of the coil frequency (fCOIL) and the H-bridge (fLAMP) is fixed. Coil As in our other EL drivers, the SP4416 uses the coil to generate current to drive the H-bridge. Energy is stored in the coil according to the equation EL = 1/2LIP2 where IP, to the first approximation, is the product IP = (tON)(VBATTERY - VCE)/L), where tON is the time it takes for the coil to reach its peak current, VCE is the voltage drop across the internal NPN transistor for fCOIL, and L is the inductance of the coil. When the NPN transistor switch is off, the energy is forced through an internal diode which drives the switched H-bridge network. This energy recovery is directly related to the brightness of the EL lamp output. Intensity Setting As with the SP4415, the SP4416 incorporates an intensity select pin that will select one of four light output intensity levels. The ENLI pin serves as both an enable function and level select. This pin is edge triggered and enables on the rising edge or LOW-HIGH transition. The ENLI input is not debounced requiring chatterless ENLI transitions. In order to set a level, the ENLI pin should be asserted with a logic HIGH, and then asserted with a logic LOW. An internal pull-down resistor will keep the EL driver disabled unless defined by a logic HIGH. To increment the intensity sequence, the ENLI should be asserted with another LOWHIGH transition within the next 800µS in order to step to the next light intensity. From power-up, the first enable high will produce 100% of the output. The next LOW-HIGH transition will start the output back at the first level of intensity. The next set of four LOW-HIGH transitions will increment the output to the highest intensity at 100%. If set to a desired intensity, the ENLI pin should remain HIGH to maintain the desired intensity. Refer to Figure 6 for a timing diagram. The fCOIL signal controls a switch that connects the end of the coil at pin 6 to ground or to open circuit. 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. When the fCOIL signal is LOW, 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. As a result, charge pulses are delivered to the lamp at a rate defined by fCOIL. Each pulse increases the voltage drop across the lamp in discrete steps. As the voltage potential approaches its maximum, the steps become smaller. The preferred coil has a typical height of 2.0mm and a maximum height of 2.2mm. The Toko D52FU family with part number 875FU-272M, which offers a 2.7mH/45ohm coil that complies with the height requirement. A time greater than 8ms between the falling edge of the previous transition to the next ENLI transition will leave the EL driver output disabled until a logic HIGH is asserted back into the ENLI pin. A timing less than 800µs between the falling edge of the previous transition to the next ENLI transition will increment to the next output intensity. Refer to Figure 7 for timing diagram. H-Bridge The H-bridge consists of two SCR structures that act as high voltage switches. These two switches control the polarity of how the lamp is charged. The SCR switches are controlled by the fLAMP signal which is the oscillator frequency divided by 32. When the energy from the coil is released, a high voltage spike is created triggering the SCR switches. The direction of current flow is determined by which SCR is enabled. When the ENLI sees the next LOW-HIGH transition, longer than 8ms, the output will revive to the output intensity (VPEAK) just before being disabled. Refer to Figure 8 for timing diagram. SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 4 © Copyright 1999 Sipex Corporation 10 10 5 5 1 1 Level 4 Intensity 16 Coil Pulses 100% of VOUT Level 3 Intensity 12 Coil Pulses 85% of VOUT Figure 2. Level 4 Output for EL1 Figure 3. Level 3 Output for EL1 5 5 1 1 Level 1 Intensity 7 Coil Pulses 75% of VOUT Level 2 Intensity 9 Coil Pulses 80% of VOUT Figure 4. Level 2 Output for EL1 SP4416DS/06 Figure 5. Level 1 Output for EL1 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 5 © Copyright 1999 Sipex Corporation VDD VDD = 3V (typ.) 10us < tENLI < 800us ENLI VDD = 3V (typ.) tDELAY tINC tINC tINC tINC EL1 Output Vpeak = 90V (typ.) 4th Level 2nd Level 1st Level 4th Level 3rd Level 4ms (1 cycle) 2ms 1/2 cycle Figure 6. Typical ENLI Timing for Intensity Strobing VDD VDD = 3V (typ.) 10us < tENLI < 800us tENLI >8ms ENLI VDD = 3V (typ.) tDELAY tINC tINC tINC EL1 Output 1st Level 4th Level 4th Level 2nd Level 2nd Level 4ms 1 cycle 2ms Figure 7. Typical ENLI Timing for Cases where tENLI < 1ms or tENLI > 8ms VDD VDD = 3V (typ.) 10us < tENLI < 800us tENLI >8ms ENLI VDD = 3V (typ.) tINC tINC tDELAY EL1 Output 4th Level 1st Level 1st Level 1st Level 2ms 4ms 1 cycle Figure 8. ENLI Timing Recall SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 6 © Copyright 1999 Sipex Corporation VPEAK= 95V (typical) EL1 output; 16 charge steps per half cycle (maximum intensity setting) Figure 9. EL Output Voltage in Discrete Steps at EL1 Output 16 coil pulses per half cycle; 75% duty cycle (maximum intensity setting) Figure 10. Voltage Pulses Released from the Coil to the EL Driver Circuitry EL1 Output EL2 Output Figure 11. EL Voltage Waveforms from the EL1 and EL2 Outputs EL1 Output VPP=190V (typical) EL2 Output Differential Representation E12 Figure 12. EL Differential Output Waveform of the EL1 and EL2 Outputs SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 7 © Copyright 1999 Sipex Corporation PERFORMANCE CHARACTERISTICS The following performance curves are intended to give the designer a relative scale from which to optimize specific applications. Absolute measurements may vary depending upon the brand of components chosen. 35 30 ICC (mA) 25 20 15 10 5 0 1.5 2 2.5 3 3.5 4 5 5 6 7 Lamp Size (sq in) Figure 13. ITOTAL vs Lamp Size Output Voltage (VPP) 250 200 150 100 50 0 1 2 3 4 Lamp Size (sq in) Figure 14. Output Voltage vs Lamp Size SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 8 © Copyright 1999 Sipex Corporation PERFORMANCE CHARACTERISTICS Luminance (fL) The following performance curves are intended to give the designer a relative scale from which to optimize specific applications. Absolute measurements may vary depending upon the brand of components chosen. 4 3.5 3 2.5 2 1.5 1 0.5 0 1 2 3 4 5 6 7 5 6 7 Lamp Size (sq in) Figure 15. Luminance (Foot-Lamberts) vs Lamp Size Luminance (cd/m 2) 14 12 10 8 6 4 2 > 0 1 2 3 4 Lamp Size (sq in) Figure 16. Luminance (Candela per Meter Square) vs Lamp Size SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 9 © Copyright 1999 Sipex Corporation PERFORMANCE CHARACTERISTICS The following performance curves are intended to give the designer a relative scale from which to optimize specific applications. Absolute measurements may vary depending upon the brand of components chosen. 300 Lamp Frequency (Hz) 250 200 150 100 50 0 -40 -35 -30 -25 -20-15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 Temperature oC Figure 17. Lamp Frequency vs Temperature, VDD = 3.0V 90 80 Peak EL Driver Voltage (V) 70 60 50 40 30 20 10 0 -40 -35 -30 -25-20 -15 -10 -5 0 5 10 15 2 25 30 35 40 45 50 55 60 65 70 75 80 85 Temperature oC Figure 18. Peak EL Driver Voltage vs Temperature, VDD = 3.0V SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 10 © Copyright 1999 Sipex Corporation PERFORMANCE CHARACTERISTICS The following performance curves are intended to give the designer a relative scale from which to optimize specific applications. Absolute measurements may vary depending upon the brand of components chosen. 25 EL Driver Current (mA) (not including coil current) 20 15 10 5 0 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 Temperature oC Figure 19. EL Driver Current (not including Coil Current) vs Temperature, VDD = 3.0V SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 11 © Copyright 1999 Sipex Corporation PACKAGE: 10-pin µSOIC Package (ALL DIMENSIONS IN MILLIMETERS) 0.50 BSC 0.50 BSC o 12.0o ±3.0 0.31 ±0.08 2.95 ±0.10 0.30 to 0.07 0.30 to 0.07 3.00 ±0.10 o 0.51 ±0.13 0.51 ±0.13 0.25 1 o 12.0o ±3.0 0.41 ±0.08 2 2.95 ±0.10 0.86 ±0.08 1.10 MAX 0.23 ±0.07 3.00 ±0.10 SP4416DS/06 3.0 o ±3.0 0.55 ±0.15 0.95BSC 2.95 ±0.10 3.00 ±0.10 0.10 ±0.05 4.90 ±0.15 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 12 © Copyright 1999 Sipex Corporation ORDERING INFORMATION Model Operating Temperature Range Package Type SP4416EU . ............................................ -40˚C to +85˚C ....................................... 10-Pin µSOIC SP4416UEB . ................................................... NA ............................................ Evaluation Board Please consult the factory for pricing and availability on a Tape-On-Reel option. Corporation SIGNAL PROCESSING EXCELLENCE Sipex Corporation Headquarters and Sales Office 22 Linnell Circle Billerica, MA 01821 TEL: (978) 667-8700 FAX: (978) 670-9001 e-mail: [email protected] Sales Office 233 South Hillview Drive Milpitas, CA 95035 TEL: (408) 934-7500 FAX: (408) 935-7600 Sipex Corporation reserves the right to make changes to any products described herein. Sipex 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. SP4416DS/06 SP4416 Electroluminescent Lamp Driver with 4-Level Light Intensity Selection Feature 13 © Copyright 1999 Sipex Corporation