IMP803 IMP803. High-Volt. iver POWER MANAGEMENT. Key Features. Applications. Block Diagram

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1 POWER MANAGEMENT High-Volt oltage e E amp p Driv iver The IMP is an Electroluminescent (E) lamp driver with the four E lamp driving functions on-chip. These are the switch-mode power supply, its high-frequency oscillator, the high-voltage H-bridge lamp driver and its low-frequency oscillator. The IMP drives E lamps of up to nf capacitance to high brightness; E lamps with capacitances greater than nf can be driven, but will be lower in light output. The typical regulated output voltage that is applied to the E lamp is V peak-topeak. The circuit requires few external components, a single inductor, single diode, two capacitors and three resistors. Two of these resistors set the frequency for two internal oscillators. The IMP operates over a.v to.v supply voltage range. A regulated, low-power source can supply the low quiescent current of the IMP. The inductor may be driven from an independent, unregulated supply voltage in dual supply applications. An internal circuit shuts down the switching regulator when the lamp drive voltage reaches V peak-to-peak. This conserves power and extends battery life. The IMP is available in MicroSO and SO- packages and in die or wafer form. Block Diagram Key Features ow Power: µa typical V DD current Wide operating voltage range - from.v to.v V peak-to-peak typical AC output voltage arge output load capability - drive lamps with more than nf capacitance Adjustable output lamp frequency for control of lamp color, lamp life, and power consumption Adjustable converter frequency to minimize power consumption Device can be Enabled/Disabled ow quiescent current na (disabled) High-Voltage CMOS Process MicroSO package option Applications GPS units/pagers/cellular phones PDAs/Handheld computers Safety illumination Portable instrumentation Battery-operated displays CD modules Toys V DD X -OSC Switch Oscillator GND Regulation Control C V REF Q Q V A IMP Bridge Output Driver Q R E-OSC amp Drive Oscillator Q _.eps IMP, Inc. --9/

2 Pin Configuration SO/ MicroSO V DD -OSC X IMP R E-OSC V A GND Pin Compatible With HV and IMP _.eps Ordering Information Part Number Input Voltage Regulated Output Voltage Temperature Range Pins-Package IMPG.V to.v Yes C to C -SO IMPIMA.V to.v Yes C to C -MicroSO IMPSX*.V to.v Yes C Dice IMP/D**.V to.v Yes C Dice * Disable pad not active ** Disable pad active Add /T to ordering part number for Tape and Reel. Absolute Maximum Ratings V DD, V RSW-OSC and V RE-OSC V to.v, X V to V Operating Temperature Range C to C Storage Temperature Range C to C Power Dissipation (SO) mw Power Dissipation (MicroSO) mw V A, V to (pin ) Note: All voltages are referenced to GND. These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. Electrical Characteristics Unless otherwise noted, V DD =.V, = kω, R E =.MΩ, and T A = C. Parameter Symbol Conditions Min Typ Max Units ON-resistance of MOS Switch R DS(ON) I = ma. Ω Output Voltage Regulation V DD =. to.v 9 V Output Voltage Peak-to-peak (in regulation) V A - V DD =. to.v V Quiescent V DD Supply Current, Disabled I DDQ V RSW-OSC < mv na Input Current at V DD Pin I DD V DD =.V, See Figure µa Input Current at V DD Pin I DD V DD =.V, See Figure µa Input Current: I DD Plus Inductor Current V DD =.V, See Figure ma Output Voltage at V DD =.V, See Figure V V A-B Output Drive Frequency f E V DD =.V, See Figure Hz Switching Frequency f SW V DD =.V, See Figure 9 khz Switching Duty Cycle D SW V DD =.V, See Figure % --9/ IMP, Inc.

3 Typical Characteristics, vs. Inductor Value V IN =.V = µh I DD vs. V DD I DD (µa)..... Inductor (µh) _.eps V DD (V) _.eps, vs. V IN, vs. V IN = µh = µh V IN (V) _.eps V IN (V) _.eps = mh, vs. V IN = µh, vs. V IN In Regulation..... V IN (V) _.eps..... V IN (V) _.eps IMP, Inc. Electroluminescent amp Driver

4 Pin Descriptions Pin Number Name Function V DD Positive voltage supply for the IMP. Inductor may be connected here or to a separate unregulated supply. -OSwitch-mode resistor pin. Switching frequency is determined by an external resistor,. Boost converter storage capacitor. The voltage across the E lamp is equal to twice the voltage at. X Connection to flyback inductance,. GND Ground pin. E lamp drive. The lamp is connected in a high-voltage bridge circuit with providing the complementary connection to V A. The peak-to-peak AC voltage across the E lamp is thus two times. V A E lamp drive. (See above) R E-OSC The E lamp oscillator frequency setting pin. The oscillator frequency is controlled by external resistor R E. External Components External Component Description and Selection Guide Diode Catch diode. A fast reverse recovery diode, with BV >, such as a N. Capacitor This is the high voltage capacitor that stores the inductive energy transferred through the catch diode. A volt capacitor between nf and nf is recommended. Resistor R E The E lamp oscillator frequency setting resistor. This resistor, connected between the R E-OSC pin and V DD, provides an oscillator frequency inversely proportional to R E ; as R E increases, the E lamp frequency decreases along with the current drawn by the lamp. amp color is also determined by this frequency. A MΩ resistor between the R E-OSC pin and the V DD supply results in a lamp frequency around Hz: a MΩ resistor will give Hz. Resistor Switching Oscillator frequency setting resistor. The switching oscillator resistor is connected between the -OSC pin and the V DD supply. The switching frequency is inversely proportional to the resistor value, dropping as the resistance increases. Inductor The inductor provides the voltage boost needed by means of inductive flyback. The internal MOSFET switch alternately opens and closes the ground connection for the inductor at the X pin. When this internal switch opens, the inductor potential will forward-bias the catch diode and the current will pass through the storage capacitor, charging it to a high voltage. amp, R C Smaller inductors are preferred to prevent saturation. As the value of the inductor increases (and the series DC resistance of the inductor decreases), the switching frequency set by should be increased to prevent saturation. In general, smaller value inductors that can handle more current are more desirable when larger area E lamps must be driven. An external resistor (R C ) in series with the lamp will protect the output drivers from high transient currents during lamp commutation. High Voltages Present The IMP generates high voltages and caution should be exercised. --9/ IMP, Inc.

5 Application Information Test and Application Circuit,.V Figure shows the IMP configured to drive a -square-inch E lamp, represented as a nf capacitor. With a.v input, the E lamp will be driven to moderate brightness. ON = V DD OFF = V MΩ R E V IN =.V µh.µf N kω.µf V V DD R E-OSC -OSC V A X GND IMP kω R C nf Equivalent to in lamp Note:. Murata part # QHNK (DC resistance <. Ω). arger values may be required depending upon supply impedance. _9.eps Figure..V Application Test and Application Circuit,.V Figure shows a.v input application driving a -square-inch E lamp. ON = V DD OFF = V MΩ R E V IN =.V µh.µf N kω.µf V V DD R E-OSC -OSC V A X GND IMP kω R C in lamp Note:. Murata part # QHNK (DC resistance <. Ω). arger values may be required depending upon supply impedance. _.eps Figure..V Application IMP, Inc. Electroluminescent amp Driver

6 Test and Application Circut,.V At higher input voltage levels, the IMP will drive large E lamps. Figure shows a.v circuit configuration that will drive a square-inch lamp. MΩ R E V IN =.V µh.µf N kω.µf V V DD R E-OSC -OSC V A X GND IMP kω R C in lamp Note:. Murata part # QHNK (DC resistance <. Ω). arger values may be required depending upon supply impedance. _.eps Figure..V Application Enable/Disable Operation Figure shows that the IMP can be enabled via a logic gate that connects to V DD, and disabled by connecting it to ground. Enable/Disable Table Connection V DD GND IMP State Enabled Disabled ON = V DD OFF = V CMOS Gate R E V DD R E-OSC V IN.µF N.µF V -OSC V A X GND IMP R C E lamp Note:. Murata part # QHNK (DC resistance <. Ω). arger values may be required depending upon supply impedance. _.eps Figure. Enable/Disable Operation --9/ IMP, Inc.

7 Dual Supply Operation with.attery The IMP can also be operate from a single battery cell when a regulated voltage higher than.v is also available. This dual supply configuration, shown in Figure, uses the regulated voltage to operate the IMP while the energy for the highvoltage boost circuit comes from the battery. The circuit of Figure thus allows operation with batteries that are below the V minimum specification or above the.v maximum operating voltage. Regulated Voltage (.V to.v) ON = V DD OFF = V R E V DD R E-OSC Battery Voltage V IN.µF * N.µF V -OSC V A X GND IMP R C E lamp * arger values may be required depending upon supply impedance _.eps Figure. Dual Supply Operation Switch Resistance The IMP inductor switch resistance is typically below.ω, as shown in Figure. On Resistance (Ω) V DD (V) Figure. Boost Switch On Resistance _.eps IMP, Inc. Electroluminescent amp Driver

8 Package Dimensions SO (-Pin) E H D A e B A MicroSO (-Pin) D e b E E A A A D.mm.in C a C MicroSO (-Pin).eps SO (-Pin).eps Min Inches Max SO (-Pin)* Min Millimeters Max A..9.. A.... B.... C...9. e.. E.... H D MicroSO (-Pin)** A.. A..9.. A b.9... C..9.. D...9. e. BSC. BSC E.9 BSC.9 BSC E a * JEDEC Drawing MS-AA ** JEDEC Drawing MO-AA _t.at IMP, Inc. Corporate Headquarters N. First Street San Jose, CA 9- Tel: --9 Fax: -- info@impinc.com The IMP logo is a registered trademark of IMP, Inc. All other company and product names are trademarks of their respective owners. IMP, Inc. Printed in USA Publication #: Revision: B Issue Date: // Type: Product