Supertex inc. High Voltage, Low Noise, Inductorless Lamp Driver Features No external components required when using an external clock frequency frequency can be set by an external resistor Low noise DC to AC converter Drives up to.0nf load (approx..in lamp) Output voltage regulation Enable function Lamp dimming Applications Cell phone keypads and displays Transceivers MP players Watches Pagers Measuring instruments/gauges General Description The Supertex is a high voltage electroluminescent () Lamp Driver IC. It is designed to drive lamps of up to.in, with capacitive values up to.0nf. The converts a low voltage DC input to a high voltage AC output across an lamp. It uses a charge pump scheme to boost the input voltage, eliminating the need for external inductors, diodes, and high voltage capacitors, components commonly found in conventional topologies. The charge pump circuit discharges its energy into an lamp through a high voltage Hbridge. Once the voltage reaches its regulated limit, it is turned off to conserve power. The lamp is then discharged to ground and the Hbridge changes state to allow the charge pump to charge the lamp in the opposite direction. The lamp frequency can be set either by an external resistor,, or by applying an external clock, where the clock frequency is divided by to set the lamp frequency. Typical Application Circuits (For =.V to.v only) = ON = OFF Lamp lamp frequency set by an external clock = ON = OFF lamp frequency set by R Lamp Supertex inc. Bordeaux Drive, Sunnyvale, CA 909 Tel: 0 www.supertex.com
Ordering Information Device Package Options Lead MSOP.00x.00mm body.0mm height (max) 0.mm pitch MGG G indicates package is RoHS compliant ( Green ) Pin Configuration Lead MSOP (MG) (top view) Absolute Maximum Ratings Parameter Value, supply voltage 0.V to.v Operating temperature Storage temperature Power dissipation C to C C to 0 C 00mW Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Product Marking Top Marking H0 LLLL Bottom Marking YYWW L = Lot Number YY = Year Sealed WW = Week Sealed = Green Packaging Package may or may not include the following marks: Si or Lead MSOP (MG) Recommended Operating Conditions Sym Parameter Min Typ Max Units Conditions Input voltage.0. V lamp frequency 0 00 Hz C LOAD lamp capacitance 0.0 nf T A Operating temperature O C Electrical Characteristics (Unless otherwise specified =.V, T A = C) Sym Parameter Min Typ Max Units Conditions I DDQ Quiescent current 0 na = 0V or V B Peak output voltage 0 V V B Peak to peak output voltage 0 V No load. lamp frequency 0 Hz =.MΩ or CLK = khz I DD Operating current ma or V B Peak output voltage V V B Peak to peak output voltage 0 V lamp frequency 0 9 Hz See Figure, =.V, =.MΩ, Load =.nf.0kω t ROUT Output voltage rise time. ms = 0Hz, in lamp, 0 to 90% of final value Supertex inc. Bordeaux Drive, Sunnyvale, CA 909 Tel: 0 www.supertex.com
Logic Inputs (Unless otherwise specified =.V, T A = C) Sym Parameter Min Typ Max Units Conditions V IL Input logic low voltage 0 0. V V IH Input logic high voltage.0 V I IL Input logic low current.0 µa I IH Input logic high current.0 µa Enable input rise time 0.0 0 ms (for delay turn on) Using external RC circuit, see Figure. Enable input fall time 0µ.0 s (for delay turn off) C IN Logic input capacitance 0 pf RISE FALL Block Diagram Capacitor Charge Pump Circuit Feedback V SSE High Voltage Level Translators Oscillator MOSFET Full Bridge Figure : Typical Application Circuit (without Enable function) Lamp Load (MΩ).nF.0kΩ. Note: =.µf,.v low ESR I DD (ma) Peak.0.9. 0..0 0. (Hz) 9 Supertex inc. Bordeaux Drive, Sunnyvale, CA 909 Tel: 0 www.supertex.com
Typical Performance Lamp Size (in ) (MΩ).0. 0..0.0. 0...0. I DD (ma) Peak.0. (Hz) Brightness (cd/m ).. 9. 0 0..0 9.9..0.... 0..0.9.90.0.... 0.9.0.0 0.9.0.... 9..0. 9.9.0..0.. 9..0.0 0.9 Typical Output Waveform =.V, F = 0.0Hz; Load =.nf.0kω; I DD = 9.9mA, CH 0V/div,.0mS/div Supertex inc. Bordeaux Drive, Sunnyvale, CA 909 Tel: 0 www.supertex.com
Figure : Push Button Turn on with Delay Turn off (For =.V to.v only) Push button turn on Lamp C R CLKN RC time constant will set Turn OFF Delay time Figure : Independent Programmable Output Frequency ( ) (For =.V to.v only) = ON = OFF Lamp Lamp Dimming Using PWM lamp dimming can be achieved by applying a PWM signal to the ABLE pin. The PWM signal duty cycle is proportional to the lamp brightness. This is done by pulse skipping the output pulses. The PWM frequency should be kept below the frequency but above 0Hz to avoid flickering. Figure : PWM Dimming Circuit (For =.V to.v only) Lamp PWM Signal Supertex inc. Bordeaux Drive, Sunnyvale, CA 909 Tel: 0 www.supertex.com
Pin Description Pin # Pad Description Input supply voltage pin. IC ground pin. An external resistor to will set the lamp frequency. The lamp frequency is inversely proportional to the resistor value. Enable input pin. Logic high will turn the device ON. An external RC circuit can be added for a delayed turn off. Logic low will turn the device OFF only for =.V to.v. For lower than.v, logic low will not turn the device OFF. Logic input pin. An external logic clock applied to this pin can be used to set the lamp frequency (see Figure ). This is useful for applications requiring the lamp to be synchronized to a system clock. Connect to ground when not in use. Logic input pin. Logic high will cause the lamp frequency to be set by the input. Logic low will cause the lamp frequency to be set by the external resistor. lamp driver output pin. The lamp is connected across and terminals. lamp driver output pin. The lamp is connected across and terminals. Supertex inc. Bordeaux Drive, Sunnyvale, CA 909 Tel: 0 www.supertex.com
Lead MSOP Package Outline (MG).00x.00mm body,.0mm height (max), 0.mm pitch D θ (x) E E Note (Index Area D/ x E/) L Gauge Plane L L θ Seating Plane A Top View View B View B A A A A e Side View b Seating Plane View AA Note:. A Pin identifier must be located in the index area indicated. The Pin identifier can be: a molded mark/identifier; an embedded metal marker; or a printed indicator. Symbol A A A b D E E e L L L θ θ Dimension (mm) MIN 0.* 0.00 0. 0..0*.*.0* 0.0 0 O O NOM 0..00.90.00 0. 0.9 0. 0.0 BSC REF BSC MAX.0 0. 0.9 0..0*.*.0* 0.0 O O JEDEC Registration MO, Variation AA, Issue E, Dec. 00. * This dimension is not specified in the JEDEC drawing. Drawings are not to scale. Supertex Doc. #: DSPDMSOPMG, Version H009. (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to http://www.supertex.com/packaging.html.) Supertex inc. does not recommend the use of its products in life support applications, and will not knowingly sell them for use in such applications unless it receives an adequate product liability indemnification insurance agreement. Supertex inc. does not assume responsibility for use of devices described, and limits its liability to the replacement of the devices determined defective due to workmanship. No responsibility is assumed for possible omissions and inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications refer to the Supertex inc. (website: http//www.supertex.com) 0 Supertex inc. All rights reserved. Unauthorized use or reproduction is prohibited. Doc.# DSFP D009 Supertex inc. Bordeaux Drive, Sunnyvale, CA 909 Tel: 0 www.supertex.com