HV857 Supertex inc. Low Noise, High Voltage EL Lamp Driver IC Features General Description Patented audible noise reduction The Supertex HV857 is a high voltage driver designed for driving Electroluminescent (EL) lamps of up to 5.0 square inches. The Patented lamp aging compensation input supply voltage range is from 1.8 to 5.0V. The device uses 190 V output voltage for higher brightness PP a single inductor and a minimum number of passive components. Patented output timing for high efficiency The nominal regulated output voltage that is applied to the EL Single cell lithium ion compatible lamp is 95V. The chip can be enabled/disabled by connecting the 150nA shutdown current resistor on RSW-Osc to VDD/GND. Wide input voltage range 1.8 to 5.0V Separately adjustable lamp and converter The HV857 has two internal oscillators, a switching MOSFET, and frequencies a high voltage EL lamp driver. The frequency for the switching Output voltage regulation MOSFET is set by an external resistor connected between Split supply capability the RSW-Osc pin and the supply pin VDD. The EL lamp driver Available in 8-Lead MSOP and DFN packages frequency is set by an external resistor connected between REL- Osc pin and VDD pin. An external inductor is connected between Applications the LX and VDD pins or V for split supply applications. A 0.003- IN 0.1F capacitor is connected between CS and ground. The EL LCD backlighting lamp is connected between VA and VB. Mobile Cellular Phone PDAs The switching MOSFET charges the external inductor and Handheld wireless communication products discharges it into the capacitor at CS. The voltage at CS will start Global Positioning Systems (GPS) to increase. Once the voltage at CS reaches a nominal value of 95V, the switching MOSFET is turned OFF to conserve power. The outputs VA and VB are configured as an H bridge and are switching in opposite states to achieve 95V across the EL lamp. Typical Application Circuit ON = V Enable Signal DD OFF = 0 1 8 VA VDD + HV857 R EL Lamp V SW DD C 7 DD 2 RSW-Osc VB 3 6 REL-Osc CS R EL D 4 5 + LX GND V C IN IN C L S X Doc. DSFP-HV857 Supertex inc. A062013 www.supertex.comHV857 Pin Configuration Ordering Information VDD 1 8 VA Part Number Package Packing VDD 1 8 VA RSW-Osc 2 7 VB HV857K7-G 8-Lead DFN 3000/Reel RSW-Osc 2 7 VB HV857MG-G 8-Lead MSOP 2500/Reel REL-Osc 3 6 CS REL-Osc 3 6 CS -G denotes a lead (Pb)-free / RoHS compliant package GND 4 5 LX GND 4 5 LX 8-Lead DFN 8-Lead MSOP Absolute Maximum Ratings (top view) (top view) Pads are at the bottom of the package. Parameter Value Exposed center pad is at ground potential. Supply voltage, V -0.5V to 6.5V DD Product Marking Operating temperature -40C to +85C Storage temperature -65C to +150C Y = Last Digit of Year Sealed H857 W = Code for Week Sealed DFN-8 power dissipation 1.6W L = Lot Number YWLL MSOP-8 power dissipation 300mW = Green Packaging Output voltage, V -0.5 to +120V CS Package may or may not include the following marks: Si or Absolute Maximum Ratings are those values beyond which damage to the 8-Lead DFN device may occur. Functional operation under these conditions is not im- plied. Continuous operation of the device at the absolute rating level may affect device reliability. All voltages are referenced to device ground. Top Marking H857 Typical Thermal Resistance LLLL L = Lot Number Package ja YY = Year Sealed Bottom Marking O 8-Lead DFN 37 C/W WW = Week Sealed O 8-Lead MSOP 171 C/W = Green Packaging YYWW Mounted on FR4 board, 25mm x 25mm x 1.57mm Package may or may not include the following marks: Si or 8-Lead MSOP Recommended Operating Conditions Sym Parameter Min Typ Max Units Conditions V Supply voltage 1.8 - 5.0 V --- DD f Operating drive frequency - - 1.0 kHz --- EL O T Operating temperature -40 - +85 C --- A Enable/Disable Function Table Sym Parameter Min Typ Max Units Conditions EN-L Logic input low voltage 0 - 0.2 V V = 1.8 to 5.0V DD EN-H Logic input high voltage V - 0.2 - V V V = 1.8 to 5.0V DD DD DD DC Electrical Characteristics (Over recommended operating conditions unless otherwise specified, T = 25C) A Sym Parameter Min Typ Max Units Conditions R On-resistance of switching transistor - - 6.0 I = 100mA DS(ON) V Max. output regulation voltage 85 95 105 V V =1.8 to 5.0V CS DD Doc. DSFP-HV857 Supertex inc. A062013 2 www.supertex.com