Supertex inc. HV857L Low Noise, High Voltage EL Lamp Driver IC Features General Description Audible noise reduction The Supertex HV857L is a low noise, high voltage driver designed for driving Electroluminescent (EL) lamps of up to five square 190 V output voltage for higher brightness PP inches. It is the low noise version of the EL lamp driver HV857. The Single cell lithium ion compatible input supply voltage range is from 1.8V to 5.0V. The device uses 150nA shutdown current a single inductor and a minimum number of passive components. Wide input voltage range 1.8V to 5.0V The nominal regulated output voltage that is applied to the EL Separately adjustable lamp and converter lamp is 95V. The chip can be enabled/disabled by connecting the frequencies resistor on RSW-Osc to VDD/ground. Output voltage regulation Split supply capability The HV857L has two internal oscillators, a switching MOSFET, Available in 8-Lead DFN and 8-Lead MSOP- and a high voltage EL lamp driver. The frequency for the switching packages MOSFET is set by an external resistor connected between the RSW- Osc pin and the supply pin, VDD. The EL lamp driver frequency Applications is set by an external resistor connected between the REL-Osc Mobile cellular phones and VDD pins. An external inductor is connected between the LX and VDD pins, or VIN for split supply applications. A 0.003-0.1F Keypad backlighting capacitor is connected between CS and ground. The EL lamp is LCD backlighting connected between the VA and VB pins. PDAs Handheld wireless communication products The switching MOSFET charges the external inductor and Global Positioning Systems (GPS) discharges it into the capacitor at CS. The voltage at CS will start 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 8 1 VDD VA EL Lamp + R HV857L SW V C DD 7 2 DD RSW-Osc VB 6 3 REL-Osc CS R + EL D 4 5 V C GND LX IN IN C S L X Doc. DSFP-HV857L Supertex inc. A062013 www.supertex.comHV857L Pin Configurations Ordering Information Part Number Package Packing VDD 1 8 VA VDD 1 8 VA HV857LK7-G 8-Lead DFN 3000/Reel RSW-Osc 2 7 VB RSW-Osc 2 7 VB HV857LMG-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 Operating temperature -40C to +85C Product Marking Storage temperature -65C to +150C Y = Last Digit of Year Sealed 8-Lead DFN power dissipation 1.6W 857L W = Code for Week Sealed 8-Lead MSOP power dissipation 300mW L = Lot Number YWLL Output voltage, V -0.5 to +120V CS = Green Packaging Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not Package may or may not include the following marks: Si or implied. Continuous operation of the device at the absolute rating level 8-Lead DFN may affect device reliability. All voltages are referenced to device ground. Typical Thermal Resistance Top Marking Package ja 857L O 8-Lead DFN 37 C/W LLLL L = Lot Number O 8-Lead MSOP 171 C/W YY = Year Sealed Mounted on FR4 board, 25mm x 25mm x 1.57mm Bottom Marking WW = Week Sealed = Green Packaging YYWW 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 kHz --- EL O T Operating temperature -40 - +85 C --- A Doc. DSFP-HV857L Supertex inc. A062013 2 www.supertex.com