Supertex inc. HV856 High Voltage Tri-EL Lamp Driver IC Features General Description High voltage, Tri-EL lamp driver with common The Supertex HV856 is a high voltage, triple EL lamp driver designed terminal 2 2 for driving combined EL lamps of up to 3.0in (1.0 in each). It is a Independent brightness control for all three lamps higher voltage version of the HV858. The input supply voltage range 210V output voltage for higher brightness is from 1.8 to 6.5V. The device is designed so that the input voltage PP 1.8 to 6.5V operating supply voltage to the inductor can differ from the input voltage to the device (split Output voltage regulation supply). The device uses a single inductor and a minimum number of passive components. The nominal regulated output voltage that Two-pin serial data communication for control is applied to the EL lamp is 105V. The HV856 has two internal Linear brightness control with seven steps at con- stant efficiency oscillators one for the internal switching MOSFET and the other 128kHz fixed switching frequency for the high voltage EL lamp driver. The EL lamp frequency is fixed internally at 500Hz. The power converter oscillator runs 256 times Split supply capability faster than the EL lamp driver at 128kHz. Patented high efficiency EL lamp driver Single miniature inductor drives all three lamps An external inductor is connected between the LX and VDD pins (or Only four external components between the LXpin and separate voltage source in the case of a split supply application). A 0.002 - 0.01F, 200V capacitor is connected Burst mode power converter for best efficiency between the CS pin and ground. The switching MOSFET charges CMOS compatible serial interface with noise rejec- tion the external inductor and discharges it into the capacitor at the CS 150nA max. leakage current when disabled pin. The voltage at CS will start to increase. Once the voltage at CS reaches a nominal value of 105V, the switching MOSFET is turned Power-on reset causes all outputs to be off when first powered up OFF to conserve power. Available in 10-Lead DFN package (0.8mm thick- One side of the three EL lamps is connected to the COM pin of ness) the HV856 and the other side to the EL1, EL2, and EL3 pins of the HV856. Each EL lamp output may be independently controlled to Applications have one of the seven brightness levels or can be completely turned OFF by a 10-bit serial data input register. The 10-bit control code Multi-segment, variable displays has three bits to control the brightness level of each EL lamp and Cell phone keypads and displays one bit to optionally control the power converter. The 3-bit binary MP3 players brightness control code controls the number of 500Hz cycles (from 0 to 7) in a group of seven cycles. Typical Application Circuit + L X D C V C S IN IN 1 10 - LX CS HV856 2 9 GND COM 3 8 VDD EL3 EL Lamp 3 + V C 4 7 DD DD SDI EL2 EL Lamp 2 - 5 6 SCK EL1 Serial Data In EL Lamp 1 Clock Supertex inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com HV856 Ordering Information 10-Lead DFN 3.00x3.00mm body Device 0.80mm height (max) 0.50mm pitch HV856 HV856K7-G -G indicates the package is RoHS compliant - Green Pin Configuration Absolute Maximum Ratings 1 10 CS LX Parameter Value GND 2 9 COM 3 8 EL3 VDD VDD -0.5 to +7V SDI 4 7 EL2 6 SCK 5 EL1 SDI, SDK -0.5 to +7V I 0.7A peak 10-Lead DFN (K7) SW (top view) Note: V 0.5 to +120V CS The pads are at the bottom of the package. The center heat slug is at ground potential. Power dissipation 1.6W O O Product Marking Storage temperature -65 C to +150 C O O Y = Last Digit of Year Sealed Operating temperature -40 C to +85 C H856 W = Code for Week Sealed Absolute Maximum Ratings are those values beyond which damage to the YWLL L = Lot Number device may occur. Functional operation under these conditions is not implied. = Green Packaging Continuous operation of the device at the absolute rating level may affect device reliability. All voltages are referenced to device ground. Package may or may not include the following marks: Si or 10-Lead DFN (K7) Recommended Operating Conditions Sym Parameter Min Typ Max Unit Conditions V Supply voltage 1.8 - 6.5 V --- DD I Peak switch current - - 0.4 A --- SW(pk) O T Operating temperature -40 - 85 C --- A O Electrical Specifications (unless otherwise specified, T = 25 C, V = 2.6V to 5.5V) A DD Sym Parameter Min Typ Max Unit Conditions On-resistance of switching R - 4.0 6.0 V = 1.8 to 6.5V, I = 100mA SW DD SW transistor V Output voltage 95 105 115 V S1...S9 = 0, V = 1.8 to 6.5V, no load CS DD V Differential lamp voltage 190 210 230 V V to any EL, no load, code* = 111 LAMP COM I V supply current 0.01 0.15 0.25 mA V = 20V, no load, PWR ON = 1 DD DD CS I V supply current 10 50 100 A V = 75V, no load CS CS CS V leakage current when S1...S9 = 0, SCK and SDI can be tied DD I - 100 150 nA DDQ disabled to V or GND DD f Inductor switching frequency 108.8 128 147.2 kHz See Fig.1 SW f Lamp frequency 425 500 575 Hz For all codes except code* = 000 EL V Logic pin input Low level -0.5 0 0.2V V --- LOW DD V Logic pin input High level 0.8V V V + 0.5 V --- HIGH DD DD DD * Code refers to the 3-bit Brightness Control Code for the respective EL Lamp Supertex inc. 1235 Bordeaux Drive, Sunnyvale, CA 94089 Tel: 408-222-8888 www.supertex.com 2