15-1 HV803 high-voltage el lamp driver features processed with hvcmos ? technology 2.4v to 9.5v operating supply voltage dc to ac conversion 180v peak-to-peak typical output voltage large output load capability typically 30nf short circuit protection on outputs adjustable output lamp frequency to control lamp color, lamp life, and power consumption adjustable converter frequency to eliminate harmonics and optimize power consumption enable/disable function low current draw under no load condition absolute maximum ratings* supply voltage, v dd -0.5v to +10v output voltage, v cs -0.5v to +120v operating temperature range -25 c to +85 c storage temperature range -65 c to +150 c power dissipation 400mw note : *all voltages are referenced to gnd. package options device input voltage 8-lead so die HV803 2.4v to 9.5v HV803lg HV803x ordering information general description the supertex HV803 is a high-voltage driver designed for driving el lamps of up to 30nf. el lamps greater than 30nf can be driven for applications not requiring high brightness. the input supply voltage range is from 2.4 to 9.5v. the device uses a single inductor and a minimum number of passive components. the nominal regulated output voltage that is applied to the el lamp is 90v. the chip can be enabled by connecting the resistors on r sw-osc and r el-osc to v dd and disabled when connected to gnd. the HV803 has two internal oscillators, a switching mosfet, and a high-voltage el lamp driver. the frequency for the switch- ing converter mosfet is set by an external resistor connected between the r sw-osc pin and the supply pin v dd . the el lamp driver frequency is set by an external resistor connected be- tween r el-osc pin and the v dd pin. an external inductor is connected between the l x and v dd pins. a 0.01 m f to 0.1 m f capacitor is connected between c s and gnd pins. the el lamp is connected between v a and v b pins. the switching mosfet charges the external inductor and discharges it into the c s capacitor. the voltage at c s will start to increase. once the voltage at c s reaches a nominal value of 90v, the switching mosfet is turned off to conserve power. the outputs v a and v b are configured as an h-bridge and are switched in opposite states to achieve 180v peak-to-peak across the el lamp. pin configuration va v dd r el-osc r sw-osc v a c s v b l x gnd applications pagers cellular phones electronic personal organizers gps units handheld personal computers portable instrumentation 1 2 3 4 8 7 6 5 so-8
15-2 symbol parameter min typ max units conditions r ds(on) on-resistance of switching transistor 3.5 8.0 w i = 100ma v cs output voltage v cs regulation 80 90 100 v v in = 2.4 to 9.5v v a - v b output peak to peak voltage 160 180 200 v v in = 2.4v to 9.5v i ddq quiescent v dd supply current, disabled 2.0 m ar sw-osc = gnd i dd input current going into the v dd pin 100 m av in = 3.0v 5%. see figure 1. 300 m av in = 5.0v 5%. see figure 2. 500 m av in = 9.0v 5%. see figure 3. i in input current including inductor current 35 ma v in = 3.0v. see figure 1. v cs output voltage on v cs 45 70 v v in = 3.0v. see figure 1. f el v a-b output drive frequency 300 430 hz v in = 3.0v. see figure 1. f sw switching transistor frequency 50 90 khz v in = 3.0v. see figure 1. d switching transistor duty cycle 88 % electrical characteristics dc characteristics (v in = 3.0v, r sw = 750k w , r el = 2.0m w , t a = 25 c unless otherwise specified) symbol parameter min typ max units conditions v dd supply voltage 2.4 9.5 v t a operating temperature -25 85 c recommended operating conditions r sw resistor HV803 v dd enabled gnd disabled enable/disable table (see figure 4) HV803
15-3 figure 1: test circuit, v in = 3.0v (low input current with moderate output brightness). note: 1. murata part # lqh4n561k04 (dc resistance < 14.5 w ) 2. larger values may be required depending upon supply impedance. 1 7 2 3 4 8 6 5 v in = 3.0v on = v dd off = 0v 0.1 m f 100v 0.1 m f 2 560 m h 1 1n4148 750k w 2m w 2.0k w 10nf equivalent to 3 square inch lamp. HV803 l x gnd v b v a r el-osc v dd r sw-osc c s block diagram switch osc c + _ vref disable output osc gnd v dd r sw-osc r el-osc q q q v a c s l x v b q for additional information, see application note an-h33. HV803
15-4 typical performance curves for figure 1 using 3in 2 el lamp. 100 90 80 70 60 50 40 2 145 3 12 10 8 6 4 2 0 2 145 3 50 45 40 35 30 25 20 2 145 3 50 45 40 35 30 25 20 60 50 80 90 70 v cs (v) i in (ma) brightness (ft-im) i in (ma) v in (v) v cs vs. v in v in (v) brightness vs. v in v in (v) i in vs. v in v cs (v) i in vs. v cs (v) 100 250 400 550 700 850 1000 90 80 70 60 50 40 30 20 10 0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0 inductor value ( m h) i in , v cs , brightness vs. inductor value i in (ma), v cs (v) i in (ma) brightness (ft-im) v cs (v) brightness (ft-im) HV803
15-5 figure 2: typical 5.0v application* 1 7 2 3 4 8 6 5 v in = 5.0v 0.1 m f 100v 1nf 560 m h 1 1n4148 750k w 2m w 2.0k w 6 in 2 lamp HV803 l x gnd v b v a r el-osc v dd r sw-osc c s on = v dd off = 0v 0.1 m f 2 typical performance curves for figure 2 90 85 80 75 70 65 5 478 6 8 7.5 7 6.5 6 5.5 5 478 6 40 38 36 34 32 30 5 478 6 40 38 36 34 32 30 70 80 85 90 75 v cs (v) i in (ma) brightness (ft-im) i in (ma) v in (v) v in (v) v in (v) v cs (v) v cs vs. v in brightness vs. v in i in vs. v in i in vs. v cs (v) note: 1. murata part # lqh4n561k04 (dc resistance < 14.5 w ) 2. larger values may be required depending upon supply impedance. for additional information, see application note an-h33. HV803
15-6 figure 3: typical 9.0v application* typical performance curves for figure 3 1 7 2 3 4 8 6 5 v in = 9.0v 0.1 m f 100v 1nf 560 m h 1 1n4148 330k w 2m w 5.1k w 10 in 2 lamp HV803 l x gnd v b v a r el-osc v dd r sw-osc c s 0.1 m f 2 100 90 80 70 60 6.5 5.5 8.5 9.5 7.5 6 5 4 3 2 1 6.5 5.5 8.5 9.5 7.5 40 38 36 34 32 30 6.5 5.5 8.5 9.5 7.5 40 38 36 34 32 30 70 65 80 85 95 90 75 v cs (v) i in (ma) brightness (ft-im) i in (ma) v in (v) v in (v) v in (v) v cs (v) v cs vs. v in brightness vs. v in i in vs. v in i in vs. v cs (v) note: 1. murata part # lqh4n561k04 (dc resistance < 14.5 w ) 2. larger values may be required depending upon supply impedance. for additional information, see application note an-h33. HV803
15-7 external component description external component selection guide line diode fast reverse recovery diode, 1n4148 or equivalent. cs capacitor 0.01 m f to 0.1 m f, 100v capacitor to gnd is used to store the energy transferred from the inductor. 0.01 m f is recommended when driver has large el lamps. r el-osc the el lamp frequency is controlled via an external r el resistor connected between r el-osc and v dd of the device. the lamp frequency increases as r el decreases. as the el lamp frequency increases, the amount of current drawn from the battery will increase and the output voltage v cs will decrease. the color of the el lamp is dependent upon its frequency. a 2m w resistor would provide lamp frequency of 300 to 430hz. decreasing the r el-osc by a factor of 2, the lamp frequency will increase by factor of 2. r sw-osc the switching frequency of the converter is controlled via an external resistor, r sw between r sw-osc and v dd of the device. the switching frequency increases as r sw decreases. with a given inductor, as the switching frequency increases, the amount of current drawn from the battery will decrease and the output voltage, v cs , will also decrease. c sw capacitor a 1nf capacitor is required on r sw-osc pin to gnd when the input voltage is equal to or greater than 5v. as the input voltage of the device increases, a faster switching converter frequency is required to avoid saturating the inductor. with the higher switching frequency, more noise will be introduced. this capacitor is used to shunt any switching noise that may couple into the r sw-osc pin. lx inductor the inductor l x is used to boost the low input voltage by inductive flyback. when the internal switch is on, the inductor is being charged. when the internal switch is off, the charge stored in the inductor will be transferred to the high voltage capacitor c s . the energy stored in the capacitor is then available to the internal h-bridge and therefore to the el lamp. in general, smaller value inductors, which can handle more current, are more suitable to drive larger size lamps. as the inductor value decreases, the switching frequency of the inductor (controlled by r sw ) should be increased to avoid saturation. 560 m h murata inductors with 14.5 w series dc resistance is typically recommended. for inductors with the same inductance value but with lower series dc resistance, lower r sw value is needed to prevent high current draw and inductor saturation. lamp as the el lamp size increases, more current will be drawn from the battery to maintain high voltage across the el lamp. the input power, (v in x i in ), will also increase. if the input power is greater than the power dissipation of the package (350mw), an external resistor in series with one side of the lamp is recommended to help reduce the package power dissipation. enable/disable configuration the HV803 can be easily enabled and disabled via a logic control signal on the r sw and r el resistors as shown in figure 4 below. the control signal can be from a microprocessor. r sw and r el are typically very high values. therefore, only 10s of microam- 1 7 2 3 4 8 6 5 v dd on =v dd off = 0v c s 100v 0.1 m f 1nf l x 1n4148 r sw r el 5.1k w el lamp HV803lg l x gnd v b v a r el-osc v dd r sw-osc c s + - enable figure 4: enable/disable configuration peres will be drawn from the logic signal when it is at a logic high (enable) state. when the microprocessor signal is high the device is enabled and when the signal is low, it is disabled. HV803
15-8 split supply configuration using a single cell (1.5v) battery the HV803 can also be used for handheld devices operating from a single cell 1.5v battery where a regulated voltage is available. this is shown in figure 5. the regulated voltage can be used to run the internal logic of the HV803. the amount of current necessary to run the internal logic is typically 30 to 60 m a. therefore, the regulated voltage could easily provide the current without being loaded down. the HV803 used in this configura- tion can also be enabled/disabled via logic control signal on the r sw and r el resistors as shown in figure 4. split supply configuration for battery voltages of higher than 9.5v figure 5 can also be used with high battery voltages such as 12v as long as the input voltage, v dd , to the HV803 device is within its specifications of 2.4v to 9.5v. figure 5: split supply configuration 1 7 2 3 4 8 6 5 battery voltage regulated voltage on off c s 100v 0.1 m f* l x 1n4148 r sw r el el lamp HV803lg l x gnd v b v a r el-osc v dd r sw-osc c s + - enable v dd gnd *larger values may be required depending upon supply impedance. for additional information, see application note an-h33. HV803
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