– E T E L – OBSO HV803 High-Voltage EL Lamp Driver Ordering Information Package Options Device Input Voltage 8-Lead SO Die HV803 2.4V to 9.5V HV803LG HV803X Features General Description Processed with HVCMOS® technology 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 RSW-osc and REL-osc to VDD and disabled when connected to GND. 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 The HV803 has two internal oscillators, a switching MOSFET, and a high-voltage EL lamp driver. The frequency for the switching converter MOSFET is set by an external resistor connected between the RSW-osc pin and the supply pin VDD. The EL lamp driver frequency is set by an external resistor connected between REL-osc pin and the VDD pin. An external inductor is connected between the Lx and VDD pins. A 0.01µF to 0.1µF capacitor is connected between CS and GND pins. The EL lamp is connected between VA and VB pins. Adjustable converter frequency to eliminate harmonics and optimize power consumption Enable/disable function Low current draw under no load condition The switching MOSFET charges the external inductor and discharges it into the Cs capacitor. The voltage at Cs will start to increase. Once the voltage at Cs reaches a nominal value of 90V, the switching MOSFET is turned OFF to conserve power. The outputs VA and VB are configured as an H-bridge and are switched in opposite states to achieve 180V peak-to-peak across the EL lamp. Applications Pagers Cellular phones Electronic personal organizers GPS units 15 Handheld personal computers Portable instrumentation Pin Configuration ςΑ Absolute Maximum Ratings* Supply Voltage, VDD -0.5V to +10V Output Voltage, VCs -0.5V to +120V Operating Temperature Range -25°C to +85°C Storage Temperature Range Power Dissipation -65°C to +150°C VDD 1 8 REL-osc RSW-osc 2 7 VA Cs 3 6 VB Lx 4 5 GND SO-8 400mW Note: *All voltages are referenced to GND. 15-1 HV803 Electrical Characteristics DC Characteristics (VIN = 3.0V, RSW = 750KΩ, REL = 2.0MΩ, TA = 25°C unless otherwise specified) Symbol Parameter Min Typ Max Units Conditions 3.5 8.0 Ω I = 100mA RDS(on) On-resistance of switching transistor VCS Output voltage VCS Regulation 80 90 100 V VIN = 2.4 to 9.5V VA - VB Output peak to peak voltage 160 180 200 V VIN = 2.4V to 9.5V IDDQ Quiescent VDD supply current, disabled 2.0 µA RSW-osc = GND IDD Input current going into the VDD pin 100 µA VIN = 3.0V ±5%. See Figure 1. 300 µA VIN = 5.0V ±5%. See Figure 2. 500 µA VIN = 9.0V ±5%. See Figure 3. 35 mA VIN = 3.0V. See Figure 1. IIN Input current including inductor current VCS Output voltage on VCS 45 70 V VIN = 3.0V. See Figure 1. fEL VA-B output drive frequency 300 430 Hz VIN = 3.0V. See Figure 1. fSW Switching transistor frequency 50 90 KHz VIN = 3.0V. See Figure 1. D Switching transistor duty cycle 88 % – E T E L O S B O – Recommended Operating Conditions Symbol Parameter Min Typ Max Units VDD Supply voltage 2.4 9.5 V TA Operating temperature -25 85 °C Enable/Disable Table (See Figure 4) RSW resistor HV803 VDD Enabled GND Disabled 15-2 Conditions HV803 Block Diagram Lx VDD Cs RSW-osc Switch Osc Q VA GND + C _ Disable Q Vref Output Osc Q VB REL-osc Q – E T E L O S B O – Figure 1: Test Circuit, VIN = 3.0V (Low input current with moderate output brightness). ON = VDD OFF = 0V 2MΩ 1 VDD 2 RSW-osc REL-osc 8 VA 7 750KΩ 560µH1 VIN = 3.0V 1N4148 10nF 3 Cs VB 4 Lx GND 0.1µF2 0.1µF 100V 2.0KΩ 6 5 Equivalent to 3 square inch lamp. HV803 Note: 1. Murata part # LQH4N561K04 (DC resistance < 14.5Ω) 2. Larger values may be required depending upon supply impedance. For additional information, see application note AN-H33. 15-3 15 HV803 Typical Performance Curves for Figure 1 using 3in2 EL Lamp. IIN vs. VIN 100 90 80 70 60 50 40 IIN (mA) VCS (V) VCS vs. VIN 1 2 3 VIN (V) 4 50 45 40 35 30 25 20 5 1 2 IIN (mA) 1 2 3 VIN (V) 4 50 5 60 70 VCS (V) – E T E L O S B O – IIN, VCS, Brightness vs. Inductor Value 9.0 80 8.0 70 7.0 6.0 VCS (V) 50 5.0 Brightness (ft-Im) 40 4.0 30 3.0 IIN (mA) 20 2.0 10 1.0 0 0 400 550 Inductor Value (µH) 15-4 700 850 1000 Brightness (ft-Im) 60 250 5 80 90 50 45 40 35 30 25 20 90 100 4 IIN vs. VCS (V) 12 10 8 6 4 2 0 IIN (mA), VCS (V) Brightness (ft-Im) Brightness vs. VIN 3 VIN (V) HV803 Figure 2: Typical 5.0V Application* ON = VDD OFF = 0V 2MΩ 1 VDD REL-osc 8 2 RSW-osc VA 7 3 Cs VB 6 4 Lx GND 5 750KΩ 560µH1 VIN = 5.0V 1N4148 2.0KΩ 6 in2 lamp 0.1µF2 0.1µF 100V 1nF HV803 Note: 1. Murata part # LQH4N561K04 (DC resistance < 14.5Ω) 2. Larger values may be required depending upon supply impedance. For additional information, see application note AN-H33. – E T E L O S B O – Typical Performance Curves for Figure 2 IIN vs. VIN 90 85 80 75 IIN (mA) VCS (V) VCS vs. VIN 70 65 4 5 6 VIN (V) 7 40 38 36 34 32 30 4 8 5 6 7 8 VIN (V) 15 IIN vs. VCS (V) 8 7.5 7 6.5 6 5.5 IIN (mA) Brightness (ft-Im) Brightness vs. VIN 4 5 6 7 8 VIN (V) 40 38 36 34 32 30 70 75 80 VCS (V) 15-5 85 90 HV803 Figure 3: Typical 9.0V Application* 2MΩ 1 VDD REL-osc 8 2 RSW-osc VA 7 3 Cs VB 6 4 Lx GND 5 330KΩ 560µH1 VIN = 9.0V 1N4148 5.1KΩ 10 in2 lamp 0.1µF2 1nF 0.1µF 100V HV803 Note: 1. Murata part # LQH4N561K04 (DC resistance < 14.5Ω) 2. Larger values may be required depending upon supply impedance. For additional information, see application note AN-H33. – E T E L O S B O – Typical Performance Curves for Figure 3 VCS vs. VIN IIN vs. VIN 100 IIN (mA) VCS (V) 90 80 70 60 5.5 6.5 7.5 VIN (V) 8.5 9.5 40 38 36 34 32 30 5.5 6.5 7.5 VIN (V) Brightness (ft-Im) 9.5 IIN vs. VCS (V) IIN (mA) 6.5 8.5 VIN (V) Brightness vs. VIN 6 5 4 3 2 1 5.5 7.5 8.5 9.5 40 38 36 34 32 30 65 70 75 80 VCS (V) 15-6 85 90 95 HV803 External Component Description External Component Selection Guide Line Diode Fast reverse recovery diode, 1N4148 or equivalent. Cs Capacitor 0.01µF to 0.1µF, 100V capacitor to GND is used to store the energy transferred from the inductor. 0.01µF is recommended when driver has large EL lamps. REL-osc The EL lamp frequency is controlled via an external REL resistor connected between REL-osc and VDD of the device. The lamp frequency increases as REL decreases. As the EL lamp frequency increases, the amount of current drawn from the battery will increase and the output voltage VCS will decrease. The color of the EL lamp is dependent upon its frequency. A 2MΩ resistor would provide lamp frequency of 300 to 430Hz. Decreasing the REL-osc by a factor of 2, the lamp frequency will increase by factor of 2. RSW-osc The switching frequency of the converter is controlled via an external resistor, RSW between RSW-osc and VDD of the device. The switching frequency increases as RSW decreases. With a given inductor, as the switching frequency increases, the amount of current drawn from the battery will decrease and the output voltage, VCS, will also decrease. CSW Capacitor A 1nF capacitor is required on RSW-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 RSW-osc pin. Lx Inductor The inductor Lx 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 CS. 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 RSW) should be increased to avoid saturation. 560µH Murata inductors with 14.5Ω series DC resistance is typically recommended. For inductors with the same inductance value but with lower series DC resistance, lower RSW 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, (VIN x IIN), 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. – E T E L O S B O – Enable/Disable Configuration The HV803 can be easily enabled and disabled via a logic control signal on the RSW and REL resistors as shown in Figure 4 below. The control signal can be from a microprocessor. RSW and REL are typically very high values. Therefore, only 10’s of microam- 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. Figure 4: Enable/Disable Configuration 15 ON =VDD Enable OFF = 0V REL 1 VDD 2 RSW-osc 3 Cs VB 6 4 Lx GND 5 RSW Lx + VDD - 1N4148 REL-osc 8 VA 7 EL Lamp 0.1µF HV803LG CS 100V 1nF 15-7 5.1KΩ HV803 Split Supply Configuration Using a Single Cell (1.5V) Battery Split Supply Configuration for Battery Voltages of Higher than 9.5V 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 60µA. Therefore, the regulated voltage could easily provide the current without being loaded down. The HV803 used in this configuration can also be enabled/disabled via logic control signal on the RSW and REL resistors as shown in Figure 4. Figure 5 can also be used with high battery voltages such as 12V as long as the input voltage, VDD, to the HV803 device is within its specifications of 2.4V to 9.5V. – E T E L – OBSO Figure 5: Split Supply Configuration ON VDD OFF REL Enable GND Regulated Voltage 1 VDD 2 RSW-osc 3 Cs VB 6 4 Lx GND 5 RSW Lx + Battery Voltage - 1N4148 REL-osc 8 VA 7 EL Lamp 0.1µF* HV803LG CS 100V *Larger values may be required depending upon supply impedance. For additional information, see application note AN-H33. 15-8