HV823 HV823 High Voltage EL Lamp Driver Ordering Information Package Options Device Input Voltage 8-Lead SO Die HV823 2.0V to 9.5V HV823LG HV823X Features General Description ❏ Processed with HVCMOS® technology ❏ 2.0V to 9.5V operating supply voltage ❏ DC to AC conversion ❏ 180V peak-to-peak typical output voltage ❏ Large output load capability typically 50nF ❏ Permits the use of high-resistance elastomeric lamp components ❏ 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 Handheld personal computers ❏ Electronic personal organizers ❏ GPS units ❏ Pagers ❏ Cellular phones ❏ 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 The HV823 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. The EL lamp is connected between VA and VB. 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 ❏ The Supertex HV823 is a high-voltage driver designed for driving EL lamps of up to 50nF. EL lamps greater than 50nF can be driven for applications not requiring high brightness. The input supply voltage range is from 2.0 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. -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. 11/12/01 Supertex Inc. does not recommend the use of its products in life support applications and will not knowingly sell its products for use in such applications unless it receives an adequate "products liability indemnification insurance agreement." Supertex does not assume responsibility for use of devices described and limits its liability to the replacement of devices determined to be defective due to workmanship. No responsibility is assumed for possible omissions or inaccuracies. Circuitry and specifications are subject to change without notice. For the latest product specifications, refer to the 1 refer to the most current databook or to the Legal/Disclaimer page on the Supertex website. Supertex website: http://www.supertex.com. For complete liability information on all Supertex products, HV823 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 2 6 Ω I = 100mA 80 90 100 V VIN = 2.0 to 9.5V 160 180 200 V VIN = 2.0V to 9.5V Quiescent VDD supply current, disabled 30 100 nA RSW-osc = Low Input current going into the VDD pin 150 200 µA VIN = 3.0V. See Figure 1. 300 µA VIN = 5.0V. See Figure 2. 500 µA VIN = 9.0V. See Figure 3. 25 33 mA VIN = 3.0V. See Figure 1. RDS(on) On-resistance of switching transistor VCS Output voltage VCS Regulation VA - VB Output peak to peak voltage IDDQ IDD IIN Input current including inductor current VCS Output voltage on VCS 60 70 85 V VIN = 3.0V. See Figure 1. fEL VA-B output drive frequency 330 380 450 Hz VIN = 3.0V. See Figure 1. fSW Switching transistor frequency 50 60 70 KHz VIN = 3.0V. See Figure 1. D Switching transistor duty cycle 88 % Recommended Operating Conditions Symbol Parameter Min Typ Max Units VDD Supply voltage 2.0 9.5 V TA Operating temperature -25 +85 °C Enable/Disable Table (See Figure 4) RSW resistor HV823 VDD Enable 0V Disable 2 Conditions HV823 Block Diagram Lx VDD Cs RSW-osc Switch Osc Enable * Q VA GND + C _ Disable Q Vref Output Osc Q VB REL-osc Q * Enable is available in die form only. Figure 1: Test Circuit, VIN = 3.0V (Low input current with moderate output brightness). ON = VDD 2MΩ OFF = 0V 1 VDD REL-osc 8 2 RSW-osc VA 7 3 Cs VB 6 4 Lx GND 5 750KΩ 560µH 1 VDD = VIN = 3.0V 1N4148 0.1µF 10nF 2 0.1µF 2.0KΩ Equivalent to 3 square inch lamp. HV823 100V Typical Performance Lamp Size 3.0 in2 VIN IIN VCS fEL Brightness 3.0v 25mA 65v 385Hz 6.5ft-lm Notes: 1. Murata part # LQH4N561K04 (DC resistance < 14.5Ω) 2. Larger values may be required depending upon supply impedance. For additional information, see Application Notes AN-H33 and AN-H34. 3 HV823 Typical Performance Curves for Figure 1 using 3in2 EL Lamp. IIN vs. VIN 30 80 25 70 20 IIN (mA) 90 60 50 40 2 3 4 5 6 7 8 15 10 5 0 9 1 2 3 4 5 6 VIN (V) Brightness vs. VIN IIN vs. VCS (V) 12 10 8 6 4 2 0 1 2 VIN (V) 3 4 5 6 7 8 40 9 50 VIN (V) 60 70 VCS (V) IIN, VCS, Brightness vs. Inductor Value 90 9.0 80 8.0 70 7.0 VCS(V) 6.0 50 5.0 4.0 Brightness (ft-lm) 30 3.0 20 2.0 IIN(mA) 10 1.0 0 0 100 250 400 550 Inductor Value (µH) 4 700 850 1000 Brightness (ft-Im) 60 40 7 8 9 30 25 20 15 10 5 0 IIN (mA) Brightness (ft-Im) 1 IIN (mA), VCS (V) Vcs (V) VCS vs. VIN 80 90 HV823 Figure 2: Typical 5.0V Application ON = VDD 2MΩ OFF = 0V 1 VDD REL-osc 8 2 RSW-osc VA 7 3 Cs VB 6 4 Lx GND 5 750KΩ 560µH 1 VDD = VIN = 5.0V 1N4148 0.1µF 3.1KΩ 20nF Equivalent to 6 square inch lamp 2 0.01µF 1nF 100V 16v HV823 Typical Performance Lamp Size 6.0 in2 VIN IIN VCS fEL Brightness 5.0v 25mA 75v 380Hz 6.5ft-lm Notes: 1. Murata part # LQH4N561K04 (DC resistance < 14.5Ω) 2. Larger values may be required depending upon supply impedance. For additional information, see Application Notes AN-H33 and AN-H34. Typical Performance Curves for Figure 2 VCS vs. VIN IIN vs. VIN 90 80 IIN (mA) VCS (V) 85 75 70 65 4 5 6 VIN (V) 7 40 38 36 34 32 30 4 8 5 6 VIN (V) 8 85 90 IIN vs. VCS (V) IIN (mA) Brightness (ft-Im) Brightness vs. VIN 5 7 VIN (V) 8 7.5 7 6.5 6 5.5 4 6 7 8 40 38 36 34 32 30 70 75 80 VCS (V) 5 HV823 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 VDD = VIN = 9.0V 1N4148 4.9KΩ 42nF Equivalent to 12 square inch lamp 0.1µF2 1nF 16v 0.01µF 100V HV823 Typical Performance Lamp Size VIN IIN VCS fEL Brightness 12.0 in2 9.0v 30mA 75v 380Hz 8.5ft-lm Notes: 1. Murata part # LQH4N561K04 (DC resistance < 14.5Ω) 2. Larger values may be required depending upon supply impedance. For additional information, see Application Notes AN-H33 and AN-H34. Typical Performance Curves for Figure 3 VCS vs. VIN IIN vs. VIN 85 IIN (mA) VCS (V) 80 75 70 65 4 5 6 VIN (V) 7 40 38 36 34 32 30 4 8 5 8 7.5 7 6.5 6 5.5 5 6 7 8 85 90 IIN vs. VCS (V) IIN (mA) Brightness (ft-Im) Brightness vs. VIN 4 6 VIN (V) 7 8 VIN (V) 40 38 36 34 32 30 70 75 80 VCS (V) 6 HV823 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. 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 330 to 450Hz. Decreasing the REL-osc by a factor of 2 will increase the lamp frequency by a 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 recommended on RSW-osc to GND when a 0.01µF CS capacitor is used. This capacitor is used to shunt any switching noise that may couple into the RSW-osc pin. The CSW capacitor may also be needed when driving large EL lamp due to increase in switching noise. 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 connected 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 (400mW), an external resistor in series with one side of the lamp is recommended to help reduce the package power dissipation. Enable/Disable Configuration The HV823 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 Remote Enable ON =VDD OFF = 0V REL 1 VDD REL-osc 8 2 RSW-osc VA 7 3 Cs VB 6 4 Lx GND 5 RSW Lx + VIN = VDD - 1N4148 4.7µF 15V EL Lamp HV823LG CS 100V 1nF 7 HV823 Split Supply Configuration Using a Single Cell (1.5V) Battery Split Supply Configuration for Battery Voltages of Higher than 9.5V The HV823 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 HV823. The amount of current necessary to run the internal logic is typically 100µA at a VDD of 3.0V. Therefore, the regulated voltage could easily provide the current without being loaded down. The HV823 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 HV823 device is within its specifications of 2.0V to 9.5V. Figure 5: Split Supply Configuration Remote Enable ON =VDD OFF = 0 REL VDD = Regulated Voltage 1 VDD 2 RSW-osc 3 Cs VB 6 4 Lx GND 5 RSW Lx + VIN = Battery Voltage - 1N4148 REL-osc 8 VA 7 EL Lamp 0.1µF* HV823LG CS 100V *Larger values may be required depending upon supply impedance. For additional information, see Application Notes AN-H33 and AN-H34. 11/12/01 ©2001 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited. 8 1235 Bordeaux Drive, Sunnyvale, CA 94089 TEL: (408) 744-0100 • FAX: (408) 222-4895 www.supertex.com