HV850 ________________________________________________________________________________ Initial Release High Voltage Low Noise Inductorless EL Lamp Driver Features General Description Supertex HV850 is a high voltage electroluminescent (EL) Lamp Driver IC. It is designed to drive EL lamps of up to 2.0in2, with capacitive values up to 4.5nF. HV850 converts a low voltage DC input to a high voltage AC output across an EL lamp. It uses a charge pump scheme to boost the input voltage eliminating the need for an external inductor, diode, and high voltage capacitor commonly found in conventional topologies. No external components required when using an external EL clock frequency EL frequency can be set by an external resistor Low Noise DC to AC converter 2 Drives up to 4.5nF load (approx. 2.0 inches) Output voltage regulation Enable function The charge pump circuit discharges its energy into an EL lamp through a high voltage H-bridge. Once the voltage reaches its regulated limit, it is turned off to conserve power. The EL lamp is then discharged to ground and the H-bridge changes state to allow the charge pump to charge the EL lamp in the opposite direction. Applications Cell phone keypads and displays Transceivers MP3 Players Watches Pagers Measuring instruments/gauges The EL lamp frequency can be set either by an external resistor REL or by applying an external clock where the clock frequency is divided by 128 to set the EL lamp frequency. Typical Application Circuits VDD=ON GND=OFF VDD=ON GND=OFF + + VDD CDD - VDD VA REL VB EN GND Clk-in VDD Clk-en VDD EL Lamp - CDD REL VDD VA REL VB EN GND Clk-in EL Lamp Clk-en HV850MG VDD HV850MG GND EL lamp frequency set by REL EL lamp frequency set by an external clock Supertex, Inc. 1 1/21/04 HV850 ________________________________________________________________________________ Ordering Information Package Device MSOP-8 HV850MG* HV850 Pin Configuration Die HV850X *Product supplied on 2500 piece Carrier Tape Reels. Absolute Maximum Ratings* Vdd, Supply Voltage Operating Temperature Storage Temperature Power Dissipation MSOP-8 -0.5V to 4.5V -25°C to +85°C -65°C to +150°C 300mW VDD VA REL VB EN GND Clk-in Clk-en MSOP (top View) *Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied. Continuous operation of the device at the absolute rating level may affect device reliability. All voltages are referenced to device ground. Electrical Characteristics (unless otherwise specified: Symbol IDDQ VA or VB VA-VB fEL IDD VA or VB VA-VB fEL trout Parameter Quiescent current Peak output voltage Peak to Peak output voltage Min EL lamp frequency 225 Operating current Peak output voltage Peak to Peak output voltage EL lamp frequency 54 110 250 Output voltage rise time 1.5 TA = 25° C, VDD = 3.5V) Typ Max Units Conditions 150 nA EN=0V 70 77 V No load. 140 154 V REL=1.65MΩ or 250 275 Hz CLK=32KHz 16 mA See Figure 1, VDD=3.5V, 61 68.5 V REL=1.5MΩ, 122 134 V Load=3.3nF+1KΩ 294 338 Hz fEL=250Hz, 1in2 lamp, 0V to ms 90% of final value 63 126 Logic Inputs Symbol VIL VIH IIL IIH ENrise ENfall Cin Parameter Input logic low voltage Input logic high voltage Input logic low current Input logic high current Enable input rise time (for delay turn off) Enable input fall time (for delay turn off) Logic input capacitance Min 0 2.0 Typ 0.01 10µ Max 0.5 VDD 1.0 1.0 10 5 10 Units V V µA µA ms s pF Max 4.2 500 3.5 +85 Units V Hz nF °C Conditions Using external R-C circuit, see Figure 2. Recommended Operating Conditions Symbol VDD freq Cload TA Parameter Input voltage EL lamp frequency EL lamp capacitance Operating Temperature Supertex, Inc. Min 3.0 50 0 -25 2 Typ Conditions 1/21/04 HV850 ________________________________________________________________________________ Typical Output Waveform Vdd=3.5V, Fel=250.0Hz; Load=3.3nF+1 kohm; Idd=9.19mA, CH1 20V/div, 1mS/div Block Diagram Vdd EN Vdd Capacitor Charge Pum p Circuit Va Vsense Feedback Clk-in Vdd Clk-en EL Oscillator Rel Vb MOS FET Full Bridge GND Supertex, Inc. High Voltage Level Translators 3 1/21/04 HV850 ________________________________________________________________________________ Pin Description Pin # 1 2 Pad VDD REL 3 EN 4 Clk-in 5 Clk-en 6 7 8 Gnd VB VA Description Input supply voltage pin. An external resistor to VDD will set the EL lamp frequency. Enable input pin. Logic high will turn the device on. An external R-C circuit can be added for a delayed turn off. Logic input pin. An external logic clock applied to this pad can be used to set the EL lamp frequency (see Figure 3). This is useful for applications requiring the EL lamp to be synchronized to a system clock. Connect to ground when no in use. Logic input pin. Logic high will cause the EL lamp frequency to be set by the Clk-in input. Logic low will cause the EL lamp frequency to be set by the external Rel resistor. IC ground pin. EL lamp driver output pin. The EL lamp is connected across VA and VB terminals. EL lamp driver output pin. The EL lamp is connected across VA and VB terminals. Figure 1: Typical Applications VDD=ON GND=OFF Rel + VDD Cdd - VDD VA REL VB EN GND Clk-in EL Lamp Clk-en HV850MG Note: Cdd=2.2µF, 6.3V low ESR Load REL 3.3nF+1KΩ 1.5MΩ VDD 3.0V 3.5V 4.0V IDD 8.9mA 10.2mA 10.4mA Peak VA 53V 61V 66V fEL 294Hz Additional Examples Lamp Size REL 1.0in2 1.65MΩ 0.5in2 2.0MΩ 1.0in2 3.3MΩ 0.5in2 3.3MΩ 1.0in2 4.7MΩ Supertex, Inc. VDD 3.0V 3.5V 4.0V 3.0V 3.5V 4.0V 3.0V 3.5V 4.0V 3.0V 3.5V 4.0V 3.0V 3.5V 4.0V IDD 8.4mA 9.4mA 9.9mA 5.5mA 5.3mA 4.9mA 5.6mA 5.4mA 5.0mA 4.6mA 4.1mA 3.8mA 4.8mA 4.4mA 5.0mA Peak VA 53V 62V 66V 62V 68V 68V 62V 67V 68V 64V 68V 68V 64V 68V 68V 4 fEL 250Hz 210Hz 128Hz 128Hz 89Hz Brightness 7.31cd/m2 10.35cd/m2 12.62cd/m2 11.54cd/m2 14.33cd/m2 14.90cd/m2 8.55cd/m2 10.29cd/m2 10.94cd/m2 8.25cd/m2 9.62cd/m2 9.95cd/m2 6.02cd/m2 7.50cd/m2 10.94cd/m2 1/21/04 HV850 ________________________________________________________________________________ Figure 2: Push Button Turn on with Delay Turn off + Cdd VDD Rel Push button turn on V DD VA R EL VB EN C GND Clk-in R EL Lamp Clk-en HV 850MG RC time constant will set Turn off Delay time Figure 3: Independent Programmable Output Frequency (fEL) V DD=ON GND=OFF + V DD Cdd - VDD VA REL VB EN Clk-in VDD EL Lamp GND Clk-en HV850MG GND Supertex, Inc. 5 1/21/04 HV850 ________________________________________________________________________________ 1/20/04natfrev15 Supertex, Inc. 2004 Supertex Inc. All rights reserved. Unauthorized use or reproduction prohibited. 6 1235 Bordeaux Drive, Sunnyvale, CA 94809 TEL: (408) 222-8888 / FAX: (408) 222-4895 1/21/04 www.supertex.com