HV862 Dimmable, Low Noise, Dual EL Lamp Driver The device uses a single inductor and a minimum number of passive components. Using the internal reference voltage, the regulated output voltage is at a nominal value of 90V. The EL Lamps will therefore see ±90V. The two EL Lamps can be turned ON and OFF using two CMOS logic inputs, EN1 and EN2. The driver is disabled when both EN1 and EN2 are at logic low. Features ► ► ► ► ► ► ► ► ► ► Adjustable output regulation for dimming Lamp fade-in/fade-out capability Low audible noise 180VPP output voltage for higher brightness 1.5V enable input logic high Single cell lithium ion compatible One miniature inductor to power both lamps Separately adjustable lamp and converter frequencies Split supply capability 16-Lead QFN package The HV862 has two internal oscillators, a switching MOSFET, and two high voltage EL Lamp driver H-bridges. Each driver has its own half bridge common output, COM1 and COM2, which significantly minimizes the DC offset seen by the EL Lamp. The frequency for the switching 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 the REL-osc pin and the VDD pin. An external inductor is connected between the LX and VDD pins or VIN for split supply applications. Depending upon the EL Lamp sizes, a 1.0nF to 10.0nF capacitor is connected between the CS and ground. Applications ► ► ► ► ► Dual display cellular phones Keypad and LCD backlighting PDAs Handheld wireless communication products Global Positioning Systems (GPS) As the switching MOSFET charges the external inductor and discharges it into the capacitor at CS, the voltage at General Description CS will start to increase. Once the voltage at CS reaches a The Supertex HV862 is a low noise, dimmable, high nominal value of 90V, the switching MOSFET is turned OFF voltage, dual EL Lamp driver designed for driving two to conserve power. electroluminescent (EL) Lamps with a combined area of 5.0 square inches. The input supply voltage range is from 2.5V EL Lamp dimming can be accomplished by applying a PWM to 4.5V. Enable input logic high can go as low as 1.5V, which logic signal to the PWM pin. The EL Lamp brightness will be allows logic interface operating from typical 1.8V supplies. proportional to the PWM duty cycle. The HV862 can also The device is designed to minimize audible noise emitted by slowly turn the EL Lamp ON/OFF giving a fade ON/OFF the EL Lamps. appearance. Typical Application Circuit VIN = 3.2V to 4.2V 4.7µF 100µH Coilcraft LPS4012 1N4148 3.3MΩ 3 VDD = 3.0V 0.1µF 15 14 VREG VOUT 7 LX EL1 COM1 2 RSW-osc 825kΩ Input Logic Control: ON = 1.5V to VDD OFF = 0V to 0.2V CS VDD 2.0MΩ 1 REL-osc EL2 4 5 EN1 EN2 VREF PWM 16 13 3.3nF 100V NPO 8 COM2 GND 2.2µF HV862K7-G 6 12 11 EL1 9 10 EL2 HV862 Pin Configuration Ordering Information VREF VREG VOUT PWM Package Option Device 16 16-Lead QFN 15 14 13 (3x3mm body, 0.80mm height (max), 0.50mm pitch) HV862 REL-osc 1 12 RSW-osc 2 11 COM1 VDD 3 10 COM2 EN1 4 9 HV862K7-G -G indicates package is RoHS compliant (‘Green’) 5 6 EN2 GND Absolute Maximum Ratings 7 8 LX CS EL1 EL2 16-Lead QFN Parameter Value VDD, Supply Voltage (top view) Note: Pads are at the bottom of the package. Center heat slug is at ground potential. -0.5V to 5.5V Operating Temperature -40°C to +85°C Storage Temperature -65°C to +150°C Power Dissipation Product Marking 1.6W VCS, Output Voltage Y = Last Digit of Year Molded W = Code for Week Molded L = Lot Number = “Green” Packaging H862 YWLL -0.5V to +120V 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. 16-Lead QFN Package Thermal Resistance Package θja 16-Lead QFN 60 °C/W Electrical Characteristics (Over recommended operating conditions unless otherwise specified) Sym Parameter Min Typ Max Units Conditions RDS(ON) On-resistance of switching transistor - - 7.0 Ω I = 100mA VCS Maximum output regulation voltage 80 90 100 V VDD = 2.5V to 4.5V - 78 - - 62 - - 45 - 0 - 1.40 V VDD = 2.5V to 4.5V VCS Output regulation voltage VDD = 2.5V to 4.5V, VREG = 1.092V V VDD = 2.5V to 4.5V, VREG = 0.862V VDD = 2.5V to 4.5V, VREG = 0.632V VREG External input voltage range VREFH VREF output high voltage 1.12 1.26 1.40 V VDD = 2.5V to 4.5V IREF(SOURCE) Average sourcing current from VREF pin - 6.0 - µA VDD = 2.5V to 4.5V Average sinking current from VREF pin - 6.0 - µA VDD = 2.5V to 4.5V - - 300 - - 400 nA - - 500 VDD = 2.5V, EN1 = EN2 = PWM = LOW VDD = 3.0V, EN1 = EN2 = PWM = LOW VDD = 4.5V, EN1 = EN2 = PWM = LOW IREF(SINK) IDDQ Quiescent VDD supply current 2 HV862 Electrical Characteristics (cont.) Symbol Parameter Min Typ Max Units Conditions IDD Input current going into the VDD pin - - 250 µA VDD = 2.5V to 4.5V, REL = 2.0MΩ, RSW = 825kΩ IIN Input current including inductor current - 25 50 mA VIN = 3.2V (see Test Circuit) fEL EL Lamp frequency 160 190 220 Hz REL = 2.0MΩ fSW Switching transistor frequency 84 100 116 kHz RSW = 825kΩ Input PWM frequency 10 - 100 kHz --- - 88 - % --- PWM D Switching transistor duty cycle VIH Enable PWM input logic high voltage 1.5 - VDD V VDD = 2.5V to 4.5V VIL Enable PWM input logic low voltage 0 - 0.2 V VDD = 2.5V to 4.5V IIH Enable PWM input logic high current - - 1.0 µA VIH = VDD = 2.5V to 4.5V IIL Enable PWM input logic low current - - -1.0 µA VIL = 0V, VDD = 2.5V to 4.5V CIN Enable PWM input capacitance - - 15 pF --- Recommended Operating Conditions Symbol Parameter Min Typ Max Units VDD Supply voltage 2.5 - 4.5 V --- fSW Switching frequency 40 - 200 kHz --- fEL EL output frequency 100 - 500 Hz --- 0 - 20 nF --- -40 - +85 °C --- CLOAD TA Total EL Lamp capacitance load Operating Temperature Conditions Function Table EN1 EN2 EL1 EL2 COM1 COM2 IC 0 0 Hi Z Hi Z Hi Z Hi Z OFF 0 1 Hi Z ON Hi Z ON ON 1 0 ON Hi Z ON Hi Z ON 1 1 ON ON ON ON ON Typical Performance VDD VIN (V) (V) 3.0 4.0 Lamp IIN VCS FEL (mA) (VPEAK) (Hz) EL1 ON 16.9 EL2 ON 11.4 EL1 and EL2 ON 25.0 3 93 188 Lamp Brightness (cd/m2) EL1 EL2 14.8 - - 18.0 14.6 17.7 HV862 Pin Configuration and External Component Description Pin # Name Description REL-Osc External resistor from REL-Osc to VDD sets the EL frequency. The EL frequency is inversely proportional to the external REL resistor value. Reducing the resistor value by a factor of two will result in increasing the EL frequency by two. fEL = (2.0MΩ • 190Hz) / REL 2 RSW-Osc External resistor from RSW-Osc to VDD sets the switch converter frequency. The switch converter frequency is inversely proportional to the external RSW resistor value. Reducing the resistor value by a factor of two will result in increasing the switch converter frequency by two. fSW = (825kΩ • 100kHz) / RSW 3 VDD Low voltage input supply pin. 4 EN1 Enable input signal for EL Lamp 1. CMOS logic input pin. Refer to the function table. 5 EN2 Enable input signal for EL Lamp 2. CMOS logic input pin. Refer to the function table. 6 GND Device ground. 1 7 LX Drain of internal switching MOSFET. Connection for an external 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. 8 CS Connect a 100V capacitor between this pin and ground. This capacitor stores the energy transferred from the inductor. 9 EL2 EL Lamp 2 connection. 10 COM2 Common connection for EL2 Lamp. 11 COM1 Common connection for EL1 Lamp. 12 EL1 13 PWM PWM pulse input for EL Lamp dimming. The duty cycle of the PWM signal is proportional to the output voltage. If PWM dimming is not desired, then the PWM pin should be tied to ground. 14 VOUT Switched internal reference voltage. VREG Input voltage to set VCS regulation voltage. This pin allows an external voltage source to control the VCS amplitude. EL Lamp dimming can be accomplished by varying the input voltage to VREG. The VCS voltage is approximately 71 times the voltage seen on VREG. 15 EL Lamp 1 connection. External resistor connected between VREG and VOUT pins controls the VCS charging rate. The charging rate is inversely proportional to the resistor value. 16 VREF Internal reference voltage to set the regulation voltage. Connect an external capacitor (CREF) from VREF to ground to slowly brighten the Lamp during power-up and dim down the Lamp during powerdown. The size of the capacitor determines the time taken to brighten up or dim down. If fade-in and fade-out are not required, this pin should be left floating. Fade in/Fade out time = CREF • 210e3. 4 HV862 Figure 1: Block Diagram EN1 EL1 Enable EN2 EL2 Enable RSW-osc CS LX VDD EL1 PWM Switch Oscillator 0 to 88% C VCS COM1 Output Drivers VSENSE + - VCS 1.26V VREF VREG 60pF EL2 VOUT VCS GND COM2 2 x EL Freq. 1 x EL Freq. REL-osc VREF PWM Figure 2: Test Circuit IIN VIN 4.7µF 100µH Coilcraft LPS4012 1N4148 3.3MΩ IDD 3 VDD 2.0MΩ 1 0.1µF 2 825kΩ Input Logic Control: ON = 1.5V to VDD OFF = 0V to 0.2V 15 14 VREG VOUT 7 LX CS EL1 VDD REL-osc COM1 RSW-osc EL2 4 5 EN1 EN2 VREF PWM GND 16 13 6 COM2 2.2µF HV862K7-G 5 3.3nF 100V NPO 8 12 620Ω 12nF 620Ω 12nF 11 9 10 HV862 Figure 3: Typical Waveform EL1, COM1 and Differential Waveform EL1 – COM1 Split Supply Configuration Enable/Disable Configuration The HV862 can also be used for handheld devices operating from a battery where a regulated voltage is available. This is shown in Figure 4. The regulated voltage can be used to run the internal logic of the HV862. The amount of current necessary to run the internal logic is 250µA max. Therefore, the regulated voltage could easily provide the current without being loaded down. EL1 and EL2 outputs can be enabled and disabled via a logic control signal on the EN1 and EN2 pins respectively. When EN1 is high/low, the Lamp1 (EL1) will be ON/OFF. When EN2 is high/low, the Lamp2 (EL2) will be ON/OFF. The control signal can be from a microprocessor. Figure 4: Split Supply and Enable/Disable Configuration Battery Voltage = VIN + _ LX CIN 3 Regulated Voltage = VDD + _ CDD D RREG REL 15 14 VREG VOUT 7 LX EL1 COM1 2 RSW-osc RSW Input Logic Control: Input Logic Control: CS VDD 1 R EL-osc EL2 4 5 EN1 EN2 VREF PWM 16 13 COM2 GND CREF HV862K7-G 6 CS 8 6 12 11 EL1 9 10 EL2 HV862 16-Lead QFN Package Outline (K7) (3x3mm body, 0.80mm height (max), 0.50mm pitch) D2 D 16 Note 1 (Index Area D/2 x E/2) 16 1 1 e Note 1 (Index Area D/2 x E/2) E E2 b View B Top View Bottom View Note 3 θ L A A3 Seating Plane L1 Note 2 A1 View B Side View Notes: 1. Details of Pin 1 identifier are optional, but must be located within the indicated area. The Pin 1 identifier may be either a mold, or an embedded metal or marked feature. 2. Depending on the method of manufacturing, a maximum of 0.15mm pullback (L1) may be present. 3. The inner tip of the lead may be either rounded or square. Symbol Dimension (mm) A A1 MIN 0.70 0.00 NOM 0.75 0.02 MAX 0.80 0.05 A3 0.20 REF b D D2 E E2 0.18 2.85 1.50 2.85 1.50 0.25 3.00 1.65 3.00 1.65 0.30 3.15 1.80 3.15 1.80 e 0.50 BSC L L1 θ 0.20* 0.00 0O 0.30* - - 0.45 0.15 14O JEDEC Registration MO-220, Variation WEED-4, Issue K, June 2006. Dimensions marked with (*) are non-JEDEC dimensions. Drawings are not to scale. (The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information go to http://www.supertex.com/packaging.html.) Doc.# DSFP-HV862 A091107 7