LDS3543 Specifications and Applications Information 02/28/08 Two Lamp DC to AC Inverter Preliminary 1.25 [31,75] MAX Powered by a regulated +12 Volt DC source, the LDS3543 is designed to power the backlight of the Optrex T-51952D065J-FW-A-ACN display. .12 [3,0] Dia. (2x) 1 J3 Product Features 9 Small Package Size, less than 9mm in height 9 J1 5.27 [133,8] MAX High Dimming Ratio 9 High Efficiency 1 4.070 [103,37] 9 Made in U.S.A. This unit complements our L Series of DC to AC Inverters 1 J2 .60[15,4] .24 [6,2] LDS Package PCB components are shown for reference only. Actual product may differ from that shown. Package Configuration The ERG LDS3543 (LDS Series) DC to AC inverter LDS Series features onboard connectors and can be easily dimmed using an external analog control signal or an external PWM generator. PCB components are shown for reference only. Actual product may differ from that shown. Mass: 26 grams Connectors Pin Descriptions Input J1 Output J2, J3 Molex 53261-0871 JST SM02(8.0)B-BHS-1-TB J2-1 ACout J2-2 ACreturn J1-1,2 J1-3,4 J1-5 J1-6 J1-7,8 +Vin GND Enable Control N/C J3-1 ACout J3-2 ACreturn page 1. LDS3543 Absolute Maximum Ratings Rating Symbol Value Units Input Voltage Range V in -0.3 to +13.2 V dc Storage Temperature T stg -40 to +85 o C Operating Characteristics With a load simulating the referenced display and lamp warm-up of 5 minutes. Unless otherwise noted Vin = 12.00 Volts dc and Ta = 25oC. Characteristic Symbol Min Typ Max Units V in +10.8 +12.0 +12.6 V dc Temperature (Note 1) Ts -20 - +80 Input Current (Note 2) I in - 0.46 0.56 A dc Input Ripple Current I rip - 20 - mA pk-pk Fo 36 41 46 kHz V out (min) 1200 - - Vrms h - 76 - % Output Current (per lamp) I out - 6.2 - mArms Output Voltage V out - 340 - Vrms Turn-off Threshold V thoff GND - 0.5 V dc Turn-on Threshold V thon 2.0 - Vi n V dc Impedance to Vin R enable 9.5 10.0 10.5 kOhm Input Voltage Component Surface Operating Frequency Minimum Output Voltage (Note 3) Efficiency o C Enable Pin Specifications subject to change without notice. (Note 1) Surface temperature must not exceed 80 degrees C; thermal management actions may be required. (Note 2) Input current in excess of maximum may indicate a load/inverter mismatch condition, which can result in reduced reliability. Please contact ERG technical support. (Note 3) Provided data is not tested but guaranteed by design. Application Notes: 1) The minimum distance from high voltage areas of the inverter to any conductive material should be .12 inches per kilovolt of starting voltage. 2) Mounting hardware is to be non-conductive. 3) Open framed inverters should not be used in applications at altitudes over 10,000 feet. 4) Contact ERG for possible exceptions. page 2. LDS3543 Onboard PWM Unless otherwise noted Vin = 12.00 Volts DC, Ta = 25 oC and unit has been running for 5 minutes. Characteristic Symbol Min Typ Max Units Frequency f pwm - 160 - HZ Control Input Bias Current I cb i a s - - 10 uA Pin Descriptions Vin Input voltage to the inverter. The two pins should be connected for optimum reliability and efficiency. GND Inverter ground. The two pins should be connected for optimum reliability and efficiency. Control Analog voltage input to the onboard pulse width modulator. Increasing this voltage increases the OFF time of the onboard PWM resulting in decreased brightness. The inverter is full ON when this voltage is near inverter ground. Enable Inverter Enable. Pull this pin low to disable inverter operation. This pin must be high to enable the inverter. The onboard PWM is always utilized. Application information The LDS series of inverters is designed to power up to four cold cathode fluorescent lamps with combined power up to twelve watts. An external analog control interfaces with an onboard pulse width modulator to provide dimming control. The LDS inverter can reliably dim to less than 5% duty cycle. External shutdown of the inverter is accomplished using the Enable pin. Pulling this pin low (below Vthoff) disables the inverter. Enabling the inverter is accomplished by pulling this pin high (above Vthon). If analog voltage dimming is required, the analog voltage is applied to the Control pin. Figure 1 shows how to connect the inverter for onboard PWM operation. Graph 1 shows the relationship of PWM duty cycle to input control voltage. If an external PWM is used, simply connect the Enable pin to the PWM source and connect the Control pin to inverter GROUND. If the onboard PWM is used, connect the analog voltage to the Control pin. page 3. LDS3543 Graph 1 +Vin +12V ACout Lamp 1 +Vin GND J2 GND ACreturn ACout Control J3 0V full on 5V full off Enable search Gr Re R 13 M (R) c. RE UL p, In ou Endi co tt + On - Off IS G I I O S TE RE D F 3 900 A3 1 Lamp 2 ACreturn Figure 1 Endicott Research Group, Inc. (ERG) reserves the right to make changes in circuit design and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by ERG is believed to be accurate and reliable. However, no responsibility is assumed by ERG for its use. page 4.