D356B Electroluminescent Lamp Driver IC

Transcription

1 Durel Division W. Chandler Blvd. Chandler, AZ - Tel:.9. / FAX: DB lectroluminescent amp Driver IC Data Sheet Features High fficiency ow Voltage Operation Small System Footprint Controlled Discharge for ow MI Capacitor or xternal Clock F Control Available in ead-free(pb-free) and Green MSOP- Package MSOP- Applications Watches Data Organizer / PDAs Pagers MP/GPS/Remote Controls amp Driver Specifications: (Using Standard Test Circuit at Ta= C unless otherwise specified.) Rogers DUR DB IC driver is part of a family of highly integrated drivers based on Rogers patented three-port (P) topology, which offers built-in MI shielding. This high efficiency device is well suited for backlighting most timepieces and liquid crystal displays for portable electronic applications. Parameter Symbol Minimum Typical Maximum Units Conditions Standby Current na = Supply Current I ma =.V nable Current ua =.V Output Voltage Vout Vpp amp Frequency F 9 Hz CF =. nf Inductor Frequency HF khz Standard Test Circuit.mH ( Ohms) CF CF.V.nF DB.uF.V oad B IT-I99 Rev A Page of

2 oad B* Typical Output Waveform nf Ω nf kω * oad B approximates a in (.cm ) lamp. Absolute Maximum Ratings: Parameter Symbol Minimum Maximum Unit Comments Supply voltage Operating Range Withstand Range V = = nable voltage -. () +. nable on. V nable off. Output Voltage V OUT Vpp Peak-to-peak Voltage CF Voltage V CF () +. V xternal clock input Operating temperature T a - C Storage temperature T s - C Note: The above table reflects stress ratings only. Functional operation of the device at these ratings or any other above those indicated in the specifications is not implied. xposure to absolute maximum rating conditions for extended periods of time may affect reliability. Physical Data: PIN # NAM FUNCTI System ground connection Negative input to inductor High voltage AC output to lamp Positive input to inductor DC power supply input CF amp frequency capacitor/clock input CF amp frequency capacitor/clock input System enable Note: Please consult factory for bare die dimensions and bond pad locations. IT-I99 Rev A Page of

3 Typical Performance Characteristics Using Standard Test Circuit F ( Hz) DC Input Voltage Output Frequency vs. DC Supply Voltage F (Hz) - - Temperature ( C) Output Frequency vs. Ambient Temperature Outp ut Voltag e ( V pp) DC Input Voltage Output Voltage vs. DC Supply Voltage Avg Supply Output Current Voltage (ma) (Vpp) Temperature ( C) Temperature ( C) Output Voltage vs. Ambient Temperature Supply Current vs. Ambient Temperature Avg Supply Current ( ma) DC Input Voltage Supply Current vs. DC Supply Voltage Avg Supply Current (ma) - - Temperature ( C) Supply Current vs. Ambient Temperature IT-I99 Rev A Page of

4 Block Diagram of the Inverter Circuitry Theory of Operation lectroluminescent () lamps are essentially capacitors with one transparent electrode and a special phosphor material in the dielectric. The phosphor glows when a strong AC voltage is applied across the lamp electrodes. The required AC voltage is typically not present in most systems and must be generated from a low voltage DC source. Rogers developed its patented three-port (P) switch-mode inverter circuit to convert the available DC supply to an optimal drive signal for high brightness and lownoise lamp applications. Rogers P topology offers the simplicity of a single DC input, single AC output, and a shared common ground that provides an integrated MI shielding. The DB IC driver drives the lamp by repeatedly pumping charge through an external inductor with current from a DC source and discharging into the capacitance of the lamp load. With each high frequency (HF) cycle, the voltage on the lamp is increased. At a period specified by the lamp frequency (F) oscillator, the voltage on the lamp is discharged to ground and the polarity of the inductive charging is reversed. By this means, an alternating positive and negative voltage is developed at the single output lead of the device to one of the electrodes of the lamp. The other lamp electrode is commonly connected to a ground plane, which can then be considered as electrical shielding for any underlying circuitry on the application. The driving system is divided into several parts: on-chip logic and control, on-chip high voltage output circuitry, discharge logic circuitry, and off-chip components. The on-chip logic controls the output frequency (F), as well as the inductor switching frequency (HF), and HF and F duty cycles. These signals are combined and buffered to regulate the high voltage output circuitry. The output circuitry handles the power through the inductor and delivers the high voltage to the lamp. The selection of offchip components provides a degree of flexibility to accommodate various lamp sizes, system voltages, and brightness levels. Since a key objective for driver systems is to save space and cost, required off-chip components are kept to a minimum. Rogers provides a DB IC Driver Designer s Kit, which includes a printed circuit evaluation board intended to aid you in developing an lamp driver configuration that meets your requirements using the DB IC driver. A section on designing with the DB IC driver is included in this datasheet to serve as a guide to help you select the appropriate external components to complete your DB IC driver system. Typical DB IC driver configurations for driving lamps in various applications are shown below. The expected system outputs, such as lamp luminance; lamp output frequency and voltage; and average supply current draw for the various sample configurations are also shown with each respective figure. IT-I99 Rev A Page of

5 Typical DB IC Driver Configurations.V Analog Watch Typical Output uminance =. f ( cd/m ) amp Frequency = Hz Supply Current = ma Vout = Vpp oad: in (.cm ) DUR Green.mH Murata QSC- DB CF CF.uF.V.nF.V amp.v Handset CD or Digital Watch Typical Output uminance =. f (9. cd/m ) amp Frequency = Hz Supply Current = ma Vout = Vpp oad: in (.cm ) DUR Green.9mH Sumida CS-9 DB CF CF.uF.V.nF.V amp.v PDA Typical Output uminance =. f (. cd/m ) amp Frequency = Hz Supply Current = 9 ma Vout = Vpp oad: in (.cm ) DUR Green.mH Bujeon BDS- DB CF CF.uF.V.nF.V amp IT-I99 Rev A Page of

6 Designing with DB IC Driver I. amp Frequency Capacitor (CF) Selection Selecting the appropriate value of capacitor for the low frequency oscillator (CF) will set the output frequency of the DB IC driver. Figure graphically represents the inversely proportional relationship between the CF capacitor value and the oscillator frequency. In this example at =.V, F = Hz at.9nf. 9 9 CF (nf) Figure : Typical amp Frequency vs. CF Capacitor Alternatively, the lamp frequency may also be controlled with an external clock signal with a % duty cycle. The output lamp frequency will be the same frequency as the input clock signal. For example, if a Hz input clock signal is used, the resulting lamp frequency will be Hz. The clock signal input voltage should not exceed. The selection of the CF value can also affect the brightness of the lamp because of its control of the lamp frequency (F). Although input voltage and lamp size can change lamp frequency as well, F mainly depends on the CF value selected or the frequency of the input clock signal to CF. The luminance of various sizes of a DUR Blue-green lamp driven by a DB IC driver at =.V using the same inductor value is shown in Figure with respect to lamp frequency. amp uminance (f) in amp in amp in amp amp Frequency (Hz) Figure : Typical amp uminance vs. amp Frequency IT-I99 Rev A Page of

7 II. Inductor () Selection The external inductor () selection for a DB IC driver circuit greatly affects the output capability and current draw of the driver. A careful designer will balance current draw considerations with output performance in the choice of an ideal inductor for a particular application. Figures,, and show typical brightness and current draw of a DB IC driver circuit with different inductor values, lamp sizes, and supply voltages while keeping the F constant. Please note that the DC resistance (DCR) of inductors with the same nominal inductance value may vary with manufacturer and inductor type. Therefore, inductors made by a different manufacturer may yield different outputs, but the trend of the different curves should be similar. amp luminance is also a function of lamp size. In each example, a larger lamp will have less luminance with approximately the same current draw. amp uminance (f) 9 uminance Current Current (ma) amp uminance (f) 9 uminance Current Current (ma) Inductor (mh) Inductor (mh) Figure : =.V, in (.cm ) amp Figure : =.V, in (.cm ) amp amp uminance (f) 9 uminance Current Current (ma) Inductor (mh) Figure : =.V, in (.cm ) amp IT-I99 Rev A Page of

8 DB IC Driver Design Ideas I. Driving Multi-segment amps The DB IC driver may be used to drive two or more lamps or lamp areas independently. An external switching circuit can be used to turn each lamp segment on or off. A high signal at the input for the corresponding lamp will power the segment when the IC is enabled. In this example, Segment is always on when the DB IC driver is enabled. Otherwise, always make sure that at least one segment is switched on when the DB IC driver is activated. CF CF CF DB.uF amp Segment amp Segment amp Segment BAST BAST BAST BAST MMBTT.kohm.kohm.kohm.kohm MMBTT MMBTT MMBTT kohm kohm nf nf II. Two-evel Dimming Toggle switching between two different lamp brightness levels may be achieved, as captioned in the circuit shown below. When DIM is low, the external PNP transistor is saturated and the lamp runs at full brightness. When DIM is high, the external PNP turns off and the ohm resistor reduces the voltage at () and dims the lamp. DIM ow B.V High B CF CF kohm CF N9 DB ohm amp.uf IT-I99 Rev A Page of

9 III. amp Frequency Control with an xternal Clock Signal An external clock signal with a % duty cycle may be used to control the lamp frequency (F). This technique allows the designer flexibility to synchronize the IC driver with other elements in the application. The output lamp frequency will be the same frequency as the input clock signal. For example, if a Hz input clock signal is used, the resulting lamp frequency will be Hz. The clock signal voltage should not exceed. CF CF amp Frequency CK.V Min kohm.v Max DB amp.uf IV. amp Brightness Regulation Regulating the DC supply input voltage to the DB IC driver will result in a constant brightness level from the lamp, regardless of battery voltage. In this example, a voltage regulator is used. OUT IN MIC CF CF CF DB amp.uf IT-I99 Rev A Page 9 of

10 V. High Brightness Through Supply Voltage Doubling (Option ) Maximum brightness from a DB IC driver is achieved at relatively high supply voltages (>.V). An external voltage boost circuit may be used to increase the voltage supplied to the DB IC driver. In the following diagram, the M boost converter is used to double the voltage supplied to the DB IC driver. This can produce about twice the brightness of the DB IC driver alone..uf CAP+ OUT N9 CF CF CF DB amp.uf VI. High Brightness Through Supply Voltage Doubling (Option ) In many cases, a resistor may replace the diode shown in the previous configuration. The diode is used by the M converter during startup (see M converter datasheet). The circuit configuration shown below ensures that the M converter starts properly before the DB IC driver is turned on..uf CAP+ OUT CAP- SD M CAP- SD M kohm CF CF CF DB amp.uf IT-I99 Rev A Page of

11 VII. High Brightness with Parallel DB IC Driver (Option ) Two or more DB IC drivers may be operated in parallel to increase the brightness of the lamp by -%. In this example, an external clock signal with % duty cycle is needed to synchronously drive both DB IC drivers. The clock signal voltage should not exceed. CF CF kohm DB amp Frequency CK.V Min.V Max CF CF kohm CF DB.uF amp VIII. High Brightness with Parallel DB IC Driver (Option ) Two or more DB IC drivers may be operated in parallel to increase the brightness of the lamp by -%. In this diagram, two DB IC drivers are operating synchronously using their internal oscillators. The lamp frequency is controlled by a shared CF capacitor. CF CF DB CF CF CF ohm ohm DB.uF amp IT-I99 Rev A Page of

12 IX. Solder Re-Flow Recommendations Classification Reflow Profiles Profile Feature Sn-Pb utectic Assembly Pb-Free Assembly Average ramp-up rate (T to T P ) C/second max. C/second max. Preheat -Temperature Min (Ts min ) -Temperature Max (Ts max ) -Time (min to max) (ts) Ts max to T -Ramp-up Rate C C - seconds C C - seconds C/second max. Time maintained above: Temperature (T ) -Time (T ) C - seconds C - seconds Peak Temperature (T P ) +/- C +/- C Time within C of actual Peak Temperature (T P ) - seconds - seconds Ramp-down Rate Time C to Peak C/second max. C/second max. Temperature minutes max. minutes max. Note: All temperatures refer to topside of the package, measured on the package body surface and to IPC/JDC J-STD-B standards. IT-I99 Rev A Page of

13 Ordering Information The DB IC driver is available as bare die in probed wafer form or in die tray, and in standard or Pbfree MSOP- package per tube or per tape and reel. A DB IC Driver Designer s Kit (DDDBB- K) provides a vehicle for evaluating and identifying the optimum component values for any particular application using DB IC driver. Rogers engineers also provide full support to customers, including specialized circuit optimization and application retrofits. RCOMMNDD PAD AYOUT MSOP- Min Typical Max mm in mm in mm in A B C D F G H I MSOP- PAD AYOUT Min Typical Max mm in mm in mm in a b c.... d e.... f MSOPs in Tape & Reel: DDDBB-M DDDBB-MO DDDBB-N DDDBB-N mbossed tape on mm diameter reel per IA--. units per reel. Quantity marked on reel label Standard MSOP- Pb-Free Green MSOP- ISO9:, ISO/TS 99:, and ISO:99 Certified The information contained in this data sheet is intended to assist you in designing with Rogers systems. It is not intended to and does not create any warranties, express or implied, including any warranty of merchantability or fitness for a particular purpose or that the results shown on the data sheet will be achieved by a user for a particular purpose. The user should determine the suitability of Rogers systems for each application. These drivers are covered by one or more of the following U.S. patents: #,,; #,,9; #,,99; #,9,; #,,. Corresponding foreign patents are issued and pending. The world runs better with Rogers. Is a licensed trademark of Rogers Corporation. DUR is a licensed trademark of Rogers Corporation. The world runs better with Rogers. TM,, Rogers Corporation, Printed in U.S.A. All Rights Reserved Revised / Publication # IT-I99A