STCF02 STMicroelectronics, STCF02 Datasheet
STCF02
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STCF02 Summary of contents
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... February 2007 High power white led driver QFN20 (4mm x 4mm) Description The STCF02 is a high efficiency power supply solution to drive a single flash LED in camera phone, PDAs and other hand-held devices buck-boost converter that guarantees a proper LED current control over the battery voltage (particularly in the case, when the output voltage is lower than the input voltage) ...
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... Detailed operating description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.2 Buck-Boost converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.3 Flash mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6.4 Medium flash mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 6.5 Torch mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6.6 Shutdown mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 6.7 Soft start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.8 LED Failure Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.9 Overvoltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.10 Thermal shutdown protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6.11 Sensing of LED temperature by NTC resistor . . . . . . . . . . . . . . . . . . . . . . . . 14 6.12 Safety shutdown in flash mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2/19 STCF02 ...
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... On the other hand the operation of STCF02 is not limited with the use of the external components listed above. - The C is optional and may be used if the error amplifier bandwidth (which by default is COMP set to 2 KHz) has to be decreased because of an unstable driver function ...
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... It is mandatory to connect VLX1A and VLX1B together. Digital input that allows selection of the operational modes of the device (refer to truth table). Digital input that allows selection of the operational modes of the device (refer to truth table). STCF02 during FLASH and TORCH . It must be FLASH . ...
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... STCF02 Pln N° Symbol Name and function 18 PGND Power ground Middle flash resistor 19 RMFL connection 20 EN1 Enable Pin 1 Exp- PGND Power ground pad Figure 3. Block diagram Note Power ground pin for power analog circuit connected to the PCB ground plane. This pin is used for the current setting in Middle Flash Mode – RMF resistor is connected to this pin ...
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... T Storage temperature range STG V ESD rating ESD 1. STCF02 is guaranteed to meet specification from 0°C to 70°C – specifications over the -40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process control. Table 4. Thermal data Symbol R Thermal resistance junction-ambient (*) thJA (*) Typical Application on a two layer board ...
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... STCF02 4 Characteristics Table 5. Electrical characteristics (All typical values are referred to T Symbol Parameter V Input Operating Voltage Under voltage lockout threshold UVLO Output Current Adjustment Range, I FLASH Output Current Adjustment I O Range, I MFLASH Output Current Adjustment Range, I TORCH ∆I Output current variation ...
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... 8/19 I LED =160mV/ TORCH ( TORCH FLASH MFLASH FLASH MFLASH I = 160mV/R FLASH FLASH I (mA) Mode LED_MAX 0 Shutdown 0 Shutdown 250 Torch 500 Medium Flash 600 Flash STCF02 NTC OFF ...
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... STCF02 5 Typical characteristics Figure torch mode IN IN Figure flash mode 600 Figure 8. Efficiency Figure 5. Figure 7. in torch mode Figure 9. Typical characteristics torch mode VFB1 vs temp in torch mode Start-up to torch mode ...
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... Typical characteristics Figure 10. Start-up to flash mode 600 3.6V BATT 10/19 STCF02 ...
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... Introduction The STCF02 is a buck-boost converter, dedicated to power and control the current of a Power White Led in a camera cell Phone. The device operates at a constant switching frequency of 1.8MHz typ. It provides an output voltage down to 2.5V and up to 5.1 V, from a single cell 2 5.5 V lithium-ion battery. The flash current is adjustable from 100mA to 600mA for the input voltage range from 2 ...
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... In medium flash mode the current is set between the Torch and the flash mode levels and can be adjusted by connecting a resistor between the RMFL pin and the ground: The medium flash current is then programmed using the following equation: -5 • [3000+(13000• 12/19 /13000+R )]. (See Figure STCF02 ...
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... To select this operating mode the Enable pins have to be connected to any one of the follow states: EN1 = 0, EN2 = 1, EN3 = x EN1 = 1, EN2 = 1, EN3 = 1. The STCF02 can continuously provide a torch current adjustable between 25mA and 250mA. The torch current adjustment is made by resistor R voltage across R ...
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... The hysteresis comparator allows for the automatic restart of the PWM controller, when the temperature is reduced by 20°C. 6.11 Sensing of LED temperature by NTC resistor The device is able to switch off the power circuit, if high temperature on the LED is detected (see Figure 14 ). 14/ will not exceed 6ms. O MAX STCF02 ...
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... STCF02 6.12 Safety shutdown in flash mode To avoid LED burning during flash mode, which could be brought micro-controller fault, a simple programmable R circuit is possible to shutdown the device after a selected time through the R C Figure 15 ). Figure 14. Typical application of LED temperature sensing by NTC resistor Figure 15. Typical Application of Safety Shutdown ...
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... These packages have a Lead-free second level interconnect. The category of second level interconnect is marked on the package and on the inner box label, in compliance with JEDEC Standard JESD97. The maximum ratings related to soldering conditions are also marked on the inner box label. ECOPACK trademark. ECOPACK specifications are available at: www.st.com. 16/19 STCF02 ® packages. ...
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... STCF02 DIM. MIN 0.18 D 3.875 D2 0.75 E 3.875 E2 0.75 e 0.45 L 0.35 ddd QFN20 (4x4) MECHANICAL DATA mm. TYP MAX. 0.9 1.00 0.02 0.05 0.65 1.00 0.25 0.23 0.30 4.00 4.125 1.7 2.25 4.00 4.125 1.7 2.25 0.50 0.55 0.55 0.75 0.08 Package mechanical data mils MIN. TYP. MAX. 31.5 35.4 0.8 25.6 9.8 7.1 9.1 152.6 157.5 162.4 29.5 66.9 152.6 157.5 162.4 29.5 66.9 17.7 19.7 13.8 21.7 7169619-D 39.4 2.0 39.4 11.8 88.6 88.6 21.7 25.9 3.1 17/19 ...
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... Revision 10-Nov-2005 1 19-Dec-2005 2 29-Jun-2006 3 27-Jul-2006 4 18-Oct-2006 5 09-Feb-2007 6 18/19 First release. Document updating. The table 5 has been updated and add typical characteristics. Mistake on table 5 figure reference T Text updates. Mistake value of I test condition RM O Changes parameter. FL/TR = 500Ω ==> 500kΩ on FLASH_MAX STCF02 Table 5. ...
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... STCF02 Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...