 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
SC621 Datasheet(PDF) 14 Page - Semtech Corporation |
|
||||||||||||||||||||||||||||||
SC621 Datasheet(HTML) 14 Page - Semtech Corporation |
|
|
14 / 23 page  SC621 14 Applications Information (continued) Backlight Quiescent Current The quiescent current required to operate all four backlights is reduced by 1.5mA when backlight current is set to 4.0mA or less. This feature results in higher efficiency under light-load conditions. Further reduction in quiescent current will result from using fewer than four LEDs. Fade-In and Fade-Out Backlight brightness can be set to automatically fade-in when current is set to increase and fade-out when current is set to decrease. When enabled with a new current setting, the current will step through each incremental setting between the old and new values. The result is a visually smooth change in brightness with a rate of fade that can be set to 8, 16, 24, or 32 ms per step. LED Flash and Spotlight Current Sink A single output current sink is provided to drive both flash and spotlight functions. In flash mode, this current sink provides up to 400mA for a flash LED or array of parallel LEDs. Flash current settings are in 50mA increments from 50mA to 400mA. The FLEN pin directly triggers the FLASH function when pulled high, or it can be wired to VIN to enable software control via the serial interface. In spotlight mode, the output can be set for up to 250mA of continuous current. Settings are available in 50mA increments from 50mA to 250mA. Continuous operation above 250mA is not recommended due to high power dissipation. Flash and Spotlight Safety Timer A safety timer disables the flash and spotlight output current sink if the sink remains active for an extended period. The timer protects the SC621 and the LED from high power dissipation that can cause overheating. The timer’s default state is on, but the timer may be disabled via the serial interface to allow continuous output current in spotlight mode. The safety timer affects only the FL pin and will turn off the sink after a period of 1 second. The timer may be reset by either forcing the FLEN pin low or by resetting the Flash/Spotlight control bits via the interface. Programmable LDO Outputs Two low dropout (LDO) regulators are provided for camera module I/O and core power. Each LDO has at least 100mA of available load current with ±3.5% accuracy. The minimum current limit is 200mA, so outputs greater than 100mA are possible at somewhat reduced accuracy. A 1μF, low ESR capacitor should be used as a bypass capacitor on each LDO output to reduce noise and ensure stability. In addition, it is recommended that a minimum 22nF capacitor be connected from the BYP pin to ground to minimize noise and achieve optimum power supply rejection. A larger capacitor can be used for this function, but at the expense of increasing turn- on time. Capacitors with X7R or X5R ceramic dielectric are strongly recommended for their low ESR and superior temperature and voltage characteristics. Y5V capacitors should not be used as their temperature coefficients make them unsuitable for this application. Shutdown State The device is disabled when the SWIF pin is low. All registers are reset to default condition when SWIF is low. Sleep Mode When all LEDs are off, sleep mode is activated. This is a reduced current mode that helps minimize overall current consumption by turning off the clock and the charge pump while continuing to monitor the serial interface for commands. Both LDOs can be powered up while in sleep mode. SemWire Single Wire Interface Functions All device functions can be controlled via the SemWire single wire interface. The interface is described in detail in the SemWire Interface section of the datasheet. |
Similar Part No. - SC621 |
|
Similar Description - SC621 |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.NET |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
| Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
|
Family Site : ic2ic.com |
icmetro.com |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
