![]() |
Electronic Components Datasheet Search |
|
LDS8680 Datasheet(PDF) 7 Page - IXYS Corporation |
|
|
LDS8680 Datasheet(HTML) 7 Page - IXYS Corporation |
7 / 12 page ![]() LDS8680 © 2009 IXYS Corp. 7 Doc. No. 8680_DS, Rev. N1.0 Characteristics subject to change without notice BLOCK DIAGRAM Figure 2. LDS8680 Functional Block Diagram BASIC OPERATION LDS8680 is a charge pump designed for converting at Li-Ion battery voltage to drive a white LED used in photo flash applications. The output current has a maximum value of 800 mA/per channel if one LED is used or 400 mA/per channel if both LEDs are used simultaneously. The output current is programmable via the Smart OneWire ™ interface signaled at the EN pin. The LDS8680 is in standby mode after applying VIN voltage until logic HIGH level is applied to EN pin. The device requires approximately 50 µs to wake up. The LDS8680 may operate in either PWM or command mode. PWM mode starts if first pulse applied to EN pin after power-up is shorter than or equal tSETUP- PWM, At this mode, second and every next pulse applied to EN pin recognizes as PWM pulse, both LEDA and LEDB channels are on, and maximum LED current is equal factory preset value. The command mode starts if first pulse applied to EN pin after power-up is longer than or equal tSETUP- COM. At this mode, every next 16 pulses applied to EN pin recognizes as command, both LEDA and LEDB channels are off, and no current is flowing through LEDs. Command mode is used to set other than factory preset LED current value, turn on/off one of the channels, or turn off timeout protection. After command provided, device goes into PWM mode with maximum current value and number of channels in ON state in respect to command provided. EN pin should be logic LOW for more than tLO to finalize command mode Device starts operating with soft-start at 1-x mode to minimize inrush current At 1-x mode, the VOUT is approximately equal to VIN (less any internal voltage losses). If the output voltage is sufficient to regulate all LED currents, the device remains in 1-x operating mode. The charge pump has two modes of operation: 1-x , and 2-x. The device changes modes if the output voltage drops below the minimum needed to support the desired ILED current. . The low dropout PowerLite ™ Current regulator (PCR) performs well at input voltages up to 150 mV above LED forward voltage VF significantly increasing driver’s efficiency. The LDS8680 monitors voltage |
Similar Part No. - LDS8680 |
|
Similar Description - LDS8680 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
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 |