Electronic Components Datasheet Search |
|
LT3593ES6-TRPBF Datasheet(PDF) 7 Page - Linear Technology |
|
LT3593ES6-TRPBF Datasheet(HTML) 7 Page - Linear Technology |
7 / 16 page LT3593 7 3593f OPERATION The LT3593 uses a constant frequency, current mode control boost scheme to provide excellent line and load regulation. Operation can be best understood by referring to the Block Diagram in Figure 1. Output Disconnect An internal switch connects between the CAP pin and the LED pin. The top of the LED string is connected to the LED pin. The string can be terminated to ground or to VIN if a low number of LEDs are driven. When the part is in shutdown, the switch is off; allowing no current to run through the LEDs. Current Programming The LED current can be set to 32 different values (625μA – 20mA) by strobing the CTRL pin. A 5-bit counter is decremented by 1 on a CTRL pin rising edge, reducing the programmed current by 625μA each time. The desired current can be calculated by: ILED = 20mA – (N – 1) • 625μA where N is the number of rising edges. When the desired current setting is reached, the CTRL pin must stay high. 128μs after the last rising edge on the CTRL pin, the regulator will enable the output and start to regulate the LED current to the programmed value. Figure 2 shows an example of how the part can be programmed. If a different current is desired, the CTRL pin can be strobed again. The first falling edge will reset the internal register to the 20mA setting. While the new current is being pro- grammed, the device will continue to regulate the previously programmed value until the CTRL pin has remained high for at least 128μs, at which time the regulated current will slew to the newly programmed value. Figure 3 shows how to program a new LED current level. If the CTRL pin is held low for longer than 128μs, the part will go into the shutdown mode. Figure 2. Current Programming CTRL 12.5mA 3593 F02 CTRL 15mA CTRL 17.5mA CTRL FULL CURRENT 20mA CTRL LED CURRENT 128μs 20mA 20mA 17.5mA 17.5mA SHDN 3593 F03 128μs 128μs Figure 3. Current Programming and Shutdown Timing |
Similar Part No. - LT3593ES6-TRPBF |
|
Similar Description - LT3593ES6-TRPBF |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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 |