 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LM3424 Datasheet(PDF) 15 Page - Texas Instruments |
|
||||||||||||||||||||||||||||||
LM3424 Datasheet(HTML) 15 Page - Texas Instruments |
|
|
15 / 62 page  T ILED 0 TBK TEND v 1 RGAIN RSNS ILED RHSP RHSN HSN HSP High-Side Sense Amplifier CSH 1.24V CCMP RCSH COMP Error Amplifier VSNS To PWM Comparator LM3424 ICSH ITF 100k 100k 100k 100k TREF TSENSE TGAIN 2.45V VS RREF2 RREF1 RBIAS RNTC RGAIN VDIF LM94022 Precision Temp Sensor NTC RSNS ILED RHSP RHSN HSN HSP High-Side Sense Amplifier CSH 1.24V CCMP RCSH COMP Error Amplifier VSNS To PWM Comparator LM3424 ITF Thermal Foldback Current ICSH LM3424 www.ti.com SNVS603B – AUGUST 2009 – REVISED OCTOBER 2009 Figure 5. LED Current Sense Circuitry Figure 6. Thermal Foldback Circuitry THERMAL FOLDBACK / ANALOG DIMMING Thermal foldback is necessary in many applications due to the extreme temperatures created in LED environments. In general, two functions are necessary: a temperature breakpoint (TBK) after which the nominal operating current needs to be reduced, and a slope corresponding to the amount of LED current decrease per temperature increase as shown in Figure 7. The LM3424 allows the user to program both the breakpoint and slope of the thermal foldback profile. Figure 7. Ideal Thermal Foldback Profile Foldback is accomplished by adding current (ITF) to the CSH summing node. As more current is added, less current is needed from the high side amplifier and correspondingly, the LED current is regulated to a lower value. The final temperature (TEND) is reached when ITF = ICSH causing no current to be needed from the high-side amplifier, yielding ILED = 0A. Copyright © 2009, Texas Instruments Incorporated Submit Documentation Feedback 15 Product Folder Links: LM3424 |
Similar Part No. - LM3424_14 |
|
Similar Description - LM3424_14 |
|
|
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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
