 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
AME5142BAEEY Datasheet(PDF) 7 Page - Analog Microelectronics |
|
||||||||||||||||||||||||||||||
AME5142BAEEY Datasheet(HTML) 7 Page - Analog Microelectronics |
|
|
7 / 18 page  AME, Inc. 9 AME5142 White LED Boost Converter In Tiny Package Rev. A.01 n Application Hints Calculating Load Current The load current is related to the average inductor cur- rent by the relation: I LOAD = IIND (AVG) x (1 - D) Where “D” is the duty cycle of the application. The switch current can be found by: I SW = IIND (AVG) + 1 /2 (IRIPPLE) Inductor ripple current is dependent on inductance, duty cycle, input voltage and frequency: I RIPPLE = D x (VIN-VSW) / (f x L) Combining all terms, we can develop an expression which allows the maximum available load current to be calculated: Thermal Considerations Shutdown Pin Operation I LOAD = ( 1-D ) x ( I SW (max) - ) D ( V IN-VSW ) 2fL At higher duty cycles, the increased ON time of the FET means the maximum output current will be deter- mined by power dissipation within the AME5142 switch. The switch power dissipation from ON-state conduction is calculated by: P (SW) = D x IIND(AVE)2 x RDS(ON) There will be some switching losses as well, so some derating needs to be applied when calculating IC power dissipation. The device is turned off by pulling the shutdown pin low. If this function is not going to be used, the pin should be tied directly to V IN. If the SHDN function will be needed, a pull-up resistor must be used to V IN (approximately 50k- 100k recommended). The EN pin must not be left unterminated. Dimming Control A. Using a PWM Signal to EN Pin For controlling the LED brightness, the AME5142 can perform the dimming control by applying a PWM signal to EN pin. The average LED current is proportional to the PWM signal duty cycle. The magnitude of the PWM signal should be higher than the maximum enable voltage of EN pin, in order to let the dimming control perform correctly. L1 10 µH AME5142 GND IN EN SW FB V IN 2.7V to 5.5V OVP V OUT C OUT 1 µF Dimming Control 25KHz to 100KHz R1 7.5 Ω C IN 4.7 µF Figure 5. PWM Dimming Control Using the EN Pin |
Similar Part No. - AME5142BAEEY |
|
Similar Description - AME5142BAEEY |
|
|
|
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
