Electronic Components Datasheet Search |
|
MIC2289C-34BML Datasheet(PDF) 5 Page - Micrel Semiconductor |
|
MIC2289C-34BML Datasheet(HTML) 5 Page - Micrel Semiconductor |
5 / 10 page Micrel, Inc. MIC2289C September 2006 5 M9999-090706 Functional Diagram GND VREF PWM Generator Ramp Generator 1.2MHz Oscillator SW EN FB OUT VIN 95mV gm OVP S MIC2289C Block Diagram Functional Description The MIC2289C is a constant frequency, PWM current mode boost regulator. The block diagram is shown above. The MIC2289C is composed of an oscillator, slope compensation ramp generator, current amplifier, gm error amplifier, PWM generator, 500mA bipolar output transistor, and Schottky rectifier diode. The oscillator generates a 1.2MHz clock. The clock’s two functions are to trigger the PWM generator that turns on the output transistor and to reset the slope compensation ramp generator. The current amplifier is used to measure the switch current by amplifying the voltage signal from the internal sense resistor. The output of the current amplifier is summed with the output of the slope compensation ramp generator. This summed current-loop signal is fed to one of the inputs of the PWM generator. The gm error amplifier measures the LED current through the external sense resistor and amplifies the error between the detected signal and the 95mV reference voltage. The output of the gm error amplifier provides the voltage-loop signal that is fed to the other input of the PWM generator. When the current-loop signal exceeds the voltage-loop signal, the PWM generator turns off the bipolar output transistor. The next clock period initiates the next switching cycle, maintaining the constant frequency current-mode PWM control. The LED is set by the feedback resistor: FB LED R 95mW I = The Enable pin shuts down the output switching and disables control circuitry to reduce input current-to- leakage levels. Enable pin input current is zero at zero volts. |
Similar Part No. - MIC2289C-34BML |
|
Similar Description - MIC2289C-34BML |
|
|
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 |