Electronic Components Datasheet Search |
|
TPS55330 Datasheet(PDF) 11 Page - Texas Instruments |
|
TPS55330 Datasheet(HTML) 11 Page - Texas Instruments |
11 / 32 page ( ) 1 He(s) Se s 1 (1 D) 0.5 2 S s n 1 2 fsw fsw = é ù æ ö ê ú ç ÷ ´ + ´ - - ç ÷ ê ú è ø ë û + + p ´ 0.32 V R 0.5 A FREQ Se 16 (1 D) 6 pF 6 pF m = + ´ - ´ V IN S R n SENSE L = ´ SH OUT SL R V 1.229V 1 R æ ö = ´ + ç ÷ è ø TPS55330 www.ti.com SLVSBX8A – MAY 2013 – REVISED DECEMBER 2014 Feature Description (continued) (3) 7.3.5 Soft-Start The TPS55330 has a built-in soft-start circuit which significantly reduces the start-up current spike and output voltage overshoot. When the IC is enabled, an internal bias current source (6 µA typical) charges a capacitor (CSS) on the SS pin. The voltage at the capacitor clamps the output of the internal error amplifier that determines the peak current and duty cycle of PWM controller. Limiting the peak switch current during start-up with a slow ramp on the SS pin will reduce in-rush current and output voltage overshoot. Once the capacitor reaches 1.8V, the soft-start cycle is completed and the soft-start voltage no longer clamps the error amplifier output. When the EN is pulled low for at least 1ms, the IC enters the shutdown mode and the SS capacitor is discharged through a 5k Ω resistor to prepare for the next soft-start sequence. 7.3.6 Slope Compensation The TPS55330 has internal slope compensation to prevent subharmonic oscillations. The sensed current slope of boost converter can be expressed as Equation 4: (4) The slope compensation dv/dt can be calculated using Equation 5. (5) In a converter with current mode control, in addition to the output voltage feedback loop, the inner current loop including the inductor current sampling effect as well as the slope compensation on the small signal response should be taken into account, which can be modeled as seen in Equation 6: where • RSENSE (15mΩ) is the equivalent current sense resistor • RFREQ is timing resistor used to set frequency • D is the duty cycle (6) NOTE If Sn << Se, the converter operates in voltage mode control rather than current mode control, and Equation 6 is no longer valid. 7.3.7 Enable and Thermal Shutdown The TPS55330 enters shutdown when the EN voltage is less than 0.68 V (min) for more than 1 ms. In shutdown, the input supply current for the device is less than 10 µA (max). The EN pin has an internal 950k Ω pull down resistor to disable the device if the pin is floating. An internal thermal shutdown turns off the device when the junction temperature exceeds 165°C (typical). The device restarts when the junction temperature drops by 15°C. Copyright © 2013–2014, Texas Instruments Incorporated Submit Documentation Feedback 11 Product Folder Links: TPS55330 |
Similar Part No. - TPS55330_15 |
|
Similar Description - TPS55330_15 |
|
|
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 |