Electronic Components Datasheet Search |
|
TPS53511RGTR Datasheet(PDF) 9 Page - Texas Instruments |
|
|
TPS53511RGTR Datasheet(HTML) 9 Page - Texas Instruments |
9 / 21 page TPS53511 www.ti.com SLUSBG4 – MARCH 2013 This unique circuit prevents current from being pulled from the output during startup if the output is pre-biased. When the soft-start commands a voltage higher than the pre-bias level (internal soft-start voltage becomes greater than feedback voltage VFB), the controller slowly activates synchronous rectification by starting the first low-side FET gate driver pulses with a narrow on-time. It then increments the on-time on a cycle-by-cycle basis until it coincides with the time dictated by (1–D), where D is the duty cycle of the converter. This scheme prevents the initial sinking of the pre-bias output, and ensures that the output voltage (the VO pin) starts and ramps up smoothly into regulation and the control loop is given time to transition from pre-biased start-up to normal mode operation. Power Good The power good function is activated after soft-start has finished. The power good function becomes active after 1.7 times soft-start time. When the feedback voltage is within ±10% of the target value, internal comparators detect power good state and the power good signal becomes high. The power good output, PG, is an open drain output. When the feedback voltage goes ±15% outside of the target value, the power good signal becomes low after 10-µs internal delay. During an undervoltage condition, when the feedback voltage returns to be within ±10% of the target value, the power good signal goes HIGH again. Output Discharge Control TPS53511 discharges the output when EN is low, or the controller is turned off by the protection function (OVP, UVP, UVLO and thermal shutdown). The output is discharged by an internal 50- Ω MOSFET which is connected from VO to PGND. The internal low-side MOSFET is not turned on during the output discharge operation to avoid the possibility of causing negative voltage at the output. Current Protection Output current is limited by cycle-by-cycle overcurrent limiting control. The inductor current is monitored during the OFF state and the controller keeps the OFF state when the inductor current is larger than the over current trip level. To provide accuracy and a cost-effective solution, the device supports temperature compensated internal MOSFET RDS(on) sensing. The inductor current is monitored by the voltage between the PGND pin and the SW pin. In an overcurrent condition, the current to the load exceeds the current to the output capacitor; thus, the output voltage tends to fall off. Eventually the output voltage becomes less than the undervoltage protection threshold and the device shuts down. Overvoltage/Undervoltage Protection The TPS53511 detects over and under-voltage conditions by monitoring the feedback voltage (the VFB pin). This function is enabled after approximately 1.7 times the soft-start time. When the feedback voltage becomes higher than 115% of the target voltage, the OVP comparator output goes high and the circuit latches the high-side MOSFET driver turns off and the low-side MOSFET turns on. Normal operation can be restored only by cycling the VCC or EN pin voltage. When the feedback voltage becomes lower than 70% of the target voltage, the UVP comparator output goes high and an internal UVP delay counter begins. After 250 µs, the device latches off both internal high-side and low-side MOSFET. Similar to the overvoltage protection, the device is latched off, and normal operation can be restored only by cycling the VCC or EN pin voltage. UVLO Protection Undervoltage lockout protection (UVLO) monitors the voltage of the VVREG5 pin. When the VVREG5 voltage is lower than UVLO threshold voltage, the TPS53511 is shut off. This protection is non-latching. Thermal Shutdown Thermal protection is self-activating. If the junction temperature exceeds the threshold value (typically 150°C), the TPS53511 shuts off. This protection is non-latching. Copyright © 2013, Texas Instruments Incorporated Submit Documentation Feedback 9 Product Folder Links: TPS53511 |
Similar Part No. - TPS53511RGTR |
|
Similar Description - TPS53511RGTR |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |