 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
RT6236BLGQUF Datasheet(PDF) 5 Page - Richtek Technology Corporation |
|
||||||||||||||||||||||||||||||
RT6236BLGQUF Datasheet(HTML) 5 Page - Richtek Technology Corporation |
|
|
5 / 22 page  RT6236A/B 5 DS6236A/B-02 August 2016 www.richtek.com © Copyright 2016 Richtek Technology Corporation. All rights reserved. is a registered trademark of Richtek Technology Corporation. “hysteresis” to discourage the IC from switching back to continuous switching unless the load increases substantially. The IC returns to continuous switching as soon as an on- time is generated before the inductor current reaches zero. The on-time is reduced back to the length needed for 650kHz switching and encouraging the circuit to remain in continuous conduction, preventing repetitive mode transitions between continuous switching and discontinuous switching. Current Limit The RT6236A/B current limit is a cycle-by-cycle “valley” type, measuring the inductor current through the synchronous rectifier during the off-time while the inductor current ramps down. The current is determined by measuring the voltage between source and drain of the synchronous rectifier. If the inductor current exceeds the current limit, the on-time one-shot is inhibited (Mask high side signal) until the inductor current ramps down below the current limit. Thus, only when the inductor current is well below the current limit is another on time permitted. This arrangement prevents the average output current from greatly exceeding the guaranteed current limit value, as typically occurs with other valley-type current limits. If the output current exceeds the available inductor current (controlled by the current limit mechanism), the output voltage will drop. If it drops below the output under-voltage protection level, the IC will stop switching (see next section). Output Over-Voltage Protection and Under-Voltage Protection If the output voltage VOUT rises above the regulation level and lower 1.2 times regulation level, the high-side switch naturally remains off and the synchronous rectifier turns on. For RT6236B, if the output voltage remains high the synchronous rectifier remains on until the inductor current reaches the low side current limit. If the output voltage still remains high, then IC's switches remain that the synchronous rectifier turns on and high-side MOS keeps off to operate at typical 500kHz switching protection, again if inductor current reaches low side current, the synchronous rectifier will turn off until next protection clock. If the output voltage exceeds the OVP trip threshold (1.25 times regulation level) for longer than 10 μs (typical), then IC's output Over-Voltage Protection (OVP) is triggered. RT6236BL chip enters latch mode. For RT6236A If the output voltage Vo rises above the regulation level and lower 1.2 times regulation level, the high-side switch naturally remains off and the synchronous rectifier turns on until the inductor current reaches zero current. If the output voltage remains high, then IC's switches remain off. If the output voltage exceeds the OVP trip threshold (1.25 times regulation level) for longer than 10 μs (typical), the IC's OVP is triggered. RT6236AL chip enters latch mode. The RT6236A/B include output Under-Voltage Protection (UVP). If the output voltage drops below the UVP trip threshold for longer than 250 μs (typical) then IC's UVP is triggered. Chip into latch or hiccup mode. (see next section). Hiccup Mode The RT6236AH/BH, use hiccup mode for UVP. When the protection function is triggered, the IC will shut down for a period of time and then attempt to recover automatically. Hiccup mode allows the circuit to operate safely with low input current and power dissipation, and then resume normal operation as soon as UVP is removed. During hiccup mode, the shutdown time is determined by the capacitor at SS. A 2 μA current source discharges VSS from its starting voltage (normally VPVCC). The IC remains shut down until VSS reaches 0.2V, about 10ms for a 3.9nF capacitor. At that point the IC begins to charge the SS capacitor at 6 μA, and a normal start-up occurs. If the fault remains, UVP protection will be enabled when VSS reaches 2.2V (typical). The IC will then shut down and discharge the SS capacitor from the 2.2V level, taking about 4ms for a 3.9nF SS capacitor. Latch-Off Mode The RT6236AL/BL, use latch-off mode OVP and UVP. When the protection function is triggered the IC will shut down in Latch-Off Mode. The IC stops switching, leaving both switches open, and is latched off. To restart operation, toggle EN or power the IC off and then on again. |
Similar Part No. - RT6236BLGQUF |
|
Similar Description - RT6236BLGQUF |
|
|
|
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
