Datenblatt-Suchmaschine für elektronische Bauteile |
|
ADM1177-1ARMZ-R7 Datenblatt(PDF) 9 Page - Analog Devices |
|
ADM1177-1ARMZ-R7 Datenblatt(HTML) 9 Page - Analog Devices |
9 / 16 page Preliminary Technical Data ADM1177 Rev. PrD | Page 9 of 16 point (4). The initial cycle delay (time point 2 to time point 4) is related to CTIMER by equation: tINITIAL ~= 270 × CTIMER ms/μF (7) When the initial timing cycle terminates, the device is ready to start a hotswap operation (assuming ON pin is asserted). In the example shown in Figure 4, the ON pin was asserted at the same time as VCC was applied, so the hotswap operation starts immediately after time-point (4). At this point the FET gate is charged up with a 12 μA current source. At timepoint (5) the threshold voltage of the FET is reached and the load current begins to flow. The FET is controlled to keep the sense voltage at 100 mV (this corresponds to a maximum load current level defined by the value of RSENSE). At timepoint (6) VGATE and VOUT have reached their full potential and the load current has settled to its nominal level. Figure 5 illustrates the situation where the ON pin is asserted after VVCC is applied. VVCC VON VGATE VOUT VTIMER INITIAL TIMING CYCLE (1) (2) (3) (4) (5) (6) VSENSE Figure 4. Start-up (ON asserts as power is applied) VVCC VON VGATE VOUT VTIMER INITIAL TIMING CYCLE (1) (2) (3)(4) (5)(6) VSENSE (7) Figure 5. Start-up (ON asserts after power is applied) HOTSWAP RETRY CYCLE ON ADM1177-1 With the ADM1177-1 the device will turn off the FET after an overcurrent fault, and will then use the TIMER pin to time a delay before automatically retrying to hotswap. As with all ADM1177 devices, on overcurrent fault is timed by charging the TIMER cap with a 60 μA pull-up current, and when the TIMER pin reaches 1.3 V the fault current limit time has been reached and the GATE pin is pulled down. On the ADM1177-1, the TIMER pin is then pulled down with a 2 μA current sink. When the TIMER pin reaches 0.2 V, it will automatically restart the hotswap operation. The cool down period is related to CTIMER by equation: tCOOL ~ = 550 × CTIMER ms/μF (8) The retry duty cycle is thus given by tFAULT/(tCOOL + tFAULT ) × 100% = 3.8% (9) |
Ähnliche Teilenummer - ADM1177-1ARMZ-R7 |
|
Ähnliche Beschreibung - ADM1177-1ARMZ-R7 |
|
|
Link URL |
Privatsphäre und Datenschutz |
ALLDATASHEETDE.COM |
War ALLDATASHEET hilfreich? [ DONATE ] |
Über Alldatasheet | Werbung | Kontakt | Privatsphäre und Datenschutz | Linktausch | Hersteller 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 |