 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LTC1642A Datasheet(PDF) 11 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LTC1642A Datasheet(HTML) 11 Page - Linear Technology |
|
|
11 / 16 page  11 LTC1642A 1642af APPLICATIO S I FOR ATIO Automatic Restart After the Circuit Breaker Opens The LTC1642A will automatically attempt to restart itself after the circuit breaker opens if the FAULT output is tied to the ON pin. The circuit is shown in Figure 5. Diode D1 blocks the weak FAULT pull-up current source from unbal- ancing the R6-R5 divider. During a continuous current limit such as a load short, Q1’s duty cycle is equal to the circuit breaker timer period, divided by the sum of the circuit breaker and system timer periods: Short - Circuit Duty Cycle = + C CC 4 410 1 • The duty cycle is 9% for the Figure 5 circuit. Waveforms during a load short are shown in Figure 6. Undervoltage Lockout An internal undervoltage lockout circuit holds the charge pump off until VCC exceeds 2.73V. If VCC falls below 2.5V, it turns off the charge pump and clears overvoltage and current limit faults. For higher lockout thresholds tie the ON pin to a resistor divider driven from VCC, as shown in Figure 7. This circuit keeps the charge pump off until VCC exceeds (1+R6/R5) • 1.34V, and also turns it off if VCC falls below (1+R6/R5) • 1.22V. D1 1N4148 D2 1N4705 18V GATE ON 14 SENSE 15 4 FAULT 6 BRK TMR 2 VCC 16 R2 0.015 Ω Q1 FDS6630A GND LTC1642A 8 RST TMR 3 R5 60.4k 1% R6 464k 1% R10 30k 1642a F05 R3 100 Ω R4 330 Ω C2 0.047 µF + C1 0.33 µF C4 0.33 µF ALL RESISTORS ±5% UNLESS NOTED VIN 12V 2.5A VOUT CLOAD Figure 5. Automatic Restart Circuit Figure 6. Automatic Retry Following a Load Short VGATE 20V/DIV VOUT 10V/DIV VBRKTMR 1V/DIV VRSTTMR 1V/DIV 40ms/DIV 1642a F06 D1 1N4705 18V GATE 14 SENSE 15 ON 4 VCC 16 R2 0.015 Ω Q1 FDS6630A GND LTC1642A 8 RST TMR 3 R6 464k 1% R5 60.4k 1% VIN 12V 2.5A 1642a F07 R3 100 Ω R4 330 Ω C2 0.047 µF + C1 0.33 µF ALL RESISTORS ±5% UNLESS NOTED VOUT UNDERVOLTAGE LOCKOUT THRESHOLD = 10.7V CLOAD Figure 7. Setting a Higher Undervoltage Lockout |
Similar Part No. - LTC1642A |
|
Similar Description - LTC1642A |
|
|
|
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
