 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LTC3857 Datasheet(PDF) 4 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LTC3857 Datasheet(HTML) 4 Page - Linear Technology |
|
|
4 / 38 page  LTC3857 4 3857fd ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). VIN = 12V, VRUN1,2 = 5V, EXTVCC = 0V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS INTVCC Linear Regulator VINTVCCVIN Internal VCC Voltage 6V < VIN < 38V, VEXTVCC = 0V 4.85 5.1 5.35 V VLDOVIN INTVCC Load Regulation ICC = 0mA to 50mA, VEXTVCC = 0V 0.7 1.1 % VINTVCCEXT Internal VCC Voltage 6V < VEXTVCC < 13V 4.85 5.1 5.35 V VLDOEXT INTVCC Load Regulation ICC = 0mA to 50mA, VEXTVCC = 8.5V 0.6 1.1 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Ramping Positive 4.5 4.7 4.9 V VLDOHYS EXTVCC Hysteresis 250 mV Oscillator and Phase-Locked Loop f25kΩ Programmable Frequency RFREQ = 25k, PLLIN/MODE = DC Voltage 105 kHz f65kΩ Programmable Frequency RFREQ = 65k, PLLIN/MODE = DC Voltage 375 440 505 kHz f105kΩ Programmable Frequency RFREQ = 105k, PLLIN/MODE = DC Voltage 835 kHz fLOW Low Fixed Frequency VFREQ = 0V, PLLIN/MODE = DC Voltage 320 350 380 kHz fHIGH High Fixed Frequency VFREQ = INTVCC, PLLIN/MODE = DC Voltage 485 535 585 kHz fSYNC Synchronizable Frequency PLLIN/MODE = External Clock l 75 850 kHz PGOOD1 and PGOOD2 Outputs VPGL PGOOD Voltage Low IPGOOD = 2mA 0.2 0.4 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 μA VPG PGOOD Trip Level VFB with Respect to Set Regulated Voltage VFB Ramping Negative Hysteresis –13 –10 2.5 –7 % % VFB with Respect to Set Regulated Voltage VFB Ramping Positive Hysteresis 710 2.5 13 % % tPG Delay for Reporting a Fault 25 μs Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Ratings for extended periods may affect device reliability and lifetime. Note 2: The LTC3857 is tested under pulsed conditions such that TJ ≈ TA. The LTC3857E is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 125°C operating junction temperature range are assured by design, characterization and correlation with statistical process controls. The LTC3857I is guaranteed over the full –40°C to 125°C operating junction temperature range. Note that the maximum ambient temperature is determined by specific operating conditions in conjunction with board layout, the rated package thermal resistance and other environmental factors. Note 3: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formula: TJ = TA + (PD • 34°C/W) Note 4: The LTC3857 is tested in a feedback loop that servos VITH1,2 to a specified voltage and measures the resultant VFB1,2. The specification at 85°C is not tested in production. This specification is assured by design, characterization and correlation to production testing at 125°C. Note 5: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency. See Applications information. Note 6: Rise and fall times are measured using 10% and 90% levels. Delay times are measured using 50% levels. Note 7: The minimum on-time condition is specified for an inductor peak-to-peak ripple current ≥40% of IMAX (See Minimum On-Time Considerations in the Applications Information section). |
Similar Part No. - LTC3857_15 |
|
Similar Description - LTC3857_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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
