LTC3865/LTC3865-1 ELECTRICAL CHARACTERISTICSThe l denotes the specifi cations which apply over the full operatingjunction temperature range, otherwise specifi cations are at TA = 25°C (Note 2). VIN = 15V, VRUN1,2 = 5V unless otherwise noted.SYMBOLPARAMETERCONDITIONSMINTYPMAXUNITS BG RDOWN BG Driver Pull-Down On-Resistance BG Low 1.4 Ω TG1,2 tr TG Transition Time: (Note 6) TG1,2 tf Rise Time CLOAD = 3300pF 25 ns Fall Time CLOAD = 3300pF 25 ns BG1,2 tr BG Transition Time: (Note 6) BG1,2 tf Rise Time CLOAD = 3300pF 25 ns Fall Time CLOAD = 3300pF 25 ns TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF Each Driver 30 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF Each Driver 30 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 90 ns INTVCC Linear Regulator VINTVCC Internal VCC Voltage 6V < VIN < 38V 4.8 5.0 5.2 V VLDO INT INTVCC Load Regulation ICC = 0mA to 20mA 0.5 2 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Ramping Positive l 4.5 4.7 V VLDO EXT EXTVCC Voltage Drop ICC = 20mA, VEXTVCC = 5V 50 100 mV VLDOHYS EXTVCC Hysteresis 200 mV Oscillator and Phase-Locked Loop fNOM Nominal Frequency RFREQ = 162k 450 500 550 kHz fLOW Lowest Frequency RFREQ = 0Ω 210 250 290 kHz fHIGH Highest Frequency RFREQ ≥ 325k 650 770 880 kHz RMODE/PLLIN MODE/PLLIN Input Resistance 250 kΩ IFREQ Frequency Setting Current VFREQ = 1.22V 6.5 7.5 8.5 μA PGOOD OUTPUT VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±2 μA VPG PGOOD Trip Level VOSENSE with Respect to Set Regulated Voltage VID11 = VID12 = VID21 = VID22 = Float VOSENSE Ramping Negative –7 –10 –12.5 % VOSENSE Ramping Postitive 7 10 12.5 % tPG PGOOD Bad Blanking Time Measured from VID Transitition Edge 100 μs Note 1: Stresses beyond those listed under Absolute Maximum Ratings Note 3: TJ is calculated from the ambient temperature TA and power may cause permanent damage to the device. Exposure to any Absolute dissipation PD according to the following formulas: Maximum Rating condition for extended periods may affect device LTC3865UH: TJ = TA + (PD • 34°C/W) reliability and lifetime. LTC3865FE: TJ = TA + (PD • 25°C/W) Note 2: The LTC3865/LTC3865-1 are tested under pulsed load conditions Note 4: The LTC3865/LTC3865-1 are tested in a feedback loop that servos such that TJ ≈ TA. The LTC3865E/LTC3865E-1 are guaranteed to meet VITH1,2 to a specifi ed voltage and measures the resultant VOSENSE1,2. performance specifi cations over the 0°C to 85°C operating junction Note 5: Dynamic supply current is higher due to the gate charge being temperature range. Specifi cations over the –40°C to 125°C operating delivered at the switching frequency. See Applications Information. junction temperature range are assured by design, characterization and Note 6: Rise and fall times are measured using 10% and 90% levels. Delay correlation with statistical process controls. The LTC3865I/LTC3865I-1 times are measured using 50% levels. are guaranteed to meet performance specifi cations over the full –40°C Note 7: The minimum on-time condition is specifi ed for an inductor peak- to 125°C operating junction temperature range. Note that the maximum to-peak ripple current 40% of IMAX (see Minimum On-Time Considerations ambient temperature consistent with these specifi cations is determined by in the Applications Information section). specifi c operating conditions in conjunction with board layout, the rated Note 8: VSENSE(MAX) defaults to 50mV for the LTC3865-1. package thermal resistance and other environmental factors. Note 9: Guaranteed by design. 3865fb 5