Datasheet LTC3871, LTC3871-1 (Analog Devices) - 5

link to page 18 LTC3871/LTC3871-1
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C, VHIGH = 50V, VRUN = 5V unless otherwise noted (Note 2). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
SYNC Phasing Phase Relative to Channel 1 VPHSMD = 0V 0 Deg VPHSMD = 1/4 VV5 90 Deg VPHSMD = Float 0 Deg VPHSMD = 3/4 VV5 0 Deg VPHSMD = VV5 0 Deg Channel to Channel 1 to Channel 2 VPHSMD = 0V 180 Deg Channel Phasing VPHSMD = 1/4 VV5 180 Deg VPHSMD = Float 180 Deg VPHSMD = 3/4 VV5 180 Deg VPHSMD = VV5 120 Deg CLKOUTHI Clock Output High Voltage ILOAD = 0.5mA 5.2 5.5 V CLKOUTLO Clock Output Low Voltage ILOAD = –0.5mA 0 0.2 V VSYNC Sync Input Threshold VSYNC Rising 2 V VSYNC Falling 1.2 V Nominal Frequency RFREQ = 51.1kΩ 180 200 220 kHz fLOW Low Fixed Frequency RFREQ = ≤20kΩ 40 50 60 kHz fHIGH High Fixed Frequency RFREQ = 117kΩ 450 500 550 kHz Synchronizable Frequency SYNC = External Clock l 60 460 kHz SYNC Input Resistance 100 kΩ IFREQ Frequency Setting Current l 18 20 22 µA FAULT Voltage Low IFAULT = 2mA 0.1 0.3 V FAULT Leakage Current VFAULT = 5.5V ±1 µA FAULT Delay Going Low 125 µs VLOW OV Comparator Threshold 1.15 1.2 1.25 V VLOW OV Comparator Hysteresis VOVLOW > 1.2V 5 µA VHIGH OV Comparator Threshold 1.15 1.2 1.25 V VHIGH OV Comparator Hysteresis VOVHIGH > 1.2V 5 µA VHIGH UV Comparator Threshold 1.15 1.2 1.25 V VHIGH UV Comparator Hysteresis VUVHIGH < 1.2V 5 µA BUCK Pin Pull-Up Resistance BUCK Pin to V5 200 kΩ
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings than 125°C. Note that the maximum ambient temperature consistent with may cause permanent damage to the device. Exposure to any Absolute these specifications is determined by specific operating conditions in Maximum Ratings for extended periods may affect device reliability conjunction with board layout, the rated package thermal impedance and and lifetime. other environmental factors.
Note 2:
The LTC3871/LTC3871-1 is tested under pulsed load conditions
Note 3:
TJ is calculated from the ambient temperature TA and such that TJ ≈ TA. The LTC3871/LTC3871-1E is guaranteed to meet power dissipation PD according to the following formula: TJ = TA + performance specifications from 0°C to 85°C junction temperature. (PD • 36°C/W). Specifications over the –40°C to 125°C operating junction temperature
Note 4:
The LTC3871/LTC3871-1 is tested in a feedback loop that servos range are assured by design, characterization and correlation with VITHHIGH and VITHLOW to a specified voltage and measures the resultant statistical process controls. The LTC3875I is guaranteed over the VFBHIGH and VFBLOW, respectively. –40°C to 125°C operating junction temperature range. The LTC3871/
Note 5:
Dynamic supply current is higher due to the gate charge being LTC3871-1H is guaranteed over the full –40°C to 150°C operating delivered at the switching frequency. See Applications Information. junction temperature range. High junction temperature degrades operating lifetimes; operating lifetime is derated for junction temperatures greater
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay times are measured using 50% levels. Rev. B For more information www.analog.com 5 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts