Datasheet LTC3862 (Linear Technology) - 4

LTC3862
e lecTrical characTerisTics (Notes 2, 3) The
l
denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, RUN = 2V and SS = open, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
fSYNC SYNC Minimum Input Frequency VSYNC = External Clock l 50 kHz SYNC Maximum Input Frequency VSYNC = External Clock l 650 kHz VSYNC SYNC Input Threshold Rising Threshold 1.5 V IPLLFLTR Phase Detector Sourcing Output Current fSYNC > fOSC –15 µA Phase Detector Sinking Output Current fSYNC < fOSC 15 µA CH1-CH2 Channel 1 to Channel 2 Phase Relationship VPHASEMODE = 0V 180 Deg VPHASEMODE = Float 180 Deg VPHASEMODE = 3V8 120 Deg CH1-CLKOUT Channel 1 to CLKOUT Phase Relationship VPHASEMODE = 0V 90 Deg VPHASEMODE = Float 60 Deg VPHASEMODE = 3V8 240 Deg DMAX Maximum Duty Cycle VDMAX = 0V (Note 9) 96 % VDMAX = Float 84 % VDMAX = 3V8 75 % tON(MIN)1 Minimum On-Time VBLANK = 0V (Note 8) 180 ns tON(MIN)2 Minimum On-Time VBLANK = Float (Note 8) 260 ns tON(MIN)3 Minimum On-Time VBLANK = 3V8 (Note 8) 340 ns
Gate Driver
RDS(ON) Driver Pull-Up RDS(ON) 2.1 Ω Driver Pull-Down RDS(ON) 0.7 Ω
Overvoltage
VFB(OV) VFB, Overvoltage Lockout Threshold VFB(OV) – VFB(NOM) in Percent 8 10 12 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
This IC includes overtemperature protection that is intended to may cause permanent damage to the device. Exposure to any Absolute protect the device during momentary overload conditions. Continuous Maximum Rating condition for extended periods may affect device operation above the specified maximum operating junction temperature reliability and lifetime. may impair device reliability.
Note 2:
All currents into device pins are positive; all currents out of device
Note 5:
Supply current in normal operation is dominated by the current pins are negative. All voltages are referenced to ground unless otherwise needed to charge the external MOSFET gates. This current will vary with specified. supply voltage and the external MOSFETs used.
Note 3:
The LTC3862E is guaranteed to meet performance specifications
Note 6:
The IC is tested in a feedback loop that adjusts VFB to achieve a from 0°C to 85°C. Specifications over the –40°C to 85°C operating specified error amplifier output voltage. junction temperature range are assured by design, characterization and
Note 7:
Guaranteed by design, not subject to test. correlation with statistical process controls. The LTC3862I is guaranteed
Note 8:
The minimum on-time condition is specified for an inductor peak- over the full –40°C to 125°C operating junction temperature range and to-peak ripple current = 30% (see Minimum On-Time Considerations in the the LTC3862H is guaranteed over the full –40°C to 150°C operating Applications Information section). junction temperature range. High junction temperatures degrade operating lifetimes. Operating lifetime is derated at junction temperatures greater
Note 9:
The maximum duty cycle limit is derived from an internal than 125°C. clock that runs at 12x the programmed switching frequency. See the Applications Information for additional information. 3862fc 4 For more information www.linear.com/LTC3862 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts