Datasheet LTC3835 (Analog Devices) - 4

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ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 12V, VRUN = 5V unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
TG/BG t1D Top Gate Off to Bottom Gate On Delay CLOAD = 3300pF 70 ns Synchronous Switch-On Delay Time BG/TG t2D Bottom Gate Off to Top Gate On Delay CLOAD = 3300pF 70 ns Top Switch-On Delay Time tON(MIN) Minimum On-Time (Note 7) 180 ns
INTVCC Linear Regulator
VINTVCCVIN Internal VCC Voltage 8.5V < VIN < 30V, VEXTVCC = 0V 5 5.25 5.5 V VLDOVIN INTVCC Load Regulation ICC = 0mA to 20mA, VEXTVCC = 0V 0.2 1.0 % VINTVCCEXT Internal VCC Voltage VEXTVCC = 8.5V 7.2 7.5 7.8 V VLDOEXT INTVCC Load Regulation ICC = 0mA to 20mA, VEXTVCC = 8.5V 0.2 1.0 % VEXTVCC EXTVCC Switchover Voltage EXTVCC Ramping Positive 4.5 4.7 V VLDOHYS EXTVCC Hysteresis 0.2 V
Oscillator and Phase-Locked Loop
fNOM Nominal Frequency VPLLLPF = No Connect 360 400 440 kHz fLOW Lowest Frequency VPLLLPF = 0V 220 250 280 kHz fHIGH Highest Frequency VPLLLPF = INTVCC 475 530 580 kHz fSYNCMIN Minimum Synchronizable Frequency PLLIN/MODE = External Clock; VPLLLPF = 0V 115 140 kHz fSYNCMAX Maximum Synchronizable Frequency PLLIN/MODE = External Clock; VPLLLPF = 2V 650 800 kHz IPLLLPF Phase Detector Output Current Sinking Capability fPLLIN/MODE < fOSC –5 µA Sourcing Capability fPLLIN/MODE > fOSC 5 µA
PGOOD Output
VPGL PGOOD Voltage Low IPGOOD = 2mA 0.1 0.3 V IPGOOD PGOOD Leakage Current VPGOOD = 5V ±1 µA VPG PGOOD Trip Level VFB with Respect to Set Regulated Voltage VFB Ramping Negative –12 –10 –8 % VFB Ramping Positive 8 10 12 %
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
The LTC3835 is tested in a feedback loop that servos VITH to a may cause permanent damage to the device. Exposure to any Absolute specified voltage and measures the resultant VFB. Maximum Rating condition for extended periods may affect device
Note 5:
Dynamic supply current is higher due to the gate charge being reliability and lifetime. delivered at the switching frequency. See Applications Information.
Note 2:
The LTC3835E is guaranteed to meet performance specifications
Note 6:
Rise and fall times are measured using 10% and 90% levels. from 0°C to 85°C. Specifications over the –40°C to 85°C operating Delay times are measured using 50% levels. temperature range are assured by design, characterization and correlation
Note 7:
The minimum on-time condition is specified for an inductor with statistical process controls. The LTC3835I is guaranteed to meet peak-to-peak ripple current ≥40% of I performance specifications over the full –40°C to 85°C operating MAX (see Minimum On-Time Considerations in the Applications Information section). temperature range.
Note 3:
TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formulas: LTC3835FE: TJ = TA + (PD • 35°C/W) LTC3835UFD: TJ = TA + (PD • 37°C/W) Rev. F 4 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts