Datasheet LTC3786 (Analog Devices) - 4

LTC3786 ELECTRICAL CHARACTERISTICS
The
l
denotes the specifications which apply over the full operating junction temperature range, otherwise specifications are at TA = 25°C. VBIAS = 12V, unless otherwise noted (Note 2). SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS INTVCC Linear Regulator
VINTVCC(VIN) Internal VCC Voltage 6V < VBIAS < 38V 5.2 5.4 5.6 V VLDO INT INTVCC Load Regulation ICC = 0mA to 50mA 0.5 2 %
Oscillator and Phase-Locked Loop
fPROG Programmable Frequency RFREQ = 25k 105 kHz RFREQ = 60k 335 400 465 kHz RFREQ = 100k 760 kHz fLOW Lowest Fixed Frequency VFREQ = 0V 320 350 380 kHz fHIGH Highest Fixed Frequency VFREQ = INTVCC 485 535 585 kHz fSYNC Synchronizable Frequency PLLIN/MODE = External Clock l 75 850 kHz
PGOOD Output
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 –12 –10 –8 % Hysteresis 2.5 % VFB Ramping Positive 8 10 12 % Hysteresis 2.5 % tPGOOD(DELAY) PGOOD Delay PGOOD Going High to Low 25 µs
BOOST Charge Pump
IBOOST BOOST Charge Pump Available VSW = 12V; VBOOST – VSW = 4.5V; 85 µA Output Current FREQ = 0V, Forced Continuous or Pulse-Skipping Mode
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings where θJA = 68°C for the QFN package and θJA = 40°C for the MSOP may cause permanent damage to the device. Exposure to any Absolute package. Maximum Rating condition for extended periods may affect device
Note 3:
This IC includes overtemperature protection that is intended to reliability and lifetime. protect the device during momentary overload conditions. The maximum
Note 2:
The LTC3786 is tested under pulsed load conditions such that rated junction temperature will be exceeded when this protection is active. TJ ≈ TA. The LTC3786E is guaranteed to meet specifications from Continuous operation above the specified absolute maximum operating 0°C to 85°C junction temperature. Specifications over the –40°C to junction temperature may impair device reliability or permanently damage 125°C operating junction temperature range are assured by design, the device. characterization and correlation with statistical process controls. The
Note 4:
The LTC3786 is tested in a feedback loop that servos VFB to the LTC3786I is guaranteed over the –40°C to 125°C operating junction output of the error amplifier while maintaining ITH at the midpoint of the temperature range. The LTC3786H is guaranteed over the –40°C to 150°C current limit range. operating temperature range. High temperatures degrade operating
Note 5:
Dynamic supply current is higher due to the gate charge being lifetimes; operating lifetime is derated for junction temperatures greater delivered at the switching frequency. than 125ºC. Note that the maximum ambient temperature consistent with these specifications is determined by specific operating conditions
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay in conjunction with board layout, the rated package thermal impedance times are measured using 50% levels. and other environmental factors. The junction temperature (T
Note 7:
see Minimum On-Time Considerations in the Applications J in °C) is calculated from the ambient temperature (T Information section. A in °C) and power dissipation (PD in Watts) according to the formula: TJ = TA + (PD • θJA) 3786fc 4 For more information www.linear.com/LTC3786