Datasheet LTC3777 (Analog Devices) - 5

LTC3777
ELECTRICAL CHARACTERISTICS The
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denotes the specifications which apply over the specified operating junction temperature range, otherwise specifications are at TA = 25°C (Note 2). BVIN = 12V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Switching Bias Supply
VBVIN Input Voltage Operating Range 4 150 V VBVOUT Output Voltage Operating Range (Note 9) 0.8 VIN V BUVLO BVIN Undervoltage Lockout BVIN Rising 3.5 3.8 4.15 V BVIN Falling 3.3 3.6 3.95 V Hysteresis 250 mV IQB DC Supply Current (Note 6) Active Mode 150 350 µA Sleep Mode No Load 12 22 µA Shutdown Mode BVRUN = 0V 1.4 6 µA VBRUN BRUN Pin Threshold BRUN Rising 1.1 1.2 1.3 V BRUN Falling 0.99 1.09 1.19 V Hysteresis 110 mV IBRUN BRUN Pin Leakage Current BRUN = 1.3V (Note 9) –10 0 10 nA VBOV BOV Pin Threshold BOV Rising 1.1 1.2 1.3 V BOV Falling 0.99 1.09 1.19 V Hysteresis 110 mV
Output Supply (BVFB)
VBVFB Feedback Comparator Threshold BVFB Rising 0.786 0.800 0.814 V VBVFBH Feedback Comparator Hysteresis BVFB Falling (Note 9) 3 5 9 mV IBVFB Feedback Pin Current BVFB = 1V (Note 9) –10 0 10 nA
Operation
IPEAKB Peak Current Comparator Threshold BISET Floating 170 240 310 mA BISET Shorted to GND 17 25 33 mA ILBSWB Switch Pin Leakage Current BVIN = 150V, BSW = 0V 0.1 1 μA tINT(SS)B Internal Soft-Start Time (Note 9) 1 ms
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings Continuous operation above the specified absolute maximum operating may cause permanent damage to the device. Exposure to any Absolute junction temperature may impair device reliability or permanently damage Maximum Rating condition for extended periods may affect device the device. reliability and lifetime.
Note 4:
When biased from an auxiliary supply through the EXTVCC pin, the
Note 2:
The LTC3777 is tested under pulsed load conditions such that TJ LTC3777 can operate from a VIN voltage lower than 4.5V. Otherwise the ≈ TA. The LTC3777E is guaranteed to meet performance specifications minimum VIN operational voltage is 4.5V after startup. from 0°C to 85°C junction temperature. Specifications over the –40°C
Note 5:
The LTC3777 is tested in a feedback loop that servos VITH to a to 125°C operating junction temperature range are assured by design, specified voltage and measures the resultant VFB. characterization and correlation with statistical process controls. The
Note 6:
Dynamic supply current is higher due to the gate charge being LTC3777I is guaranteed over the full –40°C to 125°C operating junction delivered at the switching frequency. See Applications information. temperature range. Note that the maximum ambient temperature
Note 7:
Rise and fall times are measured using 10% and 90% levels. consistent with these specifications is determined by specific operating Delay times are measured using 50% levels. conditions in conjunction with board layout, the rated package thermal
Note 8:
Do not apply a voltage or current source to these pins. They must impedance and other environmental factors. The junction temperature TJ be connected to capacitive loads only, otherwise permanent damage may is calculated from the ambient temperature TA and power dissipation PD occur. These pins are rated for an absolute maximum voltage of –0.3V according to the formula: to 11V. TJ = TA + (PD • θJA), where
Note 9:
Guaranteed by design and wafer level measurements. θJA = 36°C/W for the e-LQFP package.
Note 3:
This IC includes over temperature protection that is intended to protect the device during momentary overload conditions. The maximum rated junction temperature will be exceeded when this protection is active. Rev A For more information www.analog.com 5 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS – SWITCHING BIAS SUPPLY PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS