Datasheet LT8641 (Analog Devices) - 3

link to page 13 link to page 13 LT8641
ELECTRICAL CHARACTERISTICS The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. PARAMETER CONDITIONS MIN TYP MAX UNITS
Feedback Pin Input Current VFB = 1V –20 20 nA BIAS Pin Current Consumption VBIAS = 3.3V, ILOAD = 1A, 2MHz 9 mA Minimum On-Time ILOAD = 1.5A, SYNC = 0V l 35 50 ns ILOAD = 1.5A, SYNC = 2V l 35 50 ns Minimum Off-Time 80 110 ns Oscillator Frequency RT = 221k, ILOAD = 1A l 180 210 240 kHz RT = 60.4k, ILOAD = 1A l 665 700 735 kHz RT = 18.2k, ILOAD = 1A l 1.85 2.00 2.15 MHz Top Power NMOS On-Resistance ISW = 1A 105 mΩ Top Power NMOS Current Limit l 6.2 8.2 9.9 A Bottom Power NMOS On-Resistance VINTVCC = 3.4V, ISW = 1A 55 mΩ Bottom Power NMOS Current Limit VINTVCC = 3.4V 4.8 5.8 7.25 A SW Leakage Current VIN = 42V, VSW = 0V, 42V –15 15 µA EN/UV Pin Threshold EN/UV Rising l 0.95 1.01 1.07 V EN/UV Pin Hysteresis 45 mV EN/UV Pin Current VEN/UV = 2V –20 20 nA PG Upper Threshold Offset from VFB VFB Falling l 5 7.5 10.25 % PG Lower Threshold Offset from VFB VFB Rising l –5.25 –8 –10.75 % PG Hysteresis 0.4 % PG Leakage VPG = 3.3V –40 40 nA PG Pull-Down Resistance VPG = 0.1V l 750 2000 Ω SYNC/MODE Threshold SYNC/MODE DC and Clock Low Level Voltage 0.7 0.9 V SYNC/MODE Clock High Level Voltage 1.2 1.4 V SYNC/MODE DC High Level Voltage 2.3 2.6 2.9 V Spread Spectrum Modulation RT = 60.4k, VSYNC = 3.3V 22 % Frequency Range Spread Spectrum Modulation Frequency VSYNC = 3.3V 2.5 kHz TR/SS Source Current l 1.2 1.9 2.6 µA TR/SS Pull-Down Resistance Fault Condition, TR/SS = 0.1V 220 Ω
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings The junction temperature (TJ, in °C) is calculated from the ambient may cause permanent damage to the device. Exposure to any Absolute temperature (TA in °C) and power dissipation (PD, in Watts) according to Maximum Rating condition for extended periods may affect device the formula: reliability and lifetime. TJ = TA + (PD • θJA)
Note 2:
The LT8641E is guaranteed to meet performance specifications where θJA (in °C/W) is the package thermal impedance. from 0°C to 125°C junction temperature. Specifications over the –40°C
Note 3:
θ values determined per JEDEC 51-7, 51-12. See Applications to 125°C operating junction temperature range are assured by design, Information section for information on improving the thermal resistance characterization, and correlation with statistical process controls. The and for actual temperature measurements of a demo board in typical LT8641I is guaranteed over the full –40°C to 125°C operating junction operating conditions. temperature range. The LT8641H is guaranteed over the full –40°C to
Note 4:
This IC includes overtemperature protection that is intended to 150°C operating junction temperature range. High junction temperatures protect the device during overload conditions. Junction temperature will degrade operating lifetimes. Operating lifetime is derated at junction exceed 150°C when overtemperature protection is active. Continuous temperatures greater than 125°C. operation above the specified maximum operating junction temperature will reduce lifetime. Rev A For more information www.analog.com 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Applications Related Parts