Datasheet LT3641 (Analog Devices) - 4

LT3641
The ELECTRICAL CHARACTERISTICS
l
denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at TA = 25°C. VIN = 12V, VIN2 = 3.3V, EN/UVLO = 12V, EN2 = 3.3V, unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS
SS1, SS2 Charge Current SS1 = 0.5V, SS2 = 0.5V 1.3 2.0 2.7 μA SS1 to FB1 Offset Voltage SS1 = 0.6V 5 30 mV SS2 to FB2 Offset Voltage SS2 = 0.3V 5 30 mV RST1 Threshold as Percentage of VFB1 l 90 92 94 % RST2 Threshold as Percentage of VFB1 l 88 91 94 % Undervoltage to RST Assert Time 20 μs RST1, RST2, WDO Pull-Up Current RST1, RST2, WDO = 0V 5 15 30 μA RST1, RST2, WDO Output Voltage IRST1, IRST2, IWDO = 2mA 150 250 mV RST1, RST2 Timeout Period (tRST) CPOR = 220pF l 8 9.5 11 ms Watchdog Start Delay Time (tDLY) CWDT = 820pF 14 16 18 ms Watchdog Upper Boundary (tWDU) CWDT = 820pF l 27 32 35 ms Watchdog Lower Boundary (tWDL) CWDT = 820pF l 1.68 2 2.2 ms WDI Pull-Up Current WDI = 1.2V 4 μA WDI Voltage Threshold 0.55 0.85 1.15 V WDI Low Minimum Pulse Width 300 ns WDI High Minimum Pulse Width 300 ns WDE Pull-Down Current WDE = 2V 1 μA WDE Threshold l 0.5 0.7 0.9 V
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
The oscillator cycle is extended when DA current exceeds its limit. may cause permanent damage to the device. Exposure to any Absolute DA current limit is fl at over duty cycle. Maximum Rating condition for extended periods may affect device
Note 5:
If the SW2 NMOS current exceeds its limit at the start of an reliability and lifetime. oscillator cycle, the PMOS will not be turned on in the cycle.
Note 2:
The LT3641E is guaranteed to meet performance specifi cations
Note 6:
The QFN switch RDS(ON) is guaranteed by correlation to wafer level from 0°C to 125°C junction temperature. Specifi cations over the –40°C measurement. to 125°C operating junction temperature range are assured by design,
Note 7:
Absolute Maximum Voltage at VIN and EN/UVLO pins is 55V for characterization and correlation with statistical process controls. The nonrepetitive 1 second transients, and 42V for continuous operation. LT3641I is guaranteed and tested over the full –40°C to 125°C operating
Note 8:
This IC includes overtemperature protection that is intended junction temperature range. The LT3641H is guaranteed and tested over to protect the device during momentary overload conditions. Junction the full –40°C to 150°C operating junction temperature range. temperature will exceed the maximum operating junction temperature
Note 3:
SW1, SW2 current limit is guaranteed by design and/or correlation when overtemperature protection is active. Continuous operation above to static test. Slope compensation reduces current limit at higher duty the specifi ed maximum operating junction temperature may impair device cycle. reliability. 3641fa 4