Datasheet LTC2950-1, LTC2950-2 (Linear Technology) - 3

LTC2950-1/LTC2950-2
elecTrical characTerisTics The
l
denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 2.7V to 26.4V, unless otherwise noted. (Note 2) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN Supply Voltage Range Steady State Operation l 2.7 26.4 V IIN VIN Supply Current System Power On, VIN = 2.7V to 24V l 6 12 µA VUVL VIN Undervoltage Lockout VIN Falling l 2.2 2.3 2.4 V VUVL(HYST) VIN Undervoltage Lockout 50 300 600 mV Hysteresis
Pushbutton, Enable (PB, EN/EN)
VPB(MIN, MAX) PB Voltage Range Single-Ended l –1 26.4 V IPB PB Input Current 2.5V < VPB < 26.4V l ±1 µA VPB = 1V l –1 –6 –12 µA VPB = 0.6V l –3 –9 –15 µA VPB(VTH) PB Input Threshold PB Falling l 0.6 0.8 1 V VPB(VOC) PB Open Circuit Voltage IPB = –1µA 1 1.6 2 V tEN/EN, Lock Out EN/EN Lock Out Time (Note 5) Enable Released → Enable Asserted l 200 256 325 ms IEN/EN(LKG) EN/EN Leakage Current VEN/ EN = 1V, Sink Current Off l ±0.1 µA VEN/EN(VOL) EN/EN Voltage Output Low IEN/ EN = 3mA l 0.11 0.4 V
Debounce Timing Pins (ONT, OFFT)
IONT, OFFT(PU) ONT/OFFT Pull Up Current VONT, OFFT = 0V l –2.4 –3 –3.6 µA IONT, OFFT(PD) ONT/OFFT Pull Down Current VONT, OFFT = 1.3V l 2.4 3 3.6 µA tDB, On Internal Turn On Debounce Time ONT Pin Float, PB Falling → Enable Asserted l 26 32 41 ms tONT Additional Adjustable Turn On Time CONT = 1500pF l 9 11.5 13.5 ms tDB, Off Internal Turn Off Debounce Time OFFT Pin Float, PB Falling → INT Falling l 26 32 41 ms tOFFT Additional Adjustable Turn Off Time COFFT = 1500pF l 9 11.5 13.5 ms
µP Handshake Pins (INT, KILL)
IINT(LKG) INT Leakage Current VINT = 3V l ±1 µA VINT(VOL) INT Output Voltage Low IINT = 3mA l 0.11 0.4 V VKILL(TH) KILL Input Threshold Voltage KILL Falling l 0.57 0.6 0.63 V VKILL(HYST) KILL Input Threshold Hysteresis 10 30 50 mV IKILL(LKG) KILL Leakage Current VKILL = 0.6V ±0.1 µA tKILL(PW) KILL Minimum Pulse Width l 30 µs tKILL(PD) KILL Propagation Delay KILL Falling → Enable Released l 30 µs tKILL, On Blank KILL Turn On Blanking (Note 3) KILL = Low, Enable Asserted → Enable Released l 400 512 650 ms tKILL, Off Delay KILL Turn Off Delay (Note 4) KILL = High, INT Asserted → Enable Released l 800 1024 1300 ms
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
Note 4:
The KILL turn off delay is the maximum delay from the initiation may cause permanent damage to the device. Exposure to any Absolute of a shutdown sequence (INT falling), to the release of the enable output. Maximum Rating condition for extended periods may affect device If the KILL input switches low at any time during this period, enable is reliability and lifetime. released, thus turning off system power. This time is internally fixed at
Note 2:
All currents into pins are positive; all voltages are referenced to 1024ms. This time delay does not include tDB, OFF or tOFFT. GND unless otherwise noted.
Note 5:
The enable lock out time is designed to allow an application to
Note 3:
The KILL turn on blanking timer period is the waiting period properly power down such that the next power up sequence starts from a immediately after the enable output is asserted. This blanking time allows consistent powered down configuration. PB is ignored during this lock out sufficient time for the DC/DC converter and the µP to perform power up time. This time delay does not include tDB, ON or tONT. tasks. The KILL and PB inputs are ignored during this period. If KILL remains low at the end of this time period, the enable output is released, thus turning off system power. This time delay does not include tDB, ON or tONT. 295012fd 3 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Timing Diagrams Applications Information Typical Applications Package Description Revision History Typical Application Related Parts