LTC1921 Linear Technology, LTC1921 Datasheet
LTC1921
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LTC1921 Summary of contents
Page 1
... Overvoltage and undervoltage detectors ignore fast supply transients, eliminating false detection. The LTC1921 operates from –10V to –80V with a typical power dissipation of less than 10mW. The LTC1921 is available in an 8-pin MSOP package. , LTC and LT are registered trademarks of Linear Technology Corporation. 47k 47k R2 ...
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... OUT A, OUT B, OUT F Pins ......................... 0.3V to – 8V Maximum Junction Temperature ......................... 150 C Operating Temperature Range LTC1921CMS8 ........................................ LTC1921IMS8 .................................... – Storage Temperature Range ................. – 150 C Lead Temperature (Soldering, 10 sec).................. 300 C ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T FUSE B = –48V, unless otherwise noted. ...
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... TEMPERATURE ( C) Fuse Window Negative Threshold vs Temperature –2.0 –2.2 –2.4 –2.6 –2.8 –3.0 –3.2 90 –50 –30 – TEMPERATURE ( C) LTC1921 Undervoltage Threshold vs Temperature –37.5 –37.7 –37.9 –38.1 –38.3 –38.5 –38.7 –38.9 –39.1 –39.3 –39.5 –50 –30 – TEMPERATURE ( C) ...
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... LTC1921 W U TYPICAL PERFOR A CE CHARACTERISTICS Undervoltage Response Time 10000 1000 100 4.5 4.6 4.7 4.8 SUPPLY STEP FROM UNDERVOLTAGE RECOVERY THRESHOLD ( CTIO S V (Pin 1): Supply to be Monitored. The voltage at this pin A is compared to the valid supply voltage window and the result is output at OUT A (Pin 5) ...
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... W BLOCK DIAGRA REGULATOR RTN 3 REF FUSE A FUSE B B LTC1921 + – + – OUT F – + – + – + – 5 OUT A + – OUT B – 1921 BD 1921i 5 ...
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... If both supplies are active and their magnitude falls below 13V only one supply is active and its magnitude falls below 19V, the LTC1921 will lock all outputs into a fault condition by closing all three output switches. This state will be held until one supply magnitude is driven above 19V or both are driven above 13V ...
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... If LEDs are used instead of optocouplers, they should be green since they will be lit when the supplies are within the proper voltage range. The LTC1921 may be connected in such a way various outputs to allow the use of fewer optocouplers or LEDs (Figures 3a and 3b). One and two diode circuits are shown ...
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... OUT B –48V OUT = LOGIC COMMON 1921 F03a Figure 3a. Combined Supply Status 100k 100k MOC207 3 RTN OUT F A COMMON LTC1921 2 FUSE FUSE B OUT A 6 OUT B 48k 1/2W 1921 F03b Figure 3b. All Outputs Combined 5V FUSE STATUS V V SUPPLY STATUS ...
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... U TYPICAL APPLICATIO S LTC1921 1921i 9 ...
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... FUSE A OUT A LOGIC COMMON 7 6 FUSE B OUT B 47k 1/4W 1921 TA04 Single –48V Supply Monitor + LOGIC V 3 47k RTN OUT F A LTC1921 MOC207 2 5 FUSE A OUT A LOGIC COMMON 7 6 FUSE B OUT B 47k 1/4W 1921 TA06 SUPPLY GOOD SUPPLY GOOD 1921i ...
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... BSC 4.88 0.1 DETAIL “A” (.192 .004) 0 – 6 TYP 0.53 0.015 1.10 (.021 .006) (.043) DETAIL “A” MAX SEATING PLANE 0.22 – 0.38 (.009 – .015) LTC1921 0.52 (.206 REF 3.00 0.102 (.118 .004) NOTE 0.86 (.034) REF 0.13 0.05 (.005 .002) 0.65 MSOP (MS8) 1001 ( ...
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... FAX: (408) 434-0507 Voltage and Fuse Monitor with LED Outputs R1 R2 100k 100k 3 RTN OUT LTC1921 2 FUSE FUSE B OUT A 6 OUT 1921 TA03 COMMENTS Active Current Limiting, Supplies from –20V to –80V Fast Active Current Limiting, Supplies from –15V (Floating) ...