LTC4218 Linear Technology, LTC4218 Datasheet
LTC4218
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LTC4218 Summary of contents
Page 1
... An internal high side switch driver controls the gate of an external N-channel MOSFET for supply voltages from 2.9V to 26.5V. A dedicated 12V version (LTC4218-12) contains preset 12V specifi c thresholds, while the standard LTC4218 allows adjustable thresholds. The LTC4218 provides an accurate (5%) current limit with current foldback limiting ...
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... For more information on lead free part marking, go to: For more information on tape and reel specifi cations, go to: 2 INTV GATE (Note 3) ........................................ –0.3V to 35V Operating Temperature Range LTC4218C ................................................ 0°C to 70°C – 10V or –0. LTC4218I .............................................–40°C to 85°C DD – 10V or –0. Storage Temperature Range ...
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... GATE – GATE SOURCE Gate Drive On GATE Fast Turn Off 18V, GATE V =12V SOURCE Gate Drive Off 18V, GATE V =12V SOURCE V = 1.2V, LTC4218 Only IN LTC4218-12 Only V Rising IN V Falling 12V, LTC4218-12 Only SOURCE GATE 12V, LTC4218 Only SOURCE GATE ...
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... LTC4218 www.DataSheet4U.com ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER I TIMER Pin Current Ratio I TIMER(RATIO) I TIMER(UP Fullscale Output Current MON(FS) MON I I Pin Offset Current MON(OFF) MON G I Pin Gain IMON MON AC Characteristics t Input High (OV), Input Low (UV) to GATE ...
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... TEMPERATURE (°C) 4218 G04 Current Limit Adjustment 1.2 1k 10k 100k R (Ω) SET 4218 G07 LTC4218 T = 25° 12V unless otherwise noted Low-High Threshold vs Temperature 1.234 1.232 = 3.3V DD 1.230 1.228 1.226 –12 –14 –50 – TEMPERATURE (° ...
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... LTC4218 www.DataSheet4U.com TYPICAL PERFORMANCE CHARACTERISTICS GATE Pull-Up Current vs Temperature –26.0 –25.5 –25.0 –24.5 –24.0 –50 – TEMPERATURE (°C) Gate Drive vs Temperature 6.15 6.14 6.13 6.12 6.11 6.10 –50 – TEMPERATURE (° Sense MON 100 SENSE VOLTAGE (mV) 6 Gate Pull-Up Current ...
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... NC: No Connection OV: Overvoltage Comparator Input. Connect this pin to an external resistive divider from V (adjustable version). The LTC4218-12 version uses a fi xed internal divider with optional external adjustment for 12V operation. Open the pin if the LTC4218-12 thresholds are desired. If the voltage at this pin rises above 1.235V, an overvoltage is detected and the switch turns off ...
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... LTC4218 www.DataSheet4U.com FUNCTIONAL DIAGRAM + SENSE V DD +– 1.235V 140k * – UV 20k * + 0.62V – 224k * + OV 20k * – 1.235V – UVLO1 + 2.73V TIMER * DFN ONLY 8 – SENSE GATE – CHARGE PUMP CS AND GATE DRIVER + CM UV LOGIC RST + 0.2V TM1 – TM2 – ...
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... The fi xed 12V version, LTC4218-12, uses two separate internal dividers from V This version also features a divider from the SOURCE pin to drive the FB pin. The LTC4218-12 is available in a DFN package while the LTC4218 (adjustable version SSOP package. The output voltage is monitored using the FB pin and the PG comparator to determine if the power is available for the load ...
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... This generates a 25μs power- on-reset pulse which clears the logic’s fault register and initializes internal latches. After the power-on-reset pulse, the LTC4218 will go through the following sequence. First, the UV and OV pins must indicate that the input power is within the acceptable range. ...
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... Tying the FLT pin to the UV pin allows the part to self-clear the fault and turn the MOSFET on as soon as TIMER pin has ramped below 0.2V. In this auto retry mode, the LTC4218 CC repeatedly tries to turn on after an overcurrent at a period determined by the capacitor on the TIMER pin ...
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... UV SENSE the PG comparator drives low. 12V Fixed Version In the LTC4218-12, the UV, OV and FB pins are driven by internal dividers which may need to be fi ltered to prevent false faults. By placing a bypass capacitor on these pins the faults are delayed by the RC time constant. Use the R value from the electrical table for this calculation. In cases where the fi ...
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... APPLICATIONS INFORMATION LTC4218- 4218 F04 Figure 4. Adjusting LTC4218-12 Thresholds In this same fi gure the OV threshold is lowered from 15.05V to 13.5V. Decreasing the OV threshold requires adding a resistor between calculated as follows: ( ⎛ • NEW OLD ⎜ ⎜ SHUNT ⎜ ...
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... V = Additional Applications A The LTC4218 has a wide operating range from 2. 26.5V. The UV, OV and PG thresholds are set with a few resistors. All other functions are independent of supply voltage. The last page includes a 24V application with a UV threshold of 19.8V threshold of 28.3V and a PG threshold of 20 ...
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... TYP .016 – .050 .008 – .012 (0.406 – 1.270) (0.203 – 0.305) TYP INCHES (MILLIMETERS) LTC4218 R = 0.115 TYP 0.20 TYP 3.00 ±0.10 (2 SIDES) 1.65 ± 0.10 (2 SIDES) 8 0.25 ± 0.05 0.75 ±0.05 0.50 BSC 4.40 ± ...
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... Si7880ADP * 10Ω – SENSE GATE SOURCE + SENSE 215k FLT LTC4218GN 4.32k OV 10k PG TIMER 0.1μF INTV I CC MON GND 0.1μF COMMENTS Operates from 3V to 12V, Supports –12V, SSOP-24 Operates from 2.7V to 12V, SO-8 Operates from 3V to 16.5V, Overvoltage Protection up to 33V, SSOP-16 Operates from 3V to 12V, Power Sequencing, SO-8 or SO-14 Operates from 2 ...