lt2940 Linear Technology Corporation, lt2940 Datasheet
lt2940
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lt2940 Summary of contents
Page 1
... Bidirectional high side currents and bipolar voltage differences are correctly handled by the four-quadrant multiplier and push-pull output stage, which allows the LT2940 to indicate forward and reverse power fl ow. An integrated comparator with inverting and noninvert- ing open-collector outputs makes the LT2940 a complete power level monitor ...
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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 (Notes 1, 2) Operating Temperature Range LT2940C ................................................... 0°C to 70°C LT2940I ................................................–40°C to 85°C Storage Temperature Range ...................–65°C to 150° 16V Lead Temperature (Soldering, 10 sec) CC MSOP Package ................................................. 300° ...
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... CC PMON V = –9V 225mV 9V –225mV ≥ 12V, V ≥ 4V, and CC PMON V = –9V 225mV 9V –225mV V I LT2940 ≤ 80V, unless otherwise specifi ed. CC MIN TYP MAX UNITS 3 2.3 2.5 2 100 mV l –0.1 V – 3 ...
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... IMON 12V < V < 30V, I < 0μA CC PMON V ≥ 30V, I < 0μA CC PMON |V | ≤ 200mV, 25°C ≤ T ≤ 85° ≤ 200mV, LT2940C ≤ 200mV, LT2940I I 200mV < ≤ 225mV • ±200mV IMON IMON + CMP Rising + CMP Falling 1V ≤ ...
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... LATCH V = 80V LATCH Note 3: The LT2940 may safely drive its own PMON and IMON output voltages above the absolute maximum ratings. Do not apply any external source that drives the voltage above absolute maximum. Note 4: Full-scale equals ±200μA. + Note 5: V and V operating range specifi ...
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... LT2940 TYPICAL PERFORMANCE CHARACTERISTICS PMON Current vs Power Sense Product 1500 V ≥ 15V • 1000 500 PMON 0.5V PMON –500 PMON –1000 –1500 –4 – • IMON Current vs Current Sense Voltage 300 – – ...
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... Open Collector Current vs Open Collector Voltage 25 T I-TO-V A OUTPUT PULLING LOW AMP OUTPUT 100k 1M 10M 0.1 2940 G17 LT2940 BIAS PMON DC = 25° ± 0mV ±200mV 0V 10k 100k 1M 10M ...
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... LT2940 PIN FUNCTIONS CMPOUT (Pin 1): Inverting Open-Collector Comparator Output. When the LATCH pin’s state does not override the comparator, CMPOUT pulls low when CMP + pull-down shuts off when CMP < 1.21V when the LATCH pin is low. CMPOUT may be pulled up to 36V maximum ...
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... TEST CIRCUITS Resistor on DC Bias PMON OR IMON 2940 TC01 – 4-QUADRANT MULTIPLIER + D 1.24V – CLR LE UVLC LATCHLO LATCHHI V OUT LT2940 μ 1000 IMON V + IMON 5 – μ 500 PMON PMON 4 – CMPOUT 1 Q CMPOUT 2 2940 BD I-to-V Amplifi er 12V ...
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... Multiplier Operation The LT2940 power and current monitor contains a four- quadrant multiplier designed to measure the voltage and current of a generator or load, and output signals propor- tional to power and current. Figure 1 shows a signal path block diagram. The operating ranges of the voltage sense and current sense inputs are included. To simplify the notation, the differential input voltages are defi ...
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... APPLICATIONS INFORMATION Table 1. LT2940 Essential Operating Parameters to Achieve Specifi ed Accuracy (V SENSE PARA- INPUT PIN VOLTAGE METER PINS LIMIT + – Voltage – 12V < 18V at V ≥ 30V CC + – Current 80V* + – ...
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... • R IMON IMON IMON and the fi nal end-to-end scaling is given by • G • k • R IMON IN IMON I IMON 12 LOAD LT2940 + I IMON IMON 5 – R IMON + I PMON PMON 4 – R PMON 2940 F03 Accuracy The principal accuracies of the power and current monitor ...
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... I = PMON line (A) on Figure 5. Spans of voltage or current up to 4:1 naturally fi t into the operating range of the LT2940. Special constant-power applications are the same types of circuits (level measuring, servos) with additional restric- tions. If operating within the guaranteed accuracy region ...
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... Design in this case requires mapping the LT2940’s sense ranges to cover the maximum voltage and the maximum current, while considering whether the power represented is at, above, or below full-scale I ...
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... MAX 10% 1/8W 36V MAX + – R14 LATCH 20k CMPOUT LT2940 CMPOUT + CMP PMON GND IMON R3 R4 6.19k 13. SCALE = 10 PMON V 40W FULL-SCALE LT2940 + – and I , which extends to 80V independent LOAD R2 140k + V R1 10.0k – V 2940 F07 Voltage CC pin 2940f 15 ...
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... TO 80V 100V (MAX) OVP OVERPOWER (OVP) GOES HIGH WHEN SUPPLY POWER > 120W INPUT + 9.5V TO 14.5V C1 100μF 25V Q3 2N3906 2940 TA03 * SEVEN 50Ω, 5W RESISTORS IN PARALLEL. 16 120W Supply Monitor Includes I of LT2940 R12 50mΩ 5mA 3.9k 1W MAX 1/8W V LOGIC + – I ...
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... CMPOUT CMP 1N4148 PMON GND IMON 233 C4 R4 200mΩ 4.7μF 68k 2ms OFF LT2940 HEATSINK Q = 30W TIP129 R9 Q3 10k D44VH11 R10 100Ω 10A/V R11 100mΩ HEATSINK MUR1100E 12V 50Ω 10W 25W Q2 C2 ...
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... TEMP R10 ADJ 500Ω *THERMAL SHUTDOWN; COUPLE TO Q1’s HEAT SINK 32V, 8W Load 12V R S 200mΩ 12V R3 2k – 30k LT2940 + LM334 10k – V – V IMON GND PMON D1 1N457 200μA/A C4 100nF OUTPUT 2940 TA06 ...
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... LATCH V R1 CMPOUT 10k 1% – CMPOUT V R2B + CMP 10k IMON GND PMON 1% V PMON 100W 33nF 12.4k 4.99k 100nF LT2940 + LOAD + CHARGER CYCLON 2V, 4.5AH DT CELL* Q1 2N3904 12V + Q2 OA 2N3904 – 200Ω 200mΩ – LOAD – ...
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... HYST R9 1M REF – V GND Secondary-Side AC Circuit Breaker T1 12.6VAC SECONDARY R9 10k R S 200mΩ – LATCH + LT2940 – CMPOUT IMON Q6 Q7 CMPOUT + CMP GND PMON Q8 1A 1.25A 15k 15k TRIP LOAD R2 120k C7 R1A 10nF 30k ...
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... T1 500 4.99Ω 4.99Ω – PMON LT2940 IMON – GND 2940 TA13 LT2940 LOAD – 30k = 200mΩ – 120k R5 15k R2A 200Ω 10k R1A • ...
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... LT2940 PACKAGE DESCRIPTION 3.50 ±0.05 2.10 ±0.05 0.25 ± 0.05 RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED PIN 1 TOP MARK (SEE NOTE 6) 0.200 REF NOTE: 1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH ...
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... TYP 0.53 0.152 (.021 .006) 1.10 (.043) DETAIL “A” MAX SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP LT2940 4.039 0.102 (.159 .004) (NOTE 3) 0.406 0.076 (.016 .003 REF 3.00 0.102 (.118 .004) (NOTE 0.86 (.034) REF 0 ...
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... Integrating Watt-Hour Meter R S 100mΩ 5V C17 0.47μF + – – V – + LT2940 CMP + LTC6702 CMPOUT – LATCH + CMPOUT GND PMON GND IMON 2.2μF 2N7002 COMMENTS 2.7V to 12V Supply Voltage, 170μA Supply Current 4. Supply Voltage, 500kHz 3dB-Error 60V 100V, Gain Confi ...