LTC2931 Linear Technology, LTC2931 Datasheet
LTC2931
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LTC2931 Summary of contents
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... V a weak internal pull-up and may be externally pulled user defi ned voltage. The 52μA supply current makes the LTC2931 ideal for power conscious systems and it may be confi gured to monitor fewer than six inputs. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ...
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... VREF V4 Input Current (–ADJ Mode) ..............................–1mA RST , WDO, COMP1-6 Currents ...........................±10mA Operating Temperature Range LTC2931C ................................................ 0°C to 70°C LTC2931I.............................................. –40°C to 85°C LTC2931H .......................................... –40°C to 125°C Storage Temperature Range ................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) .................. 300°C ...
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... Note 5: The output pins RST, WDO, and COMP pull-ups typically 6μA. However, external pull-up resistors may be used when faster rise times are required or for LTC2931 MIN TYP MAX UNITS ● 1.192 1 ...
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... LTC2931 TIMING DIAGRAMS t RST RST WDI WDO www.DataSheet4U.com 4 V Monitor Timing RST t UV RST COMP n Watchdog Timing < t RST 2931 RST RST t WD 2931 TD2 2931fb ...
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... 10k PULL-UP FROM RST 100 (V) RTX 2931 G07 LTC2931 V vs Temperature REF 1.228 1.222 1.216 1.210 1.204 1.198 1.192 75 100 125 –50 25 –25 0 TEMPERATURE (°C) 2931 G02 Transient Duration vs Comparator Overdrive (V1,V2) ...
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... LTC2931 TYPICAL PERFORMANCE CHARACTERISTICS Reset Timeout Period vs Temperature 1500pF RT (SILVER MICA –50 – 100 TEMPERATURE ( Supply Voltage SINK (RST, WDO, COMP ) 0. 0. www.DataSheet4U.com (V) COMP ...
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... All status outputs are weakly pulled up to V2. COMP4 (Pin 17): Comparator Output 4. Real-time logic output with weak 6μA pull-up to V2. Pulls high when V4 is above its reset threshold. May be pulled greater than V2 using external pull-up. Leave open if unused. LTC2931 2931fb 7 ...
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... LTC2931 PIN FUNCTIONS COMP2 (Pin 18): Comparator Output 2. Real-time logic output with weak 6μA pull-up to V2. Pulls high when V2 is above its reset threshold. May be pulled greater than V2 using external pull-up. Leave open if unused. V6 (Pin 19): Adjustable Voltage Input 6. High impedance comparator input with 0.5V typical threshold. See Applications Information for details ...
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... APPLICATIONS INFORMATION Supply Monitoring The LTC2931 is a low power, high accuracy confi gurable six supply monitoring circuit with six real-time monitor outputs, a common reset output and a watchdog timer. External capacitors set the reset and watchdog timeout periods. An external resistive divider between VREF , VPG and GND selects possible input voltage monitor combinations ...
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... TRIP –2 –1.87 187 –5 –4.64 464 –5.2 –4.87 487 –10 –9.31 931 –12 –11.30 1130 R3 = 0.5V • LTC2931 VREF TRIP Figure 4. Setting the Negative Adjustable Trip Point R4 (kΩ) 100 100 100 100 100 100 100 100 ...
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... On power-down, once any of the monitor inputs drops below its threshold, RST is held at a logic low. A logic low www.DataSheet4U.com of 0.4V is guaranteed until both V1 and V2 drop below 1V. If the bandgap reference becomes invalid (V typical), the LTC2931 will enter the 150μs setup period when V rises above 2.4V max. CC Watchdog Timer The watchdog circuit monitors a microprocessor’ ...
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... LTC2950-1 brings the RUN pin of the LTM4600 high. Subsequently, the LTM4600 generates a 5V output which applies power to each of the 4 DC/DC converters. The LTC2931 is confi gured to mode 13 (see Table 1). When the threshold is reached on V1, COMP1 pulls high. COMP1 then enables the 3.3V converter fi rst. When the threshold is reached on V2, COMP2 pulls high and enables the 1 ...
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... RST 100k 121k 1% 1% VREF R1 16. 86.6k 1% LTC2931 10k 10k 12V SUPPLY STATUS COMP1 COMP2 COMP3 COMP4 COMP5 COMP6 LTC2931 WDO VPG CRT CWT WDI GND 4.7nF t = 9.4ms RST 5V 3.3V 1.8V SYSTEM LOGIC –5.2V 2.5V DONE 2931 F06 2931fb 13 ...
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... LTC2931 APPLICATIONS INFORMATION 2V/DIV www.DataSheet4U.com Figure 7. Five Supply Power-Up Sequencing (Based on Circuit in Figure 6) 14 10ms/DIV PB 5V 3.3V 2.5V 1.8V –5.2V DONE RST 2931 FO7 2931fb ...
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... LTC DWG # 05-08-1650) 1.05 ±0.10 4.50 ±0.10 0.65 BSC 4.30 – 4.50** (.169 – .177) 0.25 REF 0° – 8° 0.65 0.50 – 0.75 (.0256) BSC (.020 – .030) MILLIMETERS (INCHES) LTC2931 6.40 – 6.60* (.252 – .260 6.40 (.252) BSC 1.10 (.0433) MAX 0.05 – ...
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... Single/Dual/Quad UV and OV Voltage Monitors LTC2915-LTC2918 Single Supply Monitor with 27 Pin-Selectable Thresholds LTC2928 Quad Power Supply Sequencer and Supervisor 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● 0.1μF LTC2931 VREF R1 100k 59k 1% 1% ...