Datasheet LT1013, LT1014 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | Dual/Quad Precision Op Amps |
| Pages / Page | 26 / 10 — applicaTions inForMaTion. Comparator Applications. Voltage Follower with … |
| File Format / Size | PDF / 573 Kb |
| Document Language | English |
applicaTions inForMaTion. Comparator Applications. Voltage Follower with Input Exceeding the Negative Common Mode Range
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Text Version of Document
LT1013/LT1014
applicaTions inForMaTion
b) When the input is more than 400mV below ground (at D when A’s output is negative saturation. B’s and C’s 25°C), the input stage saturates (transistors Q3 and Q4) outputs have no effect. and phase reversal occurs at the output. This can cause At the output, the aforementioned single supply designs lock-up in servo systems. Due to a unique phase reversal either cannot swing to within 600mV of ground (OP-20) protection circuitry (Q21, Q22, Q27, Q28), the LT1013/ or cannot sink more than a few microamperes while swing- LT1014’s outputs do not reverse, as illustrated below, ing to ground (LM124, LM158). The LT1013/LT1014’s even when the inputs are at –1.5V. all-NPN output stage maintains its low output resistance There is one circumstance, however, under which the phase and high gain characteristics until the output is saturated. reversal protection circuitry does not function: when the other op amp on the LT1013, or one specific amplifier of In dual supply operations, the output stage is crossover the other three on the LT1014, is driven hard into negative distortion-free. saturation at the output.
Comparator Applications
Phase reversal protection does not work on amplifier: The single supply operation of the LT1013/LT1014 lends A when D’s output is in negative saturation. B’s and C’s itself to its use as a precision comparator with TTL com- outputs have no effect. patible output: B when C’s output is in negative saturation. A’s and D’s In systems using both op amps and comparators, the outputs have no effect. LT1013/LT1014 can perform multiple duties; for example, C when B’s output is in negative saturation. A’s and D’s on the LT1014, two of the devices can be used as op amps outputs have no effect. and the other two as comparators.
Voltage Follower with Input Exceeding the Negative Common Mode Range
4V 4V 4V 2V 2V 2V 0V 0V 0V 6VP-P INPUT, –1.5V TO 4.5V LM324, LM358, OP-20 LT1013/LT1014 EXHIBIT OUTPUT PHASE NO PHASE REVERSAL REVERSAL
Comparator Rise Response Time Comparator Fall Response Time 10mV, 5mV, 2mV Overdrives to 10mV, 5mV, 2mV Overdrives
4 4 OUTPUT (V) OUTPUT (V) 2 2 0 0 0 100 INPUT (mV) INPUT (mV) –100 0 VS = 5V, 0V 50µs/DIV VS = 5V, 0V 50µs/DIV 10134fe 10 For more information www.linear.com/LT1013 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Applications Information Typical Applications schematic diagram Package Description Revision History Typical Application Related Parts
applicaTions inForMaTion
b) When the input is more than 400mV below ground (at D when A’s output is negative saturation. B’s and C’s 25°C), the input stage saturates (transistors Q3 and Q4) outputs have no effect. and phase reversal occurs at the output. This can cause At the output, the aforementioned single supply designs lock-up in servo systems. Due to a unique phase reversal either cannot swing to within 600mV of ground (OP-20) protection circuitry (Q21, Q22, Q27, Q28), the LT1013/ or cannot sink more than a few microamperes while swing- LT1014’s outputs do not reverse, as illustrated below, ing to ground (LM124, LM158). The LT1013/LT1014’s even when the inputs are at –1.5V. all-NPN output stage maintains its low output resistance There is one circumstance, however, under which the phase and high gain characteristics until the output is saturated. reversal protection circuitry does not function: when the other op amp on the LT1013, or one specific amplifier of In dual supply operations, the output stage is crossover the other three on the LT1014, is driven hard into negative distortion-free. saturation at the output.
Comparator Applications
Phase reversal protection does not work on amplifier: The single supply operation of the LT1013/LT1014 lends A when D’s output is in negative saturation. B’s and C’s itself to its use as a precision comparator with TTL com- outputs have no effect. patible output: B when C’s output is in negative saturation. A’s and D’s In systems using both op amps and comparators, the outputs have no effect. LT1013/LT1014 can perform multiple duties; for example, C when B’s output is in negative saturation. A’s and D’s on the LT1014, two of the devices can be used as op amps outputs have no effect. and the other two as comparators.
Voltage Follower with Input Exceeding the Negative Common Mode Range
4V 4V 4V 2V 2V 2V 0V 0V 0V 6VP-P INPUT, –1.5V TO 4.5V LM324, LM358, OP-20 LT1013/LT1014 EXHIBIT OUTPUT PHASE NO PHASE REVERSAL REVERSAL
Comparator Rise Response Time Comparator Fall Response Time 10mV, 5mV, 2mV Overdrives to 10mV, 5mV, 2mV Overdrives
4 4 OUTPUT (V) OUTPUT (V) 2 2 0 0 0 100 INPUT (mV) INPUT (mV) –100 0 VS = 5V, 0V 50µs/DIV VS = 5V, 0V 50µs/DIV 10134fe 10 For more information www.linear.com/LT1013 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Applications Information Typical Applications schematic diagram Package Description Revision History Typical Application Related Parts
