Features

Ultra -low static current: 3.5 μA typical value

Open leakage output is usually depressed

greater than 20mA

Wide supply range : ( LTC1841 )

Single power supply: 2V to 11V

Double: ± 1v to ± 5.5V

The input voltage range includes negative power [123 ]

Reference output drive 0.01 μF capacitor

Available stagnation

12 μs transmission delay, 10mV driver

When switching, there is no current peak

Application

Battery power supply system monitoring

threshold detector

Window comparator

oscillator circuit

]

LTC #174; 1841/LTC1842/LTC1843 is a comparator with a built -in benchmark with ultra -low power consumption dual channel (LTC1842/LTC1843). The power supply current of the comparator is less than 5.7 μA, and the reference voltage of 1.182V ± 1%. It can be programmed for programming lag and leakage openings to reduce the current. The reference output can drive up to 0.01 μF and no oscillation. LTC1841 from a 2V to 11V power supply or dual road ± 1V to ± 5.5V power. The LTC1842/LTC1843 type works from a single 2.5V to 11V power supply or dual power supply to ± 5.5V power. LTC1842/LTC1843 Magnetic stagnation uses two resistors and HYST is easy to program. The input of the comparator starts the power supply within the 1.3V range of the positive power supply from the negative electrode. The output level of the comparator usually sinks more than 20mA. The supply failure occurs by eliminating the cross -conducting current under normal circumstances when the comparator changes the logic state. LTC1841/LTC1842/LTC1843 provides packaging in SO-8.

Absolutely maximum rated value (Note 1)

Voltage V+to V-12V to –0.3V

in+, in-, HYST (V ++ 0.3V) to (V –- 0.3V)

Judgment (v ++ 0.3V) to (v - 0.3V)

Go out 12V to (v - 0.3V)

] Current IN+, IN-, HYST20 Mia

Short-circuit duration (V+≤5.5V) continuous power consumption 500 MW

Work temperature range

LTC1841C/LTC1842C /LTC1843C 0 ° C to 70 ° C

LTC1841i/LTC1842i/LTC1843i –40 ° C to 85 ° C

Storage temperature range –65 ° C to 150 ° C

Lead temperature (welding, 10 seconds) 300 degrees Celsius

Electric characteristics v+ 5V, V - 0V, TA 25 ° C, unless there are other instructions.

Electric characteristics v+ 5V, V - 0V, TA 25 ° C, unless there is another instructions

] Indicates a standard temperature range suitable for the entire operation.

Note 1: The absolute maximum rated value means that the value device that exceeds life may be damaged.

Note 2: IN+ In -+80mV, the output is high impedance state.

Note 3: VCM 1/2 (V+--V-) of LTC1841, VCM VREF/LTC1843 of LTC1842.

Typical performance features

pin function

Output A (pin 1): Comparison A Direct Polar Output. The output can usually sink more than 20mA.

v - (needle pin 2): negative power supply.

In A+(pin 3): the non -conversion input of comparator A from V -to V+– 1.3V input 25 ° C, the current is often 10Pa.

In A - (pin 4) (LTC1841): Input of reverse comparator A. Enter the extension range from V -to V+– 1.3V. At 25 ° C, the input current is often 10Pa.

In B+(pin 4) (LTC1842): Non -alternative input of comparator B. Enter the extension of the consensus range from V to V+– 1.3V. At 25 ° C, the input current is often 10Pa.

In B - (pin 4) (LTC1843): Input of reverse comparator B. Enter the extension range from V -to V+– 1.3V. At 25 ° C, the input current is often 10Pa.

In B - (pin 5) (LTC1841): Input of reverse comparator B. Enter the extension range from V -to V+– 1.3V. At 25 ° C, the input current is often 10Pa.

HYST (pin 5) (LTC1842/LTC1843): lagging input. If not for connection. The input voltage range from VREF to VREF -50MV.

In B+(pin 6) (LTC1841): Non -alternative input of comparator B. Enter the extension of the consensus range from V to V+– 1.3V. At 25 ° C, the input current is often 10Pa.

Ref (pin 6) (LTC1842/LTC1843): Reference output. 1.182V relative to V -. It can usually be obtained more than 1mA, and sinks 10 μA under 25 ° C. Can drive 0.01 μF bypassless oscillation capacitors.

V+(pin 7) (LTC1841): Positive power. 2 to 11 volts.

V+(pin 7) (LTC1842/LTC1843): Positive power. 2.5V to 11 volts.

Output B (pin 8): Comparison BLD output. The output can usually sink more than 20mA.

Application information

LTC1841/LTC1842/LTC1843 is a dual -micro power built -in 1.182V reference voltage comparator (LTC1842/LTC1843). Features include programmable lag, the voltage range (2V to 11V) and the driver of up to 0.01 μF capacitors. The output of the leakage road of the comparator usually decreases more than 20mA, and the current failure of the power current will be reduced when switching logic state.

Power supply

The working voltage of the comparator is 2V to 11V (2.5V to LTC1842/LTC1843 is 11V) or dual -road ± 1v to ± 5.5V power supply (LTC1842/LTC1843 is ± 1.25V. To ± 5.5V). If the reference power supply is greater than 1mA or the power supply requires high output source, V+should pass the 0.1 μF capacitor.

The input of the comparator

The input of the comparator can swing from the negative direction to the 1.3V (maximum) range of the positive power V+. The input voltage can be forced to 300 MV+without damage when it is lower than V -or V, and the typical input leakage current is only ± 10Pa.

Comparison output

Each comparator output is a leakage and pull -down to V -usually sinking more than 20mA. The output leakage current in the low -ground three -state mode allows the use of high -value top resistors. Ming canal output can be wired or ED or used for level conversion applications.

Voltage benchmark

The output voltage of the internal band gap benchmark is 1.182V reference V -. The reference accuracy is 1.5%from -40 ° C to 85 ° C. It can usually produce 1mA greater than the current and reach 10 μA under 5V power. References can drive up to 0.01 μF by -to -line electric container oscillations. By inserting a series resistance, the capacitor can use a value of up to 100 μF (Figure 1).

FIG. 2 shows the capacitor value that reaches the critical damping. By preventing V+or reference failure on the load, the reference can help prevent preventionStop the COM PARATOR's wrong trip to interfere with the transient of the reference output voltage.

FIG. 3 shows square waves with V+pin. Resistance R2 and R3 set up R1 damping reference responses. Note that the output of the comparator will not trip over.

Magnetic stagnation

LTC1842/LTC1843 can increase the magnetic stagnation between REF and HYST pinch pins in the following ways (R1) and from HYST to to HYST to V's second resistor (R2) (Figure 4). Different voltage or lag voltage bands (VHB) between the upper and lower thresholds (VHB) is equal to the voltage difference between two times Ref and Hyst pins. With the increase of magnetic stagnation effects, the increase in the upper threshold is the same as the reduction of the low threshold. The maximum voltage pins allowed between the REF and HYST are 50mv, which generates a maximum lag voltage of 100 millivolal bands. The range of the stagnation belt can reach 15%. If you do not need to lag, the HYST pin should be short -circuited. The acceptable value of Iref range is 0.1 μA to 5 μA. If R2 selects 2.4m, R1 is equal to the VHB value.

window probe

LTC1843 is the ideal selection detector of the micro -power window as shown in Figure 5. The values u200bu200bof R1, R2 and R3 are 4.5V, and the overvoltage threshold is selected with 5.5V. R4 and R5 set the lagging voltage. The following design program can be used to select component values:

Application information

1. Select the required stagnation voltage belt and the formula according to the stagnation part Calculate the values u200bu200bof R4 and R5. In this example, ± 5MV increased lag at the comparator input end (VH VHB/2). Note that when the vehicle recognition number (VIN) (VIN), the stagnation phenomenon will obviously become larger due to the input resistor division.

2. Select R1. The leakage current in B is lower than 1NA, so the current of R1 should exceed 100NA to ensure the threshold accuracy. The R1 value is as high as 10 meters, but the value from 100K to 1m is usually easier to deal with. In this example, select R1 294K.

3. Calculate R2+R3. The excessive voltage should be set to 5.5V, the design formula is as follows:

4 Calculate R2. When the underwriting threshold should be set up 4.5V, the design formula is as follows:

6. Verify the resistor value. The equation is as follows below, and evaluate the above example: overvoltage threshold: