Description

TL5001 and TL5001A merged in a microcontroller

pulse width modulation (PWM) control circuit. The design is mainly used for power control TL5001/A containing an error amplifier, a regulator, an oscillator, a vein width modulation comparator (UVLO), short -circuit protection (SCP), and a route set electrode in the dead area of the dead area Output transistor. The TL5001A has a typical ± 5%of the TL5001, and the reference voltage tolerance is ± 3%. The co -mode voltage range of the error amplifier is from 0 to 1.5 volts. The non-vertical input of the error amplifier is connected to the 1-V reference. The dead zone time control (DTC) can be set to provide an external resistance between the dead diagnostic code and ground with a connection settings of 0%to 100%. The frequency of an oscillator is through an external ground resistance. Under low VCC conditions, the UVLO circuit is closed out of the output until VCC resumes the normal working range.

TL5001C and TL5001A are characterized by working at temperatures from -20 ° C to 85 ° C. TL5001i and TL5001A are operations for -40 ° C to 85 ° C. TL5001Q and TL5001AQ are used for -40 ° C to 125 ° C. The TL5001M and TL5001A are characterized by working at temperatures from -55 ° C to 125 ° C.

A 2.5 voltage regulator is used as a reference for the internal circuit of TL5001 and TL5001A as an error amplifier and SCP circuit. The resistor division provides a 1-V reference voltage for the non-vertical input of an error amplifier, and is usually within 2%of the nominal value within the working temperature range.

error amplifier

Typical application schematic diagram

Error amplifier to compare the sample of the output voltage of the DC-DC converter with the 1V reference voltage And to generate error signals for the PWM comparator. By selecting an error to place the large device gain (see Figure 1), use the following expression to set the DC-DC converter output voltage:

Error amplifier to output the DC-DC converter output voltage The sample is compared with the 1-V reference voltage, and the error signal of the pulse width modulation comparator is generated. Set out the output voltage gain of the DC-DC converter by selecting an error amplifier (see Figure 1) to use the following expression: soft off-booster circuit

The time constant RC should be T/3 to T/5. TL5001/A keeps off until V≈0.7 V (minimum slope value). C is released every time UVLO or SCP activation.

Obscated lock (UVLO) protection

When the power supply voltage drops too low (about 3 V when 25 ° C), the output transistor is turned off and reset the SCP memory to ensure normal work. The lagging voltage of 200 millivoli eliminates the error triggering of noise and jitter.

Short -circuit protection (SCP)

TL5001/A includes short -circuit protection (see Figure 3). When the converter outputs short circuit, the protection shutdown power switch to prevent damage. When activation, the SCP prevent switch from opening until the internal locking circuit is reset. The reset circuit is reduced by reducing the input voltage until UVLO is activated or the SCP terminal is grounded from the outside.

When a short circuit occurs, the output of the error amplifier at the COMP increases to increase the power switch occupation ratio and try to maintain the output voltage. When the COMP exceeds 1.5V, the SCP comparator 1 starts the RC timing circuit. If the short -circuit and error amplifier output drops below 1.5V before timeout, the normal converter operation continues. If the failure still exists at the end of the period, the timer will set the lock -up circuit and turn off the TL5001/A output transistor.

Short -circuit protection (SCP) (continued)

v (1+R1/R2) (1 volts) O -type

Figure Figure

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Error Player Bigoblea Settings

Error amplifier output is used as compensation to compensate for the stability of the DC-DC converter to control the circuit. Because the amplifier can only provide 45 Weian power, the total DC load resistance should be 100 kΩ or larger. Oscillator/PWM

By connecting a resistor between RT and GND, the oscillator frequency (F) can be set between 20 kHz and 500 kHz. The acceptable resistance range is 15 kΩ to 250 kΩ. The oscillator frequency can be determined by using the chart shown in Figure 5.

The output of the oscillator is a triangular wave with a minimum value of about 0.7 volts and a maximum value of about 1.3 volts. The PWM comparator compares the output voltage of the error amplifier and the DTC input voltage with the triangular wave. When the triangular wave is greater than the smaller value of the two, the output transistor input is turned off.

Dead Zone Time Control (DTC)

Direct torque control provides a method that limits the output switch to the duty cycle to be less than 100%. It is important. The current source generates a reference current (i) at the DTC, which is nominal equal to the current at the time of the oscillator, RT. Connect a resistor between DTC and GND to generate a dead area reference voltage (V), and the PWM/DTC comparator compares it with the oscillator triangle wave described in the previous section. In nominal, when V is less than or equal to 0.7 V, the maximum duty ratio is 0%. When VDT is greater than equal to 1.3 V, the mostThe big occupation ratio is 100%. Because the amplitude of the triangle wave is a function of the frequency, and the source impedance of RT is relatively high (1250Ω), the selection of R is used as a specific maximum duty cycle D, and the voltage limit for frequency (VMAX and VMAX and the following procedure and the following procedure and FIG. Vmin is the maximum and minimum oscillator level) Completed

Detailed description

Voltage benchmark

2.5 V regulator operated by VCC for internal circuits for TL5001 and TL5001A Power supply and reference for error amplifiers and SCP circuits. The resistance division provides a 1 volt voltage for an error amplifier. Usually, it does not exceed the non -rotating input of 2%in the operating temperature range.

Error amplifier

Soft starting circuit

If the DC-DC converter must be adjusted within the prescribed time, the time constant RC should be t/3 to t /5. TL5001/A keeps off until V≈0.7 V (minimum slope value). C is released every time UVLO or SCP activation.

UVLO Lock (UVLO) Protection

When the power supply voltage drops too low (about 3 V when 25 ° C), the underwriter locking circuit turns out the output transistor and reset the SCP lock lock Storage device to ensure normal work. The lagging voltage of 200 millivoli eliminates the error triggering of noise and jitter.

Short -circuit protection (SCP)

TL5001/A includes short -circuit protection (see Figure 3). When the converter outputs short circuit, the protection shutdown power switch to prevent damage. When activation, the SCP prevent switch from opening until the internal locking circuit is reset. The reset circuit is reduced by reducing the input voltage until UVLO is activated or the SCP terminal is grounded from the outside.

When a short circuit occurs, the output of the error amplifier at the COMP increases to increase the power switch occupation ratio and try to maintain the output voltage. When the COMP exceeds 1.5V, the SCP comparator 1 starts the RC timing circuit. If the short -circuit and error amplifier output drops below 1.5V before timeout, the normal converter operation continues. If the failure still exists at the end of the period, the timer will set the lock -up circuit and turn off the TL5001/A output transistor.

Short -circuit protection (SCP) (continued)

The timer by giving between the SCP terminal and grounding The external capacitor (CSCP) is charged to work, and the 185-kΩ resistor (RSCP) is close to 2.5 V. The circuit starts from about the initial voltage of 185 MV, and time is over time when the capacitor voltage reaches 1 V. Then the output of the SCP comparator 2 becomes higher, open Q2, and lock the timer circuit. The expression used to set SCP time period comes from the following content

Formula:

Output crystal tube

TL5001/A output is an open circuit collector transistor, the maximum set of the current electrode current is the rated value of the electrode electrode current to 21 mAh, and the rated voltage is 51V. The output is turned on under the following conditions: Compared with the output voltage of the fault diagnostic code and the error amplifier output voltage, the oscillator triangle wave is low in the non -activated state, and the short -circuit protection circuit is not activated.

The absolute maximum rated value within the free air temperature range (unless otherwise explained)

Power voltage, VCC (see 1) 41 V.

The amplifier input voltage, VI (FB). 20 volts

output voltage, VO, out. 51]

output current, IO, out. 21 mia

Output peak current, IO (peak), output 100 mAh.

Continuous total power consumption losses.

Working environment temperature range, TA: TL5001C, TL5001ac. - 20 ° C to 85 ° C

TL5001i, TL5001AI. - 40 ° C to 85 ° C

TL5001Q, TL5001AQ. - 40 ° C to 125 ° C

TL5001m, TL5001M. –55 ° C to 125 ° C

Storage temperature range, TSTG. –65 ° C to 150 ° C

The lead temperature is 1.6 mm (1/16 inches) from the shell, which lasts 10 seconds 260. The stress other than the stress listed below the absolute maximum rated value " may cause permanent damage to the device. These are only stress levels