Output current. 100 mia

Low losses. 100 mia is 1.1 volts

The scope of working. 3.5 il to 15 volts

Reference and error amplifier

Regulations

External oscillator synchronization

The device can be connected in parallel [ 123]

Compatible with acupuncture

LTC1044 /7660 type

LT1054 is a bipolar switch Voltage converter of capacitors with regulator. It provides higher output current and voltage significantly lower than the loss of converter available. The efficiency of the Anti -Adapted Switch Drive is optimized in a wide range of output current range. The total voltage drop at 100 mAh output current is usually 1.1 V. This is suitable for the range of power supply voltage from 3.5 V to 15 V. Static current is usually 2.5 mAh. The LT1054 also provides a regulatory function, which is an unavailable function converter in the switch capacitor voltage. A adjustable output can be obtained by adding an external resistor division. This output is a regulating change to the input voltage and output current. LT1054 can also close the feedback terminal by grounding. Power currents when shutting down are often 100 μA. The internal oscillator of the LT1054 runs at a nominal frequency of 25 kHz. You can use the oscillator terminal to adjust the switching frequency or the external synchronization LT1054. The LT1054C is characterized by the free air temperature range from 0 ° C to 70 ° C. LT1054I is characterized by the free air temperature range of 40 ° C to 85 ° C.

The absolute maximum rated value within the free air temperature range (unless there is another instructions)

Power supply voltage, VCC (see 1) 16 V.

The input voltage range, VI: FB/SD 0 to V. OSC 0 V to VREF.

Jiewen TJ (see Note 2): LT1054C 125. Celsius

LT1054i 135. Celsius

Packaging thermal impedance, θja (see comments 3 and 4): DW packaging 57. Celsius/tile P package 85. Celsius/tile

Storage temperature range, TSTG 55. ° C to 150 ° C #8225; more than the stress listed in the absolute maximum rated value may cause permanent damage to the device. These are only stress levels, and the functional operations of the device will not be implicitly referred to in the conditions described in the Recommended Operation Conditions or any other conditions. Long -term exposure to absolute maximum rated conditions may affect the equipmentReliability.

Note: 1. 16 V's absolute maximum power voltage rated value is suitable for unjust circuits. For the regulatory mode of VOUT ≤15 V, the rated value of the circuit can be increased to 20 V.

2. The device can work normally at the highest absolute temperature.

3. The maximum power consumption is the functions of TJ (MAX), θJa, and TA. Any allowable maximum allowable power consumption environment temperature is pd (tj (max) ta)/θja. Under the absolutely maximum TJ of 150 ° C, it may affect reliability.

4. Calculate the packaging thermal impedance based on JESD 51-7.

The electrical characteristics of the recommended operation conditions (unless there are other instructions)

The full range of the LT1054C is 0 ° C to 70 ° C, LT1054i, and LT1054I The range is 40 ° C to 85 ° C.

All typical values are TA 25 ° C.

Note: 5. All adjustment specifications are suitable for devices connected as positive-negative converters/regulators, R1 20 K , R2 102.5 k , external capacitor CIN 10 μF (10 μF (器), external capacitors COUT 100 μF (钽), C1 0.002μF (see Figure 15).

6. For the voltage loss test, the device is connected as a voltage inverter, and the terminal 1, 6 and 7 are not connected. Voltage loss may be higher in other configurations. CIN and COUT are external capacitors.

7. The output resistance is defined as the curve slope of 10 mAh to 100 mAh output current ( #8710; VO and #8710; IO). This represents the linear part of the curve. Due to this characteristic, when the current is less than 10mA, the incremental slope of the curve is higher.

Looking back on a basic switch capacitor constructing block to help understand the operation of LT1054. The switch shown in FIG. 12 is at the left side, and the capacitor C1 is charged to the voltage at V1. The total cost C1 is q1 C1V1. When the switch moves to the right, the C1 discharge to the V2 voltage. At the time of discharge, the charge on the C1 is q2 C1V2. The charge has been transmitted from the source V1 to the output V2. The charge of this transfer is shown in Formula 1.

If the switch circulates F times per second, the charge transfer of the unit time (that is, current) is shown in the equation

] In order to obtain an equivalent resistance of the switch capacitor network, this equation can be represented by the voltage rewriting impedance equivalent.

The new variable requis is defined as requet 1 ÷ FC1. The equivalent circuit of the switch capacitor network is shown in Figure 13. The LT1054 has the same switching action as the basic switch capacitor building blocks. Although this simplification does not include limited switching resistance and output voltage ripples, it provides an insight to understand the working principle of the device.

These simplified circuits interpret the voltage loss as a function of the oscillator frequency (see Figure 7). As a oscillator, the output impedance is finally controlled by 1/FC1, and the voltage loss rises. Voltage loss also increases with the increase of the frequency of oscillator. This is caused by internal switch loss to lose some limited charge in each switch cycle. The charge loss of each unit cycle is multiplied by the switch to the current loss. Under high frequency, this loss becomes significant, and the voltage loss stands up again. The oscillator of the LT1054 is designed to work in the smallest frequency band of the voltage loss.

When CIN and input power are connected in parallel, the power supply voltage VCC alternately charges CIN to the input voltage as CIN and COUT in parallel switch, and the charge is transferred to the COUT. The switch occurs at the frequency of the oscillator. During CIN charging, the peak power current is about 2.2 times the output current. During the process of conveying the charge to CIN, the power current drops to about 0.2 times the current of the output current. The input power bypass capacitors provide the current input current of part of the LT1054 and the average value of the average value from the current. The minimum input power barrier container is 2 μF, preferably 钽 or some recommended use of other low equivalent series resistance (ESR) types. In some cases, larger capacitors are desirable. For example, when the actual input power supply is connected to the LT1054 through a long lead, or the pulse current generated by the LT1054 may affect other circuits through the power coupling. In addition to the output end, VOUT is also connected to the substrate of the device. You must be careful of the LT1054 circuit to prevent VOUT be positive compared to any other terminal. For the output circuit load connected from VCC to VOUT or connected from the external positive power supply voltage to VOUT, the external transistor must be added (see Figure 14). This transistor prevents the voltage from being pulled above GND during startup. Any small ones such as 2N2222 or 2N2219 devices can be used. The resistor R1 should be selected to provide sufficient base drives to the external transistor to make it saturate the output current conditions under the rated output voltage and maximum output voltage.

Reference voltage is the reference voltage with reference voltage (reference voltage is 105V-5). This adjustment of the output voltage coefficient of the reference voltage (TC) is close to zero. As shown in the typical performance curve, this requires the reference output to have a positive TC. This non -zero drift is to offset the feedback terminal that the internal reference allocation and comparator network inherent.The overall result of these drift items is to adjust the output. When the output voltage is lower than 5 V, when the output voltage is higher than 5 V, the TC is slightly negative. For regulator feedback networks, the reference output current should be limited to about 60 μA. VREF consumes about 100 μA ground during short circuits, which does not affect the internal benchmark/regulator. This terminal can also be used as a circuit that requires synchronization for LT1054. CAP+is the positive electrode of the input capacitor CIN, alternating between VCC and ground. When driving to VCC, CAP+current source from VCC. When being driven to the ground, CAP+remit the current to the ground. Cover is one side of the negative number input capacitor, alternately driven between ground and voltage output. When it is opened to the ground, the lid sinks to the ground current. When driving to VOUT, CAP In all cases, the current flows in the switch is one -way, and it should be the case when using bipolar switches. OSC can be used to improve or reduce the frequency of oscillator or synchronize the device with the external clock. Internally, OSC is connected to the time -time capacitor (CT≈150 PF), and the current source is ± 7 μA, so the duty ratio is about 50%. The LT1054 oscillator is designed to minimize the frequency band of the running switch loss. However, the frequency can be improved, reduced, or so necessary to synchronize with the external system clock. You can add frequency+OSC by adding external capacitors (C2 in Figure 15) within the range of the capacitor 5 20 PF. This capacitor couples the charge to the current intestinal converted at the switch. This shorten the charge and discharge time multiplied by and increase the frequency of oscillator. Synchronization can achieve from OSC to VREF by adding an external pull -up resistor. It is recommended to use 20-k pull the resistor. The opening of the road ranch or NPN transistor can be used to drive OSC frequency as shown in Figure 15. By adding an external capacitor between OSC and the ground (C1 in Figure 15), the frequency can be reduced. This increases the charging and discharge time, reducing the frequency of oscillator.

Feedback/shutdown (FB/SD) terminal has two functions. Pull FB/SD to the device to stop the device below the stop threshold (≈0.45 V). During the stop, the reference/regulator is closed and the switch stops. The settings of the switch make CIN and COUT discharge through the output load. The static current dropped to about 100 μA when the static current stopped. Any open setting grille can be used to put the LT1054 in the shutdown. For normal (not adjusted) operations, the equipment will be restarted when the external departments are closed. In the LT1054 circuit adopts the adjustment function, the external resistor division can provide sufficient drop -down to keep the device in shutdown before the output capacitor (COUT) is completely discharged. For most applications, because the output of 1054 capacitors is continuously running, the problem of the capacitor does not have intermittent operations from the shutdown time of the device. The device must be lostThe capacitor (COUT) in the application that has been started before is completely discharged, and the FB/SD of the LT1054 must be performed. The use circuit is shown in Figure 16. The restart signal can be the pulse (TP GT; 100 μs) or high logic. The diode coupling restarts the signal of the input FB/SD to allow the output voltage to rise and adjust without the overwhelming. The resistance division pressure dealer R3/R4 should be shown in Figure 16 to provide a signal level of 0.7 1.1 V under FB/SD. FB/SD is also the reverse input of the LT1054 error amplifier. Therefore, it can be used to obtain a adjustable output voltage.

Select the closest 1%value. The displayed pin number is suitable for the P package.

Regulations (continued)

Error amplifier of the LT1054 driver PNP switch to control the voltage of the input capacitor (CIN), which determines the output voltage. When using the benchmark and error amplifier of the LT1054, the external resistor division is that all need to set the adjustment output voltage. FIG. 16 shows the formula of the basic regulator configuration and calculation of the appropriate resistance value. R1 should be 20 k or larger because the reference current is limited to ± 100 μA. R2 should be within the range of 100 k to 300 k Frequency compensation is achieved by adjusting the ratio of CIN to COUT. To get the best results, this ratio should be about 1:10. The C1 required for good load adjustment should be 0.002 μF. The functional frame diagram shows the maximum adjustment output voltage restricted by the power supply voltage. For basic configuration, refer to the lt1054 ground terminal #63724; vout #63724; must be less than the voltage loss caused by the total number of power supply voltage. Voltage loss and output current can be found in a typical performance curve. Other configurations, such as negative poles, can provide higher voltage while reducing the output current.

Capacitor selection

and the accuracy of CIN and COUT is non -critical, high -quality low ESR capacitors, such as solid -state is necessary to minimize voltage loss at large current. For CIN, the blood sedimentation affects the capacitor multiply, because the switching current is about twice the output current. Losses will occur in the charging and discharge cycle, which means that the ESR of a capacitor is 1 the same effect as the output impedance of the LT1054 increases 4 This means increased voltage loss. When the current is about equal, the output current is charged alternately. The ESR of the capacitor causes the output ripples at the switch to transition the step function. The output adjustment when the output load is changed at this level jump function, and it should be avoided. In order to obtain low ESR and reasonable costs, a technology is a smaller pupae container with large aluminum electrolytic capacitors.

Output ripple

The output rip of the peak is determined by the output capacitor and output current value. The output ripples of the peaks are approximately:

Where:

#8710; v Peak Board Corporation

fosc oscillator frequency

[[[

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123] For output capacitors with significant ESR, the second item must be added to illustrate the switch. This step is about equal to: 2 ESR

Power loss of COUT

must limit the power consumption of the LT1054 circuit so that the temperature of the device does not exceed the maximum knot temperature. Total power consumption can be obtained from the power loss caused by the decrease of the component-switch voltage, and the power loss loss caused by the driving current. The total power of the LT1054 consumption is as follows:

Among them, both VCC and VOUT are referenced. Its power consumption is equivalent to a linear regulator. LT1054 packaging limited power processing capacity leads to limited output current for large input or output, and measures can be taken to consume the external power differences of LT1054. This is achieved by connecting a resistor with CIN, as shown in Figure 17. Some part of the input voltage decreased through the resistance without affecting the output adjustment. Because the switching current is about 2.2 times the output current and the resistor when the CIN is charged at the same time, the selected resistance is as follows:

and the maximum output current coefficient required for iOut allow LT1054 to have a certain amount of certain LT1054. operating profit. When using 12-V to 5-V converter at 100 mAh output current, there is no external resistor.

Power consumption (continuity)

For commercial plastic devices, under the RθJA of 130 ° C/W, the knot temperature increased by 122 ° C. The highest temperature of the equipment exceeds the ambient temperature of 25 ° C. Calculating power is dissipated using the external resistor (RX) to determine how much voltage can be reduced on the RX. In this LT1054, in the standard regulator configuration, the output current is 1.6 volt at a maximum voltage of 100 mAh.

The resistor reduced the power consumed by the LT1054 (4.9 v) (100 ma) 490 mW. The dissipation of total power LT1054 is equal to (940 mW 490 mW) 450 mW. The knot temperature rose to 58 ° C. Although commercial devices can still work normally at the knot temperature of 125 ° C, these specifications are tested in this example, which means that the ambient temperature is limited to 42 ° C to allow higher environmental temperatures, LT1054 packaging The thermal resistance value indicates the number in the worst case, without sinking and static air. Small heat sinks can be used for the resistance of the LT1054 packaging on a lower heat sink. oneThe airflow in some systems helps reduce thermal resistance.The circuit board traces of the wide version of the LT1054 wire can help eliminate the heat of the equipment.Plastic is especially packaged.

Note: The motor speed table is Canon CKT26-T5-3sae.The displayed pin number is suitable for the P package.