Driving ability: 2 A, 36 V, 30 kHz

2 Logic chip enable

External circuit gain adjustment

Single power supply (18 to 36 V) [123 ]

Enter signal -to -ground symmetry

Hot Protection

L292

is an integration of 15 -drawing Mul TiWatt #174; encapsulation The single -piece LSI circuit. It is intended to use L290 and L291 together as a complete 3 -piece motor positioning system for applications, such as the location control of the car/chrysanthemum wheels in the type. The L290/1/2 system can be used by a microprocessor.

Electricity

System description

L290, L291 and L292 will be used as 3 chips Positioning system controlled by microprocessor. The device can be used alone-especially the L292 motor driver-but because they are usually used together, the typical L290/1/2 system description is as follows. At this time, the microprocessor command is switched to the position mode (the selection signal of 8 in the L291 pin) and within 3 to 4 milliseconds, the L292 drives motor to zero, and it is maintained through the electrons through the electrons. The mechanical/electrical interface includes

The system adopts two working modes to achieve high -speed and high -precision positioning.

The speed instruction of the system comes from the microprocessor. It continuously updates the pulse positioning of the L290 speed meter chip, and Whitch in Tur obtains information from an optoelectronics encoder. Based on this basic input, the microprocessor calculates a 5 -bit control word to set the system speed depends on the distance of driving. When the motor stopped running and the microprocessor commands it to reach a new position, the system starts to work in the opening configuration because there is no feedback from the speed meter generator. When the maximum speed a reaches, the speed meter chip output will return the processor signal to reduce the acceleration torque. The motor continues to run at the ROP speed, but is under closed -loop control. When it is close to the target position, the microprocessor reduces the value of the speed requirements; this reduces the voltage of the main point of the main point, which is actually a brake motor. Gradually apply brake until the motor runs at a minimum speed. The optical encoder of two different phases 90 ° sinusoidal signal (according to the motor guidance to the frequency to the rotation speed. The optical encoder also provides the output of the upper position of the disk to set the initial position. Optical encoder signal, FTA And FTB is filtered by network R2C2 and R3 C3 (Reference Figure 4) and provided to FTA/FTB inputs on L290. The main function of the L290 is to implement the following expressions:

Output signal (TACHO) dvab · fta-dvaa · ftbdt | fta | dt | FTB | Therefore, the average value of the speedometer is proportional to the speed, and its polar indicator rotation direction. The above features are implemented by enlarging the input signals in A1 and A2 to obtain VAA and VAB (typical value 7). Signals VMA and VMB supplied by VAA and VAB's external differential RC networks and R4 C4. The second input of each multiplier is composed of a symbol of the first input of another multiplier before the difference. These symbols are obtained using comparative CS1 and CS2. Output of magazines, CSA and CSB, and use A3 to obtain the final output signal Tacho. The peak peak ripple signal of the speedometer can be found from the following expression:

Use the resonant C1 and C2 to obtain the other two signals from VAA and VAB: logic signal STA and an organic set -top box. The microprocessor uses these signals to determine the position through the counting pulse. The internal reference voltage of the L2910 also comes from VAA and VAB:

Compensation at the temperature changes at the input end according to changes in the input end. Rotate a pulse each time a pulse optical encoder output is connected to the L290 (FTF) pin 12 square meters representing the STF logic output of the microprocessor. The speedometer signal and VREF are sent to L291 by the filter network R8 C8 R9 and R6 C7 R7, respectively.

The pin 12 of the chip is the main demand of the system, where the speedometer is compared with the output of the D/A converter. The input of the D/A converter consists of a symbol bit provided by 5 characters plus a microprocessor. Mark the drill bit control the direction of the motor rotation. The D/A converter's (analog) output (DAC/OUT) compares the speed meter signal. The error amplifier enlarges the sampling error signal and then appears on the pin 1. ERRV SOGNAL (from the pin 1, L291) was sent to the end chip L292 pin 6H bridge motor drive. The input signal is two -way, so it must be converted to a positive signal BA because L292 uses a single power supply voltage. This is a level-level converter completed by the first level, which uses the 8-volt voltage generated inside. The same reference voltage supply triangular wave oscillator, the frequency of the external fixing RC network (R20,

C17

-In inserting 11 and 10), where:

] The oscillator determines the output -level switching frequency, and it should be between 1 and 30. The motor current is adjusted by the internal circuit in the L292. The circuit resistor R18 and R19 perform differential current detection amplifiers. The output is filtered by the external RC network

to the error amplifier.

The selection of these RC networks (pins 5, 7, 9) is determined by the type of motor type andBandwidth requirements. The value displayed in the figure is suitable for 5 5 mH motors. (See the transmission function calculation in the L292 application information). The error signal obtained by input and current feedback signals (pin 7) is used for pulse width to modulate oscillator signals through comparators. The pulse width modulation signal controls the duty cycle of HBRIDGE to provide the output current corresponding to the L292 input signal. The interval T on one side of the bridge is disconnected from the other side, which is combined with the C17 and an internal resistor RT. This can be concluded from the following:

Because the Rτ is about 1.5 k , it is recommended to avoid the T. of 2.5 μs CPIN10 at the same time should be around 1.5 nf. The current detection resistor R18 and R19 shall be given a high -precision type (maximum tolerance ± 2%) suggestion value by the following formulas:

If necessary, you can use the network shown in Figure 2 to synchronize Two L292. Finally, two enabled inputs are provided on L292 (pin 12 and pin 13 activate low levels and high levels, respectively). Therefore, the output level can be suppressed by pins 12 high or pin 13 low. The output will also be disabled if the power supply voltage is lower than 18V. The enable input is implemented in this way because they are directly driven by microprocessors. The currently available microprocessor may generate a peak of up to 1.5V during power. These inputs can be used for various applications, such as the motor inhibitory system and power -on reset during logical reset (see Figure 3).

Application information

Add this part to help the designer best choice external value components.

RS1 RS2 RS (induction resistance)

(Director -influenza amplifier cross -guided) LM motor induction, RM motor resistance, RM motor resistance, IM motor current

Figure 8. Small signal jump response (standardized amplitude and T/RFCF).

v7 200 millival/dB.

IM 100 mAh/分 pressure.

t 100 μs/div, vi 1.5 VP.

It can verify that L292 works under the closed loop conditions during the rise of the entire motor current: error amplifier pins 7 inverted input is locked as reference voltage VR, which exists in the non -counter -phase of the same amplifier. Enter end. For this example, the previous linear analysis is correct. Reduce the value, and the current rising time decreases. But for a good stability, from the relationship (6), the maximum value of the ξ is:

(phase margin 45 °)

B) Large signal response

Limit the response of the large -scale leap signal response and inductance load.In this case, during the rising motor current, L292 work is open.The closed -loop system bandwidth.A good choice of x is 1/2.In this case:

Example:

A) Data

- Electric characteristics:

lm 5 minutes

[

123] RM 5 watts

lm/rm 1 millisecond

-The voltage and current characteristics:

vs 20 volts IM 2 Ann vi 9.1 volts [123 123

-C closed -loop bandwidth: 3 kHz

B) Calculation

From the relationship (4):