TD340

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FUNCTIONAL DESCRIPTION

Speed and Direction Control:

The TD340 IC provides the necessary interface between an H-Bridge DC-Motor Control configuration and

a micro controller. The speed and direction are given by two input signals coming from the

microprocessor.

Speed Control:

Speed control is achieved by Pulse Width Modulation (PWM).

The TD340 provides an internal PWM generator, but can accept an external PWM waveform.

IN1 can accept two different types of inputs:

- an analog input between 0 and 5V (CF must be connected to set the PWM frequency) gives an analog

value of the Internal PWM duty cycle

- a digital input (CF must be grounded) gives directly the PWM

Figure 1 represents the Duty Cycle curve versus the IN1 analog voltage.

Figure 2 shows how to use the TD340 with an analog input or a digital input.

The speed control (or duty cycle) is achieved by the Low Side Drivers which impose the PWM function

while the cross-corresponding High Side MOSFETS is kept fully ON.

Direction Control:

IN2 accepts a digital value of the rotation direction.

Brake mode:

Brake mode is achieved by a zero level on the IN1 input.

The IN2 input selects low side or high side braking.

Brake mode is activated when the IN1 is at zero volt level for more than 200 us.

Figure 1 : Duty Cycle versus IN1 voltage

100%

Voltage

Duty Cycle

1.2V

3.6V

IN1

0%