TD340

9/21

Figure 3 : Synchronous Rectification Principle

Table 1 : Function Table in Digital and Analog Modes

Notes:

- Standby state is active when STB Y pin is pulled low

- Disable state is active when one of the following conditions is met: UVLO, OVLO, Reset, Watchdog Timeout.

Stby

State

Disable

State

IN1 (V)

IN2

(V)

Mosfets Status

Comments

digital

analog

Q1L

Q1H

Q2L

Q2H

1

X

X

X

X

OFF

OFF

OFF

OFF

Motor Off in Standby Mode

X

1

X

X

X

OFF

OFF

OFF

OFF

Motor Off in Disable Mode

0

0

0 idle

0 to 1.2

0

ON

OFF

ON

OFF

Motor Brake Low

0

0

0 idle

0 to 1.2

5

OFF

ON

OFF

ON

Motor Brake High

0

0

PWM

1.2 to 3.6

0

OFF

ON

PWM

!PWM

Motor x% Forward

0

0

PWM

1.2 to 3.6

5

PWM

!PWM

OFF

ON

Motor x% Backward

0

0

5 idle

3.6 to 5

0

OFF

ON

ON

OFF

Motor 100% Forward

0

0

5 idle

3.6 to 5

5

ON

OFF

OFF

ON

Motor 100% Backward

ex1:

Speed: PWM=x%

No synchronous rectification

HIGH DISSIPATION

THROUGH FREE WHEEL DIODE!

M

PWM

FULL

FULL

x%

1-x%

FULL

ON

OFF

OFF

ex2:

Speed: PWM=x%

With synchronous rectification - TD340

LOW DISSIPATION

THROUGH LOW Rdson!

M

PWM

FULL

FULL

x%

1-x%

PWM

ON

OFF