Datasheet

Datasheet

8/13

TSZ02201-0P2P0B300110-1-2

25.Dec.2012 Rev.002

www.rohm.com

© 2012 ROHM Co., Ltd. All rights reserved.

TSZ22111･15･001

BD62321HFP

e) f) PWM control mode

The rotational speed of the motor can be controlled by the duty cycle of the PWM signal fed to the FIN pin or the

RIN pin. In this mode, the high side output is fixed and the low side output is switching, corresponding to the input

signal. The state of the output toggles between "L" and "Hi-Z".

The frequency of the input PWM signal can be between 20kHz and 100kHz. The circuit may not operate properly for

PWM frequencies below 20kHz and above 100kHz. Note that control may not be attained by switching on duty at

frequencies lower than 20kHz, since the operation functions via the stand-by mode. To operate in this mode, connect

the VREF pin to the VCC pin. In addition, establish a current path for the recovery current from the motor, by

connecting a bypass capacitor (10µF or higher is recommended) between VCC and ground.

Control input : H

Control input : L

Fig.16

PWM control operation (output stage)

Fig.17

PWM control operation (timing chart)

2)

Cross-conduction protection circuit

In the full bridge output stage, when the upper and lower transistors are turned on at the same time during high to low

or low to high transition, an inrush current flows from the power supply to ground, resulting to a loss. This circuit

eliminates the inrush current by providing a dead time (about 800ns, nominal) during the transition.

3)

Output protection circuits

a) Under voltage lock out (UVLO) circuit

To ensure the lowest power supply voltage necessary to operate the controller, and to prevent under voltage

malfunctions, a UVLO circuit has been built into this driver. When the power supply voltage falls to 5.3V (nominal) or

below, the controller forces all driver outputs to high impedance. When the voltage rises to 5.5V (nominal) or above,

the UVLO circuit ends the lockout operation and returns the chip to normal operation.

b) Over voltage protection (OVP) circuit

When the power supply voltage exceeds 45V (nominal), the controller forces all driver outputs to high impedance.

The OVP circuit is released and its operation ends when the voltage drops back to 40V (nominal) or below. This

protection circuit does not work in the stand-by mode. Also, note that this circuit is supplementary, and thus if it is

asserted, the absolute maximum rating will have been exceeded. Therefore, do not continue to use the IC after this

circuit is activated, and do not operate the IC in an environment where activation of the circuit is assumed.

FIN

RIN

OUT1

OUT2

M

ON

OFF

OFF

ON

M

ON

OFF

OFF

OFF