TPD4112K

2005-11-04

10

External Parts

Standard external parts are shown in the following table.

Part

Recommended Value

Purpose

Remarks

25 V/2.2

µF

Bootstrap capacitor

(Note 1)

0.62

Ω ± 1% (1 W)

Current detection

(Note 2)

10 V/1000 pF

± 5%

PWM frequency setup

(Note 3)

27 k

Ω ± 5%

PWM frequency setup

(Note 3)

25 V/10

µF

Control power supply stability

(Note 4)

10 V/0.1

µF

(Note 4)

5.1 k

Ω

FG pin pull-up resistor

(Note 5)

TBD

Input power supply stability

(Note 6)

Note 1: The required bootstrap capacitance value varies according to the motor drive conditions. The IC can

must be sufficiently derated for it.

Do not exceed a detection current of 1 A when using the IC.

intrinsic error factor is around 10%.

The PWM frequency is broadly expressed by the following formula. (In this case, the stray capacitance of

the printed circuit board needs to be considered.)

at least 9 k

Ω.

Note 4: When using the IC, some adjustment is required in accordance with the use environment. When mounting,

place as close to the base of the IC leads as possible to improve the noise elimination.

Note 5: The FG pin is open drain. Note that when the FG pin is connected to a power supply with a voltage higher

the FG pin, connect to the GND.

Note 6: If noise is detected on the Input signal pin, add a capacitor between inputs.

Handling precautions

(1)

still running.

(2)

discharges minute amounts of current. Therefore, subjecting the IC to noise when mounting it on the

board may distort the triangular wave or cause malfunction. To avoid this, attach external parts to

the base of the IC leads or isolate them from any tracks or wiring which carries large current.

(3)

The PWM of this IC is controlled by the on/off state of the high-side IGBT.

(4)

In the state where VBB voltage is low, and Duty100%, if a motor is made to lock, after load release

may be unable to reboot. This is the high side ON of a just before lock, when a motor is locked in the

state where VBB voltage is low. It is because time becomes long, bootstrap voltage falls, the decrease

voltage protection of a high side operates and a high side output serves as OFF. In this case, since the

level shift pulse for making a high side turn on is ungenerable, it cannot reboot. A level shift pulse is

generated from the edge of a hole sensor output and the edge of a hall sensor output edge of an

internal PWM signal, neither of the edge exists by the motor lock and Duty100% command. In order

to reboot after locke, it is required for a high side input signal to enter in the state where it recovered

to voltage with high side power supply voltage higher 0.5v than a decrease voltage protection voltage

value. Since a high side input signal is created by the above-mentioned level shift pulse, it can reboot