Continued from preceeding page.

Pin Assignment

Pin No.

Pin

Function

Equivalent circuit

No. 5975-5/8

LB1999M

21

Output block power supply

23

31

Rf (PWR)

Rf (SNS)

Output current detection. The control block current limiter

operates using the resistor Rf connected between these pins

and ground. Also, the lower side saturation prevention circuit

and the torque ripple correction circuit operate based on the

voltages to this pin. It is especially important to note that,

since the saturation prevention level is set using this voltage,

the lower side saturation prevention circuit will become less

effective in the large current region if the value of Rf is

lowered excessively. Also, the PWR and SENSE pins must

be connected together.

26

27

28

U phase output

V phase output

(Spark killer diodes are built-in.)

W phase output

32

GSENSE

Ground sensing. The influence of the common ground

impedance on Rf can be excluded by connecting this pin to

nearest ground for the Rf resistor side of the motor ground

wiring that includes Rf. (This pin must not be left open.)

33

FR

Forward/reverse selection. The voltage applied to this pin

selects the motor direction (forward or reverse).

Note: Although the FRAME pins and

the GND pins are not connected

internally, the potentials of the

GND pins and the FRAME pins

externally be identical to assure

ground potential stability.