FD0259f

Rev1.3 Aug. 12, 2009

P.2

FEELING

TECHNOLOGY

Pin Connection

Figure.2

Pin Descriptions

Legend: I=input, O=output, I/O=input/output, P=power supply, G=ground

Functional Descriptions

Refer to the block diagram (Figure.1), FD0259f is composed of the following building blocks:

Bias generator

The bias generator provides precise, temperature- and process-insensitive bias references for the analog blocks.

These references guarantee proper operation of the IC under all conditions specified in this specification.

Oscillator

The built-in oscillator provides the clock signal for the digital control logic.

Power On Reset

Used to detect the power-up ramp and reset the digital circuits.

Chopper Amplifier

To achieve a higher magnetic sensitivity the chopper amplifier structure is adopted in this design. Use of this

structure dynamically removes both the offset and flicker noise at the same time.

Digital Control Logic

Hall sensor part – generates magnetic pole signals from the Hall-effect sensor.

Driver part – generates switching signals to the H-Bridge MOS driver.

Timer part – generates an interval of time when rotor locked event is occurred.

Signal part – generates a tachometer signal(FG) output.

Name

I/O

FD0259f

Description

FG

O

1

Tachometer Signal Output

VSS

G

2

Ground

NO

O

3

Driver Output 1

SO

O

4

Driver Output 2

VCC

P

5

Positive Power Supply

VDD

P

6

Positive Power Supply

FD0259f

1

2

3

6

5

4

bi

g