3-Phase Brushless DC Motor Controller/Driver

with Back EMF Sensing

A8904

6

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Limits

Characteristic

Symbol

Test Conditions

Min.

Typ.

Max.

Units

Charging, D26 = 0, D27 = 0

-9.0

-10

-11

μA

Charging, D26 = 0, D27 =1

-18

-20

-22

μA

Charging, D26 = 1 D27 = 0

-27

-30

-33

μA

Charging, D26 = 1, D27 =1

-36

-40

-44

μA

0.22

0.25

0.28

V

2.25

2.5

2.75

V

Max. FLL Oscillator Frequency

20*

—

—

MHz

Oscillator High Duration

ton

20

—

—

ns

Oscillator Low Duration

toff

20

—

—

ns

Maximum Output Current

D3 = 0, D4 = 0, D28 = 0

1.0

1.2

1.4

A

D3 = 0, D4 = 1, D28 = 0

0.9

1.0

1.1

A

D3 = 1, D4 = 0, D28 = 0

500

600

700

mA

D3 = 1, D4 = 1, D28 = 0

—

250

—

mA

D3 = 0, D4 = 0, D28 = 1

500

600

700

mA

D3 = 0, D4 = 1, D28 = 1

415

500

585

mA

D3 = 1, D4 = 0, D28 = 1

—

300

—

mA

D3 = 1, D4 = 1, D28 = 1

—

125

—

mA

Transconductance Gain

D28 = 1

210

250

290

mA/V

D28 = 0

420

500

580

mA/V

Centertap Resistors

5.0

10

13

k



Back-EMF Threshold with respect

—

5.0

20

37

mV

-5.0

-20

-37

mV

Negative current is defined as coming out of (sourcing) the specified device terminal.

* Operation at an oscillator frequency greater than the specified minimum value is possible but not waranteed.