3

9524B–AT42–04/09

AT42QT1040

1.2

Schematic

Figure 1-1.

Typical Circuit

Suggested regulator manufacturers:

• Torex (XC6215 series)

• Seiko (S817 series)

• BCDSemi (AP2121 series)

Re Figure 1-1 check the following sections for component values:

• Section3.1 on page6: Cs capacitors (Cs0 – Cs3)

• Section3.5 on page7: Voltage levels

• Section3.3 on page6: LED traces

SLOW

FAST

OFF

VDD

VDD

2

1

3

J2

VDD

2

1

3

J1

ON

2

2

5

5

4

4

3

3

1

1

J3

N/C

19

N/C

10

OUT2

14

SNSK3

15

SNSK2

20

SNSK1

2

SNSK0

4

N/C

18

N/C

7

N/C

17

OUT1

12

OUT0

11

SNS3

16

SNS1

3

N/C

6

OUT3

13

SNS0

5

SNS2

1

SPEED SELECT

AKS SELECT

NOTES:

1) The central pad on the underside of the VQFN chip is a Vss pin and should be connected

to ground. Do not put any other tracks underneath the body of the chip.

2) It is important to place all Cs and Rs components physically near to the chip.

Add a 100 nF capacitor close to pin 9.

QT1040

Creg

Creg

VREG

Follow regulator manufacturer's

recommended values for input

and output bypass capacitors (Creg).

Key0

Key1

Key2

Key3

VUNREG

GND

Cs0

Cs1

Cs2

Cs3

RL0

RL1

RL2

RL3

RAKS

RFS

Rs0

Rs1

Rs2

Rs3

Example use of output pins