DS9490

5 of 5

ELECTRICAL CHARACTERISTICS

PARAMETER

SPECIFICATION

USB I/F

As defined in Chapter 7 of the USB Specification*

1-Wire I/F

See the DS2490 data sheet**

The DS9490R and DS9490B consume 58mA in USB active mode and 0.5mA in suspend mode*. The

available to an externally powered fixture is 42mA* (100mA to 58mA); however it is recommended that

no more than 25mA be used. Note that in suspend mode there is zero current available to an external

circuit. An external circuit cannot detect when the module is in suspend or active mode. Consequently,

when in suspend mode, the DS9490R module with external circuit combination is in violation of the USB

power specification. Application developers should be aware of this when using this module in

conjunction with an externally powered circuit on power restricted platforms such as laptops.

*Guaranteed by design, not production tested.

**Tested at DS2490 component level.

Figure 8. FUNCTIONAL DIAGRAM

EMI Filter

VBUS

D-

D+

GND

VIN

VOUT

EN

N/C

GND

LP2980IM5-3.3

PMOD

VD

NC

NC

NC

NC

NC

NC

VB

X1

SUSO

X0

D-

NC

D+

VPP

NC

NC

OW

NC

NC

NC

GND

NC

DS2490

C2

1.0uF

EMI Filter

C3

4.7

R2 24

R3 24

R1

1.5K

C1

0.1uF

OW

GND

DS2401

OW

GND

DS9503

USB

Connector

C6

33pF

C5

33pF

X1

12Mhz

L1

L2

C7

33pF

C8

33pF

U1

U2

U3

U4

J2

1

2

1

2

J1

1

2

3

4

1

3

4

5

2

1

5

7

8

12

24

19

20

17

10

1

2

3

4

5

6

Female RJ11

DS9490R

DS9490B

1

2

iButton Socket

J3

6

5

3

1