Typical operating characteristics, Electrical characteristics (continued) – Rainbow Electronics MAX6641 User Manual

Page 3

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MAX6641

SMBus-Compatible Temperature Monitor with

Automatic PWM Fan-Speed Controller

_______________________________________________________________________________________

3

Note 1: Timing specifications guaranteed by design.
Note 2: The serial interface resets when SMBCLK is low for more than t

TIMEOUT

.

Note 3: A transition must internally provide at least a hold time to bridge the undefined region (300ns max) of SMBCLK’s falling edge.

ELECTRICAL CHARACTERISTICS (continued)

(V

CC

= +3.0V to +5.5V, T

A

= 0

°C to +125°C, unless otherwise noted. Typical values are at V

CC

= 3.3V, T

A

= +25

°C.)

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

SMBus-COMPATIBLE TIMING (Note 1) (See Figures 2, 3)

Serial Clock Frequency

f

SCLK

(Note 2)

100

kHz

Clock Low Period

t

LOW

10% to 10%

4

µs

Clock High Period

t

HIGH

90% to 90%

4.7

µs

Bus Free Time Between Stop and
Start Condition

t

BUF

4.7

µs

Hold Time After (Repeated) Start
Condition

t

HD:STA

4

µs

S M Bus S tar t C ond i ti on S etup Ti m e

t

SU:STA

90% of SMBCLK to 90% of SMBDATA

4.7

µs

Start Condition Hold Time

t

HD:STO

10% of SMBDATA to 10% of SMBCLK

4

µs

Stop Condition Setup Time

t

SU:STO

90% of SMBCLK to 10% of SMBDATA

4

µs

Data Setup Time

t

SU:DAT

10% of SMBDATA to 10% of SMBCLK

250

ns

Data Hold Time

t

HD:DAT

10% of SMBCLK to 10% of SMBDATA
(Note 3)

300

ns

SMBus Fall Time

t

F

300

ns

SMBus Rise Time

t

R

1000

ns

SMBus Timeout

t

TIMEOUT

29

37

55

ms

Startup Time After POR

t

POR

500

ms

Typical Operating Characteristics

(V

CC

= 3.3V, T

A

= +25

°C, unless otherwise noted.)

OPERATING SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX6641 toc01

SUPPLY VOLTAGE (V)

OPERATING SUPPLY CURRENT (

µ

A)

5.0

4.5

4.0

3.5

350

400

450

500

550

600

300

3.0

5.5

NO SMBus ACTIVITY

REMOTE TEMPERATURE ERROR

vs. REMOTE-DIODE TEMPERATURE

MAX6641 toc02

TEMPERATURE (

°C)

TEMPERATURE ERROR (

°C)

100

75

25

50

-1.5

-1.0

-0.5

0

0.5

1.0

1.5

2.0

-2.0

0

125

LOCAL TEMPERATURE ERROR

vs. DIE TEMPERATURE

MAX6641 toc03

TEMPERATURE (

°C)

TEMPERATURE ERROR (

°C)

100

75

50

25

-1

0

1

2

-2

0

125

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