Typical operating circuit – Rainbow Electronics MAX1669 User Manual

Page 18

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MAX1669

Fan Controller and Remote Temperature Sensor
with SMBus Serial Interface

18

______________________________________________________________________________________

Typical Operating Circuit

SMBCLK

A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE

A

B

C

D

E

F

G

H

I

J

SMBDATA

t

SU:STA

t

HD:STA

t

LOW

t

HIGH

t

SU:DAT

t

SU:STO

t

BUF

K

E = SLAVE PULLS SMBDATA LINE LOW
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO MASTER
H = LSB OF DATA CLOCKED INTO MASTER

I = ACKNOWLEDGE CLOCK PULSE
J = STOP CONDITION
K = NEW START CONDITION

Figure 7. SMBus Write Timing Diagram

SMBCLK

A

B

C

D

E

F

G

H

I

J

K

SMBDATA

t

SU:STA

t

HD:STA

t

LOW

t

HIGH

t

SU:DAT

t

HD:DAT

t

SU:STO

t

BUF

A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
E = SLAVE PULLS SMBDATA LINE LOW

L

M

F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE
H = LSB OF DATA CLOCKED INTO SLAVE
I = SLAVE PULLS SMBDATA LINE LOW

J = ACKNOWLEDGE CLOCKED INTO MASTER
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION, DATA EXECUTED BY SLAVE
M = NEW START CONDITION

Figure 8. SMBus Read Timing Diagram

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