MAX6678AEP92+ Maxim Integrated Products, MAX6678AEP92+ Datasheet - Page 7

• Manufacturer Part Number: MAX6678AEP92+
• Description: Board Mount Temperature Sensors 2Ch Temperature Monitor
• Manufacturer: Maxim Integrated Products

Specifications of MAX6678AEP92+

• Full Temp Accuracy: +/- 4 C
• Package / Case: QSOP-20
• Digital Output - Bus Interface: Serial (2-Wire)
• Digital Output - Number Of Bits: 8 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Output Type: Digital
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Figure 2. SMBus Write Timing Diagram
Figure 3. SMBus Read Timing Diagram
The DXN input is biased at 0.60V above ground by an
internal diode to set up the analog-to-digital inputs for a
differential measurement. The worst case DXP-DXN dif-
ferential input voltage range is from 0.25V to 0.95V.
Excess resistance in series with the remote diode causes
about +0.5°C error per ohm. Likewise, a 200µV offset
voltage forced on DXP-DXN causes about 1°C error.
High-frequency EMI is best filtered at DXP and DXN with
an external 2200pF capacitor. This value can be
increased to about 3300pF (max), including cable capac-
itance. Capacitance higher than 3300pF introduces
errors due to the rise time of the switched current source.
2-Channel Temperature Monitor with Dual Automatic
SMBCLK
SMBDATA
SMBCLK
SMBDATA
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
A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
t
SU:STA
t
SU:STA
A
t
HD:STA
A
t
_______________________________________________________________________________________
HD:STA
t
LOW
PWM Fan-Speed Controller and Five GPIOs
t
B
LOW
t
HIGH
B
t
HIGH
t
SU:DAT
C
t
SU:DAT
C
E = SLAVE PULLS SMBDATA LINE LOW
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE
H = LSB OF DATA CLOCKED INTO SLAVE
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO MASTER
H = LSB OF DATA CLOCKED INTO MASTER
I = MASTER PULLS DATA LINE LOW
D
D
E
F
E
F
Table 1. Temperature Data Byte Format
Diode fault (open)
Diode fault (short)
t
HD:DAT
G
TEMP (°C)
G
0.50
0.00
241
240
126
25
I = MASTER PULLS DATA LINE LOW
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
M = NEW START CONDITION
H
H
ROUNDED TEMP
J = ACKNOWLEDGE CLOCKED INTO SLAVE
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION
M = NEW START CONDITION
I
+241
+240
+126
(°C)
+25
I
+1
—
—
0
J K
J
K
DIGITAL OUTPUT
t
SU:STO
t
SU:STO
1111 0001
1111 0000
0111 1110
0001 1001
0000 0001
0000 0000
1110 1111
1111 1111
L
L
t
BUF
t
BUF
M
M
7