MAX6636UP9A+ Maxim Integrated Products, MAX6636UP9A+ Datasheet - Page 8

• Manufacturer Part Number: MAX6636UP9A+
• Description: IC PREC TEMP MONITOR 7CH 20TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX6636UP9A+

• Function: Temp Monitoring System (Sensor)
• Topology: ADC, Buffer, Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -40°C ~ 125°C, External Sensor
• Output Type: SMBus™
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP
• Full Temp Accuracy: - 0.1 C, 3 C
• Digital Output - Bus Interface: Serial (2-Wire)
• Digital Output - Number Of Bits: 11 bit
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7-Channel Precision Temperature Monitor
register. If extended resolution is desired, the extended
resolution register should be read first. This prevents
the most significant bits from being overwritten by new
conversion results until they have been read. If the most
significant bits have not been read within an SMBus
timeout period (nominally 37ms), normal updating con-
tinues. Table 1 shows the main temperature register
(high-byte) data format, and Table 2 shows the extend-
ed resolution register (low-byte) data format.
Figure 2. SMBus Protocols
Table 1. Main Temperature Register
(High-Byte) Data Format
8
WRITE BYTE FORMAT
READ BYTE FORMAT
SEND BYTE FORMAT
_______________________________________________________________________________________
S
S
S = START CONDITION.
P = STOP CONDITION.
S
Diode fault (open)
Diode fault (short)
SLAVE ADDRESS: EQUIVA-
LENT TO CHIP-SELECT LINE
TEMP (°C)
ADDRESS
ADDRESS
7 BITS
7 BITS
SLAVE ADDRESS: EQUIVA-
LENT TO CHIP-SELECT LINE OF
A 3-WIRE INTERFACE
> +127
+127
+126
+25
< 0
0
ADDRESS
7 BITS
WR
WR
SHADED = SLAVE TRANSMISSION.
/// = NOT ACKNOWLEDGED.
ACK
ACK
WR
COMMAND BYTE: SENDS COM-
MAND WITH NO DATA, USUALLY
USED FOR ONE-SHOT COMMAND
1111 1111 or 1110 1110
COMMAND BYTE: SELECTS
WHICH REGISTER YOU ARE
REDING FROM
COMMAND
COMMAND
DIGITAL OUTPUT
8 BITS
8 BITS
0111 1111
0111 1111
0111 1110
0001 1001
0000 0000
0000 0000
1111 1111
ACK
ACK
ACK
P
COMMAND
8 BITS
S
RECEIVE BYTE FORMAT
If a channel’s input DXP_ and DXN_ are left open, the
MAX6636 detects a diode fault. An open diode fault does
not cause either ALERT or OVERT to assert. A bit in the
status register for the corresponding channel is set to 1
and the temperature data for the channel is stored as all
1s (FFh). It takes approximately 4ms for the MAX6636 to
detect a diode fault. Once a diode fault is detected, the
MAX6636 goes to the next channel in the conversion
sequence. Depending on operating conditions, a shorted
diode may or may not cause ALERT or OVERT to assert,
so if a channel will not be used, its DXN and DXP inputs
should be left unconnected.
Table 2. Extended Resolution Temperature
Register (Low-Byte) Data Format
SLAVE ADDRESS: REPEATED
DUE TO CHANGE IN DATA-
FLOW DIRECTION
S
ADDRESS
7 BITS
ADDRESS
7 BITS
ACK
TEMP (°C)
+0.125
+0.250
+0.375
+0.500
+0.625
+0.725
+0.875
0
RD
DATA BYTE: DATA GOES INTO THE REGISTER
SET BY THE COMMAND BYTE (TO SET
THRESHOLDS, CONFIGURATION MASKS, AND
SAMPLING RATE)
RD
8 BITS
DATA
ACK
ACK
Diode Fault Detection
DATA BYTE: READS FROM
THE REGISTER SET BY THE
COMMAND BYTE
DATA BYTE: READS DATA FROM
THE REGISTER COMMANDED
BY THE LAST READ BYTE OR
WRITE BYTE TRANSMISSION;
ALSO USED FOR SMBus ALERT
RESPONSE RETURN ADDRESS
8 BITS
DATA
DATA
8 BITS
ACK
DIGITAL OUTPUT
000X XXXX
001X XXXX
010X XXXX
011X XXXX
100X XXXX
101X XXXX
110X XXXX
111X XXXX
///
///
P
1
P
P