Re m o t e /Lo c a l Te m p e ra t u re S e n s o r
w it h S MBu s S e ria l In t e rfa c e
Table 8. RLTS and RRTE Temp Register Update Timing Chart
NEW CONVERSION RATE
(CHANGED VIA WRITE TO
WCRW)
TIME UNTIL RLTS AND RRTE
ARE UPDATED
OPERATING MODE
CONVERSION INITIATED BY:
Auto-Convert
Auto-Convert
Power-on reset
n/a (0.25Hz)
156ms max
156ms max
1-shot command, while idling
between automatic conversions
n/a
1-shot command that occurs
during a conversion
When current conversion is
complete (1-shot is ignored)
Auto-Convert
n/a
MX617A
Auto-Convert
Rate timer
Rate timer
Rate timer
Rate timer
Rate timer
Rate timer
Rate timer
Rate timer
STBY pin
0.0625Hz
0.125Hz
0.25Hz
0.5Hz
1Hz
20sec
Auto-Convert
10sec
Auto-Convert
5sec
Auto-Convert
2.5sec
1.25sec
625ms
312.5ms
237.5ms
156ms
156ms
156ms
Auto-Convert
Auto-Convert
2Hz
Auto-Convert
4Hz
Auto-Convert
8Hz
Hardware Standby
Software Standby
Software Standby
n/a
RUN/STOP bit
1-shot command
n/a
n/a
The address pin states are checked at POR and SPOR
only, and the address data stays latched to reduce qui-
escent supply current due to the bias current needed
for high-Z state detection.
Table 9. Slave Address Decoding (ADD0
and ADD1)
ADD0
GND
ADD1
GND
ADDRESS
0011 000
0011 001
0011 010
0101 001
0101 010
0101 011
1001 100
1001 101
1001 110
The MAX1617A a ls o re s p ond s to the SMBus Ale rt
Re s p ons e s la ve a d d re s s (s e e the Ale rt Re s p ons e
Address section).
GND
High-Z
GND
V
CC
P OR a n d UVLO
The MAX1617A has a volatile memory. To prevent ambig-
uous power-supply conditions from corrupting the data in
memory and causing erratic behavior, a POR voltage
High-Z
High-Z
High-Z
GND
High-Z
V
CC
V
CC
GND
detector monitors V and clears the memory if V falls
CC
CC
below 1.7V (typical, see Electrical Characteristics table).
V
CC
High-Z
When power is first applied and V rises above 1.75V
CC
V
CC
V
CC
(typical), the logic blocks begin operating, although reads
Note: High-Z means that the pin is left unconnected and floating.
and writes at V levels below 3V are not recommended.
CC
A second V comparator, the ADC UVLO comparator,
CC
prevents the ADC from converting until there is sufficient
Power-Up Defaults:
headroom (V = 2.8V typical).
CC
•
•
•
•
Interrupt latch is cleared.
The SPOR software POR command can force a power-on
reset of the MAX1617A registers via the serial interface.
Use the SEND BYTE protocol with COMMAND = FCh.
This is most commonly used to reconfigure the slave
address of the MAX1617A “on the fly,” where external
hardware has forced new states at the ADD0 and ADD1
address pins prior to the software POR. The new address
takes effect less than 100µs after the SPOR transmission
stop condition.
Address select pins are sampled.
ADC begins auto-converting at a 0.25Hz rate.
Comma nd b yte is s e t to 00h to fa c ilita te q uic k
remote Receive Byte queries.
•
T
HIGH
and T
registers are set to max and min
LOW
limits, respectively.
14 ______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
