© 2016 Integrated Device Technology, Inc.
Normal Operation Mode
Start_NOM
Power ON
Command Mode
Raw Mode
No commands possible;
measurement cycle;
conditioning calculation
(corrected bridge and
temperature values)
Depending on the
configuration, the Sig
TM
pin is
• 0 V to 1 V;
• Rail-to-rail ratiometric; or
• Digital output
Measurement cycle stopped;
full command set
Command routine will be
processed after each
command
Measurement cycle
Sig
TM
pin provides raw bridge
and temperature values in
this format:
• Bridge_high (1
st
byte)
• Bridge_low (2
nd
byte)
• Temp (3
rd
byte)
Start_RM
Command
Window (6 ms); send
Start_CM
Start_CM
No Command
Power OFF
3 Functional Description
3.1. General Working Mode
The command/data transfer takes place via the one-wire Sig™ pin, using the ZACwire™ serial communication
protocol. After power-on, the IC waits for 6 ms (i.e., the command window) for the Start_CM command. Without
this command, the Normal Operation Mode (NOM) starts. In this mode, raw bridge values are converted, and the
corrected values are presented on the output in analog or digital format (depending on the configuration stored in
EEPROM).
Command Mode (CM) can only be entered during the 6 ms command window after power-on. If the IC receives
the Start_CM command during the command window, it remains in the Command Mode. The CM allows changing
to one of the other modes via command. After command Start_RM, the IC is in the Raw Mode (RM). Without
correction, the raw values are transmitted to the digital output in a predefined order. The RM can only be stopped
by power-off. Raw Mode is used by the calibration software for collection of raw bridge and temperature data, so
the correction coefficients can be calculated.
Figure 3.1 General Working Mode
