ASAHI KASEI
[AK2570]
(2) Training mode
“Training mode” is used for the evaluation and the adjustment about AK2570. It is possible to write and read
the data in the EERPOM and the registers and to execute activating the internal circuit for setting the
temperature compensation data with the serial interface. Notice that it is possible to shift to “Training mode”
by executing ‘Command for Training mode’ and any other command is not available while operating in
“Self-operation mode”.
After executing ‘Command for Training mode’, it is necessary to input the clock or the ‘H’ level signal to
SK-pin continuously to keep the operational mode is in “Training mode“. It is able to return to “Self-
operational mode” by forcing the ‘L’ level signal to SK-pin for 50msec more in “Training mode”.
In “Training mode”, the periodical operation of temperature compensation for the LD is stopped. Also at the
time of executing ‘Command for Training mode’ while operating in “Self-operational mode”, AK2570
transfers to “Training mode” after completing the periodical operation.
Recommended sequence in ”Training mode
START
Set the temperature at the minimum value for the use (e.g. -40℃ )
Execute 'Command for Training mode' --> Initial setting : Command for Training mode
Write '00000' in RINT register --> Register access : WRITE-REG(RINT)
Add '+1' to the data
in RINT register
--> Register access
WRITE-REG(RINT) No
AD2 executes A to D conversion --> Initial Setting : Command for Selecting AD2
for the T-SENSE output
--> Activating Internal Circuit :
Command for A/D operation
Confirm the code generated by AD2
is '00000010'~'00001000' (e.g. -40℃ )
--> Register Access : READ-REG(RTMP)
Yes
(See p.15)
Change the
ambient temperature
--> Register access :
READ-REG(RTMP)
No
Set the data for DA1 & DA2 that will be retained in --> Register Access : WRITE-REG(RDA1)
EDA1 &EDA2 to fit the LD characteristics
--> Register Access : WRITE-REG(RDA2)
--> Evaluation for the LD characteristics
After execting the A to D conversion in AD1 for
the input voltage to VPDIN-pin, read the data in
RVPD register that will be retained in EDA3
--> Adjusting the monitoring PD
--> Initial Setting : Command for Selecting AD1
--> Activating Internal Circuit :
Command for A/D operation
--> Register Access : READ-REG(RVPD)
Complete the measurement for the compensation data
Yes
Make the data for writing in the EEPROM
Write the compensatory data in the EEPROM
--> EEPROM Access : EWEN
--> EEPROM Access : WRITE-EEP
FINISH
<MS0115-E-00>
7
2001/10