Rainbow Electronics MAX1386 - Manual (Page 48)

MAX1385/MAX1386
Dual RF LDMOS Bias Controllers
with I
2 C/SPI Interface
48 ______________________________________________________________________________________
limits are within the safe operating area. Configure the
ADC for continuous conversions to allow continuous
measurement and testing against configured alarm
thresholds. Connect SAFE_ to OPSAFE_ to immediately
force the gate drive to GATEGND in the event of an
alarm-related condition (current or temperature). Triggering DAC Calibration
Performing the autocalibration routines requires use of
the internal ADC, the internal ALU, and can also
increase the power dissipation of the part. Tables 28
and 29 detail which commands trigger autocalibration
and which commands do not.
ACTION REQUIRED RECOMMENDED COMMAND SEQUENCE
OTHER POSSIBLE COMMAND
SEQUENCES
Update fine DAC_ without triggering
autocalibration. Write to FINE_. Write to LDAC to update fine
DAC_. Write to FINETHRU_ to immediately
update fine DAC_.
Update high wiper coarse DAC_ without
triggering autocalibration. Write to HIWIPE_ with HCAL set to 0. Write
to LDAC to update high wiper coarse DAC_. Write to THRUHI_ to immediately
update high wiper coarse DAC_.
Update low wiper coarse DAC_ without
triggering autocalibration. Write to LOWIPE_ with LCAL set to 0. Write
to LDAC to update low wiper coarse DAC_. Write to THRULO_ to immediately
update low wiper coarse DAC_.
Immediately update fine DAC_ without
triggering autocalibration.
Write to FINETHRU_. None.
Immediately update high wiper coarse
DAC_ without triggering autocalibration.
Write to THRUHI_. None.
Immediately update low wiper coarse
DAC_ without triggering autocalibration.
Write to THRULO_. None.
Update the high, low, and fine components
of DAC_ simultaneously without triggering
autocalibration.
Write to HIWIPE_, LOWIPE, and FINE_.
Write to LDAC to update DAC_.
None.
Table 28. DAC Write Commands Without Autocalibration
0000 0000 0000
0000 0000 0001
0000 0000 0010
INPUT VOLTAGE (LSB)
1111 1111 1100
1111 1111 1110
1111 1111 1111
1111 1111 1101
FULL-SCALE TRANSITION
BINARY OUTPUT CODE
4093 4095 0 1 2 3
0000 0000 0011
V REFADC
V
REFADC
1 LSB =
V REFADC
4096
1000 0000 0000
1000 0000 0001
1000 0000 0010
-256°C
TEMPERATURE (°C)
0000 0000 0001
0111 1111 1110
0111 1111 1111
1111 1111 1111
0000 0000 0000
0111 1111 1101
1 LSB = +0.125°C
OUTPUT CODE
0°C +255.875°C
Figure 25. ADC Transfer Function Figure 26. Temperature Transfer Function