Rainbow Electronics MAX1386 - Manual (Page 26)

MAX1385/MAX1386
Dual RF LDMOS Bias Controllers
with I
2 C/SPI Interface
26 ______________________________________________________________________________________
Hysteresis-Threshold Mode
In hysteresis-threshold mode, ADC readings of
current/temperature are compared to the configured
current/temperature low/high thresholds that are pro-
grammed to cause an alarm condition. If an ADC read-
ing exceeds its respective configured threshold and
ALARM is configured for output-comparator mode,
ALARM asserts until the current/temperature reading
falls back below its respective threshold. If an ADC
reading exceeds its respective configured threshold
and ALARM is configured for output-interrupt mode,
ALARM asserts until the Flag register is read. See
Figures 9 and 10.
Register Descriptions
Communicate with the MAX1385/MAX1386 through the
I
2 C/SPI-compatible serial interface. Complete read and
write operations consist of slave address bytes, com-
mand bytes, and data bytes. The following register
descriptions cover the contents of command bytes and
data bytes. See the
Digital Serial Interface section for a
detailed description of how to construct full read and
write operations. All registers are volatile and are reset
to default states upon removal of power. These default
states are referred to as power-on reset (POR) states.
All accessible MAX1385/MAX1386 registers are shown
in Table 2.
TH1 and TH2 (Read/Write)
Write to Channel 1 and Channel 2 High Temperature
Threshold registers by sending the appropriate write
command byte followed by data bits D15–D0 (see Table
3). Bits D15–D12 are don’t care. Read channel 1 and
channel 2 high-temperature thresholds by sending the
appropriate read command byte. Channel 1 and
Channel 2 Temperature Threshold registers are com-
pared to temperature readings from the remote diode
connected transistors. Temperature data is in two’s-com-
plement format and the LSB corresponds to 1/8°C (see
Figure 26 for the Temperature Transfer Function).
TL1 and TL2 (Read/Write)
Write to Channel 1 and Channel 2 Low-Temperature-
Threshold registers by sending the appropriate write
command byte followed by data bits D15–D0 (see Table
4). Bits D15–D12 are don’t care. Read channel 1 and
channel 2 low-temperature thresholds by sending the
appropriate read command. Channel 1 and Channel 2
Temperature Threshold registers are compared to tem-
perature readings from the remote diode connected tran-
sistors. Temperature data is in two’s-complement format
and the LSB corresponds to 1/8°C (see Figure 26 for the
Temperature Transfer Function).
ALARM OUTPUT ASSERTED
WHEN MEASURED VALUE
RISES ABOVE THIS LEVEL
RANGE OF VALUES THAT DO NOT CAUSE AN ALARM
HIGHEST POSSIBLE THRESHOLD
VALUE (DEFAULT VALUE FOR HIGH
THRESHOLD REGISTER)
HIGH THRESHOLD
LOW THRESHOLD
LOWEST POSSIBLE THRESHOLD
VALUE (DEFAULT VALUE FOR LOW
THRESHOLD REGISTER)
ALARM OUTPUT ASSERTED
WHEN MEASURED VALUE
FALLS BELOW THIS LEVEL
*ONLY WHEN ALARM IS CONFIGURED FOR OUTPUT-COMARATOR MODE.
WHEN IN OUTPUT-INTERRUPT MODE, FLAG REGISTER MUST BE READ
FOR ALARM TO BE DEASSERTED.
Figure 9. Hysteresis-Threshold-Mode Diagram