MAX11014_08 Datasheet, PDF (41/70 Pages) Maxim Integrated Products – Automatic RF MESFET Amplifier Drain-Current Controllers

Automatic RF MESFET Amplifier
Drain-Current Controllers
Table 12a. GATE Voltage Hysteresis Levels
VGHYST1
0
0
1
1
VGHYST0
0
1
0
1
8 LSBs of hysteresis.
16 LSBs of hysteresis.
32 LSBs of hysteresis.
64 LSBs of hysteresis.
FUNCTION
Table 12b. Sense Voltage/Temperature Hysteresis Levels
ITHYST1
0
0
1
1
ITHYST0
0
1
0
1
8 LSBs of hysteresis.
16 LSBs of hysteresis.
32 LSBs of hysteresis.
64 LSBs of hysteresis.
FUNCTION
Table 12c. ALARM Clamp Modes
ALM_CLMP1
0
ALM_CLMP0
0
FUNCTION
Default state. The GATE_ outputs are clamped to the respective external voltage applied at
ACLAMP_ independent of alarms. GATE_ remains clamped until this register value is changed
or a software clear command is issued.
The corresponding ALARM bit in the ALARM flag register goes high if an ALARM condition is
0
1
triggered by a conversion of sense voltage, temperature, or GATE_ voltage. However, the
GATE_ outputs are not clamped.
Fully automatic clamping. The GATE_ outputs are clamped to the respective external voltage
applied at ACLAMP_ when an ALARM condition is triggered. The clamp is removed if a
1
0
subsequent temperature or sense voltage conversion removes the ALARM condition. GATE_
remains clamped when a GATE_ voltage ALARM is triggered. For a GATE_ voltage ALARM,
ALM_CLMP 10 mode functions the same as 11 mode. This exception breaks the feedback
loop created by sampling GATE_ voltage and then clamping the same signal.
Semi-automatic clamping. The GATE_ outputs are clamped to the respective external voltage
1
1
applied at ACLAMP_ when an ALARM condition is triggered. If an ALARM condition is
triggered, the ALM_CLMP bits are overwritten to 00, causing a permanent clamp condition.
Clear this permanent clamp condition with a subsequent write to reset the ALM_CLMP bits.
ALMSCFG (Read/Write)
The software ALARM configuration register controls
which voltage and temperature channels trigger the
ALARM output and whether the ALARM comparators
operate in windowing or hysteresis mode. Set the com-
mand byte to 3Eh to write to the software ALARM config-
uration register. Set the command byte to BEh to read
the software ALARM configuration register. Bits
D15–D12 are don’t care. Set the VALARM2 bit, D11, to 1
to enable ALARM functionality for GATE2 voltage mea-
surements. Set the VWIN2 bit, D10, to 1 to monitor the
GATE2 voltage with the ALARM comparator in window-
ing mode. Set VWIN2 to 0 to monitor the GATE2 voltage
with the ALARM comparator in hysteresis mode.
Set the TALARM2 bit, D9, to 1 to enable ALARM func-
tionality for channel 2 temperature measurements. Set
the TWIN2 bit, D8, to 1 to monitor the channel 2 tem-
perature with the ALARM comparator in windowing
mode. Set TWIN2 to 0 to monitor the channel 2 temper-
ature with the ALARM comparator in hysteresis mode.
Set the IALARM2 bit, D7, to 1 to enable ALARM func-
tionality for channel 2 sense voltage (RCS2+ to RCS2-)
measurements. Set the IWIN2 bit, D6, to 1 to monitor
the channel 2 sense voltage with the ALARM compara-
tor in windowing mode. Set IWIN2 to 0 to monitor the
channel 2 sense voltage with the ALARM comparator in
hysteresis mode.
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