MAX11008 Datasheet, PDF (31/67 Pages) Maxim Integrated Products – Dual RF LDMOS Bias Controller with Nonvolatile Memory

Dual RF LDMOS Bias Controller with
Nonvolatile Memory
moves the data from the FIFO and writes it to the
EEPROM. The MAX11008 remains in LUT streaming
mode until the specified amount of data is written to the
EEPROM. Set the internal watchdog oscillator when
LUT streaming mode is exited. If the FIFO is emptied
before all of the data is written to the EEPROM, the
MAX11008 waits until more data is placed into the
FIFO. If data is placed into the FIFO faster than it can
be written to the EEPROM causing the FIFO to fill com-
pletely, the FIFOOVER bit in the Flag register is set to 1
and all subsequent writes to the FIFO are ignored until
there is space for another data word.
The BUSY output goes high during LUT streaming
mode and returns low after all of the data is written to
the EEPROM.
FIFO data flow control in the LUT streaming mode can
be implemented with the following methods:
1) Open Loop—Write data to the FIFO at a rate that
does not exceed 1 word per 60µs to guarantee that
the FIFO does not overflow.
2) Software Flow Control—Check the FIFOOVER bit
(D8) in the Flag register (see Table 26) in between
FIFO write commands to ensure that the FIFO is not
full; then write data to the FIFO.
3) FIFO Status Monitoring—By setting the FIFOSTAT bit
(D11) to 1 in the Hardware Configuration register,
the ALARM output is used to indicate FIFO status.
When the FIFO is full, the ALARM output goes low
and returns high when there is space in the FIFO for
another data word. See Figures 17 and 18.
Message Mode
Use the message mode to read data from the
EEPROM. Write to the user Message register to place
the MAX11008 into message mode (see Table 23). The
FIFO is cleared when entering message mode, so
important data contained in the FIFO should be read
before entering this mode. The specified EEPROM data
is copied into the FIFO and is read by issuing a FIFO
read command. The MAX11008 remains in message
mode until all of the specified EEPROM data is copied
into and read from the FIFO. If the EEPROM data is
copied into the FIFO faster than it is read causing the
FIFO to fill completely, the copying action is suspended
until a data word is read out of the FIFO and the
FIFOOVER bit is set to indicate a not-full condition. If
the EEPROM data is read out of the FIFO faster than it
can be copied causing the FIFO to empty completely, a
data word containing the empty FIFO tag (1111) and
current status of the Flag register is read from the FIFO.
This underflow data is indistinguishable from arbitrary
EEPROM data, so it is necessary to use data flow-con-
trol methods to safely read the EEPROM.
The BUSY output goes high during message mode and
returns low after all of the specified EEPROM data is
read from the FIFO.
FIFO data flow control in message mode can be imple-
mented with the following methods:
1) Open Loop—Read data from the FIFO at a rate no
greater than 1 word per 50µs, which guarantees that
the FIFO does not empty completely before all of the
specified data is copied from the EEPROM.
2) Software Flow Control—Check the FIFOEMP bit (D9)
in the Flag register (see Table 26) in between FIFO
read commands to ensure that the FIFO is not
empty.
3) FIFO Status Monitoring—By setting the FIFOSTAT bit
(D11) to 1 in the Hardware Configuration register, the
ALARM output is used to indicate FIFO status. When
the FIFO is empty, the ALARM output goes low and
returns high after more data is copied into the FIFO.
BUSY Output
The BUSY output goes high to show that the MAX11008
is busy for the reasons listed below:
1) The ADC is in the middle of a user-commanded con-
version cycle (but not in continuous convert mode).
2) Power-up initializations are being performed.
3) A V_{GATE_} calculation is being made.
4) Data is being read from the EEPROM (message
mode).
5) Data is being written to the EEPROM (LUT streaming
mode).
6) One of the PGAs is undergoing calibration.
The serial interface remains active regardless of the state
of the BUSY output. Wait until BUSY goes low to read the
current conversion data from the FIFO. When BUSY is
high, as a result of an ADC conversion, do not enter a
second conversion command until BUSY has gone low
to indicate the previous conversion is complete.
In multiple conversion mode (CKSEL1, CKSEL0 = 01 or
CKSEL1, CKSEL0 = 00), the BUSY signal remains high
until all channels have been scanned and the data from
the final channel has been moved into the FIFO and
checked for alarm limits if enabled (see the Alarm
Software Configuration Register (ALMSCFIG)
(Read/Write) section). In continuous-conversion mode
(CONCONV = 1), the BUSY signal does not go high as
a result of ADC conversions; however, BUSY does go
high when CONCONV is cleared and BUSY remains
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