Datasheet
MAX11359A
16-Bit Data-Acquisition System with ADC, DAC,
UPIOs, RTC, Voltage Monitors, and Temp Sensor
39
Maxim Integrated
DACA_OP Register
Writing to the DACA_OP output register updates DACA
on the rising SCLK edge of the LSB data bit. The output
voltage can be calculated as follows:
V
OUTA
= V
REF
x N/2
10
where:
V
REF
is the reference voltage for the DAC.
N is the integer value of the DACA<9:0> output regis-
ter. The output buffer is in unity gain.
The DACA data is 10 bits long and right justified.
DAE: DACA enable bit. Set DAE = 1 to power up the
DACA and the DACA output buffer in the MAX11359A.
OP2E: OP2 power-enable bit. Set OP2E = 1 to power
up OP2 in the MAX11359A.
OP1E: OP1 power-enable bit. Set OP1E = 1 to power
up OP1 in the MAX11359A. This bit is mirrored in the
DACB_OP register.
DACA<9:0>: DACA data bits.
DACA_OP Register (Power-On State: 000X XX00 0000 0000)
The REF_SDC register contains bits to control the refer-
ence voltage and signal-detect comparator.
REFV<1:0>: Reference buffer voltage gain and enable
bits. Enables the output buffer, sets the gain and the
voltage at the REF pin as shown in Table 10. Power-on
state is off to enable an external reference to drive the
REF pin without contention.
AOFF: ADC and DAC/op-amp power-off bit. This bit pro-
vides a method for turning off several analog functions
with a single write. Setting AOFF = 1 deasserts the
ADCE in the ADC register and DAE/OP3E, OP2E, and
OP1E bits in the DACA_OP registers, powering down
these analog blocks. Setting AOFF = 0 has no effect.
The AON bit has priority when both AON and AOFF bits
are asserted.
Most of the analog functions can be disabled with a
single write to the REF_SDC register by using AOFF,
REFV<1:0>, and SDCE.
MSB
DAE DBE OP1E X X X DACA9 DACA8
LSB
DACA7 DACA6 DACA5 DACA4 DACA3 DACA2 DACA1 DACA0
MSB LSB
REFV1 REFV0 AOFF AON SDCE TSEL2 TSEL1 TSEL0
REF_SDC Register (Power-On State: 0000 0000)
REFERENCE
BUFFER GAIN
(V/V)
REF OUTPUT
VOLTAGE (V)
REFV1 REFV0
Disabled
Off (High
Impedance
at REF)
00
1.0 1.251 0 1
1.638 1.996 1 0
2.0 2.422 1 1
Table 10. Setting the Reference Output
Voltage