MAX1040_08 Datasheet, PDF (28/39 Pages) Maxim Integrated Products – 10-Bit, Multichannel ADCs/DACs with FIFO, Temperature Sensing, and GPIO Ports

10-Bit, Multichannel ADCs/DACs with FIFO,
Temperature Sensing, and GPIO Ports
Table 18. DAC Power-Up and Power-Down Commands
CONTROL
BITS
C3 C2 C1 C0 X X X X
DATA BITS
DESCRIPTION
D3 D2 D1 D0
FUNCTION
1 1 1 1 X X X X ———— 0 0 1 X
Power-Up
Power up individual DAC buffers indicated by data
in DAC0 through DAC3. A one indicates the DAC
output is connected and active. A zero does not
affect the DAC’s present state.
Power down individual DAC buffers indicated by
1
1
1
1
X
X
X
X ———— 0
1
0
X
Power-Down 1
data in DAC0 through DAC3. A one indicates the
DAC output is disconnected and high impedance.
A zero does not affect the DAC’s present state.
Power down individual DAC buffers indicated by
data in DAC0 through DAC3. A one indicates the
1 1 1 1 X X X X — — — — 1 0 0 X Power-Down 2 DAC output is disconnected and pulled to AGND
with a 1kΩ resistor. A zero does not affect the DAC’s
present state.
Power down individual DAC buffers indicated by
data in DAC0 through DAC3. A one indicates the
1 1 1 1 X X X X — — — — 0 0 0 X Power-Down 3 DAC output is disconnected and pulled to AGND
with a 100kΩ resistor. A zero does not affect the
DAC’s present state.
Power down individual DAC buffers indicated by
data in DAC0 through DAC3. A one indicates the
1 1 1 1 X X X X — — — — 1 1 1 X Power-Down 4 DAC output is disconnected and pulled to REF1 with
a 100kΩ resistor. A zero does not affect the DAC’s
present state.
Output-Data Format
Figures 6–9 illustrate the conversion timing for the
MAX1040/MAX1042/MAX1046/MAX1048. All 10-bit con-
version results are output in 2-byte format, MSB first,
with four leading zeros and the LSB followed by 2 sub-
bits. Data appears on DOUT on the falling edges of
SCLK. Data is binary for unipolar mode and two’s com-
plement for bipolar mode and temperature results. See
Figures 3, 4, and 5 for input/output and temperature-
transfer functions.
ADC Transfer Functions
Figure 3 shows the unipolar transfer function for single-
ended or differential inputs. Figure 4 shows the bipolar
transfer function for differential inputs. Code transitions
occur halfway between successive-integer LSB values.
Output coding is binary, with 1 LSB = V_REF1 / 1024 for
unipolar and bipolar operation, and 1 LSB = +0.125°C
for temperature measurements. Bipolar true-differential
results and temperature-sensor results are available in
two’s complement format, while all others are in binary.
See Tables 6, 7, and 8 for details on which setting
(unipolar or bipolar) takes precedence.
In unipolar mode, AIN+ can exceed AIN- by up to
V_REF1. In bipolar mode, either input can exceed the
other by up to V_REF1/2.
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