Datasheet

MAX1020/MAX1022/MAX1057/MAX1058
10-Bit, Multichannel ADCs/DACs with FIFO,
Temperature Sensing, and GPIO Ports
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Output-Data Format
Figures 6–9 illustrate the conversion timing for the
MAX1020/MAX1022/MAX1057/MAX1058. All 10-bit con-
version results are output in 2-byte format, MSB first,
with four leading zeros and with 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
(MAX1057) and 1 LSB = V
REF1
/ 1024 (MAX1020/
MAX1022/MAX1058) 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.
Table 21. DAC Power-Up and Power-Down Commands
CONTROL
BITS
DATA BITS
C3 C2 C1 C0
DAC7 DAC6 DAC5 DAC4 DAC3 DAC2 DAC1 DAC0
D3 D2 D1 D0
DESCRIPTION FUNCTION
1 1 1 1 ———————— 0 0 1 X Power-Up
Power up individual DAC buffers indicated by data
in DAC0 through DAC7. A one indicates the DAC
output is connected and active. A zero does not
affect the DAC’s present state.
1 1 1 1 ———————— 0 1 0 X Power-Down 1
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and high impedance.
A zero does not affect the DAC’s present state.
1 1 1 1 ———————— 1 0 0 X Power-Down 2
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and pulled to AGND
with a 1kΩ resistor. A zero does not affect the DAC’s
present state.
1 1 1 1 ———————— 0 0 0 X Power-Down 3
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and pulled to AGND
with a 100kΩ resistor. A zero does not affect the
DAC’s present state.
1 1 1 1 ———————— 1 1 1 X Power-Down 4
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
DAC output is disconnected and pulled to REF1 with
a 100kΩ resistor. A zero does not affect the DAC’s
present state.