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MAX1020 Datasheet, PDF (33/47 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 21. DAC Power-Up and Power-Down Commands
CONTROL
BITS
C3 C2 C1 C0
DATA BITS
DESCRIPTION
D3 D2 D1 D0
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.
Power down individual DAC buffers indicated by
1
1
1
1
———————— 0
1
0
X
Power-Down 1
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.
Power down individual DAC buffers indicated by
data in DAC0 through DAC7. A one indicates the
1 1 1 1 — — — — — — — — 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 DAC7. A one indicates the
1 1 1 1 — — — — — — — — 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 DAC7. A one indicates the
1 1 1 1 — — — — — — — — 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
MAX1020–MAX1023/MAX1057/MAX1058. All 10-bit
conversion 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 complement 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 = VREF1 / 1024
(MAX1021/MAX1023/MAX1057) and 1 LSB = VREF1 /
1024 (MAX1020/MAX1022/MAX1058) for unipolar and
bipolar operation, and 1 LSB = +0.125°C for tempera-
ture measurements. Bipolar true-differential results and
temperature-sensor results are available in two’s com-
plement 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
VREF1. In bipolar mode, either input can exceed the
other by up to VREF1 / 2.
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