MAX11156 Datasheet, PDF (17/27 Pages) Maxim Integrated Products – 18-Bit, 500ksps, ±5V SAR ADC with Internal Reference in TDFN

MAX11156
18-Bit, 500ksps, ±5V SAR ADC
with Internal Reference in TDFN
This is an indication to the user that there are insufficient
SCLK falling edges in a given readout cycle. Table 5
provides a guide to aid in the selection of the appropriate
output interface mode for a given application.
CS No-Busy Indicator Mode
The CS no-busy indicator mode is ideally suited for
maximum throughput when a single MAX11156 is con-
nected to a SPI-compatible digital host. The connection
diagram is shown in Figure 6, and the corresponding
timing is provided in Figure 7.
A rising edge on CNVST completes the acquisition, initi-
ates the conversion, and forces DOUT to high impedance.
The conversion continues to completion irrespective of
the state of CNVST allowing CNVST to be used as a
select line for other devices on the board. If CNVST is
brought low during a conversion and held low throughout
the maximum conversion time, the MSB will be output at
the end of the conversion.
When the conversion is complete, the MAX11156
enters the acquisition phase. Drive CNVST low to out-
put the MSB onto DOUT. The remaining data bits are
then clocked by subsequent SCLK falling edges. DOUT
returns to high impedance after the 18th SCLK falling
edge, or when CNVST goes high.
Table 5. ADC Output Interface Mode
Selector Guide
MODE
CS Mode,
No-Busy
Indicator
CS Mode,
With Busy
Indicator
TYPICAL APPLICATION AND BENEFITS
Single or multiple ADCs connected to SPI-
compatible digital host. Ideally suited for
maximum throughput.
Single ADC connected to SPI-compatible
digital host with interrupt input. Ideally suited
for maximum throughput.
Daisy-Chain
Mode,
No-Busy
Indicator
Multiple ADCs connected to a SPI-
compatible digital host. Ideally suited for
multichannel simultaneous sampled isolated
applications.
Daisy-Chain
Mode,
With Busy
Indicator
Multiple ADCs connected to a SPI-
compatible digital host with interrupt input.
Ideally suited for multichannel simultaneous
sampled isolated applications.
CNVST
DOUT
MAX11156
DIN
SCLK
CONVERT
DIGITAL HOST
DATA IN
CONFIG
CLK
Figure 6. CS No-Busy Indicator Mode Connection Diagram
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