MAX11166 Datasheet, PDF (27/33 Pages) Maxim Integrated Products – 16-Bit, 500ksps/250ksps, ±5V SAR ADCs with Internal Reference in TDFN

MAX11166/MAX11167
16-Bit, 500ksps/250ksps, ±5V SAR ADCs
with Internal Reference in TDFN
tCNVPW
CNVSTA(CS1)
tCYC
CNVSTB(CS2)
DIN
ACQUISITION
tSSCKCNF
SCLK
DOUT
tCONV
CONVERSION
tHSCKCNF
tEN
t_ACQ
tSCLKL
ACQUISITION
tSCLK
1
2
3
15
16
tSCLKH
tDDO
tDIS
D15 D14 D13
D1 D0
17
18
19
tEN
D15 D14 D13
tCNVPW
31
32
tDIS
D1 D0
Figure 11. Multichannel CS Configuration Timing
Daisy-Chain, No-Busy Indicator Mode
The daisy-chain mode with no-busy indicator is ideally
suited for multichannel isolated applications that require
minimal wiring complexity. Simultaneous sampling of
multiple ADC channels is realized on the serial interface
where data readback is analogous to clocking a shift
register. Figure 12 shows a connection diagram of two
MAX11166/MAX11167s configured in a daisy chain. The
corresponding timing is given in Figure 13.
A rising edge on CNVST completes the acquisition and
initiates the conversion. Once a conversion is initiated,
it continues to completion irrespective of the state of
CNVST. When a conversion is complete, the MSB is
presented onto DOUT and the MAX11166/MAX11167
return to the acquisition phase. The remaining data bits
are stored within an internal shift register. To read these
bits out, CNVST is brought low and each bit is shifted
out on subsequent SCLK falling edge. The DIN input
of each ADC in the chain is used to transfer conversion
data from the previous ADC into the internal shift register
of the next ADC, thus allowing for data to be clocked
through the multichip chain on each SCLK falling edge.
Each ADC in the chain outputs its MSB data first requir-
ing 16 × N clocks to read back N ADCs.
In daisy-chain mode, the maximum conversion rate
is reduced due to the increased readback time. For
instance, with a 6ns or less digital host setup time and
3V interface, up to four MAX11166/MAX11167 devices
running at a conversion rate of 218ksps (MAX11167) or
324ksps (MAX11166) can be daisy-chained.
Daisy-Chain with Busy Indicator Mode
The daisy-chain mode with busy indicator is ideally suited
for multichannel isolated applications that require minimal
wiring complexity while providing a conversion complete
indication that can be used to interrupt a host processor
to read data.
Simultaneous sampling of multiple ADC channels is real-
ized on the serial interface where data readback is analo-
gous to clocking a shift register. The daisy-chain mode
with busy indicator is shown in Figure 14 where three
MAX11166/MAX11167s are connected to a SPI-compatible
digital host with corresponding timing given in Figure 15.
www.maximintegrated.com
Maxim Integrated │  27