Datasheet

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DRDY
(1)
CS
(2)
SCLK
DOUT
DATAMSB
012h
(8)
DATAMID DATALSB CHECKSUM
(5)
DATAMSB
(6)
DIN
(7)
DataReady NextDataReady
t
UPDATE
(3)
Hi-Z
(4)
ADS1259
www.ti.com SBAS424D –JUNE 2009– REVISED AUGUST 2011
Data Read Operation in Stop Continuous Mode
As shown in Figure 61, after sending the RDATA
command the data are shifted out on DOUT on the
In Stop Read Data Continuous mode, a read data
rising edges of SCLK. The MSB is clocked out on the
command (RDATA) must be sent for each new data
first rising edge of SCLK. In Gate Control mode,
read operation. New conversion data are ready when
DRDY returns to high on the first falling edge of
DRDY falls low or the DRDY register bit transitions
SCLK. In Pulse Control mode, DRDY remains low
low. The data read operation may then occur. The
until a new conversion is started.
read data command must be sent at least 20 f
CLK
cycles before the DRDY falling edge or the data are
The conversion data consist of three or four bytes
incorrect. Do not the read data command during this
(MSB first), depending on whether the checksum byte
time.
is included. The data may be read multiple times by
continuing to shift the data.
(1) In Gate Control mode, DRDY returns to high on the first falling edge of SCLK. In Pulse Control mode, DRDY remains low until the next
conversion is started. The DRDY pin or DRDY register bit can also be polled to determine when data are ready.
(2) CS may be held low.
(3) t
UPDATE
= 20/f
CLK
. Do not issue the Read Data opcode during this time.
(4) During this interval, DOUT does not follow DRDY (stop continuous mode).
(5) Optional conversion data checksum.
(6) Optional repeat of previous conversion data.
(7) DIN data are latched on the falling edge of SCLK. Data are output on the rising edges of SCLK.
(8) Read Data command = 012h.
Figure 61. Data Read Operation in STOP Continuous Mode
Copyright © 2009–2011, Texas Instruments Incorporated 31