Datasheet

CLK
SCLK
DRDY
DOUT
MOD/DIN
DGND
PHS/MCLK
DR1/M1
DR0/M0
HPF/SYNC
MFLAG
DGND
BYPAS
DGND
DVDD
PINMODE
RESET
PWDN
VREFP
VREFN
AVSS
AVDD
AINN
AINP
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
ADS1281
ADS1281
www.ti.com SBAS378D –AUGUST 2007–REVISED JUNE 2010
DEVICE INFORMATION
TSSOP-24
Top View
TERMINAL FUNCTIONS
DESCRIPTION
NAME NO. FUNCTION PIN MODE (PINMODE = 1) REGISTER MODE (PINMODE = 0)
CLK 1 Digital input Master clock input Master clock input
SCLK 2 Digital input SPI serial clock input SPI serial clock input
DRDY 3 Digital output Data ready output: read data on falling edge Data ready output: read data on falling edge
DOUT 4 Digital output SPI serial data output SPI serial data output
MOD: 0 = Digital filter mode
MOD/DIN 5 Digital input DIN: SPI serial data input
1 = Filter bypass (modulator output)
(MOD = 0) PHS: If in modulator mode:
PHS/MCLK 7 Digital I/O 0 = Linear phase filter, 1 = Minimum phase filter MCLK: Modulator clock output
(MOD = 1) MCLK: Modulator clock output Otherwise, the pin is an unused input (must be tied).
If in modulator mode:
(MOD = 0) DR1 = Data rate select input 1
DR1/M1 8 Digital I/O M1: Modulator data output 1
(MOD = 1) M1 = Modulator data output 1
Otherwise, the pin is an unused input (must be tied).
If in modulator mode:
(MOD = 0) DR0 = Data rate select input 0
DR0/M0 9 Digital I/O M0: Modulator data output 0
(MOD = 1) M0 = Modulator data output 0
Otherwise, the pin is an unused input (must be tied).
(MOD = 0) HPF: 0 = High-pass filter off, 1 = HPF on
HPF/SYNC 10 Digital input SYNC: Synchronize input
(MOD = 1) SYNC = Synchronize Input
Modulator over-range flag: Modulator over-range flag:
MFLAG 11 Digital output
0 = Normal, 1 = Modulator over-range 0 = Normal, 1 = Modulator over-range
DGND 6, 12, 23 Digital ground Digital ground, pin 12 is the key ground point Digital ground, pin 12 is the key ground point
AINP 13 Analog input Positive analog input Positive analog input
AINN 14 Analog input Negative analog input Negative analog input
AVDD 15 Analog supply Positive analog power supply Positive analog power supply
AVSS 16 Analog supply Negative analog power supply Negative analog power supply
VREFN 17 Analog input Negative reference input Negative reference input
VREFP 18 Analog input Positive reference input Positive reference input
PWDN 19 Digital input Power-down input, active low Power-down input, active low
RESET 20 Digital input Synchronize input Reset input
PINMODE 21 Digital input 1 = Pin mode 0 = Register mode
DVDD 22 Digital supply Digital power supply: +1.8V to +3.3V Digital power supply: +1.8V to +3.3V
BYPAS 24 Capacitor bypass Digital core bypass; 1mF bypass capacitor to GND Digital core bypass; 1mF bypass capacitor to GND
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Product Folder Link(s): ADS1281