Datasheet
SBAS312B − JANUARY 2005 − REVISED AUGUST 2007
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6
PIN ASSIGNMENT
RGE PACKAGE
QFN−24
(TOP VIEW)
REFIN B
AGND
AV
DD
AV
DD
AGND
CLKSEL
REFIN A
AGND
AV
DD
AV
DD
REFOUT
AGND
1
2
3
4
5
6
18
17
16
15
14
13
ADS1205
(1)
NC
(2)
CH B+
CH B
−
CH A
−
CH A+
NC
(2)
24
23
22
21
20
19
CLKIN
BV
DD
BGND
CLKOUT
OUT B
OUT A
7
8
9
10
11
12
(1)
The thermal pad is internally connected to the substrate. This pad can be connected to the analog ground or left floating. Keep the thermal pad
separate from the digital ground, if possible.
(2)
NC = No Connection.
Terminal Functions
TERMINAL
NAME
NO. I/O DESCRIPTION
REFIN B 1 I Reference voltage input of channel B: pin for external reference voltage
AGND 2, 5, 13, 17 Analog ground
AV
DD
3, 4, 15, 16 Analog power supply; nominal 5V
CLKSEL 6 I Clock select between internal clock (CLKSEL = 1) or external clock (CLKSEL = 0)
CLKIN 7 I External clock input
BV
DD
8 Digital interface power supply; from 2.7V to 5.5V
BGND 9 Interface ground
CLKOUT 10 O System clock output
OUT B 11 O Bit stream from channel B modulator
OUT A 12 O Bit stream from channel A modulator
REFOUT 14 O Reference voltage output: output pin of the internal reference source; nominal 2.5V
REFIN A 18 I Reference voltage input of channel A: pin for external reference voltage
NC 19, 24 No connection; this pin is left unconnected
CH A+ 20 I Analog input of channel A: noninverting input
CH A− 21 I Analog input of channel A: inverting input
CH B− 22 I Analog input of channel B: inverting input
CH B+ 23 I Analog input of channel B: noninverting input