
AD9444
Table 7. Pin Function Descriptions—100-Lead TQFP/EP in LVDS Mode
Pin No.
Mnemonic
Description
1, 8 to 9,
16 to 18,
24 to 27,
34 to 35, 38,
41 to 42, 87,
89 to 95, 98
2 to 4
DNC
Do Not Connect. These pins
should float.
5
OUTPUT
MODE
Mode Control Pin. OUTPUT MODE
= 0 for CMOS mode, and OUTPUT
MODE = 1 (AVDD1) for LVDS
outputs.
6
DFS
Data Format Select Pin. CMOS
control pin that determines the
format of the output data. DFS =
high (AVDD1) for twos comple-
ment, DFS = low (ground) for
offset binary format.
7
LVDSBIAS
Set Pin for LVDS Output Current.
Place 3.7 k resistor terminated to
DRGND.
10
SENSE
Reference Mode Selection.
Connect to AGND for internal 1 V
reference, and connect to AVDD2
for external reference.
11
VREF
1.0 V Reference I/O—Function
Dependent on SENSE. Decouple
to ground with 0.1 μF and 10 μF
capacitors.
12, 15, 20,
23, 32, 86,
88, 96 to 97,
99, Exposed
Heat Sink
13
REFT
Differential Reference Output.
Decoupled to ground with 0.1 μF
capacitor and to REFB (Pin 14) with
0.1 μF and 10 μF capacitors.
14
REFB
Differential Reference Output.
Decoupled to ground with a 0.1 μF
capacitor and to REFT (Pin 13) with
0.1 μF and 10 μF capacitors.
19, 28 to 31,
39 to 40
21
VIN+
Analog Input—True.
22
VIN
Analog Input—Complement.
33
C1
Internal Bypass Node. Connect a
0.1 μF capacitor from this pin
to AGND.
36
CLK+
Clock Input—True.
37
CLK
Clock Input—Complement.
43
D0 (LSB)
D0 Complement Output Bit
(LVDS Levels).
Rev. 0 | Page 11 of 40
AVDD1
3.3 V (±5%) Analog Supply.
CMOS Compatible Output Logic
AGND
Analog Ground. The exposed
heat sink on the bottom of the
package must be connected to
AGND.
AVDD2
5.0 V Analog Supply (±5%).
Pin No.
44
45
46
47, 54, 62,
75, 83
48, 53, 61,
67, 74, 82
49
50
51
52
55
56
57
58
59
60
63
64
65
66
68
69
70
71
72
73
76
77
78
79
80
81
84
Mnemonic
D0+
D1
D1+
DRVDD
Description
D0 True Output Bit.
D1 Complement Output Bit.
D1 True Output Bit.
3.3 V Digital Output Supply
(3.0 V to 3.6 V).
Digital Ground.
DRGND
D2
D2+
D3
D3+
D4
D4+
D5
D5+
D6
D6+
DCO
DCO+
D7
D7+
D8
D8+
D9
D9+
D10
D10+
D11
D11+
D12
D12+
D13
D13+ (MSB)
OR
D2 Complement Output Bit.
D2 True Output Bit.
D3 Complement Output Bit.
D3 True Output Bit.
D4 Complement Output Bit.
D4 True Output Bit.
D5 Complement Output Bit.
D5 True Output Bit.
D6 Complement Output Bit.
D6 True Output Bit.
Data Clock Output—Complement.
Data Clock Output—True.
D7 Complement Output Bit.
D7 True Output Bit.
D8 Complement Output Bit.
D8 True Output Bit.
D9 Complement Output Bit.
D9 True Output Bit.
D10 Complement Output Bit.
D10 True Output Bit.
D11 Complement Output Bit.
D11 True Output Bit.
D12 Complement Output Bit.
D12 True Output Bit.
D13 Complement Output.
D13 True Output Bit.
Out-of-Range Complement
Output Bit.
Out-of-Range True Output Bit.
Clock Duty Cycle Stabilizer (DCS)
Control Pin, CMOS-Compatible.
DCS = low (AGND) to enable DCS
(recommended). DCS = high
(AVDD1) to disable DCS.
85
100
OR+
DCS MODE