Datasheet
AD9238
Rev. C | Page 36 of 48
LFCSP PCB SCHEMATICS
D7_A D7A
49
D8_A D8A
50
D9_A
D9A
51
DRVDD2
52
DRGND2
53
D10_A
D10A
54
D11_A D11A
55
D12_A D12A
56
D13_A
D13A
57
OTR_A
OTRA
58
OEB_A
59
PDWN_A
60
MUX_SEL
61
SH_REF
62
CLK_A
63
AVDD5
VD
64
EPAD
65
D7B
D7_B
32
D6B
31
D5_B
30
DRVDD
29
DRGND
28
D4B
D4_B
27
D3B
D3_B
26
D2B
D2_B
25
D1B
24
23
22
21
20
DCS
19
ENCB
D6_B
D1_B
D0_B
OEB_B
PDWN_B
DFS
CLK_B
D6_A D6A
48
D5_A D5A
47
D4_A D4A
46
D3_A
D3A
45
D2_A
D2A
44
D1_A D1A
43
D0_A D0A
42
DRVDD1
41
DRGND1
40
OTR_B
OTRB
39
D13_B D13B
38
D12_B D12B
37
D11_B D11B
36
D10_B
D10B
35
D9_B
D9B
34
D8_B D8B
33
1
AGND
2
VIN_A
3
VIN_AB
4
AGND1
VD
5
AVDD1
6
REFT_A
7
REFB_A
VREF
8
VREF
SENSE
9
SENSE
10
REFB_B
11
REFT_B
VD
12
AVDD2
13
AGND2
14
VIN_BB
15
VIN_B
16
AGND3
VCC
14
4B
13
4A
12
4Y
11
3B
10
3A
9
3Y
8
1A
1B
1Y
2A
2B
2Y
GND
1
2
3
4
5
6
7
GND
7
2Y
6
2B
5
2A
4
1Y
3
1B
2
1A
1
3Y
3A
3B
4Y
4A
4B
VCC
8
9
10
11
12
13
14
18
VD
AVDD3
17
D0B
D5B
+
+ + + ++
ENCA
VREF
C30
0.1
μ
F
R45
10k
Ω
R56
10k
Ω
E2
E27
E25
E30
E41
VD
C11
0.1
μ
F
SENSE
EXT_VREF
C2
10
μ
F
VREF AND SENSE CIRCUIT
MUX
R35
0
Ω
R38
0
Ω
R20
0
Ω
R40
0
Ω
R14
50
Ω
J5
TIEB
TIEA
TO TIE CLOCKS TOGETHER
C4
0.1
μ
F
VDD
VDD
C6
0.1
μ
F
E22
E24
VD
R67
1k
Ω
R68
1k
Ω
R70
1k
Ω
R69
1k
Ω
E21
E40
VD
E26
E29
VD
E31E33
VD
PADS TO SHORT
REFERENCES TOGETHER
P15
P16
P18
P17
REFTA
REFTB
REFBA
REFBB
REFB_B
REFT_B
AMPOUTB
R36
33
Ω
R37
33
Ω
AMPOUTBB
C3
20pF
C28
0.1μF
C7
10μF
C54
0.1μF
C23
0.1μF
C5
10μF
C55
0.1μF
C24
0.1μF
C26
0.1μF
C29
0.1μF
C27
0.1μF
H3
MTHOLE6
H1
MTHOLE6
H2
MTHOLE6
H4
MTHOLE6
4123 4123 4123
P5
P6
P7
VD
VDD
VDL
C37
10μF
C38
10μF
C16
10μF
C17
10μF
C18
10μF
C19
10μF
C39
0.1μF
C43
0
.
1μF
C44
0
.
1μF
C45
0
.
1μF
+5V
–5V
EXT_VREFVDLVDD
VD
P11
P4
P1
E34 E16
VD
VD
R55
1k
Ω
E37E38
R48
1k
Ω
0
Ω
R12
0
Ω
R13
E35
E36VD
R49
1kΩ
C41
0.1
μ
F
VD
VD
J2
ENCODE B
R51
50Ω
C42
0.1μF
R54
1kΩ
R52
1kΩ
P2
P9
U3
P13
ENCB
VD
VD
C22
10μF
C57
0.1μF
R6
100
Ω
R8
100
Ω
TIEB
1
2
3
5
4
SN74LVC1G04
NC
A
GND
VCC
Y
1
2
3
5
4
SN74LVC1G04
NC
A
GND
VCC
Y
P10
P12
C36
10μF
C58
0.1μF
ENCA
VD
VD
R33
100
Ω
R42
100
Ω
R50
22
Ω
R43
0
Ω
U1
E13 E12
VD
VD
R47
1k
Ω
E15
E14
R46
1k
Ω
0
Ω
R9
0
Ω
R10
CLKLATB
DRB
DRA
CLKLATA
J6
R61
50
Ω
C56
0.1
μ
F
VD
J3
ENCODE A
R11
50Ω
C40
0.1μF
R41
1kΩ
TIEA
R39
1kΩ
VD
C25
0.1μF
E3
E4VD
R44
1kΩ
P14
E6
E5
VD
E20
E18
VD
E9
E7
VD
R66
1k
Ω
R65
1kΩ
R64
1k
Ω
E10
E17
R63
1k
Ω
R62
1k
Ω
VD
VDD
C8
0.1μF
MUX
DUT CLOCK SELECTABLE
TO BE DIRECT OR BUFFERED
74LCX86
74LCX86
R4
33
Ω
J1
AIN B
C13
0.1
μ
F
R59
1k
Ω
R7
50
Ω
AMPINB
C10
10
μ
F
C12
0.1
μ
F
E43
E42
C9
10
μ
F
C31
0.1
μ
F
R57
1k
Ω
1
2
3
6
5
4
CTAPB
R5
33
Ω
1
2
3
6
5
4
CTAPA
AMPOUTAB
AMPOUTA
C14
0.1
μ
F
AMPINA
R3
50
Ω
J4
C1
20pF
VD
–5V
+5V
VD
VDD VDL
EXT_VREF
CTAPA
R58
1k
Ω
VD
VD
R60
1k
Ω
CTAPB
T1
T2
SEE
BELOW
DUT CLOCK SELECTABLE
TO BE DIRECT OR
BUFFERED
U5
U6
U7
AIN A
02640-069
Figure 50. PCB Schematic (1 of 3)