Datasheet
AD7264 Data Sheet
Rev. B | Page 8 of 28
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS
06732-003
PIN 1
INDICATOR
AD7264
TOP VIEW
(Not to Scale)
1
2
3
4
5
6
7
8
9
10
11
12
13 15 16 17 18 19
20 21 22 23 24
25
C
OUT
D
26
C
OUT
C
27
V
DRIVE
28
DGND
29
C
OUT
B
30
C
OUT
A
31
D
OUT
B
32
D
OUT
A
33
AV
CC
34
SCLK
35
CS
36
CAL
37
G3
38
G2
39
G1
40
G0
41
AV
CC
42
AGND
4344
45
C
B
–
46
C
B
+
47
C
A
–
48
C
A
+
14
C
A
_C
B
V
CC
AV
CC
V
A
–
V
A
+
AGND
AV
CC
AGND
V
B
+
V
B
–
AV
CC
C
C
_C
D
V
CC
AGND
C
C
+
C
C
–
C
D
+
C
D
–
C
C
_C
D
_GND
V
REF
B
AGND
AV
CC
PD2
PD1
PD0/D
IN
REFSEL
C
A
_C
B
_GND
V
REF
A
Figure 3. 48-Lead LQFP Pin Configuration
06732-004
AD7264
TOP VIEW
(Not to Scale)
C
OUT
D
C
OUT
C
V
DRIVE
DGND
C
OUT
B
C
OUT
A
D
OUT
B
D
OUT
A
AV
CC
SCLK
CAL
CS
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
1
2
3
4
5
6
7
8
9
10
11
12
35
36
34
33
32
31
30
29
28
27
26
25
PIN 1
INDICATOR
C
A
_C
B
V
CC
AV
CC
V
A
–
V
A
+
AGND
AV
CC
AGND
V
B
+
V
B
–
AV
CC
C
C
_C
D
V
CC
AGND
G3
G2
G1
G0
AV
CC
AGND
C
B
–
C
B
+
C
A
–
C
A
+
C
A
_C
B
_GND
V
REF
A
C
C
+
C
C
–
C
D
+
C
D
–
C
C
_C
D
_GND
V
REF
B
AGND
AV
CC
PD2
PD1
PD0/D
IN
REFSEL
NOTES
1. THE EXPOSED METAL PADDLE ON THE BOTTOM OF THE LFCSP PACKAGE MUST
BE SOLDERED TO PCB GROUND FOR PROPER HEAT DISSIPATION AND ALSO FOR
NOISE AND MECHANICAL STRENGTH BENEFITS.
Figure 4. 48-Lead LFCSP Pin Configuration
Table 4. Pin Function Descriptions
Pin No. Mnemonic Description
2, 7, 11, 20, 33, 41
AV
CC
Analog Supply Voltage, 4.75 V to 5.25 V. This is the supply voltage for the analog circuitry on the
AD7264. All AV
CC
pins can be tied together. This supply should be decoupled to AGND with a 100 nF
ceramic capacitor per supply and a 10 μF tantalum capacitor.
1 C
A
_C
B
V
CC
Comparator Supply Voltage, 2.7 V to 5.25 V. This is the supply voltage for Comparator A and
Comparator B. This supply should be decoupled to C
A
_C
B
_GND. AV
CC
, C
C
_C
D
V
CC
, and C
A
_C
B
V
CC
can be
tied together.
12
C
C
_C
D
V
CC
Comparator Supply Voltage, 2.7 V to 5.25 V. This is the supply voltage for Comparator C and
Comparator D. This supply should be decoupled to C
C
_C
D
_GND. AV
CC
, C
C
_C
D
V
CC
, and C
A
_C
B
V
CC
can be
tied together.
4, 3 V
A
+, V
A
− Analog Inputs of ADC A. True differential input pair.
9, 10 V
B
+, V
B
− Analog Inputs of ADC B. True differential input pair.
43, 18
V
REF
A, V
REF
B
Reference Input/Output. Decoupling capacitors are connected to these pins to decouple the
internal reference buffer for each respective ADC. Typically, 1 μF capacitors are required to decouple
the reference. Provided the output is buffered, the on-chip reference can be taken from these pins
and applied externally to the rest of a system.
34 SCLK Serial Clock. Logic input. A serial clock input provides the SCLK for accessing the data from the
AD7264. This clock is also used as the clock source for the conversion process. A minimum of
33 clocks are required to perform the conversion and access the 14-bit result.
35
CS
Chip Select. Active low logic input. This input initiates conversions on the AD7264.
36 CAL Logic Input. Initiates an internal offset calibration.
21 PD2 Logic Input. Places the AD7264 in the selected shutdown mode in conjunction with the PD1 and
PD0 pins. See Table 7.
22 PD1 Logic Input. Places the AD7264 in the selected shutdown mode in conjunction with the PD2 and
PD0 pins. See Table 7.
23 PD0/D
IN
Logic Input/Data Input. Places the AD7264 in the selected shutdown mode in conjunction with the
PD2 and PD1 pins. See Table 7. If all gain selection pins, G0 to G3, are tied low, this pin acts as the
data input pin and all programming is via the control register (see Table 8). Data to be written to the
AD7264 control register is provided on this input and is clocked into the register on the falling edge
of SCLK.