AD7755
Pin No.
21
Mnemonic
DGND
Description
This provides the ground reference for the digital circuitry in the AD7755, i.e., multiplier, filters and
digital-to-frequency converter. This pin should be tied to the analog ground plane of the PCB. The
digital ground plane is the ground reference for all digital circuitry, e.g., counters (mechanical and
digital), MCUs and indicator LEDs. For good noise suppression the analog ground plane should only
be connected to the digital ground plane at one point only, e.g., a star ground.
Calibration Frequency Logic Output. The CF logic output gives instantaneous real power informa-
tion. This output is intended to be used for calibration purposes. Also see SCF pin description.
Low Frequency Logic Outputs. F1 and F2 supply
average real power
information. The logic outputs
can be used to directly drive electromechanical counters and two phase stepper motors. See Transfer
Function section.
22
23, 24
CF
F2, F1
PIN CONFIGURATION
DIP and SSOP Packages
DV
DD
AC/DC
AV
DD
NC
V1P
V1N
V2N
V2P
RESET
REF
IN/OUT
1
2
3
4
5
6
24
23
22
21
F1
F2
CF
DGND
REVP
AD7755
20
TOP VIEW
19
NC
(Not to Scale)
18
CLKOUT
7
8
9
10
17
16
15
14
13
CLKIN
G0
G1
S0
S1
AGND
11
SCF
12
NC = NO CONNECT
–6–
REV. B
AD [ ANALOG DEVICES ]
