ADE7752 Analog Devices, ADE7752 Datasheet - Page 5

• Manufacturer Part Number: ADE7752
• Description: Three Phase Energy Metering IC with Pulse Output
• Manufacturer: Analog Devices

REV. PrB 08/01
Pin No.
1
2
3
4
5,6;
7,8;
9,10
11
12
13-16
17
18
MNEMONIC
C F
D G N D
V
REVP
I
I
I
AGND
REF
RESET
S C F
AP
BP
CP
DD
V
V
, I
, I
, I
N
BP
,V
IN/OUT
AN
BN
, V
CN
CP
;
;
AP
,
PRELIMINARY TECHNICAL DATA
Calibration Frequency Logic Output. The CF logic output gives instantaneous real
power information. This output is intended to be used for calibration purposes. Also see
SCF pin description.
This provides the ground reference for the digital circuitry in the ADE7752, i.e. multi-
plier, filters and digital-to-frequency converter. Because the digital return currents in
the ADE7752 are small, it is acceptable to connect this pin to the analog ground plane
of the whole system - see Applications Information. However high bus capacitance on the
DOUT pin may result in noisy digital current which could affect performance.
Power supply. This pin provides the supply voltage for the digital circuitry in the
ADE7752. The supply voltage should be maintained at 5V ± 5% for specified opera-
tion. This pin should be decoupled to DGND with a 10µF capacitor in parallel with a
ceramic 100nF capacitor.
This logic output will go logic high when negative power is detected on any of the three
phase inputs, i.e., when the phase angle between the voltage and the current signals is
greater that 90°. This output is not latched and will be reset when positive power is
once again detected. The output will go high or low at the same time as a pulse is is-
sued on CF.
This pin provides the ground reference for the analog circuitry in the ADE7754, i.e.
ADCs, temperature sensor, and reference. This pin should be tied to the analog ground
plane or the quietest ground reference in the system. This quiet ground reference
should be used for all analog circuitry, e.g. anti aliasing filters, current and voltage
transducers etc. In order to keep ground noise around the ADE7754 to a minimum, the
quiet ground plane should only connected to the digital ground plane at one point. It is
acceptable to place the entire device on the analog ground plane - see Applications Informa-
tion.
This pin provides access to the on-chip voltage reference. The on-chip reference has a
nominal value of 2.5V ± 8% and a typical temperature coefficient of 30ppm/°C. An
external reference source may also be connected at this pin. In either case this pin
should be decoupled to AGND with a 1µF ceramic capacitor.
Analog inputs for the voltage channel. This channel is intended for use with the voltage
transducer and is referenced as the voltage channel in this document. These inputs are
single-ended voltage inputs with maximum signal level of ±0.125V with respect to V
for specified operation. All inputs have internal ESD protection circuitry, and in addi
tion an over voltage of ±6V can be sustained on these inputs without risk of permanent
damage.
Reset pin for the ADE7752. A logic low on this pin will hold the ADCs and digital
circuitry (including the Serial Interface) in a reset condition.
Select Calibration Frequency. This logic input is used to select the frequency on the
calibration output CF. Table IV shows how the calibration frequencies are selected.
Analog inputs for current channel. This channel is intended for use with the current
transducer and is referenced in this document as the current channel. These inputs are
fully differential voltage inputs with maximum differential input signal levels of
±0.125V -See Analog Inputs. Both inputs have internal ESD protection circuitry, and in
addition an overvoltage of ±6V can be sustained on these inputs without risk of perma
nent damage.
PIN FUNCTION DESCRIPTION
– 5 –
DESCRIPTION
N