ADE7768

Rev. A | Page 7 of 20

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

V2P

2

V2N

3

V1N

4

F1

16

F2

15

CF

14

DGND

13

V1P

5

REVP

12

AGND

6

RCLKIN

11

S0

10

SCF

8

S1

9

ADE7768

TOP VIEW

(Not to Scale)

Figure 3. Pin Configuration

Table 4. Pin Function Descriptions

Pin No.

Mnemonic

Description

1

Power Supply. This pin provides the supply voltage for the circuitry in the ADE7768. The supply voltage

should be maintained at 5 V ± 5% for specified operation. This pin should be decoupled with a 10 μF

capacitor in parallel with a 100 nF ceramic capacitor.

2, 3

V2P, V2N

Analog Inputs for Channel V2 (Voltage Channel). These inputs provide a fully differential input pair. The

maximum differential input voltage is ±165 mV for specified operation. Both inputs have internal ESD

protection circuitry; an overvoltage of ±6 V can be sustained on these inputs without risk of permanent

damage.

4, 5

V1N, V1P

Analog Inputs for Channel V1 (Current Channel). These inputs are fully differential voltage inputs with a

maximum signal level of ±30 mV with respect to the V1N pin for specified operation. Both inputs have

internal ESD protection circuitry and, in addition, an overvoltage of ±6 V can be sustained on these inputs

without risk of permanent damage.

6

AGND

This pin provides the ground reference for the analog circuitry in the ADE7768, that is, the ADCs and

reference. This pin should be tied to the analog ground plane of the PCB. The analog ground plane is the

ground reference for all analog circuitry, such as antialiasing filters, current and voltage sensors, and so forth.

For accurate noise suppression, the analog ground plane should be connected to the digital ground plane at

only one point. A star ground configuration helps to keep noisy digital currents away from the analog

circuits.

7

This pin provides access to the on-chip voltage reference. The on-chip reference has a nominal value of 2.45 V

and a typical temperature coefficient of 20 ppm/°C. An external reference source may also be connected at

this pin. In either case, this pin should be decoupled to AGND with a 1 μF tantalum capacitor and a 100 nF

ceramic capacitor. The internal reference cannot be used to drive an external load.

8

SCF

Select Calibration Frequency. This logic input is used to select the frequency on the calibration output CF.

See Table 7.

9, 10

S1, S0

These logic inputs are used to select one of four possible frequencies for the digital-to-frequency conversion.

With this logic input, designers have greater flexibility when designing an energy meter. See the Selecting a

Frequency for an Energy Meter Application section.

11

RCLKIN

To enable the internal oscillator as a clock source to the chip, a precise low temperature drift resistor at a

nominal value of 6.2 kΩ must be connected from this pin to DGND.

12

REVP

This logic output goes high when negative power is detected, that is, when the phase angle between the

voltage and current signals is greater than 90°. This output is not latched and is reset when positive power is

once again detected. The output goes high or low at the same time that a pulse is issued on CF.

13

DGND

This pin provides the ground reference for the digital circuitry in the ADE7768, that is, the multiplier, filters,

and digital-to-frequency converter. This pin should be tied to the digital ground plane of the PCB. The digital

ground plane is the ground reference for all digital circuitry, such as counters (mechanical and digital), MCUs,

and indicator LEDs. For accurate noise suppression, the analog ground plane should be connected to the

digital ground plane at one point only—a star ground.

14

CF

Calibration Frequency Logic Output. The CF logic output provides instantaneous, positive-only real power

information. This output is intended for calibration purposes. See the SCF pin description.

15, 16

F2, F1

Low Frequency Logic Outputs. F1 and F2 supply average positive-only real power information. The logic

outputs can be used to directly drive electromechanical counters and 2-phase stepper motors. See the

Transfer Function section.