CS5467

DS714A1

19

ADVANCE RELEASE

Figure 6 illustrates the pulse output format with positive

active energy and negative reactive energy.

The pulse output frequency of E1 is directly proportional

to the active power calculated from the input signals. To

calculate the output frequency of E1, the following trans-

fer function can be utilized:

With MCLK = 4.096 MHz, PF = 1, and default settings,

the pulses will have an average frequency equal to the

frequency specified by PulseRateE when the input sig-

nals applied to the voltage and current channels cause

full-scale readings in the instantaneous voltage and cur-

rent registers. The maximum pulse frequency from the

E1 pin is (MCLK/K)/2048.

5.5.2 Apparent Energy Mode

Pin E2 outputs apparent energy pulses when the Oper-

ational Mode Register

bit E2MODE = 1. Pin E3 outputs

apparent energy pulses when the Operational Mode

Register

bits E3MODE[1:0] = 3 (11b). Figure 7 illus-

trates the pulse output format with apparent energy on

E2 (E2MODE = 1 and E3MODE[1:0] = 0)

The pulse output frequency of E2 (and/or E3) is directly

proportional to the apparent power calculated from the

input signals. Since apparent power is without reference

to an impedance phase angle, the following transfer

function can be utilized to calculate the output frequency

on E2 (and/or E3).

With MCLK = 4.096 MHz and default settings, the puls-

es will have an average frequency equal to the frequen-

cy specified by PulseRateE when the input signals

applied to the voltage and current channels cause

full-scale readings in the instantaneous voltage and cur-

rent registers. The maximum pulse frequency from the

E2 (and/or E3) pin is (MCLK/K)/2048. The E2 (and/or

E3) pin outputs apparent energy, but has no energy di-

rection indicator.

5.5.3 Reactive Energy Mode

Reactive energy pulses are output on pin E3 by setting

bit E3MODE[1:0] = 0 (default) in the Operational Mode

Register

. Positive reactive energy is registered by E3

falling when E2 is high. Negative reactive energy is reg-

istered by E3 falling when E2 is low. Figure 6 on

page 19 illustrates the pulse output format with negative

reactive energy output on pin E3 and the sign of the en-

ergy on E2. The E3 and E2 pulse output switching char-

acteristics are specified in Figure 2 on page 13.

The pulse output frequency of E3 is directly proportional

to the reactive power calculated from the input signals.

To calculate the output frequency on E3, the following

transfer function can be utilized:

With MCLK = 4.096 MHz, PF = 0 and default settings,

the pulses will have an average frequency equal to the

frequency specified by PulseRateE when the input sig-

nals applied to the voltage and current channels cause

full-scale readings in the instantaneous voltage and cur-

E3

E2

E1

Figure 6. Active and Reactive energy pulse outputs

where

VIN(2) = rms voltage across VIN(2)+ and VIN(2)- [V]

V(2)gain = Voltage channel gain

IIN(2) = rms voltage across IIN(2)+ and IIN(2)- [V]

I(2)gain = Current channel gain

PF(2) = Power Factor

PulseRate = PulseRateE x (MCLK/K)/2048 [Hz]

VREFIN = Voltage at VREFIN pin [V]

FREQ

P

P

Active

P2

Active

+

() 2

⁄

[] PulseRate

×

=

P2

()

Active

VIN 2

×

IIN 2

()

×

I2

×

PF 2

()

×

VREFIN

2

-----------------------------------------------------------------------------------------------------------------------------------

=

E3

E2

E1

Figure 7. Apparent energy pulse outputs

where

VIN(2) = rms voltage across VIN(2)+ and VIN(2)- [V]

V(2)gain = Voltage channel gain

IIN(2) = rms voltage across IIN(2)+ and IIN(2)- [V]

I(2)gain = Current channel gain

PulseRate = PulseRateE x (MCLK/K)/2048 [Hz]

VREFIN = Voltage at VREFIN pin [V]

FREQ

S

SS2

+

() 2

⁄

[] PulseRate

×

=

S2

()

VIN 2

×

IIN 2

()

×

I2

×

VREFIN

2

-----------------------------------------------------------------------------------------------------------

=

where

VIN(2) = rms voltage across VIN(2)+ and VIN(2)- [V]

V(2)gain = Voltage channel gain

IIN(2) = rms voltage across IIN(2)+ and IIN(2)- [V]

I(2)gain = Current channel gain

PQ =

PulseRate = PulseRateE x (MCLK/K)/2048 [Hz]

VREFIN = Voltage at VREFIN pin [V]

FREQ

Q

Q

Avg

Q2

Avg

+

() 2

⁄

[] PulseRate

×

=

Q2

()

Avg

VIN 2

×

IIN 2

()

×

I2

×

PQ 2

()

×

VREFIN

2

------------------------------------------------------------------------------------------------------------------------------------

=

1PF

2

–