SPEC-1081 (REV. 2)

9/15

29-09-2017

SA4101A

Fast Mode Select (FAST)

The FAST pin is used to select between STANDARD and

enables FAST mode.

When STANDARD mode is enabled the LED output pulses

at a low frequency. This low frequency allows a longer

accumulation period and the output pulses are therefore

proportional to the average power consumption measured.

The Rated Select Condition pins (R0, R1 and R2) are used

to select different LED output frequencies which in turn

selects the applications meter constant. Refer to Figure 9 for

the LED output timing diagram in STANDARD mode.

When the FAST mode is enabled the LED output generates

mode

the

pulse

frequency

is

proportional

to

the

instantaneous power consumption measured. This mode is

used for meter calibration purposes and can also be used

when interfacing to a microcontroller. Refer to Figure 10 for

the LED output timing diagram in FAST mode.

Select Output (SO)

The SA4101A has unique internal circuitry that can be user

enabled to stabilize the LED output. When in FAST mode,

stability feature. Stabilizing the LED pulse output allows for

shorter meter calibration times. Leaving the SO pin open or

Figure 10 indicates the operation of pulse stability.

Rated Condition Select (R0, R1, R2)

The Rated Condition Select pins R0, R1 and R2 are inputs

pins used to configure the SA4101A for different Maximum

Rated Mains Currents and Nominal Mains Voltages. This

feature allows for the use of different stepper motor gear

ratios.

To calculate the LED output pulse rate (in STANDARD mode)

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1160

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��

1000 × 3600

...(1)

where

DF_LED is the dividing factor for the LED output that depends

on R2, R1 and R0 as specified in Table 1.

Equation 1 is based on the assumption that the input current

Table 1: LED output constants

R2

R1

R0

DF_LED

322

322

322

322

225

214

214

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������������ ������������/��������ℎ

��������_��������

…(2)

where

LED imp/kWh is the LED constant as calculated using

Equation 1 and

DF_MO is the dividing factor for the motor output that

depends on R1 and R0 as specified in Table 2.

Table 2: MOTOR output constants

R1

R0

DF_MO

8

32

16

8

Table 3 shows some of the meter constants available for

220V while in STANDARD mode.

Note that the values calculated using Equations 1 and 2 are

close approximations to the values listed in Table 3. The

SA4101A has to be calibrated (using the voltage input) to give

the exact value listed.

Table 3: Examples of various meter constants

R2

R1

R0

LED

Output

Motor

Outputs

220V / 20A

3200

100

220V / 40A

1600

100

220V / 80A

800

100

220V / 100A

800

100

220V / 30A

3200

100

220V / 60A

1600

100