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sames

sames

SA2007M

http://www.sames.co.za

INPUT SIGNALS

VREF

A bias resistor of 24kW sets optimum bias and reference

conditions on chip. Calibration of the SA2007M should be

done on the voltage input as described in Typical Application.

Motor pulse rate select (MP1 and MP0)

The pulse rate of the motor driver output of the SA2007M is

selected by the inputs MP1 and MP0. Three pulses rate

options are available as shown in the following table:

Pulse rate selection

Figure 4: Motor drive on MON and MOP pins

Please note that the device will not perform metering functions

as described in this document while in test mode.

Rated condition select (RATED)

The rated condition select pin gives the option of having a 3:2:1

scaling ratio for the rated meter current. This feature is

particularly useful in circumstances where a manufacturer

requires a meter for use in a system rated for two different

conditions, for example 230V/60A and 230V40A. With the

rated condition select the SA2007M allow for the development

of different rated meters requiring minimal changes. The

following table below lists the option available (assuming the

rated condition to be 230V/60A).

Rated condition select (RATED)

Figure 5: LED pulse output

OUTPUT SIGNALS

Motor output (MOP, MON)

The MON pulse will follow the MOP pulse within 142ms. This

prevents that the motor armature is in the wrong position after a

power failure. Both MOP and MON outputs are active high.

The motor drive wave forms are shown below:

LED

t

LED

DR-01332

Signal

Output

Value

Description

SEL 1

0

1

Channel 1 selected (IIN1/IIP1)

Channel 2 selected (IIN2/IIP2)

MP1

MP0

Motor drive

output

selection

V

SS

V

SS

V

DD

V

DD

V

SS

V

DD

V

SS

V

DD

Unit

Pulse Rate

Selection Input

1

10

100

Device test mode

pulses/kWh

pulses/kWh

pulses/kWh

Signal Input RATED

Rated Conditions

V

SS

OPEN

V

DD

230V / 20A

230V / 40A

230V / 60A

LED output (LED)

The LED output pulse at a fixed rate of 6400 pulses per kWh.

The LED output is active low. The LED waveform is shown

below:

An integrated anti-creep function prevents any output pulses if

the measured power is less than 0.02% of the meters rated

current.

Selected input indicator (SEL1)

The SA2007M continuously compares the power

consumptions on current channel 1 inputs and current channel

2 inputs. The larger of the two measurements are used for

metering. The SEL1 output pin indicates which channel is

currently being used for the pulse output.

t = 142ms

m

VDD

VDD

VSS

VSS

MON

MOP

t

m

t

m

t

m

DR-01559

VDD

VSS

Switching between channels will not be faster than once per

second when both channels are balanced.

PRELIMINARY