SA9103CSA Ver la hoja de datos (PDF) - South African Micro Electronic Systems

Número de pieza

componentes Descripción

Fabricante

SA9103CSA

SINGLE PHASE BIDIRECTIONAL POWER/ENERGY METERING IC WITH SERIAL INTERFACE

South African Micro Electronic Systems 

SA9103C

TYPICAL APPLICATIONS

In the Application Circuits (Figures 1 and 2), the components required for power metering

applications, are shown.

In Figure 1 a shunt resistor is used for current sensing. In this application, the circuitry

requires a +2.5V, 0V, -2.5V DC supply.

In the case of Figure 2, when using a current transformer for current sensing, a +5V, 0V

DC supply is sufficient for the circuit.

The most important external components for the SA9103C integrated circuit are:

C1 and C2 are the outer loop capacitors for the two integrated oversampling A/D

converters. The value of these capacitors is 560pF. The actual values determine the

signal to noise and stability performance. The tolerances should be within ±10%.

C3 and C4 are the inner loop capacitors of the A/D converters. The optimum value is 3.3nF.

The actual values are uncritical. Values smaller than 0.5nF and larger than 5nF should

be avoided.

R1, R2 and RSH are the resistors defining the current level into the current sense input.

The values should be selected for an input current of 16µA into the SA9103C at rated line

current.

Values for RSH of less than 200µΩ should be avoided.

R1 = R2 = (IL/16µA) * RSH/2

Where I

L

= Line current

RSH = Shunt resistor/termination resistor

R3, R6 and R4 set the current for the voltage sense input. The values should be selected

so that the input current into the voltage sense input (virtual ground) is set to 14µA.

R7 defines all on-chip bias and reference currents. With R7 = 24kΩ, optimum conditions

are set.

XTAL is a colour burst TV crystal (f = 3.5795MHz) for the oscillator. The oscillator

frequency is divided down to 1.7897MHz on-chip to supply the A/D converters and digital

circuitry.

sames

11/16

Share Link: