71M6543F Datasheet, PDF(17/157 Page) Maxim Integrated Products – Selectable Gain of 1 or 8 for One Current Energy Meter ICs Metrology Compensation

English

English German Russian Spanish Italian Polish Chinese Japanese Korean French Portuguese	Language :

71M6543F Datasheet, PDF (17/157 Pages) Maxim Integrated Products – Selectable Gain of 1 or 8 for One Current Energy Meter ICs Metrology Compensation

◁

71M6543F/H and 71M6543G/GH Data Sheet

Using settings for the I/O RAM Mnemonics listed in Table 1 and Table 2 that do not match

those required by the corresponding CE code being used may result in undesirable side

effects and must not be selected by the MPU. Consult your local Teridian representative to

obtain the correct CE code and AFE / MUX settings corresponding to the application.

For a polyphase configuration with neutral current sensing using shunt resistor current sensors and the

71M6xx3 isolated sensors, as shown in Figure 2, the IADC0-IADC1 input must be configured as a

differential input, to be connected to a local shunt (see Figure 30 for the shunt connection details). The

local shunt connected to the IADC0-IADC1 input is used to sense the Neutral current. The voltage

sensors (VADC8, VADC9 and VADC10) are also directly connected to the 71M6543 (see Figure 27 for

the connection details) and are also routed though the multiplexer, as seen in Figure 2. Meanwhile, the

IADC2-IADC3, IADC4-IADC5 and IADC6-IADC7 current inputs are configured as remote sensor digital

interfaces and the corresponding samples are not routed through the multiplexer. For this configuration,

the multiplexer sequence is as shown in Figure 4.

For a polyphase configuration with optional neutral current sensing using Current Transformer (CTs)

sensors, as shown in Figure 3, all four current sensor inputs must be configured as a differential inputs, to

be connected to their corresponding CTs (see Figure 29 for the differential CT connection details). The

IADC0-IADC1 current sensor input is optionally used to sense the Neutral current for anti-tampering

purposes. The voltage sensors (VADC8, VADC9 and VADC10) are directly connected to the 71M6543

(see Figure 27 for the voltage sensor connection details). No 71M6xx3 isolated sensors are used in this

configuration and all sensors are routed though the multiplexer, as seen in Figure 3. For this

configuration, the multiplexer sequence is as shown in Figure 5.

The multiplexer sequence shown in Figure 4 corresponds to the configuration shown in Figure 2. The

frame duration is 13 CK32 cycles (where CK32 = 32,768 Hz), therefore, the resulting sample rate is

32,768 Hz / 13 = 2,520.6 Hz. Note that Figure 4 only shows the currents that pass through the 71M6543

multiplexer, and does not show the currents that are copied directly into CE RAM from the remote

sensors (see Figure 2), which are sampled during the second half of the multiplexer frame. The two

unused conversion slots shown are necessary to produce the desired 2,520.6 Hz sample rate.

Multiplexer Frame

MUX_DIV[3:0] = 6 Conversions

Settle

CK32

MUX STATE S

Unused

CROSS

MUX_SYNC

Figure 4: States in a Multiplexer Frame (MUX_DIV[3:0] = 6)

The multiplexer sequence shown in Figure 5 corresponds to the CT configuration shown in Figure 3.

Since in this case all current sensors are locally connected to the 71M6543, all currents are routed

through the multiplexer, as seen in Figure 3. For this multiplexer sequence, the frame duration is 15 CK32

cycles (where CK32 = 32,768 Hz), therefore, the resulting sample rate is 32,768 Hz / 15 = 2,184.5 Hz.

Multiplexer Frame

MUX_DIV[3:0] = 7 Conversions

Settle

CK32

MUX STATE S

CROSS

MUX_SYNC

Figure 5: States in a Multiplexer Frame (MUX_DIV[3:0] = 7)

v1.2

▷