Datasheet

71M6513/71M6513H

3-Phase Energy Meter IC

DATA SHEET

AUGUST 2011

A Maxim Integrated Products Brand

Figure 39: External Components for RESETZ

Connecting the V3 Pin

The following should be noted when connecting the V3 pin:

1) If the V3 pin is unused it should be left floating or terminated to the VREF pin.

2) If the V3 pin is used as a comparator input the digital input voltage applied to V3 should be limited to VBIAS ±0.9V.

3) If the V3 pin is used either as an auxiliary analog input, and temperature measurements are made and evaluated

using the alternate multiplexer cycle, the V3 input voltage range must be restricted to VBIAS ±0.9 V (i.e. 0.6 V to 2.4

V).

Otherwise, the TEMP or V3 measurement could be inaccurate. This precaution is particularly important for

customers who are using the TEMP samples for temperature compensation, especially with the 71M6513H devices.

Connecting a Battery

Many meter manufacturers assemble the meter PCB with the 71M6513 IC and the other electronic components first and then

join the meter PCB with the meter enclosure, sensors and other main components separately at a later production step.

Typically, programming, final test (ATE), and calibration are performed after this second step.

The following production sequence is strongly recommended:

1) During PCB assembly, when adding/inserting the battery, the board supply voltage (V3P3A, V3P3D) should be active

(i.e. at 3.3 VDC), which can be achieved by briefly connecting the battery to V3P3A/V3P3D through a jumper wire.

After the battery is inserted with the board power active, the jumper wire should be removed.

2) The battery should then remain connected through factory test (ATE), time on the shelf and shipment.

In cases where it is not feasible to power V3P3A/V3P3D while inserting the battery, it is recommended to isolate the battery in

its holder using a removable piece of Kapton tape or other isolating material. This isolation should then be removed once the

meter is fully powered during the calibration and test process.

RESETZ

71M6513

DGND

V3P3

Pushbutton

200Ω

1nF

10Ω