Datasheet

71M6513/71M6513H

3-Phase Energy Meter IC

DATA SHEET

AUGUST 2011

A Maxim Integrated Products Brand

For best rejection of electromagnetic interference, connect the crystal body and the ground terminals of the two

crystal capacitors to GNDD through a ferrite bead. No external resistor should be connected across the crystal,

since the oscillator is self-biasing.

Connecting LCDs

The 71M6513 has a LCD controller on-chip capable of controlling static or multiplexed LCDs. Figure 33 shows the basic

connection for a LCD.

Figure 33: Connecting LCDs

Figure 34 shows how 5V LCDs can be operated even when a 5V supply is not available. Setting the I/O RAM register

LCD_BSTEN to 1 starts the on-chip boost circuitry that will output an AC frequency on the VDRV pin. Using a small coupling

capacitor, two general-purpose diodes and a reservoir capacitor, a 5VDC voltage is generated which can be fed back into the

VLCD pin of the 71M6513. The LCD drivers are enabled with the I/O register LCD_ON; I/O register LCD_FS is used to adjust

contrast, and LCD_MODE selects the operation mode (LCD type).

segments

71M6513

LCD

commons

segments

71M6513

LCD

commons