71M6534 datasheet(77/132 Pages) MAXIM | Exceeds IEC 62053/ANSI C12.20 Standards

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FDS_6533_6534_004

71M6533/G/H and 71M6534/H Data Sheet

Rev 2

Figure 44: Connecting a Battery

Meters equipped with batteries need to contain code that transitions the chip to SLEEP mode as

soon as the battery is attached in production. Otherwise, remaining in BROWNOUT mode would

add unnecessary drain to the battery.

4.11 Flash Programming

Operational or test code can be programmed into the flash memory using either an in-circuit emulator or

the Flash Programmer Module (TFP-2). The flash programming procedure uses the E_RST, E_RXTX,

and E_TCLK pins. The FL_BANK[2:0] field must be set to the value corresponding to the bank that is

being programmed.

4.12 MPU Firmware Library

All application-specific MPU functions mentioned in Section 3 Application Information are featured in the

Teridian demonstration source code. The code is available as part of the Demonstration Kit for the

71M6533/71M6534. The Demonstration Kits come with the 71M6533/71M6534 preprogrammed with demo

firmware and mounted on a functional sample meter Demo Board. The Demo Boards allow for quick and

efficient evaluation of the IC without having to write firmware or having to supply an in-circuit emulator

(ICE).

4.13 Crystal Oscillator

The oscillator drives a standard 32.768 kHz watch crystal. The oscillator has been designed specifically

to handle these crystals and is compatible with their high impedance and limited power handling capability.

The oscillator power dissipation is very low to maximize the lifetime of any battery backup device attached

to VBAT.

Board layouts with minimum capacitance from XIN to XOUT will require less battery current. Good

layouts will have XIN and XOUT shielded from each other.

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.

71M6533/6534

V3P3A

DIO

Power

Supply

V3P3SYS

VBAT

Battery or

Super-Cap

71M6534 Datasheet(PDF) 77 Page - Maxim Integrated Products