Auxiliary and Analog Interfaces

RTC Coin Cell Interface

Overview

The RTC Coin Cell Interface is a single connector that provides coin-cell backup power to the OEM modem's real-time clock. This allows calendar time to be retained across main-battery power cycles.

Electrical Connections

All signal directions are relative to the OEM modem. Refer to the bottom connector locations figure for the physical location of the connector.

RTC Coin Cell Interface schematic connections.

RTC Coin Cell Interface Electrical Pinout

Pin Number	I/O	Pin Name	Notes
1	P	RTC_VBAT	RTC battery backup voltage supply, 1.0–5.0 V, nominal 3.0 V
2	P	GND	Board ground

Hardware Components

The RTC Coin Cell Interface uses a Molex PicoBlade connector, P/N 0510210200, or equivalent.

RTC Coin Cell Interface user-side Molex connector.

RTC Coin Cell Interface Components and Part Numbers

Part Number	Manufacturer	Description
0510211200	Molex	PicoBlade 12-position connector receptacle, 1.25 mm pitch
0500798000	Molex	PicoBlade 26–28 AWG sockets
2002181900	Molex	PicoBlade hand crimp tool
2149202211	Molex	Pre-crimped PicoBlade lead, 75 mm length