ds1302 trickle charging......

[jit_singh_tara]

Dear friends ,

i want to know that while using ds1302 and enabling the trickle charging register,DO we need to add diodes and resistor externally from Primary source Vcc2 to battery Vcc1.

In the data sheet it is mentioned that R is internal , but i am not sure about diodes.
Somebody plz share his/her experience for running rtd ds1302 in trickle charging mode for recharging Nicd 3.6V Rtc battery.

 

[ZASto]

Read carefully the datasheet, everything is written there. Page 7, Trickle-Charger Register.

 

[jit_singh_tara]

THX , i want to know whether the diodes are inbuilt the rtc or they are to be added externally...?

 

[betwixt]

The diodes and resistor are internal to the DS1302. The diodes exist so you can use them as voltage droppers if necessary and the resistor is to let you control the charge rate. All you have to do is connect a rechargeable battery or a suitable capacitor between the VCC1 pin and ground then configure the device. I use them a lot, they are very versatile RTCs.

Brian.