LTC4060 purpose using PNP transistor...?

[ylioily]

Hi,
i don't understand wat exactly purpose and function using pnp transistor(FZT948) attach to ltc4060 here. Any1 can help me try to explain to me...@@"

thx~

 

[k7elp60]

Hi,
i don't understand wat exactly purpose and function using pnp transistor(FZT948) attach to ltc4060 here. Any1 can help me try to explain to me...@@"

thx~

If I am reading the data sheet correctly the pnp transistor limits the charge current in the fast charge mode by the value of the resistor from the program pin 7 to ground. In this case 1A.

 

[Roff]

Hi,
i don't understand wat exactly purpose and function using pnp transistor(FZT948) attach to ltc4060 here. Any1 can help me try to explain to me...@@"

thx~

The PNP appears to be the only charge path for the battery. It is off-chip because it dissipates too much power to be on-chip (not to mention the problems with making a high-quality PNP on-chip with the process being used).

 

[ylioily]

i have decide to using the ltc4060 purpose for as 'UPS', 4 AA-type battery of 800mA capacity. The charge current program as 800mA, 1C-rate. and charging terminate time will be around after 1.5hours due to losses. 8.7V Vin will be apply to operating the ltc4060. The problem is, isn't the part number MJD210 PNP transistor suitable for using here? The input source will be shift between 0V to 8.7V.

 

[John Massey]

Help with a specific design for a 4060 charger.

I need a schematic for a 4060 battery charger using 4 AA batteries in series.. The charger should not put out more than 6.0 volts. It must always restart above 4.2 volts. This is an imbedded application. The draw from the application is 20 ma. The 4060 has the capability to use a thermistor. Would advise as to these advantages.