1996 Feb 26

6

Philips Semiconductors

Objective specification

Cost effective battery monitor and fast

charge IC for NiCd and NiMH chargers

TEA1104; TEA1104T

Output drivers

Several output drive possibilities are supported by the

TEA1104, to limit the fast charge current and to indicate

the mode that the charge is in.

In mains isolated systems, output drive current is available

for a bipolar or MOS switching device. Moreover, current

regulators can be driven (see Fig.4).

In non mains isolated systems, the current source can be

switched via the auxiliary winding (see Fig.6) using the

TEA140X power plugs.

In the application section, an example is shown driving two

LEDs that are indicating fast charging, protection during

fast charging, full status and removed batteries. It is also

possible to output the same information via one LED only.

Fig.3 NiCd battery characteristics during a 1.25C charge cycle.

handbook, full pagewidth

MGE355

fast charge (Ifast)

trickle charge (Ifast/40)

t

full

detection

Vbat

Icharge

Fig.4 Output drivers.

handbook, full pagewidth

MGE356

TEA1104

output

output

output

LED

TEA1104

LED

TEA1104

LED

LM317