TEA1501 Philips Semiconductors, TEA1501 Datasheet - Page 9

• Manufacturer Part Number: TEA1501
• Description: Greeny; GreenChip
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Supply current tracking
For obtaining good load regulation, especially with low
cost transformers, a tracking circuit is included. The
tracking circuit makes the supply current of Greeny a
function of the secondary load. This makes the voltage
drop across the series resistance of the auxiliary winding
proportional to the voltage drop across the series
resistance of the secondary winding. Therefore, the
secondary output voltage tracks with the Vaux regulation
voltage.
The tracking starts at a counter state of 28. For a counter
state from 28 up to 112 (typical values) the supply current
of Greeny rises linearly with the counter state according to
the following formula (see Fig.7).
For counter states of 112 and higher the supply current
remains on its maximum value.
1998 Aug 19
handbook, halfpage
I
Vaux
Greeny; GreenChip
I Vaux
(mA)
6.7
1.7
=
k
tracking
Fig.7 I
28
N
Vaux
56
versus counter state.
N data
112
counter state
I Vaux(HIGH)
I Vaux(LOW)
MGM825
9
Preliminary specification
TEA1501