TEA1832TS All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 1 — 16 December 2014 11 of 23
NXP Semiconductors
TEA1832TS
GreenChip SMPS control IC
If the system detects that the peak current already exceeds the targeted level after 1 s,
the next switching period time is extended from 7.7 s (f
sw
=130kHz) to 28s
(f
sw
= 36 kHz). The time of the secondary stroke is then sufficient to decrease the
transformer current to below the targeted peak current again.
To avoid activation at low loads, the OSCP is only enabled when the overpower timer is
active. Additionally, to avoid activation during peak power, V
out
must be below half the
OVP level.
The V
out
level is measured on the ISENSE pin in a similar way the overvoltage protection
is measured.
To limit the input power during a short circuit or an overload event, the OPP time is
reduced to 50 % when OSCP is enabled.
7.12 Peak power, high-power and low-power operation
During high-power operation, with the converter running at a 65 kHz (typical) fixed
frequency, the power is controlled by varying the peak current. A peak power mode is
implemented to supply a short overload situation. In peak power mode, both frequency
and peak current are increased.
In low-power operation, switching losses are reduced by lowering the switching frequency.
The switching frequency of the converter is reduced while the peak current is set to 22 %
of the maximum peak current (see Figure 8
and Figure 12).
Fig 11. OSCP peak current runaway
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