TEA1833LTS All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2015. All rights reserved.
Product data sheet Rev. 1 — 31 August 2015 12 of 24
NXP Semiconductors
TEA1833LTS
GreenChip SMPS control IC
7.13 Overpower or high/low line compensation
The overpower compensation function can be used to realize a maximum output power
which is nearly constant over the full input mains. The overpower compensation circuit
measures the mains detect input current on the PROTECT pin and outputs a
proportionally dependent current on the ISENSE pin. The DC voltage across resistor R3
(see Figure 3
) limits the maximum peak current on the current sense resistor (see
Figure 13
).
At low output power levels, the overpower compensation circuit is switched off.
7.14 Burst mode
If the CTRL voltage (V
CTRL
) is < 1.45 V, the system is not switching. It waits until the V
CTRL
exceeds this minimum level before starting the next cycle. During this period, the
TEA1833LTS discharges the primary VCC capacitor. If the voltage on the VCC pin then
drops to below the burst threshold level (V
th(burst)
), the system asserts two DRIVER pulses
to recharge the VCC capacitor. The assertion avoids that the voltage on the VCC pin
drops to below the UVLO level during a large off-time.
Worst off-time occurs when there is a load transient from peak load to no-load. The output
voltage shows an overshoot and stops switching until the output voltage drops to below
the regulation level while there is no-load at the output.
For minimum no-load input power, the chosen value of the external capacitor at the VCC
pin must be high enough to prevent that the voltage on the VCC pin drops below the burst
threshold level at continuous no-load operation. The burst mode is only intended to assist
at load changes until the output voltage drops to below the regulation level while there is
no-load at the output.
Fig 13. Overpower compensation
,
3527(&7
$
