tea1733t NXP Semiconductors, tea1733t Datasheet - Page 7

• Manufacturer Part Number: tea1733t
• Description: Greenchip Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA1733T_TEA1733LT_1
Objective data sheet
7.10 Overpower or high/low line compensation (VINSENSE and ISENSE
7.9 Current mode control (ISENSE pin)
Current mode control is used for its good line regulation.
The primary current is sensed by the ISENSE pin across an external resistor and
compared with an internal control voltage.The internal control voltage is proportional to
the CTRL pin voltage. (see
Leading edge blanking is added to prevent false triggering due to the capacitive discharge
when switching on the external power switch. (see
pins)
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 input voltage via the VINSENSE pin
and outputs a current depending on this voltage on the ISENSE pin. The DC voltage
across the soft start resistor will then limit the maximum peak current on the current sense
resistor.
At low output power levels the overpower compensation circuit is switched off.
See
Fig 6.
Fig 7.
Figure
Peak current control
Leading edge blanking
8.
V
sense(max)
Rev. 01 — 26 October 2009
(V)
0.6
0.4
0.2
0
0
Figure
V
frequency
reduction
sense(max)
VISENSE
LEB (t
6)
leb
1
)
TEA1733T; TEA1733LT
2
Figure
V
CTRL
3
014aaa932
014aaa931
(V)
7)
GreenChip SMPS control IC
t
4
© NXP B.V. 2009. All rights reserved.
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