tea1532ct-n1 NXP Semiconductors, tea1532ct-n1 Datasheet - Page 8

• Manufacturer Part Number: tea1532ct-n1
• Description: Greenchip Ii Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA1532BT_TEA1532CT_1
Product data sheet
7.10 Adjustable slope compensation
7.9 Continuous Conduction Mode (CCM)
In an optimum design, the reflected secondary voltage on the primary side will force the
drain voltage to zero. Thus, zero voltage switching is possible, preventing large capacitive
switching losses
results in small and cost-effective magnetics.
It is also possible to operate the IC in the so-called Fixed Frequency Continuous
Conduction Mode (FF CCM). This mode is activated by connecting pin DEM to ground
and connecting pin DRAIN to the rectified V
A slope compensation function has been added at pin CTRL; see
compensation function prevents sub-harmonic oscillation in CCM at duty cycles over
50 %. The CTRL voltage is modulated by sourcing a (non-constant) current out of
pin CTRL and adding a series resistor R
proportionally with the on-time, which therefore limits the OCP level. Thus, a longer
on-time results in a higher CTRL voltage. However, this increase in CTRL voltage will
actually decrease the on-time. Slope compensation can be adjusted by changing the
Fig 6. Signals for valley switching
(1) Start of new cycle at lowest drain voltage.
(2) Start of new cycle in a classical PWM system at high drain voltage.
secondary
oscillator
stroke
valley
drain
P
=
Rev. 01 — 18 January 2007
1
-- -
2
primary
stroke
C
V
2
secondary
f
stroke
TEA1532BT; TEA1532CT
, and allowing high frequency operation, which
slopecomp
I
voltage; see
. This increases the CTRL voltage
secondary
ringing
Figure
GreenChip II SMPS control IC
(2)
12.
Figure
mgu235
© NXP B.V. 2007. All rights reserved.
(1)
7. The slope
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