tea1733mt NXP Semiconductors, tea1733mt Datasheet - Page 7

• Manufacturer Part Number: tea1733mt
• Description: Tea1733mt Greenchip Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA1733MT
Preliminary data sheet
7.6 Duty cycle control (CTRL pin)
7.7 Slope compensation (CTRL pin)
7.8 Overpower timer (OPTIMER pin)
The PROTECT input can be used to create an overvoltage detection and OTP functions.
A small capacitor can be connected to the pin if the protections on this pin are not used.
An internal clamp of 4.1 V (typical) protects this pin from excessive voltages.
The output power of the converter is regulated by the CTRL pin. This pin is connected to
an internal 5.4 V supply using an internal 7 kΩ resistor.
The CTRL pin voltage sets the peak current which is measured using the ISENSE pin
(see
Section
After eight consecutive converter strokes at the maximum duty cycle, restart protection is
activated. Typically, this will happen when the mains input supply voltage is removed.
A slope compensation circuit is integrated in the IC for CCM. Slope compensation
guarantees stable operation for duty cycles greater than 50 %.
If the OPTIMER pin is connected to capacitor C4 (see
situation is allowed. V
400 mV, the I
voltage on the OPTIMER pin reaches the V
OverPower Protection (OPP) is triggered (see
When the V
If the overload is removed before the V
continue switching.
Fig 5.
Section
7.12). The maximum duty cycle is limited to 72 % (typical).
Overpower delay: latched
V
prot(OPTIMER)
OPTIMER
V
7.10). At low output power, the switching frequency is also reduced (see
IO(OPTIMER)
ISENSE
All information provided in this document is subject to legal disclaimers.
V
I
O
O
ctrl(Ipeak)
Rev. 1 — 4 February 2011
voltage is reached, the TEA1733MT is latched in the off-state.
current (11 μA typical) is sourced from the OPTIMER pin. If the
high load
(see
Figure
normal
prot(OPTIMER)
load
1) is set by pin CTRL. When V
prot(OPTIMER)
Figure
high load
voltage is reached, the converter will
5).
Figure
voltage (2.5 V typical) the
GreenChip SMPS control IC
3), a temporary overload
TEA1733MT
protection
400 mV
V
014aaa968
prot(OPTIMER)
© NXP B.V. 2011. All rights reserved.
ctrl(Ipeak)
is above
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