tea1733t NXP Semiconductors, tea1733t Datasheet - Page 6

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

NXP Semiconductors
TEA1733T_TEA1733LT_1
Objective 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 e.g. for creating an overvoltage detection and an OTP
function.
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 (typ.) 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 voltage source of 5 V via an internal resistor (typical resistance is 7 k ).
The CTRL pin voltage sets the maximum peak current which is measured via the ISENSE
pin. (see
Section
For CCM a slope compensation circuit is integrated. The slope compensation guarantees
stable operation for duty cycles larger than 50 %.
If the OPTIMER pin is connected to a capacitor a temporary overload situation is allowed.
If V
(10 A typ.) is sourced from the OPTIMER pin. If the voltage on the OPTIMER pin
reaches the V
triggered. (see
When the V
If the overload is removed before the V
continue switching.
Fig 5.
ctrl(Ipeak)
7.12)The maximum duty cycle is limited to 72 % (typ).
Section
Overpower delay
Output voltage
(see
Output load
prot(OPTIMER)
V
OPTIMER
prot(OPTIMER)
V
ISENSE
Figure
Figure
7.10) At low output power the switching frequency is also reduced. (see
Rev. 01 — 26 October 2009
5)
1) set by the CTRL pin is above 400 mV, a current of I
voltage is reached a restart will be made.
voltage (2.5 V typ.) the OverPower Protection (OPP) is
high load
prot(OPTIMER)
normal
load
TEA1733T; TEA1733LT
voltage is reached, the converter will
high load
GreenChip SMPS control IC
protection
400 mV
V
014aaa930
prot(OPTIMER)
© NXP B.V. 2009. All rights reserved.
IO(OPTIMER)
6 of 17