tea1733t NXP Semiconductors, tea1733t Datasheet - Page 5

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

NXP Semiconductors
TEA1733T_TEA1733LT_1
Objective data sheet
7.3 Supply management
7.4 Input voltage detection (VINSENSE pin)
7.5 Protection input (PROTECT PIN)
When the voltage on pin VCC drops below the UVLO level during normal operation, the
controller stops switching and enters Restart mode. In Restart mode the driver output is
disabled and the VCC pin voltage is recharged via the resistor to the rectified mains.
All internal reference voltages are derived from a temperature compensated on-chip band
gap circuit. Internal reference currents are derived from a trimmed and temperature
compensated current reference circuit.
In a typical application the mains input voltage can be detected by the VINSENSE pin. As
long as the voltage on VINSENSE has not reached the V
(typically 0.93 V), switching is inhibited.
When during operation the VINSENSE voltage drops below V
(typically 0.72 V) or exceeds V
switching and performs a restart.
If the pin is left open or disconnected, the pin is pulled up by the internal 20 nA (typ.)
current source and subsequently the V
trigger a restart protection.
An internal clamp of 5.2 V (typ.) protects this pin from excessive voltages.
The pin PROTECT is a general purpose input pin, which can be used to switch off the
converter (latched protection). The converter is stopped as soon as the voltage on this pin
is pulled above V
A current of 32 A (typ.) is flowing out of the chip when the pin voltage is V
A current of 107 A (typ.) is flowing into the chip when the pin voltage is V
Fig 4.
Output voltage
VINSENSE
PROTECT
OPTIMER
Start-up sequence, normal operation and restart sequence
ISENSE
charging VCC
V
CC
capacitor
det(H)(PROTECT)
Rev. 01 — 26 October 2009
converter
starting
det(H)(VINSENSE)
(typically 0.8 V) or below V
soft start
operation
normal
det(H)(VINSENSE)
TEA1733T; TEA1733LT
(typically 3.52 V), the converter stops
(power down)
protection
level is reached. This will then
start(VINSENSE)
det(L)(PROTECT)
restart
GreenChip SMPS control IC
det(L)(VINSENSE)
014aaa929
soft start
voltage
V
V
V
V
V
V
4.5 V
1.2 V
© NXP B.V. 2009. All rights reserved.
startup
th
det(VINSENSE)(H)
start(VINSENSE)
det(PROTECT)(H)
det(PROTECT)(L)
(typically 0.5 V).
(
UVLO)
det(H)(PROTECT)
det(L)(PROTECT)
5 of 17
.
.