tea1751lt NXP Semiconductors, tea1751lt Datasheet - Page 7

• Manufacturer Part Number: tea1751lt
• Description: Greenchip Iii Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA1751T_LT_1
Product data sheet
7.1.2 Supply management
7.1.3 Latch input
All internal reference voltages are derived from a temperature compensated and trimmed
on-chip band gap circuit. Internal reference currents are derived from a temperature
compensated and trimmed on-chip current reference circuit.
Pin LATCH is a general purpose input pin, which can be used to switch off both
converters. The pin sources a current I
converters is stopped as soon as the voltage on this pin drops below 1.25 V.
At initial start-up the switching is inhibited until the capacitor on the LATCH pin is charged
above 1.35 V (typ). No internal filtering is done on this pin. An internal zener clamp of
2.9 V (typ) protects this pin from excessive voltages.
Fig 4.
PROTECTION
PFCDRIVER
PFCSENSE
VINSENSE
FBDRIVER
VOSENSE
FBSENSE
FBCTRL
LATCH
Start-up sequence, normal operation and restart sequence
V
I
V
CC
HV
O
charging VCC
capacitor
Rev. 01 — 10 July 2008
converters
starting
operation
soft start
normal
soft start
O(LATCH)
TEA1751T; TEA1751LT
(typical 80 A). Switching off both
protection
GreenChip III SMPS control IC
restart
© NXP B.V. 2008. All rights reserved.
V
V
V
V
V
V
V
014aaa156
startup
th(UVLO)
trip
start(VINSENSE)
EN(LATCH)
to(FBCTRL)
start(fb)
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