AN10907
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© NXP B.V. 2010. All rights reserved.
Application note
Rev. 1 — 28 December 2010
14 of 82
NXP Semiconductors
AN10907
TEA1613T resonant power supply control IC
6.3 SUPIC supply using HBC transformer auxiliary winding
6.3.1 Start-up by SUPHV
In a stand-alone power supply application, the IC can be started by a high voltage source
such as the rectified mains voltage. For this purpose the high voltage input SUPHV can be
connected to the boost voltage (for example a PFC output voltage).
The SUPIC and SUPREG are charged by the internal HV start-up source which delivers a
constant current from SUPHV to SUPIC. SUPHV is operational at a voltage > 25 V.
As long as the voltage at SUPIC is below the short circuit protection level (0.65 V), the
current from SUPHV is low (1.1 mA). This is to limit the dissipation in the HV start-up
source when SUPIC is shorted to ground.
During normal conditions, SUPIC quickly exceeds the protection level and the HV start-up
source switches to normal current (5.1 mA). The HV start-up source switches off when
SUPIC has reached the start level (22 V). The current consumption from SUPHV is low
(7
A) when switched off.
When SUPIC has reached the start level (22 V), SUPREG is charged. When SUPREG
reaches the level of 10.7 V, it enables operation of HBC.
The auxiliary winding supply of the HBC transformer must take over the supply of SUPIC
before it is discharged to the SUPIC undervoltage stop level (15 V).
6.3.2 Block diagram for SUPIC start-up
Fig 5.
Block diagram: SUPIC and SUPREG start-up with SUPHV and auxiliary supply
001aal018
SuplcChargeLow = 1.1 mA
SuplcCharge = 5.1 mA
SuplcCharge = off
HV START-UP SOURCE
CONTROL
0.65 V
10.9 V
5.5 mA
SUPIC
SUPHV
SUPREG
SupReg
EnableSupReg
V
AUXILIARY
reduced
current
SuplcShort
startlevel Hv = 22 V
startlevel Lv = 17 V
stoplevel = 15 V
SupRegUvStart
startlevel = 10.7 V
SupRegUvStop
stoplevel = 10.3 V
SupHvPresent
CSUPREG
