AN10907
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© NXP B.V. 2010. All rights reserved.
Application note
Rev. 1 — 28 December 2010
18 of 82
NXP Semiconductors
AN10907
TEA1613T resonant power supply control IC
The series stabilizer for SUPREG is enabled after SUPIC has been charged. In this way
optional external circuitry at SUPREG does not draw from the start-up current during the
charging of SUPIC. The capacitor on SUPIC acts as a buffer at charge of SUPREG and
start-up of the IC.
To ensure that the external MOSFETs receive sufficient gate drive, the SUPREG voltage
must first reach the V
start(SUPREG)
level before the IC starts operating, provided that the
SUPIC voltage has also reached the start level.
The SUPREG has an Under-Voltage Protection. When the SUPREG voltage drops below
the 10.3 V two actions occur:
•
The IC stops operating to prevent unreliable switching due to a too low gate driver
voltage. The HBC continues until the low-side stroke is active.
•
The maximum current from the internal SUPREG series stabilizer is reduced to
5.4 mA. In case of an overload at SUPREG in combination with an external DC supply
for SUPIC, this action reduces the dissipation in the series stabilizer.
It is important to realize that in principle, SUPREG can only source current.
The GATELS driver (and indirectly the GATEHS driver) is supplied by this voltage and
takes current from it during operation depending on the operating conditions. Some
change in value can be expected due to current load and temperature.
Voltage characteristics for load
Voltage characteristics for temperature
Fig 8.
Typical SUPREG voltage characteristics for load and temperature
SUPREG load current (mA)
0
50
40
10
20
30
001aal433
10.89
10.90
10.91
10.92
SUPREG
voltage
(V)
10.88
SUPIC = 17 V
SUPIC = 20 V
Temperature (
°
C)
−
50
150
100
0
50
001aal021
10.85
10.90
10.80
10.95
11.00
SUPREG
voltage
(V)
10.75
