AN10907
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2010. All rights reserved.
Application note
Rev. 1 — 28 December 2010
28 of 82
NXP Semiconductors
AN10907
TEA1613T resonant power supply control IC
8. HBC
functions
8.1 SNSBOOST undervoltage or brownout protection level
To prevent the HBC from operating at very low boost input voltages, the voltage on the
SNSBOOST pin is sensed continuously.
After the voltage on this pin drops below VUVP(SNSBOOST) = 1.6 V, the switching of the
HBC is stopped as soon as the low-side MOSFET is on. The start level is determined by
an internal hysteresis current source of 3
A in combination with the resistance values of
the external divider. The boost voltage for starting is higher than the boost voltage for
stopping. For starting, an additional internally fixed hysteresis of 50 mV is added to the
comparator level: 1.6 V + 0.05 V = 1.65 V.
8.1.1 Start and stop voltage without series resistance
The boost voltage at which the converter starts:
(3)
The boost voltage at which the converter stops:
(4)
Example:
R
1
= 9800 k
R
2
= 47 k
R
s
= 0 k
(5)
Fig 15. SNSBOOST function
001aal439
TEA1613
SPIKE
FILTER
R1
Rs
R2
boost Uv
50 mV
16 V
3
μ
A
5.8 V
V
boost
V
Boost start
R
1
1.65
V
R
2
----------------
3
A
+
1.65
+
V
=
V
Boost stop
R
1
1.60
V
R
2
----------------
1.60
+
V
=
V
Boost start
9800
k
1.65
V
47
k
----------------
3
A
+
1.65
V
+
375
V
=
=
