NXP Semiconductors AN10907, Примечание к применению

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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 29 of 82
NXP Semiconductors
AN10907
TEA1613T resonant power supply control IC
(6)
8.1.2 Start and stop voltage with series resistance
When introducing a series resistance (Rs) in the connection of SNSBOOST, the start
voltage can be increased independently.
(7)
Example:
R
1
= 9800 k

R
2
= 47 k

R
s
= 22 k

(8)
8.1.3 SNSBOOST and compensation SNSBURST
The choices made for designing the brownout function affect the design of the burst-mode
presetting on SNSBURST. If the burst mode is implemented, mainly the choice for the
V
Boost(stop)
level has an effect on the (amount of) compensation current in SNSBURST.
For information relating to combining both functions, see Section 9.5.2 “Advanced design
of SNSBURST circuit” .
8.2 HBC switch control
The internal control for the MOSFET drivers, determines when the MOSFETs are
switched on and off. It uses several inputs from the following functions:
•
An internal divider is used to provide the alternating switching of high-side and
low-side MOSFET for every oscillator cycle.
•
The adaptive non-overlap (see Section 8.3 ) sensing on HB determines the switch-on
moment.
•
The oscillator (see Section 8.4 ) determines the switch-off moment.
•
Several protection and enable functions determine if the resonant converter is allowed
to switch.
V
Boost stop
 
9800 k

1.60 V
47 k

----------------
 
 
1.60 V +

335 V = =
V
Boost start new ( , )
R
1
1.65 V R
s
3

A
  
+
R
2
---------------------------------------------------- 3

A +
 
 
1.65 V R
s
3

A
  
+ +

=
V
Boost start new
  
9800 =
1.65 22 3
  
+
47
------------------------------------- 3 +
 
 
1.65 22 3
  
+ +

389 V =