AN10907
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© NXP B.V. 2010. All rights reserved.
Application note
Rev. 1 — 28 December 2010
39 of 82
NXP Semiconductors
AN10907
TEA1613T resonant power supply control IC
8.6 SSHBC/EN soft-start and enable
The SSHBC/EN pin provides the following three functions:
•
Enables the IC (> 2.2 V)
•
It performs an HBC frequency sweep during soft-start from 3.2 V to 8 V
•
It provides frequency control during protection
Seven internal current sources operate the frequency control depending on the required
action i.e.
•
Soft-start + Over-Current Protection: high/low charge (160
A/40
A) + high/low
discharge (160
A/40
A)
•
Capacitive Mode Regulation: high/low discharge (1800
A/440
A)
•
General: bias discharge (5
A)
8.6.1 Switching on and off using an external control function
The SSHBC/EN can be used to switch the converters on and off using an external control
function.
This function is often driven by a microcontroller from the secondary side of the
optocoupler. By doing this, the main power supply [HBC and PFC (when supplied by an
auxiliary of HBC)] can be switched off for Standby mode and on for normal operation. In
such a concept a separate standby supply is needed to supply the microcontroller
functions during the standby.
The TEA1613T also offers the possibility to switch on/off using the SNSBURST function.
This function is intended for burst-mode operation where the duration of the on- and
off-states are short.
Fig 26. SSHBC/EN: overview of sources, clamps and levels
001aal450
SSHBC/EN 19
1360
μ
A
440
μ
A
120
μ
A
40
μ
A
120
μ
A
40
μ
A
5
μ
A
high CMR
disable
low CMR
high SoSt
low SoSt
bias
TEA1613
2.2 V
ENABLE HBC
COMP
FREQUENCY
CONTROL
8 V
3.2 V
42
μ
A
3.0 V
8.4 V
