tea1553t NXP Semiconductors, tea1553t Datasheet - Page 14

• Manufacturer Part Number: tea1553t
• Description: Tea1553t Greenchip Ii Smps Control Ic
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TEA1553T_1
Product data sheet
7.14 Minimum and maximum ‘on-time’
7.15 Short winding protection
7.16 LOCK input
The charging current, I
approximately 0.5 V. If it exceeds this value, the current source will start to limit the current
I
The minimum ‘on-time’ of the SMPS is determined by the Leading Edge Blanking (LEB)
time. The IC limits the maximum ‘on-time’ to 50 s. When the system requires an ‘on-time’
longer than 50 s, a fault condition is assumed (e.g. C
switching and enter the safe restart mode.
After the leading edge blanking time, the short winding protection circuit is also activated.
If the ‘sense’ voltage exceeds the short winding protection voltage, V
stop switching. Once V
recharged and the supply will restart again. This cycle will be repeated until the short
circuit is removed (safe restart mode).
The short winding protection will also protect in case of a secondary diode short circuit.
Pin 13 is a general purpose (high impedance) input pin, which can be used to switch off
the IC. As soon as the voltage on this pin is raised above 2.5 V, switching will stop
immediately. The voltage on the V
IC will not start switching again until the latch function is reset. The latch is reset as soon
as V
latch (see
The detection level of this input is related to the VCC5V pin voltage in the following way:
0.5
voltages. No internal filtering is done on this input.
opp(adv)
Fig 12. Advanced overpower current injection
CC
V
VCC5V
.
drops below 4.5 V (typical value). The internal OVP and OTP will also trigger this
Figure
4 %. An internal Zener clamp of 5.6 V will protect this pin from excessive
3).
0.5 V
opp(adv)
CC
Rev. 01 — 3 July 2007
V OCP
drops below the V
, will flow as long as the voltage on pin ISENSE is below
F AOP
I AOP
CC
100 k
GATE ( )
pin will cycle between V
th(UVLO)
DRIVER
ISENSE
level, capacitor C
i
has been removed), the IC will stop
R SS
C SS
GreenChip II SMPS control IC
startup
014aaa011
R sense
and V
TEA1553T
swp
VCC
, the converter will
© NXP B.V. 2007. All rights reserved.
th(UVLO)
will be
, but the
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