Datasheet

TEA1832LTS All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 1 — 15 December 2014 9 of 23
NXP Semiconductors
TEA1832LTS
GreenChip SMPS control IC
Leading-edge blanking prevents false triggering due to capacitive discharge when
switching on the external power switch (see Figure 9
).
7.9 Overvoltage protection (pin ISENSE)
Accurate overvoltage protection can be realized at the ISENSE pin by sensing the
auxiliary voltage. During the primary stroke, diode D4 (see Figure 3
) is blocked so that the
converter still works under current mode control. During the secondary stroke, the
ISENSE voltage represents the output voltage via the resistor divider R5 and R3
(see Figure 3
). The ISENSE voltage is sampled 2 s after the gate signal drops to avoid
the ringing of the transformer. If the sampled voltage exceeds V
ovp(ISENSE)
for four
consecutive switching cycles, the IC triggers the latched protection.
7.10 Overvoltage protection (pin VCC)
An OverVoltage Protection (OVP) circuit is connected to the VCC pin. When the V
CC
exceeds V
th(OVP)
(36 V typical) for four consecutive switching cycles, the IC triggers the
latched protection. When V
CC
drops below V
th(OVP)
before count = 4 is reached, the
counter is reset to zero.
Fig 8. Peak current control
Fig 9. Leading-edge blanking
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