TEA1521T View Datasheet(PDF) - NXP Semiconductors.

Part Name

Description

Manufacturer

TEA1521T

SMPS ICs for low-power systems

NXP Semiconductors. 

NXP Semiconductors

TEA152x

SMPS ICs for low-power systems

40

phase

(deg)

20

mgt424

0

− 20

− 40

0

200

400

600

800

f (kHz)

Fig 5. Typical phase of drain ringing at switch-on (at N × Vo = 80 V)

8.5 Demagnetization

The system operates in discontinuous conduction mode all the time. As long as the

secondary stroke has not ended, the oscillator will not start a new primary stroke. During

the first tsuppr seconds, demagnetization recognition is suppressed. This suppression may

be necessary in applications where the transformer has a large leakage inductance and at

low output voltages.

8.6 Minimum and maximum duty factor

The minimum duty factor of the switched mode power supply is 0 %. The maximum duty

factor is set to 75 % (typical value at 100 kHz oscillation frequency).

8.7 OverCurrent Protection (OCP)

The cycle-by-cycle peak drain current limit circuit uses the external source resistor RI to

measure the current. The circuit is activated after the leading edge blanking time tleb. The

protection circuit limits the source voltage to Vsource(max), and thus limits the primary peak

current.

8.8 Short-circuit winding protection

The short-circuit winding protection circuit is also activated after the leading edge blanking

time. If the source voltage exceeds the short-circuit winding protection voltage Vswp, the IC

stops switching. Only a power-on reset will restart normal operation. The short-circuit

winding protection also protects in case of a secondary diode short circuit.

8.9 OverTemperature Protection (OTP)

An accurate temperature protection is provided in the device. When the junction

temperature exceeds the thermal shutdown temperature, the IC stops switching. During

thermal protection, the IC current is lowered to the start-up current. The IC continues

normal operation as soon as the overtemperature situation has disappeared.

TEA152X

Product data sheet

All information provided in this document is subject to legal disclaimers.

Rev. 04 — 14 September 2010

© NXP B.V. 2010. All rights reserved.

7 of 20

Share Link: