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Tfa9810, Nxp semiconductors – NXP Semiconductors TFA9810 User Manual

Page 7

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TFA9810_3

© NXP B.V. 2008. All rights reserved.

Product data sheet

Rev. 03 — 20 February 2008

7 of 29

NXP Semiconductors

TFA9810

Audio amplifier 2 x 12 W

OverVoltage Protection (OVP)

When the supply voltage applied to the TFA9810 exceeds the maximum supply
voltage threshold level the device will shut down. The device will restart when the
supply voltage is within the operating range.

UnderVoltage Protection (UVP)

When the supply voltage applied to the TFA9810 falls below the minimum supply
voltage threshold level the device will shut down. The device will restart when the
supply voltage is within the operating range.

OverDissipation Protection (ODP)

The ODP in the TFA9810 is a combination of two protections. Exceeding a
temperature threshold level of 135

°

C an internal pre-warning is generated. When an

overcurrent is detected during the pre-warning the device will shut down. When the
ENABLE pin is high the TFA9810 will restart automatically. The restart sequence
(switch-off

switch-on) will take 200 ms to 500 ms.

Window Protection (WP)

During start-up, if one of the outputs is shorted to V

SS

or V

DD

the device will not start.

This is an effective measure to protect the device against shorts between the outputs
(before the filter) and the ground or supply lines. The supply must be switched off prior
to removing any short. The WP protects the device against failure during board
assembly.

Table 6.

Overview protections

Protections

Symbol

Condition

DIAG

Outputs

Recovering

OTP

T

j

> 150

°

C

LOW

Floating

Automatic, after 5

µ

s and T

j

< 150

°

C

OCP

I

O

> I

ORM

LOW

Floating

Automatic, after 5

µ

s and I

O

< I

ORM

OVP

V

P

> 20 V

LOW

Floating

Restart (switch-off

switch-on when V

P

< 20 V)

UVP

V

P

< 8 V

LOW

Floating

Restart (switch-off

switch-on when V

P

> 8 V)

ODP

T

j

> 135

°

C and I

O

> I

ORM

LOW

Floating

Restart (switch-off

switch-on when

T

j

< 135

°

C or I

O

< I

ORM

)

WP

OUTX > V

DDA

- 1 V or

OUTX < V

SSA

+ 1 V

LOW