NXP Semiconductors TFA9810 Stereo Amplifier User Manual


 
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 µs and T
j
< 150 °C
OCP I
O
> I
ORM
LOW Floating Automatic, after 5 µs 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 °CorI
O
<I
ORM
)
WP OUTX > V
DDA
- 1 V or
OUTX < V
SSA
+ 1 V
LOW