TFA9842AJ Philips, TFA9842AJ Datasheet - Page 6

• Manufacturer Part Number: TFA9842AJ
• Description: 7.5W Stereo Power Amplifier
• Manufacturer: Philips

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Philips Semiconductors
9. Limiting values
10. Thermal characteristics
TFA9842AJ_1
Preliminary specification
8.5 Built-in protection circuits
The TFA9842AJ contains two types of temperature sensors; one measures the local
temperatures of the power stages and one measures the global chip temperature. At a
local temperature of the power stage of approximately 185 C or a global temperature of
approximately 150 C this detection circuit switches off the power stages for 2 ms. When
the outputs are switched off the voltage is measured on the outputs. In the event of a
short-circuit to ground or to V
cases the power stages switch-on automatically and the detection will take place again;
however a too high temperature will switch-off the power stages immediately. This can
result in repetitive switching during too high junction temperature. This protects the
TFA9842AJ against short-circuits to ground, to the supply voltage, across the load and too
high chip temperatures.
The protection will only be activated when necessary, so even during a short-circuit
condition, a certain amount of (pulsed) current will still flow through the short-circuit (as
much as the power stage can handle without exceeding the critical temperature level).
Table 6.
In accordance with the Absolute Maximum Rating System (IEC 60134).
Table 7.
Symbol
V
V
I
T
T
P
V
Symbol Parameter
R
R
ORM
stg
amb
CC
I
tot
CC(scp)
th(j-a)
th(j-c)
thermal resistance from junction to ambient in free air
thermal resistance from junction to case
Limiting values
Thermal characteristics
Parameter
supply voltage
input voltage
repetitive peak output
current
storage temperature
ambient temperature
total power dissipation
short-circuit protection
supply voltage
Rev. 01 — 28 April 2006
CC
the device will remain in Protection mode. In all other
7.5 W stereo power amplifier with volume control
Conditions
operating
non-operating
operating
Conditions
both channels driven
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
Min
-
-
-
0.3
0.3
55
40
TFA9842AJ
Max
+28
V
3
+150
+85
35
26
CC
+ 0.3 V
Typ
40
2.0
Unit
V
A
W
V
C
C
6 of 18
Unit
K/W
K/W