TDA8931 Datasheet, PDF (7/31 Pages) NXP Semiconductors – Power comparator 1 X 20 W

Philips Semiconductors
TDA8931
Power comparator 1 × 20 W
V_PA
R1
OVP _TDA8931
R2
001aac234
Fig 3. Overvoltage protection setting
The overvoltage protection level can be determined by the formula:
V _P(OVP) = -^R----¹--_R--⁺--₂---^R----²-- × V _OVP
(1)
Where:
V_P(OVP) = overvoltage protection level of supply voltage
R1 = external resistor
R2 = external resistor
V_OVP = 1.27 V reference voltage.
Example: The TDA8931 has to shut down at 24 V. When we choose R2 = 10 kΩ, then R1
has to be 178 kΩ and V_P(OVP) becomes 24 V.
Remark: When pin OVP is connected to V_SSD the V_{P(OVP)fix} level is used.
8.6.4 Undervoltage protection (UVP)
When the supply voltage applied to the TDA8931 drops below the minimum supply
voltage threshold level the device is internally set to Standby mode.
8.6.5 Supply voltage drop protection
When the TDA8931T is switched off with the supply, it will be switched off before it
reaches the voltage on pin HVP. This prevents switch-off pop noise. This function is not
self recovering. The TDA8931T can be recovered by switching to Sleep mode or by
removing the supply voltage.
8.6.6 Overdissipation protection (ODP)
In case of a short-circuit across the speaker the dissipation is minimized by the ODP.
When the OCP and the OTP are on the same time activated, an over dissipation is
defined. The device is set to Sleep mode and is not self-recovering. When pin
POWERUP = 0 V or the supply voltage is removed, the device is recovered.
9397 750 13847
Preliminary data sheet
Rev. 01 — 14 January 2004
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
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