Tải bản đầy đủ - 0 (trang)
Figure 21. I2S standard data format

Figure 21. I2S standard data format

Tải bản đầy đủ - 0trang



*$3*36



For qualitative load detection purposes A can be used instead of A/B to discriminate

between normal load and open-short load detection supposing supply and output voltage

conditions are known during measurement.

In both cases it is possible to chose if the signal is delivered





Differential (IB2_D7 = 1). Suggested for load condition check during normal play time of

the device; completely transparent to play signal (no noise-click during activation).







Single ended (IB2_D7 = 0): suggested for precise high frequency audio range current

measurement, like tweeter detection, since no current is lost in capacitor filter. Load

voltage signal halves when activated.



For more details and suggestions, please refer to specific application notes.



36/61



Rev 1



FDA2100LV



6.2



Diagnostics functional description



ExtTherm pin function

With the ExtTher pin (n. 37) it is possible to realize a temperature sensor with warning flag

suitable to sense over-temperature of components external the FDA4100, as example the

step-up PowerMOS transistor.

If this function is not used, the ExtTher pin must be connected to the An-P pin, through a

resistor or a short.

To implement this function, the schematic shown in Figure 15 is needed.

Rt must be in the range of 10K - 100K

Rntc (resistor with Negative Temperature Coefficient) is the thermal sensor that must be

placed near the sensed device.

Ct ~100nF, is needed to avoid spurious External Thermal Warning intervention.

The Rntc value must be:

Rntc (@ T = Twarning) = Rt.

The ExtTherm pin must be kept at voltage > 0.6V with respect V(An-N).

Figure 15. External temperature warning application schematic



!N
0

2T



#T

4O )#$"n $



%XT4HER

2.4#



!N
.

62EF%XT4HER&N &W



62EF4ES T-ODE6T

'!0'03



Rev 1



37/61

60



Diagnostics functional description



FDA2100LV



6.3



Special cases: behavior under mis-connection conditions



6.3.1



Case 1

In this case, the device has an anomalous resistive path (Rsc) to ground or to the positive

supply present on one "half bridge" output of the channel N before turn-on. (with N = 1 or 2).

If I(Rsc) > 30 mA, the channel N is maintained in 3-state mode because it is considered in

unsafe condition (short or resistive path to ground or ti +Vs).

If I(Rsc) become < 3 mA the channel N is considered in safe condition (no short or resistive

path to ground or to +VS), then, after ~200 ms, starts to work in mute condition. The unmute

soft transition is automatically generated.



6.3.2



Case 2

In this case, the device has an anomalous resistive path (Rsc) to ground or to the positive

supply present on one "half bridge" output of the channel N after turn-on.

If Iout > Isc, the channel N is kept in 3-state mode.



Note:



Isc is defined by the resistor connected between the pin 36 (IsetProt) to ground according to

Section 6.4.

With the channel N in 3-state mode:

a)



if I(Rsc) > 30 mA, the channel N is maintained in 3-state mode because it is

considered in unsafe condition (short or resistive path to ground or ti +Vs).



b)



If I(Rsc) become < 3 mA the channel N is considered in safe condition (no short or

resistive path to ground or to +VS), then, after ~200 ms, starts to work in mute

condition. The unmute soft transition is automatically generated.



The over-current event is stored in the I2C Data byte.



6.3.3



Case 3

In this case, the device has an anomalous resistive path across the outputs of the bridge N.

If Iout > Isc, the channel N is kept in 3-state mode.

After ~200 ms, starts to work in mute condition. The unmute soft transition is automatically

generated.

The over-current event is stored in the I2C Data byte. Because the device is self-protected,

it is not mandatory to reduce the input signal in case of over-current protection intervention.



38/61



Rev 1



Tài liệu bạn tìm kiếm đã sẵn sàng tải về

Figure 21. I2S standard data format

Tải bản đầy đủ ngay(0 tr)

×