KA3032
Application Information
1. REFERENCE INPUT & MUTE
Pin 46 (REF) uses the reference input pin or the all mute input pin a reference input block circuit.
• Reference input
In the case of external reference input, the applied voltage range must be between 2[V] and 6.5[V] at V =8[V].
CC
• All mute input
Using the all mute function pin, the applied voltage condition is as follows.
All mute on voltage
All mute off voltage
Below 0.5[V]
Above 2.0[V]
Mute function operation
Normal operation
2. SEPARATED CHANNEL MUTE FUNCTION
These pins are used for the individual channel mute operation.
• When the mute pins (pin22, 23 and 24) are high level, the mute circuits are activated so that the output circuit is muted.
• When the voltage of the mute pins (pin22, 23 and 24) are low level, the mute circuit is stopped and output circuits operate
normally.
• If the chip temperature rises above 175°C, then the thermal shutdown (TSD) circuit is activated and the
are muted.
output circuits
- Mute 1, 2 (pin 24)-CH1, 2 mute control input pin.
- Mute 3 (pin 23)-CH3 mute control input pin.
- Mute 4 (pin 22)-CH4 mute control input pin.
3. PROTECTION FUNCTION
• Thermal shutdown (TSD)
If the chip temperature rises above 175°C, then the thermal shutdown (TSD) circuit is activated and the output circuit is
mute. The TSD circuit is temperature hysteresis about 25°C.
• Under voltage lockout (UVLO) and over voltage protection (OVP)
It is designed to mute operate the internal bias by the function of UVLO and OVP, when the power supply voltage falls
below 3.5[V] or above 20[V].
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FAIRCHILD [ FAIRCHILD SEMICONDUCTOR ]
