YDA135 Datasheet, PDF (12/22 Pages) YAMAHA CORPORATION – STEREO 5W-20W DIGITAL AUDIO POWER AMPLIFIER CONTROLLER

YDA135
When overcurrent has been detected, Power MOSFET can be protected by the following methods.
(1)Turning off Power MOSFET when overcurrent has been detected.
Connect PROT terminal and MUTE terminal externally as shown in the following "Power MOSFET protection
circuit". With this method, the device is brought into mute state when overcurrent has been detected, where
Power MOSFET is turned off to limit the current flowing into Power MOSFET. At this time, the protected state
can be cancelled by setting SLEEP terminal to "H" level or by bringing VDD or PVDD power supply terminal
voltage to the level below the shut off voltage once.
(2)Turning off Power MOSFET when overcurrent has been detected and restarting it.
Connect PROT terminal and SLEEP terminal through external circuit as shown in the following "External
automatic restoration circuit". With this method, SLEEP terminal becomes "H" level when overcurrent has been
detected, and this IC is brought into sleep state (Power MOSFET is turned off). After this, when a certain period
that depends on the RC time constant has elapsed, SLEEP terminal becomes "L" level where this IC restarts
automatically.
PROT
MUTE
SQ
SR-FF
R
PROT
SLEEP
YDA135
Power MOSFET protection circuit
YDA135
External automatic restoration circuit
High temperature detection functions
The high temperature detection is a function that determines that the high temperature state has occurred and set
PROT terminal to "H" level when the temperature of the temperature detection element (such as posistor*1) that is
placed in the location that is thermally equivalent with Power MOSFET has become equal to or higher than the
specified value. (This IC does not internally perform processing that turns off Power MOSFET automatically in such
case.)
For the "Example of application circuit", the circuit related to the high temperature detection function is as shown in
the next page, "High temperature detection function block diagram".
*1: "posistor" is a registered trade mark of Murata Manufacturing Co., Ltd. for their positive thermisters.
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