YDA137 Datasheet, PDF (9/20 Pages) YAMAHA CORPORATION – D- 2 STEREO 5W DIGITAL AUDIO POWER AMPLIFIER

YDA137
●Over-Current Protection Function
Over-Current Protection Function is a function to detect the over-current condition and protect IC, when excessive
current flows in the digital amplifier output terminal for a given period.
At this time, in the internal of IC, digital amplifier output terminal and headphone output terminal becomes WL and L is
output from /PROT terminal. (hereinafter described as Protection Mode)
Once entering in the Protection Mode by the over-current protection, the Protection Mode is not canceled even after
over-current condition is over. The Protection Mode can be canceled by setting L to /SLEEP terminal once and again
setting H to the terminal or, by turning on the power supply again.
It is possible to resume automatically from the Protection Mode by connecting between /PROT terminal and /SLEEP
terminal as shown in the diagram below (External automatic resume circuit).
/PROT
/SLEEP
YDA137
Fig-4 外部自動復帰回路
External Automatic Resume Circuit
In Sleep Mode (/SLEEP=L) and Mute Mode (/MUTE=L), Over-Current Detection Function of both L and R channel
stops.
This IC can detect the over-current state according to the VSS short circuit of a speaker terminal (after LC filter) and
the short circuit between ± terminals.
In addition, this IC does not correspond to detect the over-current state according to between the VDD short circuit of a
speaker terminal, the VSS short circuit of IC output end (before LC filter), a VDD short circuit, and the short circuit
between ± terminals.
●Over-Temperature Protection Function
Over-Temperature Protection Function is a function to detect the over-temperature condition and protect IC, when
temperature of YDA137 goes up extraordinarily. At this time, IC enters the Protection Mode.
Once entering in the Protection Mode by the over-temperature protection, IC cancels the Protection Mode by itself after
the temperature of IC falls to a certain temperature.
In addition, it is possible to cancel the Protection Mode by the control of /SLEEP terminal and turning on the power
supply again, as well as Over-Current Protection Function.
●Sleep Function
When /SLEEP terminal is L, it enters the Sleep Mode. When H, it enters normal operation condition. In the mode, all
functions will stop and consumption power will fall to the minimum.
In the mode, digital amplifier output terminal becomes WL, and headphone amplifier output terminal becomes WL. At
this time, the protection mode is canceled, and /PROT terminal becomes H.
When /SLEEP terminal is changed from L to H, start-up sequence operates, and it enters normal operating condition after
the time set by the capacitance connected at VREFL and VREFR terminals, the input capacitance connected at INL and
INR terminals, and input resistance elapsed (Starting-time). General time is shown in the table.
Table: Starting-time
CREF capacitance
33μF
33μF
33μF
CIN capacitance
4.7μF
10μF
33μF
Input sensitivity
1.0Vrms
1.0Vrms
1.0Vrms
Starting time
1.8 sec
3.0 sec
7.5 sec
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