BU7150NUV_15 Datasheet, PDF (11/22 Pages) Rohm – Headphone Amplifier Designed for 0.93V Low Voltage Operation

BU7150NUV
Technical Note
[About Time until Signal Output]
BU7150NUV need wait-time for BIAS charge sweep time and pop-noise reduction.
In the Fig. 37, Ts1 is BIAS charge sweep time from power on or SDB=H. Ts2 is time until signal output from power on or
SDB=H. Also, in the Fig. 38, Tb1 is BIAS charge sweep time from power on. Tb2 is time until signal output from power on.
Tb3 is BIAS charge sweep time from SDB=H. Tb4 is time until signal output from SDB=H.
These values are decided equation (1) ~ (6). However, BIAS charge sweep time (Ts1, Tb1, Tb3) have uneven ±50%, and
wait-time (70msec) is 40msec ~ 126msec for process parameter distribution. (Ta=25°C)
Ts1 =
VDD× C_BYPASS
2.5 ×10 ^-6
　[sec]　・・・　
(1)
Ts2 = Ts1+ 0.07[sec]　・・・(　2)
Tb1 =
( ) VDD + 2 × C_BYPASS
27.5×10 ^-6
[sec]　・・・　
(3)
Tb2 = Tb1+ 0.07[sec]　・・・(　4)
Tb3
=
VDD× C_BYPASS
27.5×10 ^-6
[sec]　・・・　
(5)
Tb4 = Tb3 + 0.07[sec]　・・・(　6)
In the Fig. 38, Tb1 and Tb3 is differ value, because BU7150NUV’s default is single-ended mode. BU7150NUV need
BYPASS>100mV to recognize for BTL mode.
Also, Td is delay time to CI1=VDD/2 from BYPASS=VDD/2. Td is decided by CI1, RI1, and RF1.
Fig. 39 Flow of Time until Signal Output
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11/18
2015.1 - Rev.E