BU7150NUV Datasheet, PDF (10/17 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 C_I1=VDD/2 from BYPASS=VDD/2. Td is decided by C_I1, R_I1, and R_F1.
Fig. 39 Flow of Time until Signal Output
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10/16
2011.05 - Rev.C