Audio Accessory IC Series
Ground Isolation
Amplifier
BA3121F, BA3123F
No.09092EAT01
●Description
The BA3121F/BA3123F are ground isolation amplifiers developed for use in car audio applications.
This IC efficiently eliminate problems caused by wiring resistance, and remove noise generated by the electrical devices
used in automobiles. The capacitance values of the external capacitors required for the ICs are small to allow compact
and reliable set design.
●Features
1) Large capacitors not required
2) High common-mode rejection ratio (57dB typ. at f = 1kHz).
3) Low noise (VNO = 3.5μVrms Typ.).
4) Low distortion (THD = 0.002% Typ.).
5) Two channels.
●Applications
Car audio systems
●Line
up matrix
Operation temperature
BA3121F
－30½＋85C
BA3123F
－40½＋85C
●Absolute
maximum ratings
(Ta = 25C)
Parameter
Symbol
Limits
18
450*
－30½＋85
－40½＋85
－55½＋125
Unit
V
mW
℃
℃
℃
Power supply voltage
Vcc
Power dissipation
Pd
BA3121F
Operation
Topr
temperature
BA3123F
Storage temperature
Tstg
＊Reduced
by 4.5mW in Ta of 1C over 25C.
●Recommended
operating conditions
(Ta = 25C)
Parameter
Power supply voltage
Symbol
Vcc
Min.
4
Typ.
12
Max.
18
Unit
V
www.rohm.com
© 2009 ROHM Co., Ltd. All rights reserved.
1/8
2009.08 - Rev.A
BA3121F, BA3123F
●Electrical
characteristics
(unless otherwise noted, Ta = 25C, VCC = 12V, f = 1kHz, Rg = 1.8k)
Parameter
Quiescent current
Output noise voltage
Voltage gain
Maximum output voltage
Total harmonic distortion
Common-mode rejection ratio
Common-made voltage
Ripple rejection ratio
Channel separation
Slew rate
Input resistance
Symbol
I
Q
V
NO
G
V
V
OM
THD
CMRR
V
CM
RR
CS
SR
R
IN
Min.
5.6
－
-1.5
1.8
－
41
2.5
72
－
－
44
Typ.
9.0
3.5
-0.04
2.0
0.002
57
3.75
80
82
2.0
55
Max.
14.0
8.0
1.5
－
0.02
－
－
－
－
－
66
Unit
mA
μV
rms
dB
V
rms
％
dB
V
rms
dB
dB
V/μS
kΩ
Technical Note
Conditions
V
IN
＝0V
rms
BPF＝20Hz-20kHz
V
O
＝－10dBm,
R
g
＝0Ω
THD＝0.1％, Vcc＝8V
V
O
＝0.7V
rms
Vcc＝8V,CMRR＝40dB
f
RR
＝100Hz,V
RR
＝－10dBm,
R
g
＝0Ω
V
IN
＝－10dBm,
R
g
＝1.8kΩ/OPEN
◎Not
designed for radiation resistance
●Electrical
characteristics curves
Fig.1 Quiescent current
vs. power supply voltage
Fig.2 Maximum output voltage
vs. power supply voltage
Fig.3 Output noise voltage
vs. power supply voltage
Fig.4 Voltage gain
vs. power supply voltage
Fig.5 Voltage gain vs. frequency
Fig.6 Channel separation
f
www.rohm.com
© 2009 ROHM Co., Ltd. All rights reserved.
2/8
2009.08 - Rev.A
BA3121F, BA3123F
Technical Note
Fig.7 Ripple rejection ratio
vs. frequency
Fig.8 Total harmonic distortion
vs. output voltage
Fig.9 Total harmonic distortion
vs. frequency
Fig.10 Common-mode rejection ratio
vs. frequency
Fig.11Common-mode rejection ration
vs. input voltage
www.rohm.com
© 2009 ROHM Co., Ltd. All rights reserved.
3/8
2009.08 - Rev.A
BA3121F, BA3123F
●Measurement
circuits
Technical Note
BA3121F / BA3123F
Fig.12
www.rohm.com
© 2009 ROHM Co., Ltd. All rights reserved.
4/8
2009.08 - Rev.A
BA3121F, BA3123F
●Block
Diagram
Technical Note
Fig.13
www.rohm.com
© 2009 ROHM Co., Ltd. All rights reserved.
5/8
2009.08 - Rev.A
京公网安备 11010802033920号
EEWORLD
