bd5468gul-e2 ROHM Co. Ltd., bd5468gul-e2 Datasheet - Page 8

• Manufacturer Part Number: bd5468gul-e2
• Description: Analog Input Monaural Class-d Speaker Amplifier
• Manufacturer: ROHM Co. Ltd.

< Audio Source >
© 2010 ROHM Co., Ltd. All rights reserved.
BD5468GUL
www.rohm.com
Vins
Vins
Shutdown Signal
○Gain calculation
H : IC Active
L : IC Shutdown
When Input Level is calculated at IC typical and audio source typical, when input coupling capacitor (Ci) value is large
enough,every gain during the differential input and single end input will become:
1. IC reference(Difference Input, Single End Input) :Formula ①
2. Audio Source reference(Differential Input) : Formula ②
3. Audio Source reference (Single End Input) :Formula ①
VIN means the Input Voltage between IC Input Pin (IN+, IN-), VOUT means the output voltage between IC Output Pin
( OUT+, OUT- ). During differential input and single end input, the gain calculation formula at IC reference which
includes ALC operation is written below:
When the input level of audio source is Vins, the relation with the input voltage VIN between IC input pin is written
below:
During differential input, at audio source referece that includes ALC operation, gain calculation formula will become :
When the Input level of audio source is Vins, the relation with input voltage VIN between IC input pin (IN+,IN-)
becomes:
During single end input, at the audio source that includes ALC operation, gain calculation formula becomes:
0 . 1 uF
0 . 1 uF
Ci
Ci
Typical Input Level
(= 2Vins)
Audio Source
VIN
SDNB
IN+
Gain = 20×log | VOUT/VIN | =+13～-2 (Typ.) [dB] ・・・ Formula①
Vins = VIN / 2
Gain = 20×log | VOUT / Vins | = 20×log | 2×VOUT / VIN | = +19～+4 (Typ.) [dB] ・・・Formula②
Vins = VIN
Gain = 20×log | VOUT / Vins | = 20×log | VOUT / VIN | = +13～-2 (Typ.) [dB] ・・・ Formula①
IN-
C2
A 1
C1
IC
Ri
Ri
(Typ .)
150k
【Differential Input】
Rf
Rf
VDD
Shutdown
GND
Control
ALC
B 1
A 2
+Battery
B 3 PGND
B 2
Differential Output
BIAS
OSC
PWM
PVDD
Formula②
Cs
H -
Bridge
C3
A3
OUT+
OUT-
Formula①
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< Audio Source >
Single End Output
Vins
Shutdown Signal
Formula①
H: IC Active
L: IC Shutdown
0.1uF
0.1uF
Ci
Ci
(=Vins)
VIN
SDNB
IN+
IN-
C2
C1
A1
Ri
Ri
(Typ.)
【single end input】
150k
Rf
Rf
VDD
Shutdown
GND
Control
ALC
B 1
A 2
+Battery
B 3 PGND
B 2
BIAS
OSC
PWM
PVDD
Technical Note
2010.09 - Rev.A
Cs
H -
Bridge
C3
A3
OUT+
OUT-