bd5445efv ROHM Co. Ltd., bd5445efv Datasheet - Page 13

• Manufacturer Part Number: bd5445efv
• Description: Analog Input / Single End Output Class-d Speaker Amplifier
• Manufacturer: ROHM Co. Ltd.

●Audio input circuit (pin4 and pin5)
© 2010 ROHM Co., Ltd. All rights reserved.
BD5445EFV
www.rohm.com
Connect the audio input pin with a prior-stage circuit via coupling capacitors C4 and C5. Because C4, C5 and input
impedance R4, R5 of the IC circuit compose the primary HPF, the values determine an input low-band cutoff frequency. Input
cutoff frequencies are calculated by the following formulas:
An excessively high capacitance of an input coupling capacitor results in a longer period required for stabilizing a power input
pin voltage after turning on the power supply. Note that placing the MUTEX pin (pin11) at "L" level (mute turned off) for
avoidance of Pop-noise before stabilizing an input pin. R4 and R5 are changed by Gain setting.
No.
Pin
22
23
24
25
26
27
28
GAIN1
(3pin)
H
H
L
L
Pin name
GNDP1
VCCP1
BSP1
OUT1
GAIN0
(2pin)
H
H
L
L
C f
Pin voltage
0V～Vcc
=
Vcc
2πR4
5V
0V
Fig. 29 Coupling capacitors of audio input pins
1
•
C4
impedance(TYP.)
[ ]
Prior-stage
Gnd pin for ch1 PWM signal
Boot-strap pin of ch1
Please connect the capacitor.
Output pin of ch1 PWM
Please connect to Output LPF.
Power supply pin for ch1 PWM signal
Hz
R4,R5 input
circuit
26.7kΩ
40kΩ
40kΩ
16kΩ
C f
=
13/31
2πR5
Pin explanation
C4
C5
1
•
C5
Amplifier Gain (SE)
4
5
[ ]
Hz
R4
R5
14dB
20dB
26dB
32dB
Amplifier Gain (BTL)
Internal equivalence circuit
20dB
26dB
38dB
32dB
Technical Note
2010.05 - Rev.B