SM6453AB_02 Datasheet, PDF (13/19 Pages) Nippon Precision Circuits Inc – 3-wire Serial Data Volume Control for Headphone Amplifier IC

SM6453AB
Bass boost function (BSTO, BSTN, BSTC)
The bass boost characteristic (BB1, BB2) is selected using bit D10. The left-channel and right-channel bass
components are mixed and amplified, and then added to the headphone driver amplifier. A capacitor (0.1µF std)
connected between BSTC and VREF1 forms a lowpass filter through which the signal from the EVR block
passes, boosting the bass component, which is then added to the original signal.
Bass boost examples
IC internal components are R_IN = 23kΩ, R1 = 20kΩ, R2 = 10kΩ, R3 = 15kΩ (BB1) or 60kΩ (BB2). The bass
boost characteristic also depends on the external resistor and capacitor components connected between BSTO
and BSTN, as indicated below.
I Example 1
C₁ = 0.1µF, C₂ = 2200pF, C_IN = 1µF, C_OUT = 220µF, R_OUT = 16Ω (Measurement circuit)
15
10
5
0
-5
-10
-15
10
BB2
BB1
BB OFF
100
1000
Frequency [Hz]
I Example 2
C₁ = 0.1µF, C₂ = 0.01µF, C_IN = 1µF, C_OUT = 220µF, R_OUT = 16Ω
10000
15
10
5
0
-5
-10
-15
10
BB2
BB1
BB OFF
100
1000
Frequency [Hz]
10000
NIPPON PRECISION CIRCUITS INC.—13