ISIS31AP4991 Datasheet, PDF (2/5 Pages) Integrated Silicon Solution, Inc – Near-zero click-and-pop

IS31AP4991A 1.1W AUDIO POWER AMPLIFIER
WITH ACTIVE-LOW SHUTDOWN MODE
EVALUATION BOARD OPERATION
The IS31AP4991A demo board features the
IS31AP4991A Class-AB power amplifier IC, designed
to drive speaker impedance of 8Ω or larger.
HIGH-PASS FILTER
The input capacitor C_I (C₃, C₄) and input resistor R_I (R₁,
R₂) form a high-pass filter with the corner frequency, f_C,
determined in Equation (2) and refer to IS31AP4991A
datasheet for more detail.
CUSTOMIZING THE GAIN
The IS31AP4991A demo board is shipped with a gain
of 6dB and is set by resistors R_I (R₁, R₂) and R_F (R₃,
R₄). Change resistors R_I and R_F to reconfigure the gain
of the board and gain determined in Equation (1):
Gain  ^{2  RF} _ ^V _
(1)
R_{I }V _
1
fc  _{2RI CI }
(2)
SHUTDOWN MODE
Jumper (JP1) controls the shutdown pin of the
IS31AP4991A IC. Connect the jumper (JP1) to enter
the shutdown mode of the board.
CON1
DC IN
TP1
VCC
C1
10uF
C6
NC
R4
20k
VCC C2
TP2
TP4 ^{IN- C4 100nF}
TP3
IN+
C3 100nF
CON2
AUDIO IN
IN-
R2 20k
INN 4
R1 20k
C7
0.47uF
VCC
INP 3
C5
R3
20k
NC
Bypass 2
1
SDB
R5
100k
JP1
U1
IN-
IN+
BYPASS
SDB
1uF
OUT- ⁵
OUT-
TP6
OUT+
CON3
AUDIO OUT
8
TP5
OUT+
IS31AP4991A-GRLS2
CLOSE=SD
VCC C8
1uF
U2
INN 4 _IN-
INP 3 _IN+
OUT- ^{5 OUT-}
Bypass 2
SDB 1
BYPASS
SDB
OUT+ ^{8 OUT+}
IS31AP4991A-SLS2
Figure 2: IS31AP4991A Application Schematic
Integrated Silicon Solution, Inc. – www.issi.com
2
Rev. A, 12/31/2014