DESCRIPTION APPLICATIONS FEATURES BLOCK DIAGRAM

PT2812
3W Stereo Class-D Amplifier with
3 Inputs and Volume
DESCRIPTION
FEATURES
The PT2812 is an integrated 3W stereo Class-D
amplifier with audio processor. The input selector
supports 2 Single-Ended and 1 Fully-Differential input
can be chose. The highly integration of the audio
processor and class-D amplifier can further reduce
external components BOM and provides better audio
experience. All of functions are controlled via I2C bus.
APPLICATIONS
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PC/Video Projector
Portable media player
Audio duck system
Flat panel display with audio inputs
Supply Voltage: 3~6V
3W X 2 Class-D power amplifier (VDD=5V, RL=4Ω)
1 Fully-Differential input
2 Single-Ended audio inputs
Programmable input gain from 0 to +15dB
Master volume in 1dB/step from 0 to -79dB
Advanced soft-mute and multiple soft-step volume
technology eliminate audible click during volume and
input sources changing.
Built-in RF noise filter
Shutdown function for power saving
Over temperature and over current protection
2
Controlled by I C interface
Available in 32 Pins, 4x4 mm QFN package
BLOCK DIAGRAM
LON
LGND
LVDD
LOP
ROP
RVDD
RGND
RON
LINP
RINP
LCH CLASS-D
(+20/+26 dB)
RCH CLASS-D
(+20/+26 dB)
OSC Generator
LINN
RINN
SD
OE
SDA
Digital
Interface
Logic
Control
SCL
VDD
Power
Management
Bypass
GND
LOUT
ROUT
Volume
(0~-79dB)
Protection Circuitry
Volume
(0~-79dB)
INPUT
Gain
INPUT
Gain
INPUT
Multiplexer
L2
L1
Fully-Differential
input
DIFFL+
DIFFL- DIFFR-
DIFFR+
INPUT
Multiplexer
R1
R2
Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, No.233-1, Baociao Rd., Sindian Dist., New Taipei City 23145, Taiwan
PT2812
3W Stereo Class-D Amplifier with
Audio Processor
APPLICATION CIRCUIT
L1
P1
FB
+5V
C14
10u
1uF
C10
L2
FB
C15
HOST MCU
P2
100u
C12
1uF
GND
C16 10uF
13
LOP
12
LVDD
11
8
9
LINN
LON
7
L2
LINP
32
6
10
GND1
LGND
5
L1
GND2
31
C17 1uF
L4
FB
L5
FB
C18 1uF
L6
FB
C23 1nF C24 1nF
ROP
FB
C21 1nF C22 1nF
DIFFL+
RINN
RINP
VDD1
30
17
18
19
VDD2
DIFFL-
U1
RSPK
U2
LSPK
Lowpass Filter (option)
C9
2.2u
C13
C21
1u
1uF
C11
V1.0
20
1u
29
PT2812
14
4
C8
DIFFR-
RVDD
OE
1u
SD
C7
21
1u
28
15
3
C6
DIFFR+
RGND
BYPASS
1u
SDA
C5
27
22
1u
R1
16
2
C4
26
RON
NC
1u
R2
1
C3
25
LOUT
1u
SCL
AUX
C2
ROUT
BT
1u
23
24
Tuner
C1
L3
1uF
2
August 2013
PT2812
3W Stereo Class-D Amplifier with
Audio Processor
ORDER INFORMATION
Valid Part Number
PT2812-QFN
Package Type
32 Pins, QFP, 4 X 4 mm
Top Code
PT2812-QFN
V1.0
16
15
14
13
12
11
10
9
RON
RGND
RVDD
ROP
LOP
LVDD
LGND
LON
PIN CONFIGURATION
LINN
8
RINP
LINP
7
19
VDD1
GND1
6
20
VDD2
GND2
5
21
SD
OE
4
22
SDA
BYPASS
3
23
SCL
NC
2
24
ROUT
LOUT
1
DIFFL+
30
L2
DIFFL29
32
DIFFR28
L1
DIFFR+
27
3
31
R1
PT2812-QFN
PT2812
26
18
R2
RINN
25
17
August 2013
PT2812
3W Stereo Class-D Amplifier with
Audio Processor
PIN DESCRIPTION
Pin Name
LOUT
NC
BYPASS
OE
GND1
GND2
LINP
LINN
LON
LGND
LVDD
LOP
ROP
RVDD
RGND
RON
RINN
RINP
VDD1
VDD2
I/O
O
P
I
P
P
I
I
O
P
P
O
O
P
P
O
I
I
P
P
SD
I
SDA
SCL
ROUT
R2
R1
DIFFR+
DIFFRDIFFLDIFFL+
L1
L2
I
I
O
I
I
I
I
I
I
I
I
V1.0
Description
Pin No.
Left channel line out
1
No connection
2
Bypass cap for Internal Voltage Reference, a 2.2µF cap is recommended.
3
4
Output Enable setting, connect a 0.22F cap to GND.
Ground for internal circuits
5
Ground for internal circuits
6
Positive input of left channel Class-D amp
7
Negative input of left channel Class-D amp
8
Negative output of left channel Class-D amp
9
Power ground of left channel Class-D amp
10
Power input of left channel Class-D amp
11
Positive output of left channel Class-D amp
12
Positive output of right channel Class-D amp
13
Power input of right channel Class-D amp
14
Power ground of right channel Class-D amp
15
Negative output of right channel Class-D amp
16
Negative input of right channel Class-D amp
17
Positive input of right channel Class-D amp
18
Power input for internal circuits
19
Power input for internal circuits
20
Shutdown. Sets to low level will turn off whole chip and pull up to High level is back to
21
normal operation.
2
I C bus data input
22
2
I C bus clock input
23
Right channel line out
24
Input 2 of right channel
25
Input 1 of right channel
26
Differential right channel “+” input
27
Differential right channel “-” input
28
Differential left channel “-“ input
29
Differential left channel “+” input
30
Input 1 of left channel
31
Input 2 of left channel
32
4
August 2013
PT2812
3W Stereo Class-D Amplifier with
Audio Processor
IMPORTANT NOTICE
Princeton Technology Corporation (PTC) reserves the right to make corrections, modifications, enhancements,
improvements, and other changes to its products and to discontinue any product without notice at any time.
PTC cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a PTC product. No
circuit patent licenses are implied.
Princeton Technology Corp.
2F, 233-1, Baociao Road,
Sindian Dist., New Taipei City 23145, Taiwan
Tel: 886-2-66296288
Fax: 886-2-29174598
http://www.princeton.com.tw
V1.0
17
August 2013