Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
2W x 2 Class AB Audio Power Amplifier
PT2300
DESCRIPTION
The PT2300 is a power amplifier utilizing CMOS Technology specially designed for audio purpose. It
can deliver 2W × 2 power output to the 4Ω load. The power consumption is very low in stand-by. Total
harmonic distortion is lower than 0.03%. The output mode can be switched between the SE
(Single-Ended) or BTL (Bridge-Tied Load) mode. The built-in volume controller can change the output
volume by an external supplied DC voltage. Built-in over-temperature protection, package size is not
occupies PCB space. It is suitable for small or portable products.
FEATURES
•
•
•
•
•
•
•
•
•
CMOS Technology
Stereo input
Output power 2W × 2 (Vcc=6V, THD=1%, RL=4Ω)
Low harmonics distortion (0.03%)
Include 32 steps volume controller
SE and BTL modes operation
Suppress the pop and click noise when mode changed
Shutdown function, turn on can into save mode (Icc<0.7µA)
Built-in overheat protect
APPLICATIONS
•
•
•
•
LCD monitor (for TV)
Portable audio
Multimedia speakers
Other audio applications
PT2300 V1.0
-1-
December, 2005
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
2W x 2 Class AB Audio Power Amplifier
PT2300
BLOCK DIAGRAM
Rf
Ri
Vo1
20K
20K
+
+
Voltage
Bypass and
De-Pop Noise
32 steps
DC Control
Volume
+
Vin2
Vo2
-
Ri
20K
Power
Management
Rf
20K
Vcc
Shutdown
GND
+
AMP2N
+
DC Vol
PT2300 V1.0
-2-
-
Bypass
-
-
-
Vin1
-
AMP1N
AMP1P
AMP2P
-OUT1
+OUT1
+
SE/BTL
-OUT2
+OUT2
December, 2005
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
2W x 2 Class AB Audio Power Amplifier
PT2300
PIN CONFIGURATION
S h u t do w n
Vcc
DC Vo l
V o1
V in 1
V in 2
V o2
GND
1
2
3
4
5
6
7
8
P T 2 30 0
16
15
14
13
12
11
10
9
+O UT 1
Vcc
- OU T1
Byp a ss
S E /B TL
- OU T2
Vcc
+O UT 2
PIN DESCRIPTION
Pin Name
Shutdown
Vcc
DC Vol
Vo1
Vin1
Vin2
Vo2
GND
+OUT2
Vcc
-OUT2
SE/BTL
Bypass
-OUT1
Vcc
+OUT1
I/O
I
I
I
I
I
I
O
O
I
O
O
O
O
Description
Pin No.
Shutdown pin。Entire IC into the shutdown mode when this pin
1
connected to the Vcc,
Supply voltage input
2
DC Volume control input pin
3
Channel 1 output for external feedback circuit
4
Channel 1 audio input
5
Channel 2 audio input
6
Channel 2 output for external feedback circuit
7
Ground
8
Channel 2 output (+)
9
Supply voltage input
Channel 2 output (-)
11
Output mode select, connected to the Vcc for SE mode or
12
GND for BTL mode
Internal bias reference bypassing
13
Channel 1 output (-)
14
Supply voltage input
15
Channel 1 output (+)
16
PT2300 V1.0
-3-
December, 2005
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
2W x 2 Class AB Audio Power Amplifier
PT2300
FUNCTION DESCRIPTION
POWER SUPPLY
The operating voltage of PT2300 is from 3V to 6V, In general operation 5V is recommended. When the
supply voltage less then 3V the IC can work properly, but the distortion reading will rise. After the
supply voltage over 6.5V, the higher stand-by current consumption will rising the temperature on chip
surface。
SHUTDOWN
When the DC supply still powered the chip Vcc, pull-up the shutdown pin to the Vcc level will take the
chip into the shutdown mode. After the shutdown mode is active the total current consumption is less
than 0.7µA, and the all of input or output pins no voltage output. When shutdown pin set to GND, the IC
is back to the normal operation.
Shutdown pin
Vcc
GND
Output state
Shutdown ON
Normal
INPUT GAIN ADJUST
The output gain of the PT2300 can be adjust by the external resistor, in normal operation 0dB gain
setting is recommended, please refer to the application circuit. If the source output level is not so high
(ex :< 2Vpp), input gain can be increase to get the proper volume. The minimum value of the input
series resistance is 10KΩ for the modest input impedance.
To make sure the input stage will not be distortion by overload, please confirm the input signal level, for
the gain set please refer to the following table:
Operating voltage
VDD=3V
VDD=5V
Input gain = –6dB
Vin <5Vpp
Vin <8Vpp
Input gain = 0dB
Vin <2.5Vpp
Vin<4Vpp
Input gain = +6dB
Vin <1.25Vpp
Vin<2Vpp
SE/BTL MODE SWITCHING
PT2300 have two output mode, SE (Single-Ended) or BTL (Bridge-Tied Load). When driving a speaker
load suggestion set to the BTL mode for get the more power output. And driving a headphone load, it
can be set to SE mode and turn-off the un-work amplifier to decrease stand-by power consumption.
Switching between the SE/BTL modes is controlled by the SE/BTL pin, please refer to following table:
SE/BTL
Vcc
GND
Mode
SE
BTL
PT2300 V1.0
-4-
December, 2005
Tel: 886-2-66296288
Fax: 886-2-29174598
URL: http://www.princeton.com.tw
2W x 2 Class AB Audio Power Amplifier
PT2300
OVER TEMPERATURE PROTECTION
The PT2300 has a built-in over temperature protection circuit, it will turn off all power output when the
chip temperature over 120℃, the chip will return to normal operation automatically after the
temperature cool down to 80℃.
POP AND CLICK SURPPRESS
A power amplifier uses single supply voltage may almost have noise on output in the power-on period.
It is because of the output DC potential needs time to stable on 1/2Vcc, the period relative with the
capacitance on the Bypass pin. Higher CB value will extend the stable time, and also can suppress the
noise when power-on. In supply voltage=5V and CB=2.2µF, stable time is about 300ms. The value of
CB also relative with the value of the DC blocking capacitor connected in input terminal. In general
condition the time constant of DC blocking capacitor should be less than CB stable time.
Recommend parts values please refer to application circuit.
VOLUME CONTROLLER
The PT2300 has a built-in 32 steps volume controller, output volume is determinate by the voltage
applied on the DC Vol pin. Higher DC voltage means more output level, the relation between the
volume setup and DC Vol, please refer the following table.
[Supply voltage 5V, DC Vol input voltage showing by percentage of Vcc]
Step
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Volume
(dB)
0
-1.5
-3
-4.5
-6
-7.5
-9
-10.5
-12
-13.5
-15
-16.5
-18
-19.5
-21
-22.5
Voltage range (%VCC)
High
Vcc
64.1
63.1
61.1
60.4
57.8
56.4
53.8
52.1
48.7
47.5
45.4
44.7
41.8
40.4
37.8
Low
64.0
62.6
60.9
59.2
57.6
55.7
53.8
51.3
48.5
46.8
45.1
43.3
41.6
39.5
37.4
35.4
Step
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
Volume
(dB)
-24
-25.5
-27
-28.5
-30
-31.5
-33
-34.5
-36
-37.5
-39
-40.5
-42
-43.5
-45
MUTE
Voltage range (%VCC)
High
36.0
29.9
28.7
26.6
26.0
23.2
21.8
19.3
17.2
13.7
12.4
10.2
9.5
6.7
5.2
2.7
Low
29.7
28.0
26.3
24.6
22.9
20.9
18.9
15.9
13.4
11.6
9.8
8.0
6.3
4.2
2.1
GND
PT2300 V1.0
-5-
December, 2005