PT2308P 2-Channel 300mW Class AB Power Amplifier DESCRIPTION FEATURES PT2308P is a 2 channel Class AB stereo speaker driver utilizing CMOS technology designed by AB push-pull, the original sound will be low distortion amplify and low consumption. The power of PT2308P will be reach 300mW on THD=10% and deliver 8Ω load. • Wild operating temperature large • Excellent Power Signal-to-Noise Repel Rate (PSRR) • Low static state current consumption • Output power (THD=10％) - Load is 16Ω/190mW - Load is 8Ω/300mW • Low harmonics distortion (THD=0.03%) • Large output amplitude APPLICATIONS • • • • Walkman Portable audio HI-FI audio system CD-ROM BLOCK DIAGRAM Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, 233-1, Baociao Road, Sindian, Taipei 23145, Taiwan PT2308P APPLICATION CIRCUIT 15K VIN 1 15K VOUT 1 220uF 2.2uF 4 3 2 RL 1 VSS GND PT2308P VREF (typ. 1/2VDD) 100uF VDD VDD 5 6 7 8 VIN 2 VOUT 2 2.2uF 15K 15K 220uF RL V1.1 2 July, 2009 PT2308P ORDER INFORMATION Valid Part Number PT2308P-S Package Type 8 Pins, SOP, 150mil Top Code PT2308P-S PIN CONFIGURATION PIN DESCRIPTION Pin Name OUT1 IN1IN1+ VSS IN2+ IN2OUT2 VDD V1.1 I/O O I I I I O - Description Output pin 1 Inverting input pin 1 Non-inverting input pin 1 Negative power supply Non-inverting input pin 2 Inverting input pin 2 Output pin 2 Positive power supply 3 Pin No. 1 2 3 4 5 6 7 8 July, 2009 PT2308P BASIC APPLICATION DESCRIPTION PT2308P is a low power amplifier which operates with a 5V input voltage, it can be used to drive regular earphones or low power speakers with a load resistance of 8ohm or higher. The operation mechanics is much like the typical OPAMP. (The picture below shows the basic application circuit of PT2308P as an inverted amplifier). R2 Vin Ci Co R1 Vout VREF Show in one side R3 RL PT2308P Typical Application Circuit 1. Gain Settings The inverted amplifier’s amplification is equal to the ratio between R2 and R1 (Av= -(R2÷R1)). Please take note that the maximum supply voltage for the PT2308P is 5V, voltage gain setting should depend on the input level amplitude; too much voltage gain may increase the chance of causing clipping at the output. 2. VREF Because the PT2308P operates with a single power source, to ensure the best output performance, the suggested value for VREF is 1/2 VDD. 3. Input Coupling Capacitor Ci In typical applications, this input coupling capacitor transfers signals between the input and PT2308P, it allows block DC bias of the PT2308P flowing into input signal, and thus the user must be aware of the voltage tolerance and the polarity of this Cap. Referring to the diagram above, Ci and R1 forms a 1st order high-pass filter; the lower-cutoff frequency is determined by the equation: fc(highpass)=1/2πR1Ci The diagram below shows the frequency response when: Ci=10µF/1µF/0.47µF/0.22µF/0.1µF V1.1 4 July, 2009 PT2308P 4. Output Coupling Capacitor Co Single power single-ended (SE) configuration generates a DC bias at the output of the amplifier; a coupling capacitor must be placed at the output to block the DC bias from being sent to the load and connect a RL at the signal output terminal. The low cut-off frequency may be needs to adjust to correspond to different load (speaker or earphone) specifications. Similar to the input coupling capacitor, the output coupling capacitor and impedance of the load form a 1st order high-pass filter, the low cut-off frequency is determined by the equation: fc(highpass)=1/2πRLCo The diagram below shows the frequency response when: Co=1000µF/470µF/220µF/100µF. 5. Discharging Resistor (R3) When the PT2308P is powered ON, the output coupling capacitor Co will start charging. When there is no load connected at Vout, there will be a DC voltage present. At this time, if a load is suddenly connected (usually earphone or speaker for general applications), the charged Co will then discharge through Vout to the load, causing a very loud popping sound, thus, it is recommended to connect a R3 to regulate the discharge of Co. The time it takes to discharge is T=CoR3. The recommended resistance value for R3 is between 1KΩ ~ 10KΩ, to prevent loading effect from the amplifier. If the load (ex. Speaker) is permanently connected then R3 can be neglected. V1.1 5 July, 2009 PT2308P ABSOLUTE MAXIMUM RATING Parameter Supply voltage Operating temperature Storage temperature Symbol VDD Topr Tstg Rating 8 -40∼+85 -65∼+150 Unit V ℃ ℃ ELECTRONICAL CHARACTERISTICS (Unless otherwise specified, VDD=5V, VSS=0V, Ta=25℃, fin=1KHz, RL=8Ω) Parameter Symbol Condition Supply voltage VDD Supply current IDD No Load Input offset voltage VI(OS) Total harmonic PO=200mW, RL=8Ω, F=1KHZ THD+N distortion PO=120mW, RL=16Ω, F=1KHZ THD=0.2%, f=1KHz, RL=8Ω Maximum output THD=0.2%, f=1KHz, RL=16Ω PO power THD=10%, f=1KHz, RL=8Ω THD=10%, f=1KHz, RL=16Ω Output noise VN VDD=3V Supply current IDD No Load Input offset voltage VI(OS) Total harmonic PO=50mW, RL=8Ω, F=1KHZ THD+N distortion PO=40mW, RL=16Ω, F=1KHZ THD=0.2%, f=1KHz, RL=8Ω Maximum output THD=0.2%, f=1KHz, RL=16Ω PO power THD=10%, f=1KHz, RL=8Ω THD=10%, f=1KHz, RL=16Ω Output noise VN V1.1 6 Min. 2.7 200 100 250 160 - Typ. 5 3 5 0.04 0.03 250 130 300 190 20 Max. 5.5 4 50 0.1 0.06 50 Unit V mA mV % % mW mW mW mW µV 60 40 70 55 - 2 5 0.02 0.02 80 50 100 70 20 3 50 0.05 0.05 50 mA mV % % mW mW mW mW µV July, 2009 PT2308P PACKAGE INFORMATION 8 PINS, SOP, 150MIL Symbol A A1 A2 b c e D E E1 L θ Dimensions(MM) Nom. 1.60 0.15 1.40 1.27 BSC 4.90 6.00 3.90 0.60 - Min. 1.35 0.08 1.20 0.33 0.17 4.70 5.80 3.70 0.38 0° Max. 1.77 0.28 1.65 0.51 0.26 5.10 6.20 4.10 1.27 8° Note: Refer to JEDEC MS-012 AA V1.1 7 July, 2009 PT2308P 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, Taipei 23145, Taiwan Tel: 886-2-66296288 Fax: 886-2-29174598 http://www.princeton.com.tw V1.1 8 July, 2009