Overview
The TPA6138A2PW is a stereo headphone amplifier IC produced by Texas Instruments, utilizing their patented DirectPath™ technology. This amplifier is designed to drive loads ranging from 16 Ω to 32 Ω and can deliver up to 40 mW of power from a 3.3V supply voltage. It features adjustable gain functionality, differential inputs, and single-ended outputs, eliminating the need for output DC-blocking capacitors. The device includes built-in active-mute control and under-voltage protection, ensuring a pop-free audio signal during power-up and power-down cycles.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage | 3.0 - 3.6 | V |
| Load Impedance | 16 - 32 | Ω |
| Maximum Power Output | 40 | mW |
| Total Harmonic Distortion + Noise (THD+N) | < 0.01% | - |
| Signal-to-Noise Ratio (SNR) | 90 dB | - |
| Dynamic Range (DNR) | 100 dB | - |
| Output Impedance (Muted) | 110 mΩ | - |
| Current Limit | 50 mA | - |
| Operating Temperature | -40 to 85 | °C |
Key Features
- Adjustable Gain: Gain can be set individually using external gain-setting resistors, supporting a gain range of ±1 V/V to ±10 V/V.
- Pop-Free Mute: Built-in active-mute control and under-voltage protection ensure a pop-free audio signal during power-up and power-down cycles.
- Ground-Referenced Outputs: Eliminates the need for output DC-blocking capacitors, reducing component count and production cost.
- Second-Order Low-Pass Filter: Can be configured as a second-order low-pass filter, ideal for interfacing with PWM audio sources.
- ESD Protection: Audio output complies with ±8-kV IEC ESD protection, requiring a simple resistor-capacitor ESD protection circuit.
Applications
- Sound Cards: Suitable for sound cards requiring high-quality audio output.
- LCD and TVs: Used in LCD and TV audio systems for enhanced audio performance.
- Mobile Phones: Ideal for mobile phones needing compact and efficient headphone amplifiers.
- Laptops: Used in laptop audio systems to drive headphones efficiently.
- Set-Top Boxes: Employed in set-top boxes for improved audio quality.
Q & A
- What is the maximum power output of the TPA6138A2PW?
The TPA6138A2PW can deliver up to 40 mW of power into a 32 Ω load from a 3.3V supply voltage.
- What is the load impedance range supported by the TPA6138A2PW?
The TPA6138A2PW supports load impedances ranging from 16 Ω to 32 Ω.
- Does the TPA6138A2PW require output DC-blocking capacitors?
No, the TPA6138A2PW does not require output DC-blocking capacitors due to its ground-referenced outputs.
- How is the gain adjusted in the TPA6138A2PW?
The gain can be adjusted using external gain-setting resistors, supporting a gain range of ±1 V/V to ±10 V/V.
- What is the purpose of the built-in active-mute control in the TPA6138A2PW?
The built-in active-mute control ensures a pop-free audio signal during power-up and power-down cycles.
- What type of filter can the TPA6138A2PW be configured as?
The TPA6138A2PW can be configured as a second-order low-pass filter, ideal for interfacing with PWM audio sources.
- What is the ESD protection level of the TPA6138A2PW?
The audio output complies with ±8-kV IEC ESD protection.
- What is the operating temperature range of the TPA6138A2PW?
The operating temperature range is -40°C to 85°C.
- What are some common applications of the TPA6138A2PW?
Common applications include sound cards, LCD and TVs, mobile phones, laptops, and set-top boxes.
- What is the package type of the TPA6138A2PW?
The TPA6138A2PW is packaged in a 14-pin TSSOP.
