Overview
The TPA321, produced by Texas Instruments, is a 350-mW mono audio power amplifier designed for low-voltage applications, particularly where internal speakers are required. This bridge-tied load (BTL) amplifier is optimized for narrow band applications such as cellular communications and operates efficiently with supply voltages ranging from 2.5 V to 5.5 V. It is characterized for both 3.3-V and 5-V operation, making it versatile for various battery-powered devices. The TPA321 features a shutdown mode with an ultra-low supply current of 0.15 µA, thermal and short-circuit protection, and is available in surface-mount packages including SOIC and PowerPAD™ MSOP, which reduces board space and height significantly.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Output Power (VDD = 5 V, RL = 8 Ω) | 350 mW | mW |
| Output Power (VDD = 3.3 V, RL = 8 Ω) | 250 mW | mW |
| Supply Voltage Range | 2.5 V to 5.5 V | V |
| Supply Current (SHUTDOWN = 0 V, RF = 10 kΩ) | 0.7 to 1.5 mA | mA |
| Supply Current in Shutdown Mode | 0.15 µA | µA |
| Power Supply Rejection Ratio (PSRR) | 85 dB | dB |
| Output Offset Voltage (measured differentially) | 5 to 20 mV | mV |
| Package Types | SOIC, PowerPAD™ MSOP |
Key Features
- Bridge-tied load (BTL) configuration eliminating the need for external coupling capacitors on the output in most applications.
- Ultralow supply current in shutdown mode (0.15 µA).
- Thermal and short-circuit protection.
- Wide power supply compatibility (2.5 V to 5.5 V).
- Surface-mount packaging options (SOIC and PowerPAD™ MSOP) reducing board space and height.
- Optimized for narrow band applications such as cellular communications.
Applications
The TPA321 is particularly suited for low-voltage applications requiring internal speakers, such as:
- Cellular phones and other handheld communication devices.
- Portable audio equipment.
- Battery-powered devices where power efficiency is crucial.
- Small form factor audio systems where space is limited.
Q & A
- What is the maximum output power of the TPA321 at 5 V supply voltage?
The maximum output power is 350 mW into an 8-Ω load. - What is the supply voltage range for the TPA321?
The supply voltage range is from 2.5 V to 5.5 V. - What is the typical supply current in active mode?
The typical supply current is between 0.7 mA and 1.5 mA. - How much current does the TPA321 consume in shutdown mode?
The supply current in shutdown mode is 0.15 µA. - What type of protection does the TPA321 have?
The TPA321 features thermal and short-circuit protection. - What are the package options available for the TPA321?
The TPA321 is available in SOIC and PowerPAD™ MSOP packages. - Why is the BTL configuration beneficial?
The BTL configuration eliminates the need for external coupling capacitors on the output in most applications. - What is the power supply rejection ratio (PSRR) of the TPA321?
The PSRR is 85 dB. - What is the output offset voltage of the TPA321?
The output offset voltage is between 5 mV and 20 mV when measured differentially. - For what type of applications is the TPA321 optimized?
The TPA321 is optimized for narrow band applications such as cellular communications.
