WT1312 Mono Audio Amplifier IC
2.3W Class‑D · 0.58Ω RON · 3µA Standby · 1.8–6V · SOT23‑6
The WT1312 is a high‑efficiency, low‑cost mono Class‑D audio power amplifier designed for portable and battery‑powered devices. With a 0.58Ω low on‑resistance and ultra‑low 3µA standby current, it maximizes battery life. It delivers 2.3W output power into a 4Ω load at 5V supply, making it ideal for driving small speakers. The device operates over a wide 1.8–6V voltage range and includes thermal overload protection with hysteresis. Housed in a compact SOT23‑6 package, it saves valuable PCB space for space‑constrained applications like toys, greeting cards, and small home appliances.
- 2.3W output @ 5V, 4Ω load
- 0.58Ω typical on‑resistance
- < 3µA standby current
- 1.8–6V wide supply range
- SOT23‑6 miniature package
- Over‑temperature shutdown & hysteresis
Key Features
Electrical Specifications (TA = 25°C, VCC = 5V)
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage | — | 1.8 | 5 | 6 | V |
| Quiescent Current | No load | — | 70 | — | µA |
| Quiescent Current | INA=INB=1.8V | — | — | 150 | µA |
| Standby Current | INA=INB=0, >10ms | — | 1 | 3 | µA |
| On‑Resistance | ILOAD=500mA | — | 0.58 | — | Ω |
| On‑Resistance | ILOAD=1000mA | — | 0.7 | — | Ω |
| High‑Level Input Voltage | — | 1.8 | — | — | V |
| Low‑Level Input Voltage | — | — | — | 0.7 | V |
| Thermal Shutdown | — | — | 150 | — | °C |
| Thermal Hysteresis | — | — | 50 | — | °C |
Output power: 2.3W into 4Ω at 5V, 1kHz. Peak output current: 2A.
Pin Description – SOT23‑6
| Pin | Name | Function |
|---|---|---|
| 1 | OUTB | B output (speaker negative) |
| 2 | GND | Ground |
| 3 | INB | B input (differential) |
| 4 | INA | A input (differential) |
| 5 | VDD | Power supply (1.8–6V) |
| 6 | OUTA | A output (speaker positive) |
The device uses a differential input stage. Both inputs must be properly biased for correct operation. Refer to the application circuit.
Typical Application Circuit
Key design notes:
- Place decoupling capacitors (C1, C3) as close as possible to the chip (<1cm).
- C3 is required when VDD > 5.5V.
- Input traces and components should be kept away from interference sources (antennas, high‑frequency signals, PWM).
- Output traces to the speaker should be short and at least 1mm wide.
- Use ground‑surround routing for audio signal paths to reduce noise.
- A series diode (D1) can be added for reverse‑polarity protection (drops 0.7V).
For detailed component values, refer to the datasheet.
Applications
Why Choose WT1312
FAQs
What is the WT1312?
A mono Class‑D audio amplifier IC delivering 2.3W into 4Ω at 5V, with ultra‑low standby current and SOT23‑6 package.
What is the supply voltage range?
1.8V to 6V, making it suitable for battery‑powered and USB‑powered devices.
How much current does it draw in standby?
Less than 3µA, which extends battery life significantly.
What load impedance is recommended?
4Ω to 8Ω speakers are typical; output power varies with load.
Does it have thermal protection?
Yes, it includes over‑temperature shutdown at 150°C with 50°C hysteresis.
What is the input signal frequency range?
1 kHz to 65 kHz, suitable for audio and PWM applications.
Can I use it with a single‑ended input?
The inputs are differential; you can bias one input and apply signal to the other.
What is the package type?
SOT23‑6, a compact surface‑mount package.
Note: For optimal performance, place decoupling capacitors close to the IC pins, keep output traces short and wide, and ensure proper grounding. The device is compatible with 1.8V logic levels. Refer to the datasheet for complete application guidelines and PCB layout recommendations.
