Overview
The SSM4567ACBZ-R7, produced by Analog Devices Inc., is a digital input Class-D power amplifier designed for high-efficiency and low-noise audio applications. This amplifier integrates a boost converter, allowing it to deliver higher output power than traditional battery-supplied amplifiers. It is particularly suited for power-sensitive applications such as mobile phones, tablets, and portable media players, where system noise can corrupt small analog signals.
The SSM4567 combines an audio digital-to-analog converter (DAC), a power amplifier, and PDM or PCM (I2S/TDM) digital audio interfaces on a single chip. This integration significantly reduces the impact of noise sources on the transmitted audio and eliminates the need for input coupling capacitors. The amplifier can deliver 2.5 W of continuous output power with less than 1% THD + N driving a 4 Ω load from a 3.6 V supply.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Output Power | POUT | - | 2.5 | - | W |
| THD + N | - | - | <1% | - | - |
| Load Resistance | RLOAD | - | 4 | - | Ω |
| Supply Voltage (VBAT) | VBAT | -0.3 | - | 6 | V |
| Input Voltage (IOVDD) | IOVDD | -0.3 | - | 2 | V |
| Boost Converter Output Voltage | VOUT | - | 5.1 | - | V |
| Boost Converter Input Current Limit | IMAX | - | 2.2 | - | A |
| Switching Frequency | fBOOSTSW | - | 1.536 | - | MHz |
| Efficiency (ηBOOST) at 200 mA output | ηBOOST | - | 91% | - | - |
| Operating Temperature Range | - | -40 | - | 85 | °C |
| Package Type | - | - | - | 19-ball WLCSP (1.74 mm × 2.1 mm) | - |
Key Features
- Filterless Class-D amplifier with spread-spectrum Σ-Δ modulation and integrated boost regulator (5.1 V)
- Digitized output of output voltage, output current, and VBAT supply voltage
- Multiple serial data formats: PDM input/output, TDM slave with support for up to 8 chips on a single bus
- Control interfaces: I2C, PDM pattern control, TDM control, and standalone mode without a control interface
- Automatic gain control (AGC) circuit to limit maximum output at low battery voltages, extending battery life
- High efficiency, low noise modulation scheme requiring no external LC output filters
- Closed-loop, five-level modulator design for good PSRR and audio performance
- Spread spectrum pulse density modulation to reduce EMI radiated emissions
- Micropower shutdown mode with a typical shutdown current of 0.2 μA for the VBAT power supply
- Built-in thermal shutdown and amplifier and boost output short-circuit protection
Applications
The SSM4567ACBZ-R7 is ideal for various power-sensitive audio applications, including:
- Mobile phones
- Tablets
- Portable media players
- Other battery-powered audio devices where minimizing noise and maximizing battery life are critical
Q & A
- What is the maximum output power of the SSM4567ACBZ-R7?
The SSM4567ACBZ-R7 can deliver up to 2.5 W of continuous output power.
- What is the typical THD + N of the SSM4567ACBZ-R7?
The typical THD + N is less than 1% driving a 4 Ω load from a 3.6 V supply.
- What is the operating temperature range of the SSM4567ACBZ-R7?
The operating temperature range is from -40°C to +85°C.
- What control interfaces does the SSM4567ACBZ-R7 support?
The SSM4567ACBZ-R7 supports I2C, PDM pattern control, TDM control, and can also operate in standalone mode without a control interface.
- Does the SSM4567ACBZ-R7 have built-in protection features?
Yes, it includes built-in thermal shutdown and amplifier and boost output short-circuit protection.
- What is the purpose of the automatic gain control (AGC) in the SSM4567ACBZ-R7?
The AGC limits the maximum output at low battery voltages to avoid drawing too much current from the battery, thereby extending battery life.
- What is the package type of the SSM4567ACBZ-R7?
The SSM4567ACBZ-R7 is available in a 19-ball wafer level chip scale package (WLCSP) with dimensions of 1.74 mm × 2.1 mm.
- How does the SSM4567ACBZ-R7 reduce noise in audio applications?
The SSM4567ACBZ-R7 reduces noise by transmitting audio digitally to the amplifier, eliminating the need for input coupling capacitors and minimizing the effect of noise sources on the transmitted audio.
- What is the typical shutdown current of the SSM4567ACBZ-R7 in micropower shutdown mode?
The typical shutdown current is 0.2 μA for the VBAT power supply.
- Does the SSM4567ACBZ-R7 require external LC output filters?
No, the SSM4567ACBZ-R7 features a high-efficiency, low-noise modulation scheme that does not require external LC output filters.
