TAS2557 Datasheet, PDF (1/110 Pages) Texas Instruments – 5.7-W Class-D Mono Audio Amplifier with Class-H Boost and Speaker Sense

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TAS2557
SLASEC2 – NOVEMBER 2016
TAS2557 5.7-W Class-D Mono Audio Amplifier with Class-H Boost and Speaker Sense
1 Features
•1 Ultra Low-Noise Mono Boosted Class-D Amplifier
– 5.7 W at 1% THD+N and 6.9 W at 10%
THD+N into 4-Ω Load from 4.2-V Supply
– 3.8 W at 1% THD+N and 4.5 W at 10%
THD+N into 8-Ω Load from 4.2-V Supply
• Output Noise for DAC + Class-D (ICN) is 15.9 µV
• DAC + Class-D SNR 111 dB at 1%THD+N/8 Ω
• THD+N –90 dB at 1 W / 8 Ω with Flat Frequency
Response
• Post-Filter Feedback (PFFB)
• PSRR 110 dB for 200 mV_pp ripple at 217 Hz
• Input Sample Rates from 8 kHz to 96 kHz
• Built-In Speaker Sense
– Measures Speaker Current and Voltage
– Measures VBAT Voltage, Chip Temperature
• Dedicated Real-Time Dual-Core DSP for Speaker
Protection
– Thermal and Excursion Protection
– Detects Speaker Leaks and Damage
• High Efficiency Class-H Boost Converter With
Multi-Level Tracking
– 86% at 500 mW in 8 Ω with 3.6 V V_BAT
– 87% at 700 mW in 8 Ω with 4.2 V V_BAT
• Configurable Automatic Gain Control (AGC)
– Limits Battery Current Consumption
• Adjustable Class-D Switching Edge-Rate Control
• Thermal, Short-Circuit, and Under-Voltage
Protection
• I²S, Left-Justified, Right-Justified, DSP, and TDM
Input and Output Interface,
• I²C or SPI Interface for Register Control
• Stereo Configuration Using Two TAS2555
Devices
• Power Supplies
– Boost Input: 2.9 V to 5.5 V
– Analog/Digital: 1.65 V to 1.95 V
– Digital I/O: 1.62 V to 3.6 V
• 3.47 mm x 3.23 mm, 0.5 mm pitch, 42-ball WCSP
2 Applications
• Mobile Phones & Tablets
• Video Doorbells & Voice Enabled Thermostats
• Personal Computers
• Bluetooth Speakers and Accessories
1
3 Description
The TAS2557 device is a state-of-the-art Class-D
audio amplifier which is a full system on a Chip
(SoC). The device features a ultra low-noise audio
DAC and Class-D power amplifier which incorporates
speaker voltage and current sensing feedback. An
on-chip, low-latency DSP supports Texas Instruments
SmartAmp speaker protection algorithms to
maximizes loudness while maintaining safe speaker
conditions.
The device can be used easily with any processor
with an I2S output and stereo implementations are
possible when using two TAS2557 devices. Separate
tuning for different speakers is supported allowing
customers to add value while maintaining form factor
designs. Additionally, the TAS2557 supports separate
voice and audio tuning dynamically with ultra-low 15.9
µV ICN regardless of mode of operation making
receiver/speaker implementations possible.
A Class-H boost converter generates the Class-D
amplifier supply rail. When the audio signal only
requires a lower Class-D output power, the boost
improves system efficiency by deactivating and
connecting V_BAT directly to the Class-D amplifier
supply. When higher audio output power is required,
the multi-level boost quickly activates tracking the
signal to provide the additional voltage to the load.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TAS2557
DSBGA (42)
3.47 mm × 3.23 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
L1
MCLK
I2S
4
I2C
2
/RESET
VBAT
2 SW
C1
VREG
TAS2557
VBOOST
2
C2
Ferrite bead
(optional)
OUT+
+
OUT-
To Speaker
-
Ferrite bead
(optional)
VSENSE+
VSENSE-
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.