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CS35L32

Product catalog summary

Overview: The document provides comprehensive technical details on the CS35L32, a low-quiescent power-integrated audio IC. It features a mono full-bridge Class D speaker amplifier with a self-boosted Class G supply, integrated dual LED drivers, and supports I2C and I2S interfaces. It is suitable for smartphones and tablets, designed to manage audio and LED loads efficiently.

Specifications:

Class D Amplifier: Offers two-level Class G operation with boosted (5V) and bypassed modes, achieving 1.7 W into 8 Ω at 10% THD+N, 102-dB SNR, and 90% efficiency.
Audio Input and Gain: Features one differential analog input with speaker gain options of 9, 12, 15, and 18 dB, including mute and pop suppression.
LED Drivers: Integrated dual LED drivers with programmable settings for Flash, Flash-Inhibit, and Movie Modes, supporting up to 750 mA per LED.

Functional Description:

Power Management: Includes low-battery management, undervoltage lockout, and thermal management through boost-voltage regulation.
Protection Features: Provides latched shutdowns for overtemperature, short circuits, and LED faults, with autorecovery for certain conditions.
Monitoring: Monitors speaker current and voltage, battery voltage, and reports errors via I2S and I2C buses.

Procedures and Recommendations:

Typical Connection Diagram: A schematic is provided for connecting the device, highlighting the use of low ESR, X7R/X5R capacitors, and specific resistor values for optimal performance.
Protection Circuitry: It is recommended to add protection circuitry to comply with absolute maximum ratings, ensuring device reliability.
Capacitor Selection: Guidelines for selecting capacitors based on passband requirements and temperature coefficients are provided.

Characteristics and Specifications:

Operating Conditions: The device's functionality is guaranteed within specified voltage and temperature limits, with detailed tables outlining recommended operating conditions and absolute maximum ratings.
Boost Converter Characteristics: Specifications include boost output voltage, load and line regulation, and efficiency metrics.
LED Drive Characteristics: Details on current settings for Flash and Movie Modes, along with accuracy and matching specifications, are provided.
Speaker Amplifier Output Characteristics: Information on power delivery, total harmonic distortion, signal-to-noise ratio, and efficiency is included.
Signal Monitoring Characteristics: Specifications for ADC characteristics, dynamic range, and total harmonic distortion for VSENSE and ISENSE monitoring are detailed.

Key Tables and Figures:

Table 1-1: Pin Descriptions
Figure 2-1: Typical Connection Diagram
Table 3-1 to 3-7: Various operational characteristics and specifications, including operating conditions, boost converter, LED drive, and speaker amplifier output characteristics.

Specifications and Modes:
The document discusses the operational modes of the CS35L32 audio amplifier, focusing on Class G and Class D configurations. Class G can be disabled, allowing the speaker amplifier supply to be set by LEDs, ignoring thresholds. In Boost Mode, the boost converter can be set to 5V, also ignoring thresholds.

Error Conditions:
Error conditions for the Class D audio amplifier are detailed, including AMP_SHORT and OTE errors. The CS35L32 monitors output terminals for discrepancies indicating shorts, triggering Speaker-Safe Mode. Overtemperature conditions also trigger this mode, muting outputs to protect the speaker.

Speaker-Safe Mode:
Speaker-Safe Mode is activated by AMP_SHORT or OTE errors, muting amplifier outputs to Hi-Z. Normal operation resumes once error conditions cease.

Low-Battery Management:
Low-Battery Mode is triggered when battery voltage falls below a set threshold during high current events. Flash current is reduced until voltage recovers.

Undervoltage Lockout (UVLO):
UVLO protection shuts down analog circuitry if VP falls below a threshold, with autorecovery upon voltage rise.

Boost Converter:
The boost converter powers the audio amplifier and LEDs, with a current-limiting circuit to clamp peak inductor current.

Die Temperature Monitoring:
Temperature monitoring prevents overheating, with two thresholds for warnings and errors. Exceeding these thresholds triggers protective actions.

Signal Monitoring:
Signal-monitoring ADCs provide data on voltage and current, with overflow conditions monitored to prevent errors.

LED Driver:
The CS35L32 includes a high-current flash LED driver with two channels, capable of driving up to 1.5 A by combining channels.

Flash LED Current Drivers Overview:
The document provides a detailed technical overview of the CS35L32 LED driver, focusing on control, sensing, and fault protection mechanisms. It includes specifications for flash and movie mode currents, controlled via an I2C interface, and outlines the procedures for managing these modes.

Specifications and Control:
The CS35L32 is designed to drive LEDs in flash mode when the FLEN signal is high. The I2C interface allows programming of flash and movie mode currents, as well as a flash timer. Key registers include LED_FLCUR, LED_MVCUR, and TIMER. Flash events are controlled by the flash timer and the FLEN signal, with current adjustments possible via the FLINH signal.

LED Driver Protection:
The LED controller includes protection features that shut down the system if the temperature exceeds a specified threshold. It also detects and responds to shorted or open LED conditions during flash or movie mode events. Recovery from these conditions requires user intervention to clear error status bits.

Interrupts and Fault Conditions:
An interrupt is generated for various fault conditions, including LED short or open circuits, current limit breaches, and boost output overvoltage. These conditions are logged in interrupt status registers, and the system resets the interrupt once the error conditions are resolved.

Power Budgeting:
Power management is configurable through ILED_MNG, AUDIOGAIN_MNG, and VBOOST_MNG settings. The system can automatically adjust power usage based on conditions like boost converter output voltage drops or overtemperature warnings. Different modes allow for automatic, semi-automatic, or manual power management.

Audio/Data Serial Port (ADSP):
The ADSP supports traditional I²S mode for audio and data transmission, with controls for clock rate management in master or slave configurations. The serial port includes power-down and tristate controls to manage power consumption effectively.

Signaling Format:
The CS35L32 supports I²S format with up to 32 bits per channel. Data is transmitted in MSB to LSB order, with real-time monitoring of internal and external signals via integrated ADCs. Status bits provide information on amplifier shorts, undervoltage lockouts, and temperature conditions.

Conclusion:
The document provides comprehensive technical details on the CS35L32 LED driver, emphasizing its control capabilities, protection features, and power management strategies. It is designed to ensure efficient and safe operation of LED and audio systems.

Specifications and Procedures:
The document outlines the I2C communication protocol for reading and writing data to a chip. It specifies the chip address for read (0x81) and write (0x80) operations, and details the sequence of sending start conditions, chip addresses, and receiving acknowledge bits. It emphasizes the importance of reading interrupt status registers individually to avoid clearing their contents prematurely.

Initialization Sequences:
Several initialization sequences are provided to address specific issues such as audio output signal dips, spurious tones on ADCs, and incorrect boost converter output. Each sequence involves writing specific values to designated registers.

Boost Converter and Flash Event Management:
The document advises configuring the boost converter for a fixed 5-V operation to avoid current transients during flash events. It provides a sequence for issuing a flash event and recommends reconfiguring the boost converter management mode post-event.

EMI and PCB Design Considerations:
To minimize EMI, the document suggests adding passive filtering to the output stage and using a ferrite-bead capacitor output filter. It also provides guidelines for PCB routing to manage thermal dissipation effectively.

Inductor Selection:
A table lists recommended inductors with specifications such as inductance, DC resistance, and saturation current.

Register Quick Reference:
The document includes a quick reference for registers, detailing their addresses, functions, and default values. It specifies which registers are read-only and provides descriptions for each bit within the registers.

Power and Clock Control:
Registers for power control configure the power states of various components like the Class D amplifier and ADCs. Clocking control registers manage the clock rates and configurations.

Battery and Boost Converter Monitoring:
Registers for monitoring battery voltage and boost converter peak current protection are described, including their default values and configurations.

Performance Plots: The document includes plots for efficiency and current versus output power, THD+N ratio versus output power and frequency, and frequency response in different modes (Bypass and Fixed Boost). These plots help in understanding the device's performance under various conditions.

Parameter Definitions: Key parameters such as signal-to-noise ratio (SNR), total harmonic distortion plus noise (THD+N), and output offset voltage are defined. These parameters are crucial for assessing the audio quality and performance of the amplifier.

Package Dimensions: The CS35L32 is available in a 30-ball WLCSP package. Detailed dimensions are provided, adhering to ASME Y 14.5M–1994 standards, ensuring compatibility with various design requirements.

Ordering Information: The product is available in a commercial temperature range (-10°C to 70°C) and is halogen and Pb-free. The order number for the tape and reel packaging is CS35L32-CWZR.

Revisions and References: The document includes a revision history detailing updates to specifications and package dimensions. References include the I²C-Bus Specification and User Manual by NXP Semiconductors.

Legal and Safety Notices: Important notices regarding the use of Cirrus Logic products in critical applications are provided, emphasizing the need for adequate design and operating safeguards.

Catalog excerpts

CS35L32 Boosted Class D Amplifier with Speaker-Protection Monitoring and Flash LED Drivers Mono Class D Speaker Amplifier • Two-level Class G operation: • Boosted: 5 V nominal • Bypassed: battery voltage is supplied directly • 2.5-mA quiescent current, monitors powered down • 1.7 W into 8 (@ 10% THD+N) • 102-dB signal-to-noise ratio (SNR, A-weighted) • Idle channel noise 25 Vrms (A-weighted) • 90% efficiency • Integrated dual LED drivers using the following: • Boost supply output voltage • Dual matched current regulators, 750 mA max each • Programmable setting for Flash Mode current: 50–750 mA, in 50-mA steps • Programmable setting for Flash-Inhibit Mode current: 50–350 mA, in 50-mA steps • Programmable setting for Movie Mode current: 150, 120, 100, 80, 60, 40, 20 mA • Programmable flash timer setting: 50–500 ms, in 25-ms steps • Dedicated pin for flash trigger (FLEN) • Dedicated pin for flash inhibit (FLINH) • Thermally managed through boost-voltage regulation Audio Input and Gain • One differential analog input • Speaker gain: • 9, 12, 15, and 18 dB and mute • Pop suppression, zero-crossing detect transitions Class D Power Stage SPKR SUPPLY Control, Sensing, and Fault Protection FLEN FLINH Current Mode Synchronous Boost Controller Soft Ramp SPKR SUPPLY Current Sense Bandgap Voltage Generation VREF Generation (Features continue on page 2) Flash LED Current Driver Temperature Sensor Overtemp Protection SPKOUT+ SPKOUT–/ VSENSE– Short Circuit Protection Power Budgeting Serial Port Clock Generation LRCK Range Scaling Serial Audio/Data Port GNDP VSENSE+ VSENSE– ISENSE+ ISENSE– ISENSE+ ISENSE–/ VSENSE+ I²C Control Port Level Shifters Copyright  Cirrus Logic, Inc

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CS35L32 • Error status bit, including the following: • Stopped MCLK error • Protection: • Low battery detection with programmable thresholds • Latched overtemperature shutdown • VP UVLO error • Latched amplifier output short circuit shutdown • Overtemperature warning • LED short or open detection and LED driver shutdown • Overtemperature error • Flash inhibit LED current reduction • Boost converter overvoltage error • Low battery flash LED current reduction • Boost inductor current-limiting error • VP undervoltage lockout (UVLO) shutdown • Amplifier short-circuit error • Programmable boost inductor...

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CS35L32 The battery voltage, speaker voltage, and speaker current signals are monitored, digitized using  converters, and serialized over an I2S bus. The speaker monitoring signals are part of a speaker-protection algorithm that is managed externally to the CS35L32. Outgoing data is sent over I2S with the CS35L32 in Slave or Master Mode. Battery voltage monitor data is accessible through I2C. An integrated dual LED driver operates up to two LEDs in Flash Mode or Movie Mode. A flash event is triggered by an external signal. A flash-inhibit event is triggered by an external signal, and causes...

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CS35L32 Table of Contents 1 Pin Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 6 Register Quick Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 2 Typical Connection Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 7 Register Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 3 Characteristics and Specifications . . . . . . . . . . . . . . . . . . . . . . 8 7.1 Device ID A and B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Table 3-1. Recommended Operating Conditions...

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CIRRUS LOGIC SPKOUT+ SPKOUT-/ _Power Supply Figure 1-1. Top-Down (Through-Package) View—30-Ball WLCSP Package Ball Name Number Supply Ball Description Driver Receiver A1 VA I/O |2C Serial Data Input. Serial data for the PC serial port A2 VA I |2C Clock Input. Serial clock for the RC serial A5 VA I Master Clock Source. Clock source for A/D Weak pull- converters and audio/data serial port (ADSP). down MCLK|NT, derived from MCLK, is used for other H MQ) blocks (see Section 4.13 and Section 7.7). Hysteresis Pulled I/O Serial Clock. Serial shift clock for the serial audio interface Weak pull- CMOS...

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1 Pin Descriptions Table 1-1. Pin Descriptions (Cont.) Ball Name RESET Ball Power Internal I/O Ball Description Number Supply Connection — B3 VA I Reset. When asserted, the device enters a low-power mode, outputs are set to Hi-Z, and I²C register values are set to defaults. Outputs are Hi-Z except those with weak pull-ups or pull-downs as mentioned. State at Reset Hysteresis Low on CMOS input Receiver Flash Enable. Input signal commanding a Weak pullflash event into both LEDs. It is asserted high. down (~1 M Weak pullVA I Flash Inhibit. Input signal determining down whether the LEDs are in...

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2 Typical Connection Diagram 2 Typical Connection Diagram 1 H Battery See Note 7 for LED and I2C addressing options. Applications Processor FLEN FLINH ISENSE–/ VSENSE+ SPKOUT+ LRCK SPKOUT–/ VSENSE– Notes: • All external passive component values are nominal values. Key for capacitor types required: * Use low ESR, X7R/X5R capacitors. ** Use low ESR, X7R capacitors. If no type symbol is shown next to a capacitor, any type may be used. • As required, add protection circuitry to ensure compliance with the absolute maximum ratings in Table 3-2. 1. CBST is a ceramic capacitor and derates at DC voltages...

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3 Characteristics and Specifications Table 3-1. Recommended Operating Conditions GNDA = GNDP = 0 V, all voltages with respect to ground. Device functional operation is guaranteed within these limits. Functionality is not guaranteed or implied outside of these limits. Operation outside of these limits may adversely affect device reliability. Parameters DC power supply Analog (and digital I/O and core) Battery External voltage applied to analog inputs powered by VA (IREF+, FILT+) 1 External voltage applied to analog inputs powered by SPKRSUPPLY (IN+, IN–, ISENSE+, ISENSE–,VSENSE+, VSENSE–) External...

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CS35L32

CS35L32

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