CS35L32 Datasheet, PDF (2/51 Pages) Cirrus Logic – Boosted Class D Amplifier with Speaker-Protection Monitoring and Flash LED Drivers

CS35L32
Monitors and Protection
• Protection:
• Latched overtemperature shutdown
• Latched amplifier output short circuit shutdown
• LED short or open detection and LED driver shutdown
• Flash inhibit LED current reduction
• Low battery flash LED current reduction
• VP undervoltage lockout (UVLO) shutdown
• Programmable boost inductor current limiting
• Audio and LED shutdown upon stopped MCLK, with
autorecovery
• Interrupt driven error reporting
• Speaker current and voltage monitoring:
• 16-bit resolution
• 60-dB dynamic range (unweighted) for voltage
• 56-dB dynamic range (unweighted) for current
• Bused over I²S bus
• Battery voltage monitoring:
• 7-bit resolution
• Bused over I²S and I²C bus
• System reset
I²C Control Settings and Registers
• Low-power standby
• LED and audio power budgeting programmable settings
• Boost inductor current limit programmable setting
• Speaker programmable settings:
• Pop suppression through zero-crossing transitions
• Gain and mute
• Battery voltage monitor register, 8 bits
• LED driver programmable settings:
• Flash current register
• Flash inhibit current register
• Movie Mode current register
• Flash timer register
• Error status bit, including the following:
• Stopped MCLK error
• Low battery detection with programmable thresholds
• VP UVLO error
• Overtemperature warning
• Overtemperature error
• Boost converter overvoltage error
• Boost inductor current-limiting error
• Amplifier short-circuit error
• Shorted or open LED error
I²S Reporting
• Monitoring:
• Speaker voltage monitor
• Speaker current monitor
• Battery voltage monitor
• Error reporting:
• VP UVLO shutdown error
• Overtemperature warning
• Overtemperature error
• Boost converter overvoltage error
• Boost inductor current limiting error
• Amplifier short-circuit error
• Speaker voltage monitor overflow error
• Speaker current monitor overflow error
• Battery voltage monitor overflow error
• Status reporting:
• Power-down done
• LED flash event
• LED Movie Mode event
• Flash timer on
Package
• 30-ball WLCSP
Applications
• Smart phones
• Tablets
General Description
The CS35L32 is a low-quiescent power-integrated audio IC, with a mono full-bridge Class D speaker amplifier operating
with a self-boosted Class G supply. Audio input is received differentially. Pop-and-click reduction is achieved with zero-
crossing transitions at turn-on, turn-off and upon gain changes. Communication with the host processor is done using an
I²C interface. In addition, an I²S bus is used to send monitor and status data.
When two CS35L32 devices are available on the same board, each is identified by its I²C chip address. Upon power-up
or upon deasserting RESET, each CS35L32 reads the AD0 pin logic level and configures its I²C device address.
The speaker amplifier, using closed-loop  modulation, achieves low levels of distortion. Class D amplifier efficiency
allows operation at higher speaker power levels without generating excessive heat and without wasting power. Automatic
Class G operation using a boosted supply to the speaker allows for even higher powers and higher crest factor. With a
boosted speaker supply, operation at a fixed 5 V is achieved independently of line supplied battery voltage. The user can
disable Class G operation.
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