CS35L32
Boosted Class D Amplifier with Speaker-Protection Monitoring
and Flash LED Drivers
Mono Class D Speaker Amplifier
Flash LED Drivers
Two-level Class G operation:
Integrated dual LED drivers using the following:
Boosted: 5 V nominal
Boost supply output voltage
Bypassed: battery voltage is supplied directly
Dual matched current regulators, 750 mA max each
2.5-mA quiescent current, monitors powered down
Programmable setting for Flash Mode current:
50750 mA, in 50-mA steps
1.7 W into 8 (@ 10% THD+N)
Programmable setting for Flash-Inhibit Mode current:
102-dB signal-to-noise ratio (SNR, A-weighted)
50350 mA, in 50-mA steps
Idle channel noise 25 Vrms (A-weighted)
Programmable setting for Movie Mode current:
90% efficiency
150, 120, 100, 80, 60, 40, 20 mA
Programmable flash timer setting:
Audio Input and Gain
50500 ms, in 25-ms steps
One differential analog input
Dedicated pin for flash trigger (FLEN)
Speaker gain:
Dedicated pin for flash inhibit (FLINH)
9, 12, 15, and 18 dB and mute
Thermally managed through boost-voltage regulation
Pop suppression, zero-crossing detect transitions
(Features continue on page 2)
SPKR
VP VBST SW IREF+
VA SUPPLY FLEN FLINH FLOUT1 FLOUT2/AD0
Current
Sense
ADC
GNDPLED
Control,
Current Mode Synchronous
Bandgap
Sensing,
Boost Controller
Voltage
Soft Ramp
and Fault
Generation
Protection
VCOM Low Battery Management
Flash LED Current Driver
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Class G I C Class G Override Class D Power Stage
V
REF
SPKR SUPPLY
FILT+
Temperature Overtemp
Generation
Class D Front End
Sensor Protection
VREF
Class D Modulator SPKOUT+
IN+ + SPKOUT/
VSENSE
IN
Short Circuit Protection
9,12,15, or
Power
18 dB + Mute
GNDP
Budgeting
VMON ADC
VSENSE+
Error
Front End
ADC
LP
MCLK
Watchdog
VSENSE
IMON ADC
GNDA ISENSE+
Serial Port
ISENSE+
Range
Front End
Clock Generation
ADC
Scaling
LP ISENSE/
ISENSE
VSENSE+
LRCK SCLK
Serial Audio/Data Port IC Control Port
Level Shifters
SCLK LRCK SDOUT SCL SDA
RESET INT
Copyright Cirrus Logic, Inc. 20122015
DS963F5
(All Rights Reserved)
AUG 15
CS35L32
Error status bit, including the following:
Monitors and Protection
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 current limiting
Shorted or open LED error
Audio and LED shutdown upon stopped MCLK, with
autorecovery
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I S Reporting
Interrupt driven error reporting
Monitoring:
Speaker current and voltage monitoring:
Speaker voltage monitor
16-bit resolution
Speaker current monitor
60-dB dynamic range (unweighted) for voltage
Battery voltage monitor
56-dB dynamic range (unweighted) for current
Error reporting:
2
Bused over I S bus
VP UVLO shutdown error
Battery voltage monitoring:
Overtemperature warning
7-bit resolution
Overtemperature error
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Bused over I S and I C bus
Boost converter overvoltage error
System reset
Boost inductor current limiting error
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I C Control Settings and Registers
Amplifier short-circuit error
Low-power standby
Speaker voltage monitor overflow error
LED and audio power budgeting programmable settings
Speaker current monitor overflow error
Boost inductor current limit programmable setting
Battery voltage monitor overflow error
Speaker programmable settings:
Status reporting:
Pop suppression through zero-crossing transitions
Power-down done
Gain and mute
LED flash event
Battery voltage monitor register, 8 bits
LED Movie Mode event
LED driver programmable settings: Flash timer on
Flash current register
Package
Flash inhibit current register
30-ball WLCSP
Movie Mode current register
Applications
Flash timer register
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
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I C interface. In addition, an I S bus is used to send monitor and status data.
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When two CS35L32 devices are available on the same board, each is identified by its I C chip address. Upon power-up
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or upon deasserting RESET, each CS35L32 reads the AD0 pin logic level and configures its I C 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.
2 DS963F5