Cirrus Logic CS42L56 - Manual (Page 2)

2 DS851F2
CS42L56
SYSTEM FEATURES
 Audio (11.2896 MHz or 12.288 MHz) or USB
(12 MHz) Master Clock Input
 Low-power Operation
– Stereo Anlg. Passthrough: 3.3 mW @1.8 V
– Stereo Rec. and Playback: 8.3 mW @1.8 V
 Headphone Detect Input
 High Performance 24-bit Converters
– Multi-bit Delta–Sigma Architecture
 Integrated High Efficient Power Management
Reduces Power Consumption
– Step-down Charge Pump Improves
Efficiency
– Inverting Charge Pump Accommodates
Low System Voltage by Providing Negative
Rail for HP/Line Amp
– LDO Reg. Provides Low Digital Supply
Voltage
 Digital Power Reduction
– Very Low ADC/DAC Oversampling Rate
– Bursted Serial Clock Providing up to 24 Bits
per Sample
 Power Down Management
– ADC, DAC, CODEC, PGA, DSP
 Analog & Digital Routing/Mixes
– Line/Headphone Out = Analog In (ADC
Bypassed)
– Line/Headphone Out = ADC Out
– Internal Digital Loopback
– Mono Mixes
 I²C or SPI™ Control Port
 I²S or Left-justified Digital Interface Format
 Flexible Clocking Options
– Master or Slave Operation
– Wide Range of Sample Rates Supported
APPLICATIONS
 HDD and Flash-based Portable Audio Players
 PDAs
 Personal Media Players
 Portable Game Consoles
 Digital Voice Recorders
 MD Players/Recorders
 Digital Camcorders
 Digital Cameras
 Smart Phones
GENERAL DESCRIPTION
The CS42L56 is a highly integrated, 24-bit, ultra-low-
power stereo CODEC based on multi-bit delta-sigma
modulation. Both the ADC and DAC offer many features
suitable for low power portable system applications.
The analog input path allows independent channel
control of a variety of features. The Programmable Gain
Amplifier (PGA) provides analog gain with zero cross
transitions. The ADC path includes a digital volume at-
tenuator with soft ramp transitions and a programmable
ALC and noise gate monitor the input signals and adjust
the volume appropriately. An analog passthrough also
exists, accommodating a lower noise, lower power ana-
log in to analog out path to the headphone and line
amplifiers, bypassing the ADC and DAC.
The DAC output path includes a fixed-function digital
signal processing engine. Tone control provides bass
and treble adjustment at four selectable corner frequen-
cies. The digital mixer provides independent volume
control for both the ADC output and PCM input signal
paths, as well as a master volume control. Digital vol-
ume controls may be configured to change on soft ramp
transitions while the analog controls can be configured
to occur on every zero crossing. The DAC path also in-
cludes de-emphasis, limiting functions and a beep
generator delivering tones selectable across a range of
two full octaves.
The Class H stereo headphone amplifier combines the
efficiency of an integrated step-down and inverting
charge pump with the linearity and low EMI of a Class
AB amplifier. A step-down/inverting charge pump oper-
ates in two modes: ±VCP mode or ±VCP/2) mode.
Based on the amplifier’s output signal, internal logic au-
tomatically adjusts the output of the charge pump,
+VHPFILT and –VHPFILT, to optimize efficiency. With
these features, the amplifier delivers a ground-centered
output with a large signal swing even at low voltages
and eliminates the need for external DC-blocking
capacitors.
These features make the CS42L56 the ideal solution for
portable applications which require extremely low pow-
er consumption in a minimal amount of space.
The CS42L56 is available in a 40-pin QFN package for
the Commercial (-40 to +85° C) grade. The CDB42L56
Customer Demonstration board is also available for de-
vice evaluation and implementation suggestions.
Please see
“Ordering Information” on page 93 for com-
plete details.