Ultra Low Power, Stereo Codec with Class H Headphone Amplifier

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 CS42L56 includes a stereo ADC, stereo DAC, and stereo headphone driver. The analog input path includes independent channel control of a variety of features including a Programmable Gain Amplifier, digital volume control with soft ramp transitions, and an analog pass-through mode for low power operation. It also includes an analog input mux and mic bias generation for supporting a variety of analog audio inputs. The DAC output includes a DSP engine with parametric EQ, volume control, limiting functions, and a beep generator. 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. The output is ground centered, eliminating the need for large DC blocking capacitors. 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 device evaluation and implementation suggestions.



Digital to Analog Features
  • 5 mW Stereo playback power consumption
  • 99 dB dynamic range (A-wtd)
  • -86 dB THD+N
  • Digital signal processing engine
    • Bass & treble tone control, de-emphasis
    • Main volume control (+12 to -102 dB in 0.5 dB steps)
    • Soft-ramp & zero-cross transitions
    • Programmable peak-detect and limiter
    • Beep generator w/ full tone control
Stereo Headphone and Line Amplifiers
  • Step-down/inverting charge pump
  • Class H amplifier - automatic supply adj.
    • High efficiency
    • Low EMI
  • Pseudo-differential ground-centered outputs
  • High HP power output at -75 dB THD+N
    • 2 x 20 mW into 16 Ω @ 1.8 V
  • 1 VRMS line output @ 1.8 V
  • Analog vol. ctl. (+12 to -60 dB in 1 dB steps)
  • Analog in to analog out passthrough
  • Pop and click suppression
Analog to Digital Features
  • 3.5 mW Stereo record power consumption
  • 95 dB dynamic range (A-wtd)
  • -87 dB THD+N
  • Configurable analog inputs
    • Two pseudo-differential Stereo inputs or
    • One pseudo-differential Stereo inputs + one standard Stereo input + one standard mono input or
    • Three standard Stereo inputs
    • Pseudo-differential inputs reduce common mode signal noise
    • 3:1 Stereo input MUX for ADC or passthrough
  • Analog Programmable Gain Amplifier (PGA)
    • +12 to -6 dB in 0.5 dB steps
    • +10 dB or +20 dB additional gain for microphone inputs
  • Programmable, low-noise MIC bias output
  • Programmable Automatic Level Control (ALC)
    • Noise gate for noise suppression
    • Programmable threshold & attack/release rates
  • Independent ADC channel control
  • High-pass filter disable for DC measurements
System Features
  • Audio (11.2896 MHz or 12.288 MHz) or USB (12 MHz) main clock input
  • Low-power operation
    • Stereo analog passthrough: 3.3 mW @1.8 V
    • Stereo record 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
  • 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
    • Main or secondary operation
    • Wide range of sample rates supported

Parametric Specifications

Discontinued Product

Technical Documents

CS42L56 Product Data Sheet

Apr 11, 2014, DS851F2 : 4003 Kb

Design Resources

CDB42L56 Evaluation Board Datasheet

Apr 11, 2014, DS851DB1 : 4594 Kb


Comprehensive Solutions