Cirrus Logic CS4234 - Manual (Page 2)

DS899F1 2
CS4234
General Description
The CS4234 is a highly versatile CODEC that combines 4 channels of high performance analog to digital conver-
sion, 4 channels of high performance digital to analog conversion for audio, and 1 channel of digital to analog
conversion to provide a nondelayed audio reference signal to an external Class H tracking power supply. If not used
to drive a tracking power supply, the 5
th DAC can instead be used as a standard audio grade DAC, with performance
specifications identical to that of the 4 DACs in the audio path. Additionally, the CS4234 includes tunable group de-
lay for each of the 4 audio DAC paths to provide lead time for the external switch-mode power supply, and a
nondelayed path into the DAC outputs for input signals requiring a low-latency path to the outputs.
Targeting the automotive audio market, this controller was specifically designed to work with Apex Precision Power’s
CS44417 Class AB audio amplifier, but remains flexible enough to allow any standard Class AB amplifier to be op-
erated as a Class H amplifier in order to maximize efficiency. Class H control provides significant efficiency gains
over traditional Class AB amplifiers, while avoiding the increased electromagnetic interference (EMI) and cost of
Class D amplifiers.
The Class H controller provides a reference signal which tracks the envelope of the maximum (on a sample by sam-
ple basis) of up to 32 channels of serial data in the TDM slots input on the SDINx lines. This reference signal is sent
to the 5
th DAC to create an analog reference signal for an external switch-mode power supply that supplies rail volt-
ages to an external Class AB amplifier, thereby turning any standard Class AB amplifier into a Class H amplifier. If
desired, the internal tracking power supply circuitry can be bypassed, which allows a DSP generated tracking signal
to be used to control the SMPS. This feature allows an unlimited number of channels to be tracked, using a DSP to
create the tracking signal.
This product is available in a 40-pin QFN package in Automotive (-40 °C to +105 °C) temperature grade. See “Or-
dering Information” on page 74 for complete details.