xwm8722eds ETC-unknow, xwm8722eds Datasheet
xwm8722eds
Related parts for xwm8722eds
xwm8722eds Summary of contents
Page 1
Stereo DAC with Integrated Tone Generator and Line/Variable DESCRIPTION The WM8722 is a high performance stereo DAC designed for audio applications such as digital TV and set top boxes. The WM8722 has two stereo analogue outputs, one at line level ...
Page 2
... Analogue output 14 MXINL 15 CAP Analogue output 16 DVDD 17 DIN 18 LRCIN 19 BCKIN 20 SCKI Note: Digital input pins have Schmitt trigger input buffers. ORDERING INFORMATION DEVICE 20 SCKI XWM8722EDS 19 BCKIN 18 LRCIN 17 DIN 16 DVDD 15 CAP 14 MXINL 13 LINEOUTL 12 VAROUTL 11 AVDD TYPE Digital input Tone generator master-clock input. ...
Page 3
WM8722 ABSOLUTE MAXIMUM RATINGS Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical Characteristics ...
Page 4
WM8722 ELECTRICAL CHARACTERISTICS Test Conditions AVDD, DVDD = 5V, AGND, DGND = 0V, T PARAMETER SYMBOL DAC Circuit Specifications SNR (Note 1 and 2) THD (Note 2) Dynamic range (Note 2) Passband Stopband Passband ripple Stopband Attenuation Channel Separation Gain ...
Page 5
WM8722 Test Conditions AVDD, DVDD = 5V, AGND, DGND = 0V, T PARAMETER SYMBOL Gain mismatch Frequency Bandwidth Master volume max gain Master volume min gain Master volume step size (Note 4) Master volume gain code 80 – 127 (mute) ...
Page 6
WM8722 LRCIN BCKIN DIN Figure 1 Audio Data Input Timing Test Conditions AVDD, DVDD = 5V, AGND, DGND = 0V, T PARAMETER SYMBOL Audio Data Input Timing Information BCKIN pulse cycle time t BCKIN pulse width high t BCKIN pulse ...
Page 7
WM8722 LATCH MC MD Figure 3 Program Register Input Timing – 3-Wire MPU Serial Control Mode Test Conditions AVDD, DVDD = 5V, AGND, DGND = 0V, T PARAMETER Program Register Input Information MC pulse cycle time MC pulse width low ...
Page 8
WM8722 Figure 4 Program Register Input Timing – 2-Wire MPU Serial Control Mode Test Conditions AVDD, DVDD = 5V, AGND, DGND = 0V, T PARAMETER Program Register Input Information MC Frequency MC Low Pulsewidth ...
Page 9
WM8722 DEVICE DESCRIPTION WM8722 is a complete low cost stereo audio DAC, including digital interpolation filter, multi-bit sigma delta with dither, and switched capacitor multi-bit stereo DAC and output smoothing filters. A novel multi-bit sigma-delta DAC design is used, utilising ...
Page 10
WM8722 TONE GENERATOR DAC The tone generator comprises a digital frequency synthesiser, which is used to create a clock at 128x the required tone frequency, and a 128 step per cycle, sine weighted DAC, which converts the clock into one ...
Page 11
WM8722 SAMPLING RATE Table 1 System Clock Frequencies versus Sampling Rate AUDIO DATA INTERFACE The serial data interface to WM8722 is fully compatible with both normal (MSB first, right-justified interfaces. Data may be packed (number of ...
Page 12
WM8722 MODES OF OPERATION The software control interface may be operated using either a 3-wire (SPI-compatible) or 2-wire MPU interface. Selection of interface format is achieved by monitoring the state of BUSY pin at power up. In 3-wire mode, MD ...
Page 13
WM8722 To control the WM8722 on the bus, the master must initiate a data transfer by establishing a start condition, defined by a high-to-low transition on MD whilst MC remains high. This indicates that an address and data transfer will ...
Page 14
WM8722 DAC digital volume Mixer Volume Control Mixer Output Selection Tone amplitude Tone frequency Tone duration Tone (TFIN) Tone Waveform Tone Burst Table 4 Control Functions FUNCTION OPTIONS Lch, Rch individually Lch, Rch common Lch, Rch individually Lch, Rch both ...
Page 15
WM8722 REGISTER MAP The WM8722 controls the device functions using 15 program registers, each of which is 16-bits long. These registers are all loaded via the serial control interface in either 2 or 3-wire mode. There are two type of ...
Page 16
WM8722 REGISTER REG BIT NAME NAME ADDRESS TFREQ 1 F[14:0] Register 0 000 0000 DAL[7:0] LDL Register 1 000 0001 DAR[7:0] LDR Register 2 000 0010 MU DE PWD IW[1:0] PL[3:0] Register 3 000 0011 I2S LRP ATC Register 4 ...
Page 17
WM8722 REGISTER 0/1 DAC OUTPUT ATTENUATION A digital attenuator is provided to allow the levels of DAC signals to be attenuated in the digital domain. Register 0 (A[1:0] = 00) is used to control left channel attenuation. Bits 0-7 (AL[7:0]) ...
Page 18
WM8722 DAC OUTPUT CONTROL Bits and 8 (PL[3:0]) of register 2 are used to control the output format. PL0 PL1 PL2 ...
Page 19
WM8722 BOTH In register 4 and 5, a further bit BOTH is available: When a write is made to either register and BOTH is set high, then the same value written to the register will also be ...
Page 20
WM8722 Figure 9 Output Mixer Configuration M6DB In each of the 4 MUX control registers there is an M6DB bit relevant to that channel. Setting M6DB high reduces the relevant output signal by 6dB. BOTH When a write to any ...
Page 21
WM8722 SQR The WM8722 can generate three different tone types. The default setting is a sinusoidal tone. Square waves are generated by setting the SQR bit. F2F A two-tone output that generates one cycle at the chosen frequency, followed by ...
Page 22
WM8722 RECOMMENDED EXTERNAL COMPONENTS DVDD + C 1 DGND SPI or 2-wire Interface DVDD 2-wire Interface R1 SPI Interface DGND Audio Serial Data I/F Notes: 1. AGND and DGND should be connected as close to the WM8722 ...
Page 23
WM8722 PACKAGE DIMENSIONS DS: 20 PIN SSOP (7.2 x 5.3 x 1.75 mm Dimensions Symbols MIN A ----- 0.22 c 0.09 D 6.90 e 0.65 BSC ...
Page 24
... WM’s publication of information regarding any third party’s products or services does not constitute WM’s approval, license, warranty or endorsement thereof. Reproduction of information from the WM web site or datasheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations and notices. Representation or reproduction of this information with alteration voids all warranties provided for an associated WM product or service unfair and deceptive business practice, and WM is not responsible nor liable for any such use ...