AK4650 Datasheet, PDF (83/86 Pages) Asahi Kasei Microsystems – 16Bit ΔΣ CODEC with MIC/HP/SPK-AMP & TSC

[AK4650]
1. Grounding and Power Supply Decoupling
The AK4650 requires careful attention to power supply and grounding arrangements. AVDD, DVDD, HVDD and
TSVDD are usually supplied from the system’s analog supply. If AVDD, DVDD, HVDD and TSVDD are supplied
separately, the correct power up sequence should be observed. AVSS, DVSS, HVSS and TSVSS of the AK4650 should
be connected to the analog ground plane. System analog ground and digital ground should be connected together near to
where the supplies are brought onto the printed circuit board. Decoupling capacitors should be as near to the AK4538 as
possible, with the small value ceramic capacitor being the nearest.
2. Voltage Reference
VCOM is a signal ground of this chip. A 2.2μF electrolytic capacitor in parallel with a 0.1μF ceramic capacitor attached
to the VCOM pin eliminates the effects of high frequency noise. No load current may be drawn from the VCOM pin. All
signals, especially clocks, should be kept away from the VREF and VCOM pins in order to avoid unwanted coupling into
the AK4650.
3. Analog Inputs
The Mic, Beep and stereo line inputs are single-ended. AUX input is differential. The input signal range scales with
nominally at 0.06 x AVDD Vpp for the Mic input, 0.6 x AVDD Vpp for the Beep input, stereo line input and AUX input,
centered around the internal common voltage (0.45 x AVDD). Usually the input signal is AC coupled using a capacitor.
The cut-off frequency is fc = 1/(2πRC). The AK4650 can accept input voltages from AVSS to AVDD.
4. Analog Outputs
The input data format for the DAC is 2’s complement. The output voltage is a positive full scale for 7FFFH(@16bit) and
a negative full scale for 8000H(@16bit). Mono output from the MOUT2 pin and Mono Line Output from the
MOUT+/MOUT− pins are centered at 0.45 x AVDD, Headphone-Amp is centered at 0.44 x AVDD and Speaker-Amp
output is centered at HVDD/2, respectively.
MS0502-E-01
- 83 -
2007/04