Texas Instruments manual DEM-DAI1717 System Board Information, DEM-PCM17178

DEM-DAI1717 SYSTEM BOARD INFORMATION

GENERAL SPECIFICATIONS

Table I lists the specifications for the DEM-DAI1717 sys- tem board.

SPDIF Interface	Optical via Toslink
	RCA with 75Ω impedance.
System Clock Frequency	256 times sampling frequency, fs
Digital Audio Interface	16 bits, Normal Format, MSB last
	18 bits, Normal Format, MSB last
	I2S 16 or 18 bits
THD+N	0.004% typical, with internal 20kHz Low
	Pass Filter.
	0.08% typical, direct out, with external
	30kHz Low Pass Filter.
Dynamic Range	94dB typical, (EIAJ method, A-weighted
	filter)
SNR	100dB typical, (EIAJ method, A-weighted
	filter)
Maximum Output	2Vrms (using internal low pass filter out)
+VCC range	+4.5 to +5.5
+ICC	+60mA (no external load) to +120mA
±VS	±5V ~ ±15V
±IS	±15mA (no external load)

TABLE I. DEM-DAI1717 General Specifications.

SPDIF INTERFACE OPTIONS

The DEM-DAI1717 employs a SPDIF receiver chip. This receiver extracts 4 signals from a two wire signal that is interfaced to the board. The receiver can supply these four digital audio signals in up to eight different formats. Of these formats only three are useful or valid for the PCM1717. The output format is commanded by the setting switches S0, S1, and S2. Figure 7 shows the switches and resulting output configurations from the settings. Only the three configura- tions shown will produce valid outputs from the PCM1717E.

		S0			S1	S2
	L
	H
S0	S1	S2		SPDIF Output Format
H	L	H	16 bits Normal Format MSB First
L	H	H	18 bits Normal Format MSB First
L	H	L			I2S 16 or 18 bits

FIGURE 7. SPDIF Interface Options.

JUMPER SETTINGS

The DEM-DAI1717 system board has 5 jumpers blocks that allow the digital outputs from the SPDIF receiver chip to be connected to the PCM1717. The four jumpers that intercon- nect the four digital audio signals from the receiver chip are

®

installed by default. An optional ground connection can be made between the receiver chip and the PCM1717E. Refer to Figure 8 for the orientation of these jumpers.

JP

256fs

LRCK

BCK

DATA

GND

CS8412 PCM1717E

FIGURE 8. DEM-DAI1717 Jumper Configuration.

MODE CONTROL SWITCH SETTINGS

The DEM-DAI1717 system board uses 5 switches, labeled as S3, to select between software and hardware control and to provide settings for the hardware mode. When the DEM- DAI1717 is to be used with the system software then it is necessary for all of the mode switches to be in the high or off position. Figure 9 shows the functions of all five of these switches.

			DEM-DAI1717
Low	Mute	Off		Off	Reset	Hardware	On
	On	48kHz		44.1kHz	Off
		De-Emphasis
High	Mute	44.1kHz		48kHz	Reset	Software	Off
	Off	32kHz		32kHz	On
	ML	MC		MD	RSTB	Mode

FIGURE 9. DEM-DAI1717 Mode Control Switch Settings.

PARALLEL PORT CONNECTIONS

Figure 10 shows the connections made between the parallel port connector and the pins on the PCM1717.

1	2	3	4	5	18
19					36
			PARALLEL		PCM1717E
				2	ML
				3	MC
				4	MD
				5	RSTB
				19 ~ 30	GND

FIGURE 10. DEM-DAI1717 Parallel Port Connections.

DEM-PCM17178