Document
NJU26901
Digital Audio Delay
General Description
Package
The NJU26901 is a digital audio delay. The NJU26901 provides delay-time adjustment function and digital audio interface.
FEATURES
NJU26901M
• 2-Channel Audio Delay (24 bits data width). Delay Time 85msec at fs = 48kHz ( 128msec at fs = 32kHz , 43msec at fs = 96kHz)
• 4 delay time modes( ¼, ½, ¾, 1 max. delay ) are selectable without a micro-computer. • To make long delay time, the NJU26901 can be connected serially. • Non-audio-signal data can be delayed by the NJU26901.
Hardware Specification
• Digital Audio Interface • Digital Audio Format • Audio Bit Clock (BCK) Frequency • Package • Power Supply
: 1 Input port / 1 Output port : I2S 24bit BCK : 64fs, Slave Mode : 13MHz Max ( approximate fs=200KHz) : DMP8 ( Pb-Free ) : 2.5V ( +3.3V input tolerant )
Function Block Diagram
LRI BCKI SDI
SERIAL AUDIO INTERFACE
L/R in
NJU26901
BCKI LRI
Delay RAM
SERIAL AUDIO INTERFACE
L/R out
Control Logic
COUNT[1:0]
Fig. 1 Function Block Diagram
SDO
Ver.2008-12-01
-1-
NJU26901
Pin Assignment
SDI 1 LRI 2 BCKI 3 VSS 4
NJU26901
8 VDD 7 SDO 6 COUNT[1] 5 COUNT[0]
Pin Description
Fig. 2 Pin Assignment
Table 1 Pin Description
Pin No. Symbol
I/O
1 SDI
I
2 LRI
I
3 BCKI
I
4 VSS
-
5 COUNT[0]
Ipu
6 COUNT[1]
Ipu
7 SDO
O
8 VDD
-
I : Input
Ipu : Input(internal pull-up)
O : Output
Description
Audio Data Input LR Clock Input Bit Clock Input
GND Delay Time Control 0 Delay Time Control 1 Audio Data Output Power Supply +2.5V
Absolute Maximum Ratings
Table 2 Absolute Maximum Ratings
Parameter
Symbol
Power Supply Voltage
VDD
Input Pin Voltage
VTMI
Power Dissipation Operating Temperature Storage Temperature
PD TOPR TSTR
Rating
-0.3 to +3.05 -0.3 to +3.6 (VDD ≥ 2.25V) -0.3 to +3.05 (VDD < 2.25V)
100
-40 to +85 -40 to +125
Units V
V
mW °C °C
-2-
Ver.2008-12-01
NJU26901
Electric Characteristics
Table 3 Electric Characteristics
Parameter
Symbol
Operating VDD Voltage
VDD
Operating Current
IDD
Operating Temperature High Level Input Voltage Low Level Input Voltage
TOPR VIH VIL
High Level Output Voltage
VOH
Low Level Output Voltage
Input Current Input Current Input Capacitance Input Rise/Fall transition Time
VOL
IIN IIN(PU) CIN tr / tf
Test Condition
BCKI:13MHz SDO:CL=25pF
IOH= -2mA IOH= -100µA IOL= 2mA IOL= 100µA VIN= VSS to 3.6V VIN= VSS to 3.6V
(VDD=2.5V,Ta=25°C) Min. Typ. Max. Units
2.25 2.5 2.75 V
- 1.0 - mA
-40 25 85 °C
2.0 - 3.3 V
- - 0.5 V
VDD-0.4 VDD-0.1
-
-
V
-
-
0.4 0.1
V
-15 - +15 µA
-100 - +15 µA
- 10 - pF
- - 100 ns
Equivalent Circuit
Input terminal
VDD VSS
Input terminal
VDD VSS
Output terminal
VDD VSS
Input Pin #1,2,3
Input Pin #5,6
Output Pin #7
Fig. 3 Input Terminal Equivalent Circuit
Ver.2008-12-01
-3-
NJU26901
Serial Audio Timing
Table 4 Serial Audio Input Timing Parameters
Parameter
Symbol
Test Condition
BCKI Frequency BCKI Period
L Pulse Width H Pulse Width
BCKI to LRI Time
fBCK
tSIL tSIH TSLI
LRI to BCKI Time
tLSI
Data Setup Time
tDS
Data Hold Time
tDH
Data Output Delay
tDOD SDO=25pF
Min Typ. Max Units - - 13 MHz
35 35
- ns
15 -
- ns
15 -
- ns
15 -
- ns
15 -
- ns
- 15 ns
LRI BCKI SDI
tSIH tSIL tSLI tLSI tDS tDH
SDO
tDOD
Fig. 4 Serial Audio Input / Output Timing
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Ver.2008-12-01
NJU26901
Serial Audio Interface
Digital Audio format is I2S 24bit 64fs in fig. 5. The input and output format are the same I2S 24bit 64fs.
LRI BCKI SDI, SDO
Left Channel
Right Channel
MSB LSB 23 2221 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
MSB LSB 23 22 21 20 19 18 17 16 15 14 13 12 1110 9 8 7 6 5 4 3 2 1 0
32 Clocks
32 Clocks
Fig 5 Digital Audio Format (I2S 24bits 64fs)
Function Description
• SDI(#1) is serial audio input pin. The input audio data should be connected to this pin. The NJU26901 fetches in the input audio data every LRI edge.
• LRI(#2) is LR clock input pin. This LR clock frequency is the same frequency of the input audio signal. LRI=”Low” shows SDI and SDO data are left channel data. LRI=”High” shows SDI and SDO data are right channel data.
• BCKI(#3) is bit clock input pin. This BCKI clock frequency is 64 times as large as the input audio signal. • SDO(#7) is serial audio output pin. The delayed audio data come out through this pin. • VDD(#8) is 2.5V power supply pin. VSS(#4) is GND pin. The decoupling capacitor is necessary between VDD
and VSS. • The input pins can interface to 3.3V ICs. The output pins can interface to 2.5V ICs. Refer to table3 “Electric
Characteristics”. • After Power-on RESET, there is possibility the NJU26901 generates random data for the delay time period set
by COUNT[0],[1] pins. If necessary, the mute circuit should be added.
Delay Time
• The NJU26901 provides maximum 4097 samples delay and slave-mode audio interface. The delay time
depends on sampling frequency.
• Delay time is controlled by COUNT[0], COUNT[1]. Table 5 shows Delay T.