NJU8713
2V Operation Switching Driver for Class D Amplifier
GENERAL DESCRIPTION
The
NJU8713
is a Switching Driver for a class D
Amplifier including Separated Power Source terminals
between Input and Output, BEEP and BPZ (Bipolar Zero)
output circuits. It converts 1bit digital signal input, such
as PWM or PDM signal, to an analog signal output through
a simple external LC low-pass filter.
The
NJU8713
realizes very high power-efficiency
because of the class D operation. Therefore, it is suitable
for portable audio set and others.
PACKAGE OUTLINE
NJU8713V
FEATURES
2-channel 1bit Audio Signal Input
Standby(Hi-Z), BPZ Control
Internal BPZ Charger
Beep Function
Operating Voltage
: 1.7V to 2.7V
Driving Voltage
: 1.7V to V
DD
CMOS Technology
Package Outline
: SSOP14
PIN CONFIGURATION
MCK
V
SS
IN
1
EN
1
V
SSO
OUT
1
V
DDO
1
2
3
4
5
6
7
14
13
12
11
10
9
8
BEEP
V
DD
IN
2
EN
2
V
SSO
OUT
2
V
DDO
BLOCK DIAGRAM
V
DD
V
SS
BPZ Output
V
DDO
V
SSO
IN
1
OUT
1
BEEP
IN
2
Output Control
BPZ Output
OUT
2
MCK
EN
1
EN
2
Ver.2004-06-02
-1-
NJU8713
TERMINAL DESCRIPTION
No.
13
2
7
8
5
10
1
4
11
3
12
14
SYMBOL
V
DD
V
SS
V
DDO
V
SSO
MCK
EN
1
EN
2
IN
1
IN
2
BEEP
I/O
-
-
-
Function
Operation Power Supply, V
DD
=2V
Operation Power GND, V
SS
=0V
Driving Power Supply, V
DDO
=2V
Terminal No.7 and No.8 should be connected to the same electric
potential.
Driving Power GND, V
SSO
=0V
Terminal No.5 and No.10 should be connected to the same electric
potential.
Master Clock Input Terminal
-
I
I
I
I
The condition of the data input terminal is fetched with the rising
edge of this signal.
Output Control Terminal
Output circuit is selected by the condition of this terminal.
Audio Signal Input Terminal
1-bit Audio Signal inputs into this terminal.
Beep Signal Input Terminal
Beep signal inputs into this terminal.
Output Terminal
•
When Output Terminal selects Audio Signal, IN
1
terminal input data
outputs from OUT
1
terminal and IN
2
terminal input data outputs from
OUT
2
terminal.
•
When Output Terminal selects Beep Signal, BEEP terminal input
data outputs from OUT
1
and OUT
2
terminals.
6
9
OUT
1
OUT
2
O
INPUT TERMINAL STRUCTURE
V
DD
Input Terminal
Inside Circuit
V
SS
-2-
Ver.2004-06-02
NJU8713
NJU3555
FUNCTIONAL DESCRIPTION
(1) Signal Output
PWM signals of L channel and R output from OUT
1
and OUT
2
terminals respectively. These signals are
converted to analog signal by external 2nd-order or over LC filter. The output driver power supplied from V
DDO
and V
SSO
are required high response power supply against voltage fluctuation like as switching regulator
because Output T.H.D is effected by power supply stability.
(2) Master Clock
Master clock (MCK) synchronizes the Audio signal inputs (IN
1
and IN
2
). The setup time and the hold time
should be kept in the AC characteristics because IN
1
and IN
2
are fetched with the rising edge of MCK. MCK
requires jitter-free or jitter as small as possible because the jitter downs S/N ratio.
OUT
1
and OUT
2
occur the pop noise when MCK is stopped in operation without standby mode.
Therefore,
the standby mode should be set before MCK stop.
(3) Output Control
Output circuit is selected by the conditions of EN
1
and EN
2
terminals.
EN
2
0
0
1
1
EN
1
0
1
0
1
Output State of OUT
1
& OUT
2
Standby(High impedance)
Audio Signal Output
BPZ Output
Beep Signal Output
(4) Beep Function
The beep signal must be input before the rising edge of EN
2
signal and must be stopped after the falling edge
of EN
2
signal.
EN
1
EN
2
MCK
BEEP
Audio Signal Output
Beep Signal Output
Audio Signal Output
Ver.2004-06-02
-3-
NJU8713
(5) BPZ Function
BPZ Function operates to charge the external AC coupling capacitor for the BPZ level which is a point of the
analog signal common. Be sure to input sound-less data to IN
1
and IN
2
in busy of the BPZ function. At this
time, the sound-less signal must be input before the rising edge of EN
2
signal and must be continue after the
falling edge of EN
2
signal. The charging time is in proportion to the capacity value of the external AC coupling
capacitor.
EN
1
EN
2
MCK
IN
1
, IN
2
Standby
Sound-less Data
BPZ Output
Audio Data
Audio Signal Output
Standby
-4-
Ver.2004-06-02
NJU8713
NJU3555
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Operation Supply Voltage
Driving Supply Voltage
Input Voltage
Operating Temperature
Storage Temperature
Power Dissipation
SSOP14
Power Supply Voltage Condition
SYMBOL
V
DD
V
DDO
Vin
Topr
Tstg
P
D
-
RATING
-0.3 to +4.0
-0.3 to +2.7
-0.3 to V
DD
+0.3
-40 to +85
-40 to +125
300
V
DD
≥
V
DDO
(Ta=25°C)
UNIT
V
V
V
°C
°C
mW
V
Note 1) All voltage values are specified as V
SS
=V
SSO
=0V.
Note 2) If the LSI is used on condition beyond the absolute maximum rating, the LSI may be destroyed.
Using LSI within electrical characteristics is strongly recommended for normal operation. Use beyond
the electrical characteristics conditions will cause malfunction and poor reliability.
Note 3) Decoupling capacitors should be connected between V
DD
-V
SS
and V
DDO
-V
SSO
due to the stabilized
operation.
ELECTRICAL CHARACTERISTICS
(Ta=25°C, V
DD
=V
DDO
=2.0V, V
SS
=V
SSO
=0.0V, Load Impedance=32Ω, f
S
=44.1kHz, unless otherwise noted)
PARAMETER
SYMBOL
CONDITIONS
MIN.
TYP.
MAX.
UNIT
V
DD
Supply Voltage
V
DDO
Supply Voltage
BPZ Driving Voltage
Output Driver
High side Resistance
Output Driver
Low side Resistance
Beep
High side Current
Beep
Low side Current
Operating Current
At Standby
Operating Current
At no input signal
V
DD
V
DDO
V
BPZ
R
H
R
L
I
BH
I
BL
I
ST
I
DD
I
DDO
V
IH
Input Voltage
V
IL
Input Leakage Current
I
LK
0
-
-
-
0.3V
DD
±1
V
uA
load operating
MCK=256f
S
IN
1
, IN
2
=32f
S
Duty50%
V
OUT
=V
DDO
-0.1V
V
OUT
=0.1V
V
OUT
=V
DDO
-1V
V
OUT
=1V
Stopping MCK, IN
1
, IN
2
,
BEEP
No-load operating
IN
1
, IN
2
=32f
S
MCK=256f
S
1.7
1.7
V
DDO
/2-0.2
-
-
20
20
-
-
-
0.7V
DD
2.0
2.0
V
DDO
/2
1.5
1.5
50
50
-
0.05
0.6
-
2.7
V
DD
V
DDO
/2+0.2
2
2
150
150
1
0.1
1.2
V
DD
V
V
V
Ω
Ω
uA
uA
uA
mA
V
Ver.2004-06-02
-5-
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