NJRC NJU8714

NJU8714
NJU3555
STEREO BTL OUTPUTS SWITCHING DRIVER
FOR Class D AMPLIFIER
GENERAL DESCRIPTION
PACKAGE OUTLINE
The NJU8714 is a stereo BTL outputs switching driver
for class D amplifier. It receives PWM/PDM signals from
DSP outputs, and drives headphones or speakers by BTL
outputs.
Output drivers are composed of Series-Connected
N-channel FETs, and output voltage levels can be
controlled by variable power supply with keeping all of
input signal information.
The NJU8714 incorporates BTL outputs amplifiers,
which eliminate AC coupling capacitors. Also, it provides
“SEL” terminal which selects “Synchronous” or
“Asynchronous”. “Asynchronous” can be reduced the
operating current. Therefore, it is suitable for portable
audio set and others.
NJU8714VB2
PIN CONFIGURATION
FEATURES
2-channel 1bit Audio Signal Input
Stereo BTL Outputs
Output Power
: Typ.150mW@8Ω
BEEP Function
Standby Function
Output Driver Control Function
Operating Voltage
VDD: 1.7V to 2.7V
VDDO: 0V to 2.0V
VG: 4.5V to 5.25V
CMOS Technology
Package Outline :SSOP20-B2
MCK
VSS
HALTB
DIN1
BEEPIN
OBEEP1
OUT1
VSSO
OUT1X
VDDO1
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
VDD
SEL
STBYB
DIN2
VG
OBEEP2
OUT2
VSSO
OUT2X
VDDO2
BLOCK DIAGRAM
VDD VSS
VG
VDDO1
DIN1
Level
Shifter
OUT1
Control
Logic
Pre
Driver
OUT1X
VSSO
VDDO2
DIN2
Level
Shifter
MCK
Level
Shifter
STBYB
Level
Shifter
HALTB
Level
Shifter
SEL
Level
Shifter
OUT2
Control
Logic
Pre
Driver
OUT2X
VSSO
OBEEP1
BEEPIN
OBEEP2
Ver.2004-05-21
-1-
NJU8714
TERMINAL DESCRIPTION
No.
1
2
3
4
5
6
7
8,13
9
10
11
12
14
15
16
17
18
SYMBOL
MCK
VSS
HALTB
DIN1
BEEPIN
OBEEP1
OUT1
VSSO
OUT1X
VDDO1
VDDO2
OUT2X
OUT2
OBEEP2
VG
DIN2
STBYB
I/O
I
I
I
I
O
O
O
O
O
O
I
I
FUNCTION
Master Clock Input Terminal
Power GND: VSS=0V (Note.1)
Output Driver Control Terminal
1bit Data Input Terminal 1
BEEP Signal Input Terminal
BEEP Output terminal 1
Positive Output Terminal 1
Output GND terminal: VSS=0V (Note. 1)
Negative Output 1
Output Power supply 1(Note. 2)
Output Power supply 2(Note. 2)
Negative Output 2
Positive Output Terminal 2
BEEP Output terminal 2
Pre-driver Power supply
1bit Data Input Terminal 2
Standby control terminal (L:Standby)
Input Signal Synchronization With “MCK”
19
SEL
I
(H: Synchronous., L: Asynchronous.)
20
VDD
Power Supply: VDD=2.5V
(Note. 1) Pin No.2(VSS), 8(VSSO) and 13(VSSO) should be connected at the nearest point to the IC.
(Note. 2) Pin No.10(VDDO1) and 11(VDDO2) should be connected at the nearest point to the IC.
INPUT TERMINAL STRUCTURE
VDD
Input Terminal
VSS
MCK, HALTB, DIN1, DIN2, BEEPIN, STBYB, SEL
-2-
Ver.2004-05-21
NJU8714
NJU3555
FUNCTIONAL DESCRIPTION
(1) Signal Output
The OUT1/1X and OUT2/2X generate respectively L-channel and R-channel output signals, which will be
converted to analog signals via external 2nd-order or higher LC filter. A switching regulator with a high response
against a voltage fluctuation is the best selection for the VDDO1 and VDDO2, which are the power supply for output
drivers. To obtain better T.H.D. performance, the stabilization of the power is required.
(2) Master Clock (MCK)
Input 1-bit audio signals such as PWM or PDM to the DIN1 and DIN2 pins. By setting the SEL pin to ”H”, master
clock (MCK) synchronizes the audio signal inputs (DIN1 and DIN2). In case of “SEL” = “L”, input signals go into the
amplifier circuits by own timing. Therefore, it requires careful design of PCB patterns from DSP to NJU8714.
The setup time and the hold time should be kept in the AC characteristics because DIN1 and DIN2 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.
(3) Power Supply
VDD : Power supply for input part.
VG : Power supply for control logic and pre-driver which drives the transistor gates of output drivers.
It requires much higher power supply voltage than VDDO1 and VDDO2 for better T.H.D..
VDDO1, VDDO2 : Power supply for output drivers.
(4) Output Control
Output circuit is selected by the conditions of STBYB, HALTB, SEL, DIN1, DIN2 and MCK.
STBYB
L
H
L
HALTB
H
H
L
H
SEL
*
*
*
L
H
DIN1, DIN2
*
*
*
L
H
L
H
MCK
*
*
*
*
OUT1
OUT2
OUT1X
OUT2X
VSSO
VSSO
VSSO
VSSO
Hi-z
VSSO
VDDO1
VSSO
VDDO1
Hi-z
VSSO
VDDO2
VSSO
VDDO2
Hi-z
VDDO1
VSSO
VDDO1
VSSO
Hi-z
VDDO2
VSSO
VDDO2
VSSO
*Don’t care
BEEP circuit is operated regardless of STBYB and HALTB.
(5) Input Signal Synchronization Function
DIN1 and DIN2 are synchronized with master clock by setting SEL pin to ”H”.
By setting SEL pin to ”L”, DIN1 and DIN2 are asynchronous with master clock.
(6) Output Driver Control Function
By setting HALTB pin to ”L”, high side output drivers become OFF and Low side output drivers become ON,
then both of OUT1/1X and OUT2/2X output VSSO level signals. This function works regardless of STBYB pin
setting.
(7) Standby Control Function
By setting STBYB pin to ”L”, the NJU8714 becomes standby condition. During standby condition, by setting
HALTB to ”L”, OUT1/1X and OUT2/2X become VSSO, and by setting HALTB pin to ”H”, OUT1/1X and OUT2/2X
become Hi-z.
To save the power supply current at standby, MCK requires ”L” level.
Ver.2004-05-21
-3-
NJU8714
ABSOLUTE MAXIMUM RATINGS
(Ta=25°C)
PARAMETER
SYMBOL
VDD
VG
VDDO
RATING
-0.3 to +2.75
VDD to +5.5
-0.3 to +5.5
UNIT
Input Voltage
Vin
-0.3 to VDD+0.3
V
Operating Temperature
Topr
-40 to +85
°C
Storage Temperature
Tstg
-40 to +125
°C
PD
450*
mW
Supply Voltage
Power Dissipation
V
* : Mounted on two-layer board of based on the JEDEC.
Note.1) All voltage values are specified as VSS=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) The relations of VDDO < VG must be maintained during operations.
ELECTRICAL CHARACTERISTICS
(Ta=25°C, VDD=2.5V, VG=5.0V, VDDO1= VDDO2=1.7V, VSS=VSSO=0V,
STBYB=HALTB=SEL=2.5V, Load Impedance=32Ω, fS=44.1kHz, unless otherwise noted)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
VDD Supply Voltage
VDD
-
1.7
2.5
2.7
VDDO1,2 Input Voltage
VG Supply Voltage
VDDO
VG
0
4.5
5.0
2.0
5.25
V
Output Driver
High side Resistance
RHPH
-
1.2
2
Ω
Output Driver
Low side Resistance
RHPL
OUT1, OUT1X,
OUT2, OUT2X
= VDDO1,2 – 0.1V
VG=5.0V
OUT1, OUT1X,
OUT2, OUT2X
= 0.1V
VG= 5.0V
-
1.2
2
Ω
Beep
High side Resistance
RBEEPH
OBEEP1, OBEEP2= VDD– 0.1V
-
9.0
15
Ω
Power Supply Current
At Standby
IST
-
-
1.0
uA
-
0.05
0.1
-
0.25
0.5
1.0
2.0
0.7VDD
-
VDD
V
0
-
0.3VDD
V
-
-
±1.0
uA
Power Supply Current
At Operating
(Mute signal input)
Input Voltage
Input Leakage Current
IDD
IDDO
IG
VIH
VIL
ILK
Stopping
MCK, DIN1, DIN2, BEEPIN
STBYB= 0V
No-load operating,
MCK= 256fS,
DIN1, DIN2= 32fS,
VDDO1= VDDO2= 0.18V
MCK, DIN1, DIN2, BEEPIN,
HALTB, STBYB, SEL
mA
Note 1) High side resistance and low side resistance depend on VG and VDDO. Therefore, VG and VDDO should be
adjusted on the application system.
Note 2) Output power using 8Ω speaker is 150mW(TYP:THD+N=10%) at the following condition.
→VDD=2.5V, VG=5.0V, VDDO1= VDDO2=3.0V
-4-
Ver.2004-05-21
NJU8714
NJU3555
TIMING CHARACTERISTICS
•
Audio Signal Input
tMCKL
tMCKH
0.7VDD
0.3VDD
MCK
0.7VDD
DIN1,DIN2
0.3VDD
tDS
tDH
(Ta=25°C, VDD=2.5V, VDDO1=VDDO2=1.7V, VSS=VSSO=0V,
STBYB=HALTB=SEL=2.5V, fs=44.1kHz, unless otherwise noted)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
•
MCK Frequency
fMCKI
8
-
35
MHz
MCK Pulse Width (H)
tMCKH
9
-
-
ns
MCK Pulse Width (L)
tMCKL
9
-
-
ns
DIN1,DIN2 Setup Time
tDS
5
-
-
ns
DIN1,DIN2 Hold Time
tDH
5
-
-
ns
BEEP Frequency
fb
0.1
20
kHz
Output Control Signal Input
0.9VDD
BEEPIN, HALTB
STBYB, SEL
0.1VDD
tUP
tDN
(Ta=25°C, VDD=2.5V, VDDO1=VDDO2=1.7V, VSS=VSSO=0V,
STBYB=HALTB=SEL=2.5V, fs=44.1kHz, unless otherwise noted)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNIT
Rise Time
tUP
-
-
50
ns
Fall Time
tDN
-
-
50
ns
Ver.2004-05-21
-5-
NJU8714
APPLICATION CIRCUIT
-Load Impedance: 32Ω
100uH
OUT1(7)
MCK(1)
0.22uF
HALTB(3)
100uH
STBYB(18)
OUT1X(9)
DIN1(4)
DIN2(17)
VDD
10uF 2.2u
NJU8714
SEL(19)
32Ω
Speaker
100uH
OUT2(14)
0.22uF
100uH
0.22uF
OUT2X(12)
VG(16)
VDDO1(10)
VDD(20)
0.22uF
32Ω
Speaker
VG
2.2uF 100uF
VDDO
VSSO(8)
VSS(2)
VDDO2(11)
2.2uF 100uF 2.2uF 10uF
VSSO(13)
-Load Impedance: 8Ω
22uH
OUT1(7)
MCK(1)
1.0uF
HALTB(3)
22uH
STBYB(18)
OUT1X(9)
DIN1(4)
DIN2(17)
VDD
10uF 2.2u
VDD(20)
NJU8714
SEL(19)
1.0uF
8Ω
Speaker
22uH
OUT2(14)
1.0uF
22uH
1.0uF
OUT2X(12)
VG(16)
VDDO1(10)
2.2uF 100uF
8Ω
Speaker
VG
VDDO
VSSO(8)
VSS(2)
VDDO2(11)
2.2uF 100uF 2.2uF 10uF
VSSO(13)
Note 3) De-coupling capacitors must be connected between each power supply pin and GND pin.
Note 4) The power supply for VDDO requires fast driving response performance such as a switching regulator
for T.H.D..
Note 5) The above circuit shows only application example and does not guarantee the any electrical
characteristics. Therefore, please consider and check the circuit carefully to fit your application.
-6-
Ver.2004-05-21
NJU8714
NJU3555
[CAUTION]
The specifications on this databook are only
given for information , without any guarantee
as regards either mistakes or omissions. The
application circuits in this databook are
described only to show representative usages
of the product and not intended for the
guarantee or permission of any right including
the industrial rights.
Ver.2004-05-21
-7-