NJU8721 Datasheet, PDF (1/13 Pages) New Japan Radio – CLASS D HEADPHONE AMPLIFIER FOR DIGITAL AUDIO

NJU8721
PRELIMINARY
CLASS D HEADPHONE AMPLIFIER FOR DIGITAL AUDIO
! GENERAL DESCRIPTION
The NJU8721 is a class D Headphone Amplifier
featuring 6^th ∆Σ modulation. It includes Digital
Attenuator, Mute, and De-emphasis circuits. It
converts Digital source input to PWM signal output
which is output PWM signal converted to analog
signal with simple external LC Filter. The NJU8721
realizes very high power-efficiency by class D
operation. Therefore, it is suitable for portable audio
set and others.
! PACKAGE OUTLINE
NJU8721V
! FEATURES
! PIN CONFIGURATION
# Stereo Headphone Power Amplifier
: 50mW+50mW
# Sixth-order 32f_S Over Sampling ∆Σ & PWM
# Internal 8f_S Over Sampling Digital Filter
STBY
1
20
TEST
2
19
# Sampling Frequency : 96kHz (Max.)
V_SSR
3
18
# De-Emphasis
# System Clock
# Digital Processing
: 32kHz, 44.1kHz, 48kHz
: 256f_S
: Attenuator 107step, LOG Curve
: Mute
OUT_R
V_DDR
V_DDL
4
5
6
17
16
15
# Digital Audio Interface : 16bit, 18bit
: I²S, LSB Justified, MSB Justified
# Operating Voltage : 3.0 to 3.6V
# Driving Voltage
: V_DD to 5.25V
# C-MOS Technology
OUT_L
V_SSL
MODE
RST
7
8
9
10
14
13
12
11
# Package Outline
: SSOP20
V_DD
F0/DATA
F1/REQ
F2/SCK
MUTE
DIN
LRCK
BCK
MCK
V_SS
! BLOCK DIAGRAM
V_DD
V_SS
RST
MCK
LRCK
BCK
DIN
MUTE
STBY
MODE
F0/DATA
F1/REQ
F2/SCK
Power On
Reset Circuit
Synchronization
Circuit
Serial
Audio Data
Interface
System
Control
8f_S
Over Sampling
Digital Filter
32f_S 6^th ∆Σ
&
PWM
V_DDL
OUT_L
V_SSL
V_DDR
OUT_R
V_SSR
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