SM6451A
Audio Variable Volume IC
OVERVIEW
The SM6451A is a 3-wire serial-controlled electronic variable volume IC for audio applications. It provides
electronic volume control for a stereo system (left and right channels), and independent channel attenuation
and muting, with greatly enhanced digital zip noise suppression. The chip address function allows up to four
SM6451A devices to be connected and individually controlled over the 3-wire control interface from a single
CPU. It is available in 16-pin TSSOP packages.
FEATURES
I
I
PINOUT
(Top view)
I
I
I
I
I
I
I
Stereo inputs and outputs
Attenuation function
• 2-channel independent control
• 1.0dB/step over 80 steps
• 0 to
−
80dB range
Mute function
3-wire serial data control (MDT, MCK, MLEN)
Chip addressing (up to 4 devices can be connected
in parallel)
Low noise
•
≤
0.002% THD + noise
• 10µVrms residual noise
5V single power supply
Silicon-gate CMOS process
Package: 16-pin TSSOP (Pb free)
RSTN
ADRS1
ADRS2
DVDD
LOUT
LIN
AVDD
VRL
1
16
MDT
MCK
MLEN
DVSS
ROUT
RIN
AVSS
8
9
VRR
APPLICATIONS
I
PACKAGE DIMENSIONS
(Unit: mm)
Weight: 0.07g
Audio equipment
ORDERING INFORMATION
Device
SM6451AT
Package
16-pin TSSOP
4.40 ± 0.1
6.40 ± 0.2
0.44TYP
1.00TYP
5.20MAX
5.00 ± 0.08
0.17 ± 0.05
1.00 ± 0.05
0 to 8
0.225TYP
+ 0.03
0.07
−
0.04
0.65
0.08
+ 0.08
0.22
−
0.07
0.13 M
SEIKO NPC CORPORATION —1
+ 0.03
1.07
−
0.07
0.50 ± 0.10
SM6451A
BLOCK DIAGRAM
DVDD
DVSS
LIN
Attenuation
Control
1/2V
DD
LOUT
MLEN
MCK
MDT
RSTN
VRL
Reference
Voltage
Circuits
Attenuation Decoder
Interface Control
Chip
Address
Decoder
ADRS1
ADRS2
VRR
1/2V
DD
RIN
Attenuation
Control
AVDD
ROUT
AVSS
PIN DESCRIPTION
Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
1.
Name
RSTN
ADRS1
ADRS2
DVDD
LOUT
LIN
AVDD
VRL
VRR
AVSS
RIN
ROUT
DVSS
MLEN
MCK
MDT
I/O
1
Ip
Ip
Ip
–
O
I
–
O
O
–
I
O
–
Ip
Ip
Ip
A/D
1
D
D
D
D
A
A
A
A
A
A
A
A
D
D
D
D
Description
System reset input (LOW-level reset)
Chip address set 1
Chip address set 2
Digital supply
Left-channel audio output
Left-channel audio input
Analog supply
Left-channel reference voltage (0.5V
DD
). Connect a 10µF capacitor
between VRL and AVSS.
Right-channel reference voltage (0.5V
DD
). Connect a 10µF capacitor
between VRR and AVSS.
Analog ground
Right-channel audio input
Right-channel audio output
Digital ground
Microcontroller latch enable input
Microcontroller clock input
Microcontroller data input
Ip = input pin with pull-up, A = analog, D= digital
SEIKO NPC CORPORATION —2
SM6451A
SPECIFICATIONS
Absolute Maximum Ratings
DVSS = AVSS = 0V, DVDD = AVDD = V
DD
Parameter
Supply voltage
Input voltage
Power dissipation
Storage temperature
Note. Rating applies at power-ON and power-OFF.
Symbol
V
DD
V
IN
P
D
T
stg
Rating
−0.3
to 7.0
V
SS
−
0.3 to V
DD
+ 0.3
150
−55
to 125
Unit
V
V
mW
°C
Recommended Operating Conditions
DVSS = AVSS = 0V, DVDD = AVDD = V
DD
Parameter
Supply voltage
Supply voltage deviation
Operating temperature
Symbol
V
DD
DV
DD
−
AV
DD
, DV
SS
−
AV
SS
T
opr
Rating
4.5 to 5.5
±0.1
−40
to 85
Unit
V
V
°C
DC Characteristics
DVDD = AVDD = V
DD
= 4.5 to 5.5V, V
SS
= 0V, Ta =
−40
to 85°C
Rating
Parameter
Symbol
Condition
min
I
DDD1
I
DDD2
AVDD Current consumption
HIGH-level input voltage
1
LOW-level input voltage
1
Input current
1
Input leakage current
1
1.
I
DDA
V
IH
V
IL
I
IL
I
IH
V
IN
= 0V
V
IN
= V
DD
Data transfer stopped, MDT, MCK,
MLEN, RSTN, ADRS1, ADRS2 = V
DD
ADRS1 = ADRS2 = 0V, 1.2Vrms analog
input, ATT = 0dB, data transfer active
–
–
–
0.7V
DD
–
–
–
typ
0.3
1
4.5
–
–
230
–
max
1.0
2
8
–
0.3V
DD
400
1.0
µA
mA
mA
V
V
µA
µA
Unit
DVDD Current consumption
MDT, MCK, MLEN, RSTN, ADRS1, ADRS2
SEIKO NPC CORPORATION —3
SM6451A
AC Digital Characteristics
DVDD = AVDD = V
DD
= 4.5 to 5.5V, V
SS
= 0V, Ta =
−40
to 85°C
Serial inputs (MDT, MCK, MLEN)
Rating
Parameter
MCK, MLEN rise time
MCK, MLEN fall time
MCK pulse cycle
MDT setup time
MDT hold time
MLEN setup time
MLEN hold time
MLEN LOW-level pulsewidth
MLEN HIGH-level pulsewidth
Symbol
min
t
r
t
f
t
MCK
t
MDS
t
MDH
t
MCS
t
MCH
t
MEWL
t
MEWH
–
–
100
50
50
50
50
16
50
typ
–
–
–
–
–
–
–
–
–
max
100
100
10000
–
–
–
–
–
5000
ns
ns
ns
ns
ns
ns
ns
t
MCK
ns
Unit
MDT
0.5V
DD
t
MDS
t
MDH
MCK
0.5V
DD
t
MCS
MLEN
t
MCH
0.5V
DD
t
MEWL
t
f
t
MEWH
t
r
0.9V
DD
0.1V
DD
MCK
MLEN
0.9V
DD
0.1V
DD
0.5V
DD
Reset input (RSTN)
Rating
Parameter
RSTN LOW-level pulsewidth
Symbol
min
t
RSTN
100
typ
–
max
–
ns
Unit
SEIKO NPC CORPORATION —4
SM6451A
AC Analog Characteristics
V
DD
= 5.0V, 1.2Vrms amplitude, 1kHz input frequency, 100kΩ output load resistance, Ta = 25°C,
AC-coupled inputs
Analog inputs (LIN, RIN)
Rating
Parameter
Input reference amplitude
Input resistance
Input clipping voltage
Symbol
V
AI
R
IN
V
CLP
THD + N = 1%, ATT = 0dB
Condition
min
–
40
–
typ
1.2
50
1.75
max
–
60
–
Vrms
kΩ
Vrms
Unit
Analog outputs (LOUT, ROUT)
Rating
Parameter
Residual noise voltage
Signal-to-noise ratio
Total harmonic distortion + noise
Gain control range
Step size
Attenuation error (1k to 20kHz)
Symbol
V
NS
SNR
THD + N
R
CNT
Step
ERR
1
ERR
2
AT
0
AT
2
Absolute attenuation (1kHz)
AT
4
AT
6
AT
8
Mute attenuation (1kHz)
Channel crosstalk
Frequency response
Quiescent output zip noise voltage
(while ATT value adjusting)
Minimum driver load resistance
Mute
CT
FR
N
J
R
ML
0 to
−60dB
−61
to
−80dB
ATT = 0dB
ATT =
−20dB
ATT =
−40dB
ATT =
−60dB
ATT =
−80dB
ATT = Mute
ATT = 0dB
ATT = 0dB, f = 200kHz
0Vrms input
ATT = 0dB, THD + N = 1%
Condition
min
Input signal: 0Vrms,
A-weight filter, 0dBr =
1.2Vrms, ATT = 0dB
ATT = 0dB, 20kHz lowpass
filter
–
95
–
−80
0.8
−2
−5
–
–
–
–
–
−88
−105
–
–
–
typ
10
100
0.0017
–
1
–
–
−0.1
−20.1
−40.3
−60.5
−83.0
−92
−112
−5
–
6
max
20
–
0.0025
0
1.5
1
0
–
–
–
–
–
–
–
–
3
10
µVrms
dBr
%
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
mV
kΩ
Unit
Reference voltage (VRL, VRR)
Rating
Parameter
Reference voltage output
Symbol
V
REF
Condition
min
0.45V
DD
typ
0.5V
DD
max
0.55V
DD
V
Unit
SEIKO NPC CORPORATION —5
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
