SGM8903
Capless 3Vrms Line Driver
with Adjustable Gain
GENERAL DESCRIPTION
FEATURES
The SGM8903 is a 3Vrms pop/click-free stereo line
Capless Structure
driver designed to allow the removal of the output
Eliminates Pop/Clicks
DC-blocking capacitors for reduced component count
Eliminates Output DC-Blocking Capacitors
and cost. The device is ideal for single supply
Provides Flat Frequency Response from DC to
electronics where size and cost are critical design
20kHz
parameters.
Typical SNR = 114dB
The SGM8903 is capable of driving 3Vrms into a 2.5kΩ
Typical VN = 5.5μVrms
load with 5V supply voltage. The device has differential
Typical THD+N = 0.001% (f = 1kHz)
inputs and uses external gain setting resistors that
supports a gain range of ±1V/V to ±10V/V. The use of
Low Noise and THD
3Vrms Output Voltage into 2.5kΩ Load with 5V
Supply Voltage
external gain resistors also allows the implementation
of a 2nd-order low pass filter to compliment DAC's and
Differential Input
SOC converters. The SGM8903 has build-in shutdown
-40℃ to +85℃ Operating Temperature Range
control for pop/click-free on/off control.
Available in the Green TSSOP-14 Package
Using the SGM8903 in audio products can reduce
component count compared to traditional methods of
generating a 3Vrms output. The SGM8903 doesn't
require a power supply greater than 5V to generate an
8.5VPP output, nor does the device require a split rail
power supply. The SGM8903 integrates a charge pump
to generate a negative supply rail that provides a clean,
APPLICATIONS
Set-Top Box
LCD TV
Blue-Ray DVD-Players
Home Theater in a Box
pop/click-free ground-biased 3Vrms output.
The SGM8903 is available in Green TSSOP-14
package. It operates over an ambient temperature
range of -40℃ to +85℃.
SG Micro Corp
www.sg-micro.com
DECEMBER 2016 – REV. C. 2
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
PACKAGE/ORDERING INFORMATION
MODEL
PACKAGE
DESCRIPTION
SPECIFIED
TEMPERATURE
RANGE
ORDERING
NUMBER
PACKAGE
MARKING
PACKING
OPTION
SGM8903
TSSOP-14
-40℃ to +85℃
SGM8903YTS14G/TR
SGM8903
YTS14
XXXXX
Tape and Reel, 3000
NOTE: XXXXX = Date Code and Vendor Code.
Green (RoHS & HSF): SG Micro Corp defines "Green" to mean Pb-Free (RoHS compatible) and free of halogen substances. If
you have additional comments or questions, please contact your SGMICRO representative directly.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage..................................................... -0.3V to 6V
Input Voltage.................................... VSS - 0.3V to VDD + 0.3V
Minimum Load Impedance (RL) .....................................600Ω
EN to GND ...............................................-0.3V to VDD + 0.3V
Junction Temperature .................................................+150℃
Storage Temperature Range......................... -65℃ to +150℃
Lead Temperature (Soldering, 10s) ............................+260℃
ESD Susceptibility
HBM ............................................................................. 6000V
MM ................................................................................. 300V
CDM ............................................................................ 1000V
RECOMMENDED OPERATING CONDITIONS
Supply Voltage Range ...........................................3V to 5.5V
Operating Temperature Range ....................... -40℃ to +85℃
OVERSTRESS CAUTION
Stresses beyond those listed may cause permanent damage
to the device. Functional operation of the device at these or
any other conditions beyond those indicated in the operational
section of the specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
reliability.
ESD SENSITIVITY CAUTION
This integrated circuit can be damaged by ESD if you don’t
pay attention to ESD protection. SGMICRO recommends that
all integrated circuits be handled with appropriate precautions.
Failure to observe proper handling and installation procedures
can cause damage. ESD damage can range from subtle
performance degradation to complete device failure. Precision
integrated circuits may be more susceptible to damage
because very small parametric changes could cause the
device not to meet its published specifications.
DISCLAIMER
SG Micro Corp reserves the right to make any change in
circuit design, specification or other related things if necessary
without notice at any time.
TYPICAL OPERATION CIRCUIT
_
DAC
SOC
DAC
SG Micro Corp
www.sg-micro.com
RIGHT
+
SGM8903
+
LEFT
_
DECEMBER 2016
2
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
PIN CONFIGURATION
(TOP VIEW)
+INR
1
14
+INL
-INR
2
13
-INL
OUTR
3
12
OUTL
11
UVP
External
Under
Voltage
Detector
SGND
4
EN
5
10
PGND
PVSS
6
9
PVDD
CN
7
8
CP
Charge Pump
TSSOP-14
PIN DESCRIPTION
PIN
NAME
1
2
3
4
5
6
7
8
9
10
11
12
13
14
+INR
-INR
OUTR
SGND
EN
PVSS
CN
CP
PVDD
PGND
UVP
OUTL
-INL
+INL
SG Micro Corp
www.sg-micro.com
FUNCTION
Right Channel OPAMP Positive Input.
Right Channel OPAMP Negative Input.
Right Channel OPAMP Output.
Signal Ground.
Enable Input. Active high.
Negative Supply Voltage Output.
Charge Pump Flying Capacitor Negative Terminal.
Charge Pump Flying Capacitor Positive Terminal.
Positive Supply.
Power Ground.
Under-Voltage Protection Input.
Left Channel OPAMP Output.
Left Channel OPAMP Negative Input.
Left Channel OPAMP Positive Input.
DECEMBER 2016
3
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
ELECTRICAL CHARACTERISTICS
(TA = +25℃, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
5.5
V
ELECTRICAL CHARACTERISTICS
DC Supply Voltage (VDD)
Output Offset Voltage (|VOS|)
3
VDD = 3V to 5V
Power Supply Rejection Ratio (PSRR)
VDD = 3V to 5V
High-Level Output Voltage (VOH)
VDD = 3.3V, RL = 2.5kΩ
Low-Level Output Voltage (VOL)
VDD = 3.3V, RL = 2.5kΩ
1.2
5
97
dB
3.18
V
-3.05
V
High-Level Input Current (EN) (|IIH|)
VDD = 5V, VI = VDD
1
μA
Low-Level Input Current (EN) (|IIL|)
VDD = 5V, VI = 0V
1
μA
Supply Current (IDD)
VDD = 3.3V, No load, EN = VDD
10.5
14.5
VDD = 5V, No load, EN = VDD
11.3
15.5
Shutdown mode, VDD = 3V to 5V
0.13
0.18
mA
OPERATING CHARACTERISTICS (VDD = 3.3V, RL = 2.5kΩ, CPUMP = CPVSS = 1µF, CIN = 10µF, RIN = 10kΩ, RFB = 20kΩ.) (1)
Output Voltage (Outputs in Phase) (VO)
THD = 1%, VDD = 3.3V, f = 1kHz
2.05
THD = 1%, VDD = 5V, f = 1kHz
3.05
THD = 1%, VDD = 5V, f = 1kHz, RL = 100kΩ
3.1
Vrms
Total Harmonic Distortion Plus Noise (THD+N)
VO = 2Vrms, f = 1kHz
0.001
%
Crosstalk
VO = 2Vrms, f = 1kHz
113
dB
Output Current Limit (IO)
VDD = 3.3V
20
mA
Input Resistor Range (RIN)
10
kΩ
Feedback Resistor Range (RFB)
20
kΩ
Slew Rate
10
V/μs
Maximum Capacitive Load
220
pF
Noise Output Voltage (VN)
A-weighted, BW = 20kHz
5.5
μVrms
Signal to Noise Ratio (SNR)
VO = 3Vrms, THD+N = 0.1%, BW = 20kHz,
A-weighted
114
dB
7.8
MHz
Unity Gain Bandwidth (GBW)
Open-Loop Voltage Gain (AVO)
120
dB
Charge Pump Frequency (FCP)
330
450
560
kHz
External Under-Voltage Detection (VUVP)
1.05
1.13
1.25
V
External Under-Voltage Detection Hysteresis
Current (IHys)
EN PIN
4.8
Input High Voltage (VINH)
EN
Input Low Voltage (VINL)
EN
μA
1.2
V
0.6
V
NOTE:
1. For CPUMP, CPVSS, CIN, RIN and etc, please refer to the TYPICAL APPLICATION CIRCUIT on page 7.
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
4
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
TYPICAL PERFORMANCE CHARACTERISTICS
VDD = 3.3V, TA = +25℃, RL = 2.5kΩ, CPUMP = CPVSS = 1µF, CIN = 10µF, RIN = 10kΩ, RFB = 20kΩ, unless otherwise noted.
THD+N vs. Output Voltage
THD + N (%)
1
THD+N vs. Output Voltage
10
VDD = 5V, RL = 600Ω,
f = 1kHz
VDD = 5V, RL = 2.5kΩ,
f = 1kHz
1
THD + N (%)
10
0.1
0.01
0.001
0.1
0.01
0.001
0.0001
100m
200m
500m
1
2
5
0.0001
10
100m
200m
500m
Output Voltage (Vrms)
1
2
5
10
Output Voltage (Vrms)
THD+N vs. Output Voltage
10
1
THD+N vs. Frequency
1
VDD = 5V, RL = 100kΩ,
f = 1kHz
VDD = 5V, RL = 100kΩ
VO = 2Vrms
THD + N (%)
THD + N (%)
0.1
0.1
0.01
0.01
Left_Cyan Right_Green
0.001
0.001
0.0001
100m
200m
500m
1
2
5
10
Output Voltage (Vrms)
0.0001
20
50
100
200
500
1k
2k
5k
10k
20k
Frequency (Hz)
FFT vs. Frequency
+0
-20
VDD = 5V, RL = 100kΩ,
VO = 3mVrms
FFT (dBr)
-40
-60
-80
-100
-120
-140
-160
2k
4k
6k
8k
10k
12k
14k
16k 18k
20k
22k
24k
Frequency (Hz)
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
5
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
TYPICAL PERFORMANCE CHARACTERISTICS (continued)
VDD = 3.3V, TA = +25℃, RL = 2.5kΩ, CPUMP = CPVSS = 1µF, CIN = 10µF, RIN = 10kΩ, RFB = 20kΩ, unless otherwise noted.
Crosstalk vs. Frequency
Crosstalk vs. Frequency
-20
VDD = 3.3V, RL = 2.5kΩ
-40
-40
-60
-60
Crosstalk (dB)
Crosstalk (dB)
-20
-80
Left to Right_Cyan
Right to Left_Green
-100
-120
VDD = 5V, RL = 2.5kΩ
-80
Right to Left_Cyan
Left to Right_Green
-100
-120
-140
20
50
100 200
500
1k
2k
5k
10k
20k
50k 100k
Frequency (Hz)
-140
20
50
100 200
500
1k
2k
5k
10k 20k
50k 100k
Frequency (Hz)
Supply Current vs. Supply Voltage
14
VIN = 0V
No Load
Supply Current (mA)
12
10
8
6
4
2
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
Supply Voltage (V)
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
6
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
TYPICAL APPLICATION CIRCUIT
RFB
LEFT
OUTPUT
C1
R1
Supply
C2
Line
Driver
PGND
CP
C1
UVP
RFB
OUTL
R1
RIN
-INL
CIN
CBYP
1μF
PVDD
RIN
+INL
LEFT
INPUT
+
CIN
Short Circuit
Protection
CPUMP
1μF
+
RIGHT
INPUT
-
RIN
R1
C2
CIN
RIN
C1
R1
RFB
10kΩ
RIGHT
OUTPUT
CN
PVSS
Bias
Circuitry
EN
OUTR
-INR
C1
+INR
RFB
CIN
SGND
Click and
Pop
Suppression
Line
Driver
CPVSS
1μF
To External Power
Supply or Control I/O
NOTES:
1. In order to get good performance, it’s important to select the right CPUMP, CPVSS and CBYP in application. All tests
are performed with circuit set up with X5R and X7R capacitors. Capacitors having high dissipative loss, such as Y5V
capacitor, may cause performance degradation and unexpected system behavior.
2. A 10kΩ resistor is recommended to be put between EN pin and external power supply or control I/O.
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
7
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
APPLICATION INFORMATION
Decoupling Capacitors
The SGM8903 is a capless line driver amplifier that requires adequate power supply decoupling to ensure that the
noise and total harmonic distortion (THD) are low. A good low equivalent-series-resistance (ESR) ceramic capacitor,
typically 1µF, placed as close as possible to the device VDD lead, works best. Placing this decoupling capacitor close
to the SGM8903 is important for the performance of the amplifier. For filtering lower frequency noise signals, a 10µF
or larger capacitor placed near the audio power amplifier would also help, but it is not required in most applications
because of the high PSRR of this device.
Gain Setting Resistors Ranges
The gain setting resistors, RIN and RFB, must be chosen so that noise, stability and input capacitor size of the
SGM8903 are kept within acceptable limits. Voltage gain is defined as RFB divided by RIN.
Selecting values that are too low demands a large input AC coupling capacitor, CIN. Selecting values that are too
high increases the noise of the amplifier. Table 1 lists the recommended resistor values for different gain settings.
Table 1. Recommended Resistor Values
INPUT RESISTOR
VALUE, RIN
FEEDBACK RESISTOR
VALUE, RFB
DIFFERENTIAL INPUT
GAIN
INVERTING
INPUT GAIN
NON INVERTING
INPUT GAIN
22kΩ
22kΩ
1.0V/V
-1.0V/V
2.0V/V
20kΩ
30kΩ
1.5V/V
-1.5V/V
2.5V/V
33kΩ
68kΩ
2.1V/V
-2.1V/V
3.1V/V
10kΩ
100kΩ
10.0V/V
-10.0V/V
11.0V/V
CIN
-IN
RIN
CIN
RFB
_
Differential
Input
+IN
CIN
_
Inverting
+
RIN
RFB
RIN
-IN
+
RFB
Figure 1. Differential Input
Figure 2. Inverting
CX
RIN
RFB
_
Non
Inverting
+IN
CIN
+
RX
Figure 3. Non-Inverting
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
8
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
APPLICATION INFORMATION (continued)
Input-Blocking Capacitors
DC input-blocking capacitors are required to be added in series with the audio signal into the input pins of the
SGM8903. These capacitors block the DC portion of the audio source and allow the SGM8903 inputs to be properly
biased to provide maximum performance. The input-blocking capacitors also limit the DC-gain to one, limiting the
DC-offset voltage at the output.
These capacitors form a high-pass filter with the input resistor, RIN. The cutoff frequency is calculated using
Equation 1. For this calculation, the capacitance used is the input-blocking capacitor and the resistance is the input
resistor chosen from Table 1, then the frequency and/or capacitance can be determined when one of the two values
are given.
fc I N =
1
1
or CI N =
2πfc INR IN
2πR IN C IN
(1)
Using the SGM8903 as 2nd-Order Filter
Several audio DACs used today require an external low-pass filter to remove out of band noise. This is possible with
the SGM8903 as it can be used like a standard OPAMP.
Several filter topologies can be implemented both single-endedly and differentially. In Figure 4, a Multi Feedback
(MFB), with differential input and single-ended input is shown.
An AC coupling capacitor to remove DC-content from the source is shown. It serves to block any DC-content from
the source and lowers the DC-gain to one, helping reducing the output DC-offset to minimum.
RFB
CIN
-IN
RIN
RFB
R1
CIN
_
C1
-IN
RIN
_
C2
C1
CIN
RIN
C1
C2
+
+IN
R1
+
R1
RFB
Figure 4. 2nd-Order Active Low Pass Filter
The resistor values should be kept low to obtain low noise, but should also be high enough to get a small size AC
coupling cap. Using 5.6kΩ for the resistors, C1 = 220pF, and C2 = 470pF, an SNR of 114dB can be achieved with a
10μF input AC coupling capacitor.
Pop-Free Power-Up
Pop-free power-up is ensured by keeping the SD (EN) (shutdown pin) low during power supply ramp up and down.
The EN pin should be kept low until the input AC coupling capacitors are fully charged before asserting the EN pin
high. This way proper precharge of the AC coupling is performed, and pop-free power-up is achieved. Figure 5
illustrates the preferred sequence.
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
9
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
APPLICATION INFORMATION (continued)
Supply
SD
Supply Ramp
Time for AC coupling
capacitors to charge
Figure 5. Power-Up Sequence
External Under-Voltage Detection
External under-voltage detection can be used to mute/shut down the SGM8903 before an input device can generate
a pop.
The threshold seen at the UVP pin is 1.13V. A hysteresis is introduced with a resistive divider, where thresholds for
startup and shutdown are determined respectively as follows:
Startup Threshold: VUDPR = 1.13V × (R11 + R12) / R12
Shutdown Threshold: VUDPF = 1.13V × (R11+R12) / R12 - 4.8μA × (R13 + R11 || R12) × (R11 + R12) / R12
Hysteresis: 4.8μA × (R13 + R11 || R12) × (R11 + R12) / R12
The R13 is optional. If the R13 is not used, the UVP pin connects to the divider center tap directly.
VSUP_MO
R11
R13
UVP pin 11
R12
Capacitive Load
The SGM8903 has the ability to drive large capacitive load up to 220pF directly, and larger capacitive loads can be
accepted by adding a series resistor of 47Ω or larger.
Gain-Setting Resistors
The gain setting resistors, RIN and RFB, must be placed close to the input pins to minimize the capacitive loading on
these pins and to ensure maximum stability of the SGM8903.
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
10
Capless 3Vrms Line Driver
with Adjustable Gain
SGM8903
APPLICATION INFORMATION (continued)
PCB Layout Guide
+INR
1
14
+INL
-INR
2
13
-INL
OUTR
3
12
OUTL
SGND
4
11
UVP
EN
5
10
PGND
SGM8903
PVSS
6
9
PVDD
CN
7
8
CP
0.1μF
VDD
TSSOP-14
NOTE: 0.1μF decoupling capacitor must be close to PGND and PVDD pins; capacitor can be connected between PVDD and
PGND pins directly and then connect PGND pin to GND layer.
The reference PCB layout is shown in below:
Zoomed in:
SG Micro Corp
www.sg-micro.com
DECEMBER 2016
11
PACKAGE INFORMATION
PACKAGE OUTLINE DIMENSIONS
TSSOP-14
D
E
E1
5.94
1.78
e
b
0.42
0.65
RECOMMENDED LAND PATTERN (Unit: mm)
L
A
A1
θ
A2
Symbol
c
H
Dimensions
In Millimeters
MIN
MAX
Dimensions
In Inches
MIN
MAX
1.200
0.047
A
A1
0.050
0.150
0.002
0.006
A2
0.800
1.050
0.031
0.041
b
0.190
0.300
0.007
0.012
c
0.090
0.200
0.004
0.008
D
4.860
5.100
0.191
0.201
E
4.300
4.500
0.169
0.177
E1
6.250
6.550
0.246
e
L
0.650 BSC
0.500
H
θ
SG Micro Corp
www.sg-micro.com
0.700
0.02
7°
1°
0.25 TYP
1°
0.258
0.026 BSC
0.028
0.01 TYP
7°
TX00019.001
PACKAGE INFORMATION
TAPE AND REEL INFORMATION
REEL DIMENSIONS
TAPE DIMENSIONS
P2
W
P0
Q1
Q2
Q1
Q2
Q1
Q2
Q3
Q4
Q3
Q4
Q3
Q4
B0
Reel Diameter
K0
A0
P1
Reel Width (W1)
DIRECTION OF FEED
NOTE: The picture is only for reference. Please make the object as the standard.
KEY PARAMETER LIST OF TAPE AND REEL
Reel
Diameter
Reel Width
W1
(mm)
A0
(mm)
B0
(mm)
K0
(mm)
P0
(mm)
P1
(mm)
P2
(mm)
W
(mm)
Pin1
Quadrant
TSSOP-14
13″
12.4
6.95
5.60
1.20
4.0
8.0
2.0
12.0
Q1
SG Micro Corp
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TX10000.000
DD0001
Package Type
PACKAGE INFORMATION
CARTON BOX DIMENSIONS
NOTE: The picture is only for reference. Please make the object as the standard.
KEY PARAMETER LIST OF CARTON BOX
Length
(mm)
Width
(mm)
Height
(mm)
Pizza/Carton
13″
386
280
370
5
SG Micro Corp
www.sg-micro.com
DD0002
Reel Type
TX20000.000
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