Global Mixed-mode Technology Inc.
G1426
2.2W Stereo Audio Amplifier
Features
Depop Circuitry Integrated Output Power at 10% THD+N, VDD=5V --2.2W/CH (typical) into a 4Ω Load Output Power at 1% THD+N, VDD=5V --2W/CH (typical) into a 4Ω Load --1.2W/CH (typical) into a 8Ω Load Bridge-Tied Load (BTL) Shutdown Control Available Thermal protection Surface-Mount Power Package 20-Pin TSSOP-P
General Description
The G1426 is a stereo audio power amplifier in 20pin TSSOP package. It can deliver 2W continuous RMS power into 4Ω load per channel in Bridge-Tied Load (BTL) mode at 5V supply voltage under 1% THD. To simplify the audio system design in the notebook application, The G1426 supports the Bridge-Tied Load (BTL) mode for driving the speakers. For the low current consumption applications, the SHDN mode is supported to disable the G1426 when it is idle. The current consumption can be further reduced to below 2µA.
Applications
Stereo Power Amplifiers for Notebooks or Desktop Computers Multimedia Monitors Stereo Power Amplifiers for Portable Audio Systems
Ordering Information
ORDER MARKING NUMBER
G1426D5X G1426F2X G1426 G1426
TEMP. RANGE
PACKAGE
-40°C to +85°C TSSOP-20L -40°C to +85°C TSSOP-20L (FD)
Note: X Specify the packing type U: Tape & Reel T: Tube * TSSOP-20L (FD): Thermal Pad
Pin Configuration
G1426
SHUTDOWN GND/HS +OUTA VDD -OUTA -INA GND/HS +INA NC 1 2 3 4 5 6 7 8 9 20 19 18 17 16 15 14 13 12 11 GND/HS GND/HS GND/HS +OUTB VDD -OUTB -INB BYPASS +INB NC NC
Thermal Pad
GND/HS 10
Top View 20Pin TSSOP
Bottom View
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Absolute Maximum Ratings
Supply Voltage, VCC…………………..…...…….……...6V Operating Ambient Temperature Range TA…….…………………………….……….-40°C to +85°C Maximum Junction Temperature, TJ…..……….….150°C Storage Temperature Range, TSTG….….-65°C to+150°C Soldering Temperature, 10seconds, TS……….……260°C
G1426
Power Dissipation (1) TA ≤ 25°C………………………………………….2.7W TA ≤ 70°C………………………………………….1.7W TA ≤ 85°C………………….………………………1.4W Electrostatic Discharge, VESD Human body mode..…………………….-3000 to 3000(2)
Note: (1) : Recommended PCB Layout (2) : Human body model : C = 100pF, R = 1500Ω, 3 positive pulses plus 3 negative pulses
Electrical Characteristics
DC Electrical Characteristics, VDD = 5.0V, TA=+25°C, unless otherwise noted PARAMETER
Supply Current DC Differential Output Voltage IDD in Shutdown
SYMBOL
IDD VO(DIFF) ISD
CONDITION
VDD = 5V VDD = 5V,Gain = 2 VDD = 5V
MIN
-
TYP
8.5 5 0.1
MAX
15 50 2
UNIT
mA mV µA
(AC Operation Characteristics, VDD = 5.0V, TA=+25°C, RL = 4Ω, unless otherwise noted) PARAMETER
Output power (each channel) see Note
SYMBOL
P(OUT)
CONDITION
THD = 1%, BTL, RL = 4Ω THD = 1%, BTL, RL = 8Ω THD = 10%, BTL, RL = 4Ω THD = 10%, BTL, RL = 8Ω PO = 1.6W, BTL, RL = 4Ω PO = 1W, BTL, RL = 8Ω VI = 1V, RL = 10KΩ, G = 1 G = 10, THD = 1% RL = 4Ω, Open Load f = 120Hz f = 1kHz PO = 500mW, BTL Output noise voltage
MIN
-
TYP
2 1.25 2.5 1.6 300 100 10 20 65 75 80 2 90 55
MAX
-
UNIT
W
Total harmonic distortion plus noise Maximum output power bandwidth Phase margin Power supply ripple rejection Channel-to-channel output separation Input impedance Signal-to-noise ratio Output noise voltage
THD+N BOM PSRR ZI Vn
m% kHz ° dB dB MΩ dB µV (rms)
Note :Output power is measured at the output terminals of the IC at 1kHz.
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Global Mixed-mode Technology Inc.
Pin Description
PIN
1 2,7,10,19,20 3 4,17 5 6 8 9 11 12 13 14 15 16 18
G1426
NAME
SHUTDOWN GND/HS +OUTA VDD -OUTA -INA +INA NC NC NC +INB BYPASS -INB -OUTB +OUTB
I/O
I high, IDD is below 2µA.
FUNCTION
Shutdown mode control signal input, places entire IC in shutdown mode when held Ground connection for circuitry, directly connected to thermal pad.
O O I I I I I I O O
A channel + output Supply voltage for circuitry. A channel - output A channel input signal A channel positive input of OPAMP, biasing DC operation of OPAMP NC NC NC B channel positive input of OPAMP, biasing DC operation of OPAMP Connect to voltage divider for internal mid-supply bias. B channel input signal B channel - output B channel + output
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Typical Characteristics
Table of Graphs FIGURE
THD +N Total harmonic distortion plus noise Vn Output noise voltage Supply ripple rejection ratio Crosstalk Closed loop response IDD Supply current PO Output power PD Power dissipation vs Frequency vs Output power vs Frequency vs Frequency vs Frequency vs Frequency vs supply voltage vs supply voltage vs Load resistance vs Output power 2,4,6,9,11 1,3,5,7,8,10 13 12 14 17 15 16 18 19,20
G1426
TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY
10 5
10
20kHz
5
2 1 0.5 % 0.2 0.1 0.05
2 1
Po=1.8W
1kHz
%
0.5
0.2
20Hz
0.02 0.01 3m
VDD=5V RL=3Ω BTL Av=-2V/V
20m 50m 100m W 200m 500m 1 2 3
0.1 0.05
0.02 0.01 20
VDD=5V RL=3Ω BTL Av=-2V/V
50 100 200 500 Hz 1k 2k 5k 10k 20k
5m
10m
Figure 1
Figure 2
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Global Mixed-mode Technology Inc.
G1426
TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY
10 5
10 5
2 1 0.5 % 0.2 0.1 0.05
20kHz
Av=-4V/V Av=-2V/V
2 1 0.5 % 0.2 0.1 0.05
1kHz
20Hz
0.02 0.01 3m
VDD=5V RL=4Ω BTL Av=-2V/V
20m 50m 100m W 200m 500m 1 2 3
Av=-1V/V
0.02 0.01 20
VDD=5V RL=4Ω BTL Po=2W
500 Hz 1k 2k 5k 10k 20k
5m
10m
50
100
200
Figure 3
Figure 4
TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY
10 5
10
20kHz
2 1 0.5 % 0.2 0.1 0.05
VDD=5V RL=8Ω BTL Av=-2V/V
5
2 1 0.5
VDD=5V RL=8Ω BTL Po=1W Av=-2V/V
Av=-4V/V
1kHz
% 0.2 0.1
20Hz
0.05
0.02 0.01 2m
0.02 0.01 20
Av=-1V/V
50 100 200 500 Hz 1k 2k 5k 10k 20k
5m
10m
20m
50m W
100m
200m
500m
1
2
Figure 5
Figure 6
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Global Mixed-mode Technology Inc.
G1426
TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER
TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER
10 5
10
2 1 0.5 % 0.2 0.1 0.05
20kH
VDD=5V RL=32Ω BTL Av=-2V/V
5
20kHz
2 1
1kHz
0.5 % 0.2
1kHz
0.1 0.05
0.02 0.01 1m
20Hz
2m 5m 10m 20m W 50m 100m 200m 500m 1
0.02 0.01 1m
VDD=3.3V RL=4Ω BTL Av=-2V/V
2m 5m 10m 20m W
20Hz
50m
100m
200m
500m
1
Figure 7
Figure 8
TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY
TOTAL HARMONIC DISTORTION PLUS NOISE vs OUTPUT POWER
10 5
10
2 1 0.5 % 0.2 0.1 0.05
VDD=3.3V RL=4Ω BTL Po=0.75W
5
Av=-4V/V
2 1 0.5
20kHz
Av=-2V/V
% 0.2 0.1 0.05
1kHz
0.02 0.01 20
Av=-1V/V
50 100 200 500 Hz 1k 2k 5k 10k 20k
0.02 0.01 1m
VDD=3.3V RL=8Ω BTL Av=-2V/V
2m 5m 10m 20m
20Hz
50m W
100m
200m
500m
1
Figure 9
Figure 10
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Global Mixed-mode Technology Inc.
G1426
TOTAL HARMONIC DISTORTION PLUS NOISE vs FREQUENCY
SUPPLY RIPPLE REJECTION RATIO vs FREQUENCY
10 5
+0 -10
-5
2 1 0.5 % 0.2 0.1 0.05
VDD=3.3V RL=8Ω BTL Po=0.45W Av=-2V/V
-15 -20 -25
Av=-4V/V
d B
-30 -35 -40 -45 -50 -55 -60 -65 -70 -75 -80 -85
VDD=5V RL=4Ω CB=4.7µF Vripple=0.5Vpp
BTL Mode
0.02 0.01 20
Av=-1V/V
50 100 200 500 Hz 1k 2k 5k 10k 20k
-90 -95 -100 20 50 100 200 500 Hz 1k 2k 5k 10k 20k
Figure 11
Figure 12
OUTPUT NOISE VOLTAGE vs FREQUENCY
100u 90u 80u 70u 60u 50u 40u
CHANNEL SEPARATION
-30 -35 -40 -45 -50 -55
VDD=5V Po=1.5W RL=4Ω BTL Channel A to B
V
30u
VDD=5V RL=4Ω BTL Mode 20kHz
-60 d B -65 -70 -75
20u
-80 -85 -90 -95
Channel B to A
50 100 200 500 Hz 1k 2k 5k 10k 20k
10u 20
50
100
200
500 Hz
1k
2k
5k
10k
20k
-100 20
Figure 13
Figure 14
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Global Mixed-mode Technology Inc.
G1426
SUPPLY CURRENT vs SUPPLY VOLTAGE
9 8.5 3 2.5
OUTPUT POWER vs SUPPLY VOLTAGE
THD+N=1% BTL Each Channel RL=4Ω RL=3Ω
Supply Current(mA)
Output Power(W)
8 7.5 7 6.5 6 5.5 5 3 3.5
Stereo BTL
2
1.5 1
RL=8Ω
0.5 0 4 4.5 5 5.5 6 2.5 3.5 4.5 5.5 6.5
Supply Voltage(V)
Supply Voltage(V)
Figure 15
Figure 16
OPEN LOOP RESPONSE
Figure 17
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Global Mixed-mode Technology Inc.
G1426
OUTPUT POWER vs LOAD RESISTANCE
2.5 1.8
POWER DISSIPATION vs OUTPUT POWER
1.6 1.4
2
Power Dissipation
Output Power(W)
THD+N=1% BTL Each Channel
RL=3Ω
1.2 1 0.8 0.6 0.4
1.5
RL=4Ω
1
VDD=5V
0.5
RL=8Ω
VDD=3.3V
0 0 5 10 15 20 25 30 35
0.2 0 0 0.5 1 1.5
VDD=5V BTL Each Channel
2
2.5
Load Resistance(Ω)
Po-Output Power(W)
Figure 18
Figure 19
POWER DISSIPATION vs OUTPUT POWER
0.8 0.7
Recommended PCB Layout Unit:mm
RL=3Ω
Power Dissipation(W)
0.6 0.5 0.4 0.3 0.2 0.1 0
0 0.2 0.4 0.6 0.8 1 1.2
RL=4Ω
RL=8Ω
VDD=3.3V BTL Each Channel
Po-Output Power(W)
Figure 20
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Block Diagram
VDD CS + 1µF TANT 6 8 -IN A +IN A
G1426
Audio Input C1 1µF
RF 20kΩ R1 20kΩ
4,17 Amp A1
- OUT A 5 20kΩ 20kΩ +OUT A 3 RL 8Ω
+ 20kΩ 50kΩ
14 + CB 0.33µF Audio Input C1 1µF
Bypass
Amp A2
VDD/2
+
50kΩ R1 20kΩ RF 20kΩ 9,11,12 NC 15 13 -IN B +IN B Amp A1
- OUT B 16 20kΩ 20kΩ Amp A2
+ 20kΩ
RL 8Ω 18
+OUT B
+ 1 Shutdown GND 2,7,10,19,20
Application Circuits
4,17 6 8 -IN A +IN A VDD AmpA1
- OUT A 5 20kΩ 20kΩ +OUT A 3
+ 20kΩ 50kΩ
14
Bypass
AmpA2
VDD/2
+
50kΩ 15 13 -IN B +IN B AmpA1
- OUT B 16 20kΩ 20kΩ
+ 20kΩ
9,11,12
NC
Amp A2
+OUT B
18
+ 1 Shutdown GND 2,7,10,19,20
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Application Information
Bridged-Tied Load Mode Operation G1426 has two linear amplifiers to drive both ends of the speaker load in Bridged-Tied Load (BTL) mode operation. Figure 1 shows the BTL configuration. The differential driving to the speaker load means that when one side is slewing up, the other side is slewing down, and vice versa. This configuration in effect will double the voltage swing on the load as compared to a ground reference load. In BTL mode, the peak-to-peak voltage VO(PP) on the load will be two times than a ground reference configuration. The voltage on the load is doubled, this will also yield 4 times output power on the load at the same power supply rail and loading. Another benefit of using differential driving configuration is that BTL operation cancels the dc offsets, which eliminates the dc coupling capacitor that is needed to cancelled dc offsets in the ground reference configuration. Low-frequency performance is then limited only by the input network and speaker responses. Cost and PCB space can be minimized by eliminating the dc coupling capacitors. Optimizing DEPOP Operation
G1426
Circuitry has been implemented in G1426 to minimize the amount of popping heard at power-up and when coming out of shutdown mode. Popping occurs whenever a voltage step is applied to the speaker and making the differential voltage generated at the two ends of the speaker. To avoid the popping heard, the bypass capacitor should be chosen promptly, 1/(CBx100kΩ) ≦ 1/(CI*(RI+RF)). Where 100kΩ is the output impedance of the mid-rail generator, CB is the mid-rail bypass capacitor, CI is the input coupling capacitor, RI is the input impedance, RF is the gain setting impedance which is on the feedback path. CB is the most important capacitor. Besides it is used to reduce the popping, CB can also determine the rate at which the amplifier starts up during startup or recovery from shutdown mode. De-popping circuitry of G1426 is shown on Figure 2. The PNP transistor limits the voltage drop across the 225kΩ by slewing the internal node slowly when power is applied. At start-up, the voltage at BYPASS capacitor is 0. The PNP is ON to pull the mid-point of the bias circuit down. So the capacitor sees a lower effective voltage, and thus the charging is slower. This appears as a linear ramp (while the PNP transistor is conducting), followed by the expected exponential ramp of an R-C circuit.
VDD VDD
Vo(PP) RL 2xVo(PP) -Vo(PP)
VDD
VDD
Figure 1
Vo(PP)+VDD/2 RL VDD/2 VDD/2 Vo(PP)
SHUTDOWN Mode Operations G1426 implements the shutdown mode operations to reduce supply current, IDD, to the absolute minimum level during nonuse periods for battery-power conservation. When the shutdown pin (pin 1) is pulled high, all linear amplifiers will be deactivated to mute the amplifier outputs. And G1426 enters an extra low current consumption state, IDD is smaller than 2µA. Shutdown pin should never be left unconnected, this floating condition will cause the amplifier operations unpredictable.
Figure 2
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Package Information
D
C
G1426
L
E1 E1 E
θ
A2 A1 e b
A
y
TSSOP-20L Package NOTE: 1. Package body sizes exclude mold flash protrusions or gate burrs 2. Tolerance ±0.1mm unless otherwise specified 3. Coplanarity : 0.1mm 4. Controlling dimension is millimeter. Converted inch dimensions are not necessarily exact. 5. Follow JEDEC MO-153 SYMBOL
A A1 A2 b C D E E1 e L y θ
MIN.
----0.05 0.80 0.19 0.09 6.40 ----4.30 ----0.45 ----0°
DIMENSION IN MM NOM.
--------1.00 --------6.50 6.40 4.40 0.65 0.60 ---------
MAX.
1.20 0.15 1.05 0.30 0.20 6.60 ----4.50 ----0.75 0.10 8°
MIN.
----0.002 0.031 0.007 0.004 0.252 ----0.169 ----0.018 ----0°
DIMENSION IN INCH NOM.
--------0.039 --------0.256 0.252 0.173 0.026 0.024 ---------
MAX.
0.048 0.006 0.041 0.012 0.008 0.260 ----0.177 ----0.030 0.004 8°
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D
C
G1426
L
D1 E1 E
E2
Note 5
θ
A2 A1 e b
A
y
TSSOP-20L (FD) Package NOTE: 1. Package body sizes exclude mold flash protrusions or gate burrs 2. Tolerance ±0.1mm unless otherwise specified 3. Coplanarity : 0.1mm 4. Controlling dimension is millimeter. Converted inch dimensions are not necessarily exact. 5. Die pad exposure size is according to lead frame design. 6. Follow JEDEC MO-153 SYMBOL
A A1 A2 b C D E E1 e L y θ D1 E2
MIN.
0.80 0.00 0.80 0.19 0.09 6.40 ----4.30 ----0.45 ----0° 3.90 2.30
DIMENSION IN MM NOM.
--------1.00 --------6.50 6.40 4.40 0.65 0.60 -----------------
MAX.
1.15 0.10 1.05 0.30 0.20 6.60 ----4.50 ----0.75 0.10 8° 4.28 2.78
MIN.
0.031 0.000 0.031 0.007 0.004 0.252 ----0.169 ----0.018 ----0° 0.153 0.091
DIMENSION IN INCH NOM.
--------0.039 --------0.256 0.252 0.173 0.026 0.024 -----------------
MAX.
0.045 0.004 0.041 0.012 0.008 0.260 ----0.177 ----0.030 0.004 8° 0.168 0.109
Taping Specification
Feed F eed Direction Typical TSSOP Package Orientation
GMT Inc. does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and GMT Inc. reserves the right at any time without notice to change said circuitry and specifications.
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