Global Mixed-mode Technology Inc.
G1420
2W Stereo Audio Amplifier
Features
Depop Circuitry Integrated Output Power at 1% THD+N, VDD=5V --1.8W/CH (typical) into a 4Ω Load --1.2W/CH (typical) into a 8Ω Load Bridge-Tied Load (BTL), Single-Ended (SE) Stereo Input MUX Mute and Shutdown Control Available Surface-Mount Power Package 24-Pin TSSOP-P
General Description
G1420 is a stereo audio power amplifier in 24pin TSSOP thermal pad package. It can drive 1.8W continuous RMS power into 4Ω load per channel in Bridge-Tied Load (BTL) mode at 5V supply voltage. Its THD is smaller than 1% under the above operation condition. To simplify the audio system design in the notebook application, G1420 supports the Bridge-Tied Load (BTL) mode for driving the speakers, Single-End (SE) mode for driving the headphone. G1420 can mute the output when Mute-In is activated. For the low current consumption applications, the SHDN mode is supported to disable G1420 when it is idle. The current consumption can be further reduced to below 5µA. G1420 also supports two input paths, that means two different gain loops can be set in the same PCB and choosing either one by setting HP/ LINE pin. It enhances the hardware designing flexibility.
Applications
Stereo Power Amplifiers for Notebooks or Desktop Computers Multimedia Monitors Stereo Power Amplifiers for Portable Audio Systems
Ordering Information
ORDER NUMBER
G1420F31U Note: F3: TSSOP-24 (FD) U: Tape & Reel
ORDER NUMBER (Pb free)
G1420F31Uf
TEMP. RANGE
-40°C to +85°C
PACKAGE
TSSOP-24 (FD)
Pin Configuration
G1420
GND/HS TJ LOUT+ LLINEIN LHPIN LBYPASS LVDD SHUTDOWN MUTE OUT 1 2 3 4 5 6 7 8 9 24 23 22 21 20 19 18 17 16 15 14 13 GND/HS NC ROUT+ ROUT+ RLINEIN RHPIN RBYPASS RVDD NC HP/LINE ROUTSE/BTL GND/HS 14
Thermal Pad
LOUT- 10 MUTE IN 11 GND/HS 12
Top View TSSOP-24 (FD)
Bottom View
Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation.
Ver: 1.5 Aug 04, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
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 Reflow Temperature (soldering, 10sec)…………260°C
G1420
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) (2)
: Recommended PCB Layout : Human body model : C = 100pF, R = 1500Ω, 3 positive pulses plus 3 negative pulses
Electrical Characteristics
DC Electrical Characteristics, TA=+25°C PARAMETER
Supply Current
SYMBOL
IDD VDD = 5V
CONDITIONS
VDD =3.3V Stereo BTL Stereo SE Stereo BTL
MIN
---------------
TYP
7 3.5 8 4 5 8 4 2
MAX
13 8 16 10 50 16 10 5
UNIT
mA
DC Differential Output Voltage Supply Current in Mute Mode IDD in Shutdown
VO(DIFF) IDD(MUTE) ISD
Stereo SE VDD = 5V,Gain = 2 Stereo BTL Stereo SE
mV mA µA
VDD = 5V VDD = 5V
(AC Operation Characteristics, VDD = 5.0V, TA=+25°C, RL = 4Ω, unless otherwise noted) PARAMETER SYMBOL CONDITIONS
THD = 1%, BTL, RL = 4Ω THD = 1%, BTL, RL = 8Ω THD = 10%, BTL, RL = 4Ω Output power (each channel) see Note P(OUT) THD = 10%, BTL, RL = 8Ω THD = 1%, SE, RL = 4Ω THD = 1%, SE, RL = 8Ω THD = 10%, SE, RL = 4Ω THD = 10%, SE, RL L = 8Ω THD = 0.5%, SE, RL = 32Ω PO = 1.6W, BTL, RL = 4Ω Total harmonic distortion plus noise THD+N PO = 1W, BTL, RL = 8Ω PO = 75mW, SE, RL = 32Ω VI = 1V, RL = 10KΩ, G = 1 G = 1, THD = 1% RL = 4Ω, Open Load f = 120Hz f = 1kHz
MIN
-----------------------------------------------
TYP
1.8 1.12 2 1.4 500 320 650 400 90 500 150 20 10 20 60 75 85 82 80 85 2 90 55
MAX
-----------------------------------------------
UNIT
W
mW
m%
Maximum output power bandwidth Phase margin Power supply ripple rejection Mute attenuation Channel-to-channel output separation Line/HP input separation BTL attenuation in SE mode Input impedance Signal-to-noise ratio Output noise voltage
BOM PSRR
kHz ° dB dB dB dB dB MΩ dB µV (rms)
ZI PO = 500mW, BTL Vn Output noise voltage
Note :Output power is measured at the output terminals of the IC at 1kHz.
Ver: 1.5 Aug 04, 2005
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Global Mixed-mode Technology Inc.
(AC Operation Characteristics, VDD = 3.3V, TA=+25°C, RL = 4Ω, unless otherwise noted) PARAMETER SYMBOL CONDITIONS
THD = 1%, BTL, RL = 4Ω THD = 1%, BTL, RL = 8Ω THD = 10%, BTL, RL = 4Ω THD = 10%, BTL, RL = 8Ω THD = 1%, SE, RL = 4Ω THD = 1%, SE, RL = 8Ω THD = 10%, SE, RL = 4Ω THD = 10%, SE, RL L = 8Ω THD = 0.5%, SE, RL = 32Ω PO = 1.6W, BTL, RL = 4Ω PO = 1W, BTL, RL = 8Ω PO = 75mW, SE, RL = 32Ω VI = 1V, RL = 10KΩ, G = 1 G = 1, THD 1% RL = 4Ω, Open Load f = 120Hz f = 1kHz
G1420
MIN
-----------------------------------------------
TYP
0.8 0.5 1 0.6 230 140 290 180 43 270 100 20 10 20 60 75 85 80 80 85 2 90 55
MAX
-----------------------------------------------
UNIT
W
Output power (each channel) see Note
P(OUT)
mW
Total harmonic distortion plus noise Maximum output power bandwidth Phase margin Power supply ripple rejection Mute attenuation Channel-to-channel output separation Line/HP input separation BTL attenuation in SE mode Input impedance Signal-to-noise ratio Output noise voltage
THD+N BOM PSRR
m% kHz ° dB dB dB dB dB MΩ dB µV (rms)
ZI Vn PO = 500mW, BTL Output noise voltage
Note :Output power is measured at the output terminals of the IC at 1kHz.
Ver: 1.5 Aug 04, 2005
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Global Mixed-mode Technology Inc.
Typical Characteristics
THD +N Total Harmonic Distortion Plus Noise Output Noise Voltage Vn Supply Ripple Rejection Ratio Crosstalk Closed Loop Response Supply Current Output Power Power Dissipation vs Output Power vs Frequency vs Frequency vs Frequency vs Frequency vs Frequency vs Supply Voltage vs Load Resistance vs Load Resistance vs Output Power
G1420
FIGURE
Table of Graphs
1,3,6,9,10,13,16,19,22,25,28,31 2,4,5,7,8,11,12,14,15,17,18,20,21,23,24,26,27,29,30,32,33 34,35 36,37 38,39,40,41 42,43,44,45 46 47,48 49,50 51,52,53,54
IDD PO PD
Total Harmonic Distortion Plus Noise vs Output Power
10 5 10 5
Total Harmonic Distortion Plus Noise vs Output Frequency
20kHz
2 1 0.5 % 0.2 0.1 0 .05 2 1
Po=1.8W
1kHz
%
0.5
0.2 0.1
20 Hz
Po=1.5W
0 .02 0 .01 3m
VDD=5V RL=3Ω BTL
20m 5 0m 1 00m W 20 0m 500 m 1 2 3
0 .05
VDD=5V RL=3Ω BTL A v=-2V/V
0 .02 0 .01 20
5m
10m
50
10 0
2 00
5 00 Hz
1k
2k
5k
10 k
20k
Figure 1
Figure 2
Total Harmonic Distortion Plus Noise vs Output Power
10 5 10 5
Total Harmonic Distortion Plus Noise vs Output Frequency
A v=-4V/V
2 1
2 1 0.5 % 0.2 0.1 0 .05
20kHz
A v=-2V/V
1kHz
%
0.5
0.2 0.1
20 Hz
0 .02 0 .01 3m
VDD=5V RL=4Ω BTL
20m 5 0m 1 00m W 20 0m 500 m 1 2 3
A v=-1V/V
0 .05
0 .02 0 .01 20
VDD=5V RL=4Ω BTL Po=1.5W
1k 2k 5k 10 k 20k
5m
10m
50
10 0
2 00
5 00 Hz
Figure 3
Figure 4
Ver: 1.5 Aug 04, 2005
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Global Mixed-mode Technology Inc.
G1420
Total Harmonic Distortion Plus Noise vs Output Power
VDD=5V RL=8Ω BTL A v=-2V/V
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 10
2 1 0.5 % 0.2 0.1 0 .05
VDD=5V RL=4Ω BTL A v=-2V/V
5
Po=1.5W Po=0.25W
%
2 1 0.5
20kHz
0.2
1kHz
Po=0.75W
0.1 0 .05
0 .02 0 .01 20
0 .02 0 .01 3m
20Hz
5m 10m 20m 5 0m 1 00m W 20 0m 500 m 1 2 3
50
10 0
2 00
5 00 Hz
1k
2k
5k
10 k
20k
Figure 5
Figure 6
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 10
Total Harmonic Distortion Plus Noise vs Output Frequency
5
2 1 0.5 % 0.2 0.1 0 .05
VDD=5V RL=8Ω BTL A v=-2V/V Po=0.25W
Po=1W
2 1 0.5 % 0.2 0.1
VDD=5V RL=8Ω BTL Po=1W A v=-2V/V
A v=-4V/V
Po=0.5W
0 .05
0 .02 0 .01 20
0 .02 0 .01 20
Av=-1V/V
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
50
10 0
2 00
5 00 Hz
1k
2k
5k
10 k
20k
Figure 7
Figure 8
Total Harmonic Distortion Plus Noise vs Output Power
10 5 10 5
Total Harmonic Distortion Plus Noise vs Output Power
20kHz
2 1 0.5 % 0.2 0.1 0 .05 2 1
20kHz
1kHz
%
0.5
1kHz
0.2 0.1
0 .02 0 .01 1m
VDD=3.3V RL=3Ω BTL
2m 5m 1 0m
20Hz
0 .05
0 .02 0 .01 1m
VDD=3.3V RL=4Ω BTL
2m 5m 1 0m
20Hz
20 m W
50 m
10 0m
2 00 m
500 m
1
20 m W
50 m
10 0m
2 00 m
500 m
1
Figure 9
Figure 10
Ver: 1.5 Aug 04, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
G1420
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 10
Total Harmonic Distortion Plus Noise vs Output Frequency
5
2 1 0.5 % 0.2 0.1 0 .05
VDD=3.3V RL=4Ω BTL Po=0.65W
A v=-4V/V A v=-2V/V
2 1 0.5 % 0.2 0.1 0 .05
VDD=3.3V RL=4Ω BTL A v=-2V/V
Po=0.7W
Po=0.1W Po=0.35W
A v=-1V/V
0 .02 0 .01 20
0 .02 0 .01 20
50
10 0
2 00
5 00 Hz
1k
2k
5k
10k
20k
50
100
2 00
5 00 Hz
1k
2k
5k
10k
20k
Figure 11
Figure 12
Total Harmonic Distortion Plus Noise vs Output Power
10 5 10
Total Harmonic Distortion Plus Noise vs Output Frequency
5
2 1 0.5 % 0.2 0.1 0 .05
20kHz
VDD=3.3V RL=8Ω BTL
2 1 0.5
VDD=3.3V RL=8Ω BTL Po=0.4W A v=-2V/V
A v=-4V/V
1kHz
% 0.2 0.1 0.05
20Hz
0 .02 0 .01 1m 0.02 0.01 20
A v=-1V/V
2m
5m
10m
20 m W
50 m
10 0m
2 00m
500 m
1
50
10 0
200
500 Hz
1k
2k
5k
10 k
20k
Figure 13
Figure 14
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 10
Total Harmonic Distortion Plus Noise vs Output Power
5
2 1 0.5 % 0.2 0.1 0 .05
VDD=3.3V RL=8Ω BTL A v=-2V/V
2
VDD=5V RL=4Ω SE 20kHz
Po=0.4W
1 0.5
Po=0.1W
% 0.2 0.1 0.05
1kHz
Po=0.25W
0 .02 0 .01 20
100Hz
0.02 0.01 1m 20k
50
10 0
2 00
5 00 Hz
1k
2k
5k
10k
2m
5m
1 0m
20m W
50 m
10 0m
2 00 m
500 m
1
Figure 15
Figure 16
Ver: 1.5 Aug 04, 2005
TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
G1420
Total Harmonic Distortion Plus Noise vs Output Frequency
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 10
2 1 0.5 % 0.2 0.1 0 .05
VDD=5V RL=4Ω SE Po=0.5W
5
A v=-4V/V
2 1 0.5
VDD=5V RL=4Ω SE A v=-2V/V
Po=0.4W
A v=-2V/V
% 0.2 0.1 0 .05
Po=0.1W
A v=-1V/V
Po=0.25W
0 .02 0 .01 20
0 .02 0 .01 20
50
10 0
2 00
5 00 Hz
1k
2k
5k
10 k
20k
50
10 0
2 00
5 00 Hz
1k
2k
5k
10 k
20k
Figure 17
Figure 18
Total Harmonic Distortion Plus Noise vs Output Power
10 5 10
Total Harmonic Distortion Plus Noise vs Output Frequency
5
2 1 0.5 % 0.2 0.1 0 .05
VDD=5V RL=8Ω SE 20kHz
%
2 1 0.5
VDD=5V RL=8Ω SE Po=0.25W A v=-2V/V
0.2 0.1
1kHz 100Hz
2m 5m 1 0m 20 m W 50 m 10 0m 2 00 m 500 m 1
A v=-4V/V
0 .05
0 .02 0 .01 1m
0 .02 0 .01 20
A v=-1V/V
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
Figure 19
Figure 20
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 10
Total Harmonic Distortion Plus Noise vs Output Power
5 2 1 0.5 0.2 % 0.1 0 .05 0 .02
2 1 0.5 % 0.2 0.1 0 .05
VDD=5V RL=8Ω SE A v=-2 Po=0.05W
VDD=5V RL=32Ω SE 20kHz
20Hz
Po=0.1W Po=0.25W
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
0 .01 0.0 05 0.0 02 0.0 01 1m
0 .02 0 .01 20
1kHz
2m 5m 10 m W 20 m 50m 10 0m 2 00m
Figure 21
Figure 22
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Global Mixed-mode Technology Inc.
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 2 1 0.5 0.2 % 0.1 0 .05 0 .02 0 .01 0.0 05 0.0 02 0.0 01 20 % 10
G1420
Total Harmonic Distortion Plus Noise vs Output Frequency
VDD=5V RL=32Ω SE Po=75mW
5 2 1
VDD=5V RL=32Ω SE Po=25mW
Av=-4V/V
0.5 0.2 0.1 0 .05 0 .02 0 .01 0.0 05
A v=-2V/V
Po=50mW
A v=-1V/V
0.0 02 0.0 01 20 50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k 50 10 0 2 00 5 00 Hz 1k
Po=75mW
2k 5k 10 k 20k
Figure 23
Figure 24
Total Harmonic Distortion Plus Noise vs Output Power
10 5 10
Total Harmonic Distortion Plus Noise vs Output Frequency
5
2 1 0.5 % 0.2 0.1 0 .05
VDD=3.3V RL=4Ω ,SE A v=-2
20kHz
2 1 0.5 %
VDD=3.3V RL=4Ω SE Po=0.2W
A v=-4V/V
1kHz
0.2 0.1 0 .05
A v=-2V/V
0 .02 0 .01 1m
100Hz
2m 5m 1 0m 20 m W 50 m 10 0m 2 00 m 500 m 1
0 .02 0 .01 20
A v=-1V/V
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
Figure 25
Figure 26
Total Harmonic Distortion Plus Noise vs Output Frequency
10
Total Harmonic Distortion Plus Noise vs Output Power
10 5
RR
5
2 1 0.5 % 0.2 0.1 0 .05
VDD=3.3V RL=4Ω SE A v=-2
Po=50mW
2 1 0.5 %
VDD=3.3V RL=8Ω ,SE A v=-2 20kHz
Po=100mW
0.2 0.1 0 .05
1kHz
0 .02 0 .01 20
Po=150mW
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
0 .02 0 .01 1m
100Hz
2m 5m 10 m W 20 m 50m 10 0m 2 00m
Figure 27
Figure 28
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TEL: 886-3-5788833 http://www.gmt.com.tw
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Global Mixed-mode Technology Inc.
G1420
Total Harmonic Distortion Plus Noise vs Output Frequency
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 10 5
2 1 0.5 % 0.2 0.1 0 .05
VDD=3.3V RL=8Ω SE Po=100mW
2 1 0.5 % 0.2
VDD=3.3V RL=8Ω SE Po=25mW Po=50mW
A v=-4V/V
A v=-2V/V
0.1 0 .05
0 .02 0 .01 20
A v=-1V/V
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
0 .02 0 .01 20
Po=100mW
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
Figure 29
Figure 30
Total Harmonic Distortion Plus Noise vs Output Power
10 5 10
Total Harmonic Distortion Plus Noise vs Output Frequency
5 2
2 1 0.5 % 0.2 0.1 0 .05
VDD=3.3V RL=32Ω SE 20kHz
1kHz
1 0.5 0.2 % 0.1 0 .05 0 .02
VDD=3.3V RL=32Ω SE Po=30mW A v=-2V/V
A v=-4V/V
20Hz
0 .01 0.0 05
A v=-1V/V
0 .02 0 .01 1m
0.0 02 0.0 01 20
2m
5m
1 0m W
2 0m
50 m
1 00m
50
10 0
2 00
5 00 Hz
1k
2k
5k
10 k
20k
Figure 31
Figure 32
Total Harmonic Distortion Plus Noise vs Output Frequency
10 5 2 1 0.5 0.2 % 0.1 0 .05 0 .02 0 .01 0.0 05 0.0 02 0.0 01 20 V
Output Noise Voltage vs Frequency
10 0u 9 0u 8 0u 7 0u 6 0u
VDD=3.3V RL=32Ω SE Po=10mW
VDD=5V RL=4Ω
BW=22Hz to 20kHz
5 0u 4 0u
Vo BTL
3 0u
Po=20mW
2 0u
Vo SE
Po=30mW
50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k 1 0u 20 50 10 0 2 00 5 00 Hz 1k 2k 5k 10 k 20k
Figure 33
Figure 34
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Global Mixed-mode Technology Inc.
G1420
Output Noise Voltage vs Frequency
10 0u 9 0u 8 0u 7 0u 6 0u 5 0u 4 0u V d B
Supply Ripple Rejection Ratio vs Frequency
+0
VDD=3.3V RL=4Ω
T
BW=22Hz to 20kHz
-10 -20 -30 -40 -50 -60
Vo BTL
VDD=5V RL=4Ω CB=4.7uF
3 0u
BTL
2 0u
Vo SE
-70 -80 -90
SE
1 0u 20
50
1 00
2 00
5 00 Hz
1k
2k
5k
10k
20k
-1 00 20
50
1 00
2 00
5 00 Hz
1k
2k
5k
10k
20k
Figure 35
Figure 36
Supply Ripple Rejection Ratio vs Frequency
+0 -10 -20 -30 -40 d B -50 -60 -70 -80 -90 -1 00 20
Crosstale vs Frequency
-20 -25
T
VDD=3.3V RL=4Ω CB=4.7uF
-30 -35 -40 -45 -50 -55 d B -60 -65 -70 -75 -80 -85
VDD=5V Po=1.5W RL=4Ω BTL
BTL
L to R
SE
50 1 00 2 00 5 00 Hz 1k 2k 5k 10k 20k
-90 -95 -100 20
R to L
50 100 200 500 Hz 1k 2k 5k 10k 20k
Figure 37
Figure 38
Crosstale vs Frequency
-20 -25 -30 -35 -40 -45 -50 -55 d B -60 -65 -70 -75 -80 -85 -90 -95 -100 20 50 100 200 500 Hz 1k 2k 5k 10k 20k
d B -30
Crosstale vs Frequency
-35 -40 -45 -50 -55 -60 -65 -70 -75 -80 -85
VDD=3.3V Po=0.75W RL=4Ω BTL
VDD=5V Po=75mW RL=32Ω SE
L to R
R to L
R to L
-90 -95 -1 00 20 50 10 0 20 0 50 0 Hz 1k 2k
L to R
5k 10 k 20k
Figure 39
Figure 40
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Global Mixed-mode Technology Inc.
G1420
Closed Loop Response
Crosstale vs Frequency
-30 -35 -40 -45 -50 -55 -60 d B -65 -70 -75 -80 -85 -90 -95 -1 00 20 50 10 0 20 0 50 0 Hz 1k 2k 5k
VDD=3.3V Po=35mW RL=32Ω SE
R to L
L to R
10 k 20k
Figure 41
Figure 42
Closed Loop Response
Closed Loop Response
Figure 43
Figure 44
Closed Loop Response
10 9 8 Supply Current(mA) 7 6 5 4 3 2 1 0 3
Supply Current vs Supply Voltage
Stereo BTL
Stereo SE
4 5 Supply Voltage (V)
6
Figure 45
Figure 46
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Global Mixed-mode Technology Inc.
G1420
Output Power vs Supply Voltage
THD+N=1% SE Each Channel RL=8Ω
Output Power vs Supply Voltage
2.5 THD+N=1% BTL Each Channel 0.7 0.6 Po-Output Power(W) RL=4Ω 0.5 0.4 0.3 0.2 0.1 0 2.5 3.5 4.5 Supply Voltage (V) 5.5 6.5 2.5
2 Po-Output Power (W)
1.5 RL=3Ω RL=8Ω 0.5
RL=4Ω RL=32Ω
1
0
3.5
4.5 Supply Voltage(V)
5.5
6.5
Figure 47
Figure 48
Output Power vs Load Resistance
2 1.8 1.6 Po-Output Power(W) 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 4 8 12 16 20 24 28 32 Load Resistance( Ω) VDD=3.3V VDD=5V THD+N=1% BTL Each Channel 0.7 0.6 Po-Output Power(W) 0.5 0.4 0.3 0.2 0.1 0 0 4
Output Power vs Load Resistance
VDD=5V
THD+N=1% SE Each Channel
VDD=3.3V 8 12 16 20 24 Load Resistance( Ω) 28 32
Figure 49
Figure 50
Power Dissipation vs Output Power
1.8 1.6 Power Dissipation(W) 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0 0.5 1 1.5 Po-Output Pow er(W) 2 2.5 RL=8Ω RL=4Ω VDD=5V BTL Each Channel RL=3Ω 0.8 0.7 Power Dissipation(W) 0.6 0.5 0.4 0.3 0.2 0.1 0 0
Power Dissipation vs Output Power
RL=3Ω
RL=4Ω
RL=8Ω
VDD=3.3V BTL Each Channel
0.25
0.5 Output Pow er(W)
0.75
1
Figure 51
Figure 52
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Global Mixed-mode Technology Inc.
G1420
Power Dissipation vs Output Power
Power Dissipation vs Output Power
0.35 0.3 Power Dissipation(W) 0.25 0.2 0.15 0.1 0.05 0 0 0.2 0.4 Output Pow er(W) 0.6 0.8 RL=32Ω RL=8Ω VDD=5V SE Each Channel RL=4Ω Power Dissipation(W) 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0
RL=4Ω RL=8Ω VDD=3.3V SE Each Channel RL=32Ω 0.05 0.1 0.15 0.2 Output Pow er (W) 0.25 0.3
Figure 53
Figure 54
Recommended Minimum Footprint
TSSOP-24 (FD)
Ver: 1.5 Aug 04, 2005
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Pin Description
PIN
1,12,13,24 2
G1420
NAME
GND/HS TJ
I/O
O
FUNCTION
Ground connection for circuitry, directly connected to thermal pad. Source a current inversely to the junction temperature. This pin should be left unconnected during normal operation. For more information, see the junction temperature measurement section of this document. Left channel + output in BTL mode, + output in SE mode. Left channel line input, selected when HP/ pin is held low. Left channel headphone input, selected when HP/pin is held high. Connect to voltage divider for left channel internal mid-supply bias. Supply voltage input for left channel and for primary bias circuits. Shutdown mode control signal input, places entire IC in shutdown mode when held high, IDD = 5µA. Follows MUTE IN pin, provides buffered output. Left channel - output in BTL mode, high impedance state in SE mode. Mute control signal input, hold low for normal operation, hold high to mute.
3 4 5 6 7 8 9 10 11 14
LOUT+ LLINE IN LHP IN LBYPASS LVDD SHUTDOWN MUTE OUT LOUTMUTE IN SE/ BTL
O I I I I O O I
I O I
Mode control signal input, hold low for BTL mode, hold high for SE mode. Right channel - output in BTL mode, high impedance state in SE mode. MUX control input, hold high to select headphone inputs (5,20), hold low to select line inputs (4,21). Supply voltage input for right channel. Connect to voltage divider for right channel internal mid-supply bias. Right channel headphone input, selected when HP/pin is held high. Right channel line input, selected when HP/pin is held low. Right channel + output in BTL mode, + output in SE mode. Recommend connecting the Thermal Pad to the GND for excellent power dissipation.
15 16 17,23 18 19 20 21 22 Thermal Pad
ROUTHP/ LINE NC RVDD RBYPASS RHP IN RLINE IN ROUT+
I I I O
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Block Diagram
20k
G1420
21 20
RLINEIN RHPIN RIGHT MUX
_
ROUT+ ROUT-
22 15
19
RBYPASS
+ RVDD 18
11 9 8
MUTEIN MUTEOUT SHUTDOWN
BIAS CIRCUITS MODES CONTROL CIRCUITS
HP/LINE SE/BTL TJ
16 14 2
LVDD
7
6
LBYPASS + LOUTLOUT+ 10 3
5 4
LHPIN LLINEIN LEFT MUX _
20k
Parameter Measurement Information
11 8
MUTEIN SHUTDOWN HP/LINE SE/BTL 16 14
LVDD 6 CB 4.7µF CI AC source RI 5 4 LHPIN LLINEIN LEFT LEFT MUX LBYPASS
7 RL 4/8/32ohm
+ _
LOUTLOUT+
10 3
RF
BTL Mode Test Circuit
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Parameter Measurement Information (Continued)
G1420
11 8
MUTEIN SHUTDOWN HP/LINE SE/BTL 16 14 VDD
LVDD 6 CB 4.7µF CI AC source RI 5 4 LHPIN LLINEIN LEFT LEFT MUX LBYPASS
7
+ _
LOUTLOUT+
10 3
RL 32ohm
RF
SE Mode Test Circuit
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Application Circuits
G1420
GND/HS TJ LOUT+
RFL 20KΩ CIR CFR AUDIO SOURCE 1µF RIR 10KΩ
1 2 3 4 5 6 19 8 9 10 11 12
24 23 22 21 20 7
GND/HS GND/HS NC ROUT+ RLINEIN RHPIN LVDD RVDD NC HP/LINE ROUTR CSR 4.7µF RIL 10KΩ CIL RFL 1µF AUDIO SOURCE 20KΩ CFL
LLINEIN LHPIN
LBYPASS RBYPASS
4.7µF
G1420
18 17 16 15 14 13
R 100KΩ
4.7µF
SHUTDWON MUTE OUT LOUTMUTE IN GND/HS
COUTR 220µF
SE/BTL
100KΩ
1KΩ
1 3 4 2
GND/HS
0.1µF
PHONOJACK
COUTR 220µF 1KΩ
Logical Truth Table INPUTS Mute In HP/ LINE
X X X Low High Low High ---High High Low Low Low Low
SE/ BTL
X Low High Low Low High High
Shutdown
High ------Low Low Low Low
OUTPUT Mute Out
---High High Low Low Low Low
Input
X X X L/R Line L/R HP L/R Line L/R HP
AMPLIFIER STATES L/R Out+ L/R Out---VDD/2 VDD/2 BTL Output BTL Output SE Output SE Output ---VDD/2 ---BTL Output BTL Output -------
Mode
Mute Mute Mute BTL BTL SE SE
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Application Information
Input MUX Operation There are two input signal paths – HP & Line. With the prompt setting, G1420 allows the setting of different gains for BTL and SE modes. Generally, speakers typically require approximately a factor of 10 more gain for similar volume listening levels as compared with headphones.
SE Gain(HP) = -(RF(HP)/RI(HP)) -2(RF(LINE)/RI(LINE))
fc -3 dB
G1420
BTL Gain(LINE) =
To achieve headphones and speakers listening parity, (RF(LINE/RI(LINE)) is suggested to be 5 times of (RF(HP)/ RI(HP)). The ratio of (RF(HP)/RI(HP)) can be determined by the applications. When the optimum distortion performance into the headphones (clear sound) is important, gain of –1 ((RF(HP) / RI(HP)) = 1) is suggested.
Figure B
Bridged-Tied Load Mode Operation G1420 has two linear amplifiers to drive both ends of the speaker load in Bridged-Tied Load (BTL) mode operation. Figure C 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.
VDD
Single Ended Mode Operation G1420 can drive clean, low distortion SE output power into headphone loads (generally 16Ω or 32Ω) as in Figure A. Please refer to Electrical Characteristics to see the performances. A coupling capacitor is needed to block the dc offset voltage, allowing pure ac signals into headphone loads. Choosing the coupling capacitor will also determine the 3 dB point of the high-pass filter network, as Figure B.
fC=1/(2πRLCC) For example, a 68uF capacitor with 32Ω headphone load would attenuate low frequency performance below 73Hz. So the coupling capacitor should be well chosen to achieve the excellent bass performance when in SE mode operation.
VDD VDD
Vo(PP)
Vo(PP) RL 2xVo(PP) -Vo(PP)
CC RL Vo(PP)
VDD
Figure A
Figure C
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MUTE and SHUTDOWN Mode Operations G1420 implements the mute and 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 8) is pulled high, all linear amplifiers will be deactivated to mute the amplifier outputs. And G1420 enters an extra low current consumption state, IDD is smaller than 5µA. If pulling mute-in pin (pin 11) high, it will force the activated linear amplifier to supply the VDD/2 dc voltage on the output to mute the AC performance. In mute mode operation, the current consumption will be a little different between BTL, SE. (SE < BTL) Typically, the supply current is about 2.5mA in BTL mute operation. Shutdown and Mute-In pins should never be left unconnected, this floating condition will cause the amplifier operations unpredictable.
Optimizing DEPOP Operation
G1420
VDD 100 kΩ 50 kΩ
Bypass Bypass 100 kΩ
Figure D
Junction Temperature Measurement
Circuitry has been implemented in G1420 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 G1420 is shown on Figure D. The PNP transistor limits the voltage drop across the 50kΩ 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.
Characterizing a PCB layout with respect to thermal impedance is very difficult, as it is usually impossible to know the junction temperature of the IC. G1420 TJ (pin 2) sources a current inversely proportional to the junction temperature. Typically TJ sources–120µA for a 5V supply at 25°C. And the slope is approximately 0.22µA/°C. As the resistors have a tolerance of ±20%, these values should be calibrated on each device. When the temperature sensing function is not used, TJ pin can be left floating or tied to VDD to reduce the current consumption. Temperature sensing circuit is shown on Figure E.
VDD
R
R 5R TJ
Figure E
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Package Information
D 24 D1 E1 E
C
G1420
L
E2
1
Note 5
θ
A2 A1 e b
A
TSSOP-24 (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
SYMBOLS
A A1 A2 b C D D1 E E1 E2 e L θ
MIN
----0.00 0.80 0.19 0.20 7.7 4.4 4.30 2.7 0.45 0º
DIMENSION IN MM NOM
--------1.00 --------7.8 ----6.40 BSC 4.40 ----0.65 BSC 0.60 -----
MAX
1.20 0.15 1.05 0.30 ----7.9 4.9 4.50 3.2 0.75 8º
MIN
----0.000 0.031 0.007 0.008 0.303 0.173 0.169 0.106 0.018 0º
DIMENSION IN INCH NOM
--------0.039 --------0.307 ----0.252 BSC 0.173 ----0.026 BSC 0.024 -----
MAX
0.047 0.006 0.041 0.012 ----0.311 0.193 0.177 0.126 0.030 8º
Taping Specification
PACKAGE
TSSOP-24 (FD)
Feed F eed Direction T ypical T S SO P Package O rientation
Q’TY/REEL
2,500 ea
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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