G1422 GMT | Alldatasheet
Document overview
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Technical content
Features
Depop Circuitry Integrated 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), Single-Ended (SE) Shutdown Control Available Thermal protection Surface-Mount Power Package 20-Pin TSSOP-P
Applications
Stereo Power Amplifiers for Notebooks or Desktop Computers Multimedia Monitors Stereo Power Amplifiers for Portable Audio Systems General Description The G1422 is a stereo audio power amplifier in 20pin TSSOP thermal pad package. It can drive 2W con- tinuous RMS power into 4 Ω 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, the G1422 supports the Bridge- Tied Load (BTL) mode for driving the speakers, Sin- gle-End (SE) mode for driving the headphone. For the low current consumption applications, the SHDN mode is supported to disable the G1422 when it is idle. The current consumption can be further reduced to below 2µA.
Ordering Information
(Pb free) MARKING TEMP. RANGE PACKAGE G1422F2U G1422F2Uf G1422 -40°C to +85°C TSSOP-20 (FD) Note:F2: TSSOP-20 (FD) U: Tape & Reel Pin Configuration HP-IN GND/HS +OUTB VDD -OUTB -INB BYPASS SHUTDOWN +OUTA VDD -OUTA -INA GND/HS +INA GND/HS GND/HS G1422 TSSOP-20 (FD) GND/HS Top View +INB
12 GND/HS
Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation. HP-IN GND/HS +OUTB VDD -OUTB -INB BYPASS SHUTDOWN +OUTA VDD -OUTA -INA GND/HS +INA GND/HS GND/HS G1422 TSSOP-20 (FD) GND/HS Top View +INB +OUTB VDD -OUTB -INB BYPASS SHUTDOWN +OUTA VDD -OUTA -INA GND/HS +INA GND/HS GND/HS G1422 TSSOP-20 (FD) GND/HS Top View +INB Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation.
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc. Absolute Maximum Ratings Operating Ambient Temperature Range T Maximum Junction Temperature, TJ…..……….….150°C Storage Temperature Range, TSTG….…-65°C to+150°C Reflow Temperature (soldering, 10sec)….……..260°C Power Dissipation (1) 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
PARAMETER SYMBOL CONDITION MIN TYP MAX UNIT Stereo BTL --- 8.5 15 Supply Current I DD V DD = 5V STEREO SE --- 4 8 mA DC Differential Output Voltage V O(DIFF) V DD = 5V,Gain = 2 --- 5 50 mV IDD in Shutdown I SD V DD = 5V --- 0.1 2 µA Headphone High Input Voltage V IH 4 --- --- V Headphone Low Input Voltage V IL --- --- 0.8 V (AC Operation Characteristics, VDD = 5.0V, TA=+25°C, RL = 4Ω, unless otherwise noted) PARAMETER SYMBOL CONDITION MIN TYP MAX UNIT THD = 1%, BTL, RL = 4Ω --- 2 --- THD = 1%, BTL, RL = 8Ω --- 1.25 --- THD = 10%, BTL, RL = 4Ω --- 2.5 --- THD = 10%, BTL, RL = 8Ω --- 1.6 --- W THD = 10%, SE, RL L = 8Ω --- 440 --- Output power (each channel) see Note P (OUT) mW PO = 1.6W, BTL, RL = 4Ω --- 300 --- PO = 1W, BTL, RL = 8Ω --- 100 --- PO = 75mW, SE, RL = 32Ω --- 15 --- Total harmonic distortion plus noise THD+N Maximum output power bandwidth B OM G = 1, THD = 1% --- 20 --- kHz Phase margin RL = 4Ω, Open Load --- 65 --- ° Power supply ripple rejection PSRR f = 120Hz --- 75 --- dB Channel-to-channel output separation f = 1kHz --- 80 --- dB Input separation --- 80 --- dB BTL attenuation in SE mode --- 85 --- dB Input impedance ZI --- 2 --- MΩ Signal-to-noise ratio P O = 500mW, BTL --- 90 --- dB Output noise voltage V n Output noise voltage --- 55 --- µV (rms) Note :Output power is measured at the output terminals of the IC at 1kHz.
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc. 0.01 0.02 0.05 0.1 0.2 0.5 20 20k50 100 200 500 1k 2k 5k 10k Hz VDD=3.3V RL=8Ω BTL Po=0.45W Av=-4V/V Av=-2V/V Av=-1V/V 0.01 0.02 0.05 0.1 0.2 0.5 1m 500m2m 5m 10m 20m 50m 100m 200m W VDD=5V RL=16Ω SE Av=-2V/V 1kHz 20 Hz 20kHz 0.01 0.02 0.05 0.1 0.2 0.5 20 20k50 100 200 500 1k 2k 5k 10k Hz VDD=5V RL=16Ω SE Po=150mW Av=-1V/V Av=-2V/V Av=-4V/V 0.01 0.02 0.05 0.1 0.2 0.5 1m 12m 5m 10m 20m 50m 100m 200m 500m W VDD=5V RL=32Ω SE Av=-2V/V
20 Hz1kHz
0.01 0.02 0.05 0.1 0.2 0.5 1m 12m 5m 10m 20m 50m 100m 200m 500m W VDD=5V RL=4Ω SE Av=-2V/V 1kHz 100Hz 20kHz 0.01 0.02 0.05 0.1 0.2 0.5 1m 12m 5m 10m 20m 50m 100m 200m 500m W VDD=5V RL=8Ω SE Av=-2V/V 1kHz 100kHz 20kHz Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Total Harmonic Distortion Plus Noise vs Frequency Total Harmonic Distortion Plus Noise vs Output Power Total Harmonic Distortion Plus Noise vs Output Power Total Harmonic Distortion Plus Noise vs Output Power Total Harmonic Distortion Plus Noise vs Frequency Total Harmonic Distortion Plus Noise vs Output Power
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc. Pin Description PIN NAME I/O FUNCTION
1 SHUTDOWN I Shutdown mode control signal input, places entire IC in shutdown mode when held
high, IDD is below 2µA. 2,7,9,10,11,12,19 GND/ HS Ground connection for circuitry, directly connected to thermal pad. 3 +OUTA O A channel + output in BTL mode, high impedance state in SE mode 4,17 VDD Supply voltage for circuitry. 5 -OUTA O A channel - output in BTL mode, - output in SE mode. 6 -INA I A channel input signal I, se lected when MUXCTRL is held low. 8 +INA I A channel positive input of OPAMP, biasing DC operation of OPAMP 13 +INB I B channel positive input of OPAMP, biasing DC operation of OPAMP 14 BYPASS Connect to voltage divider for internal mid-supply bias. 15 -INB I B channel input signal I, se lected when MUXCTRL is held low. 16 -OUTB O B channel - output in BT L mode, - output in SE mode. 18 +OUTB O B channel + output in BTL mode, high impedance state in SE mode 20 HP-IN I Mode control signal input, hold low for BTL mode, hold high for SE mode. Thermal Pad Recommend connecting the Thermal P ad to the GND for excellent power dissipation.
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc. Block Diagram Parameter Measurement Information _ 16 -INB +INB 4,17VDD +OUTB -OUTB -INA 5-OUT +OUT BIAS CIRCUITS MODES CONTROL CIRCUITS 20HP-INSHUTDOWN BYPASS 8 +INA 20k 20k _ 16 -INB +INB 4,17VDD +OUTB -OUTB -INA 5-OUT +OUT BIAS CIRCUITS MODES CONTROL CIRCUITS 20HP-INSHUTDOWN BYPASS 8 +INA 20k 20k 4,17 RF RI CI CB 4.7µF -INA +INA SHUTDOWN HP-IN VDD -OUTA +OUTA RL 4/8/32Ω BTL Mode Test Circuit AC source
14 BYPASS
4,17 RF RI CI CB 4.7µF -INA +INA SHUTDOWN HP-IN VDD -OUTA +OUTA RL 4/8/32Ω BTL Mode Test Circuit AC source
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc. Parameter Measurement Information (Continued) 4,17 RF RI CI CB 4.7µF -INA +INA SHUTDOWN HP-IN VDD -OUTA +OUTA SE Mode Test Circuit AC source RL 32Ω 4,17 RF RI CI CB 4.7µF -INA +INA SHUTDOWN HP-IN VDD -OUTA +OUTA SE Mode Test Circuit AC source RL 32Ω
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc. Application Circuits Logical Truth Table INPUTS AMPLIFIER STATES HP-IN Shutdown A/B Out- A/B Out+ Mode X High ---- ---- Mute Low Low BTL Output BTL Output BTL Low Low BTL Output BTL Output BTL High Low SE Output ---- SE High Low SE Output ---- SE G1422 SHUTDOWN HP-IN GND +OUTB VDD -OUTB -INB BYPASS +INB GND GND GND +OUTA VDD -OUTA -INA GND +INA GND GND 201 COA 100µF PHONEJACK RFA1 20K RA1 20K CA1 1µF RCA RCA COB 100µF 100K 0.1µF R3 100K SPEAKERSPEAKER CS 1µF RFB1 20K RB1 20K CB1 1µF CB 0.33µF G1422 SHUTDOWN HP-IN GND +OUTB VDD -OUTB -INB BYPASS +INB GND GND GND +OUTA VDD -OUTA -INA GND +INA GND GND 201 COA 100µF PHONEJACK RFA1 20K RA1 20K CA1 1µF RCA RCA COB 100µF 100K 0.1µF R3 100K SPEAKERSPEAKER CS 1µF RFB1 20K RB1 20K CB1 1µF CB 0.33µF
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc.
Application Information
Single Ended Mode Operation The G1422 can drive clean, low distortion SE output power into headphone loads (generally 16 Ω or 32 Ω) as in Figure A. Please refer to Electrical Characteris- tics 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. f C=1/(2πRLCC) For example, a 68uF capacitor with 32 Ω headphone load would attenuate low frequency performance be- low 73Hz. So the coupling capacitor should be well chosen to achieve the excellent bass performance when in SE mode operation. Bridged-Tied Load Mode Operation The G1422 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 V O(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 off- sets, which eliminates the dc coupling capacitor that is needed to cancelled dc offsets in the ground reference configuration. Low-frequency performance is then lim- ited only by the input network and speaker responses. Cost and PCB space can be minimized by eliminating the dc coupling capacitors. VDD Vo(PP) Vo(PP) CC RL Figure A VDD Vo(PP) Vo(PP) CC RL Figure A -3 dB fc Figure B -3 dB fc Figure B VDD Vo(PP) VDD -Vo(PP) 2xVo(PP)RL Figure C VDD Vo(PP) VDD -Vo(PP) 2xVo(PP)RL Figure C
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc. SHUTDOWN Mode Operations The G1422 implements the shutdown mode opera- tions to reduce supply current, I DD, to the absolute minimum level during nonuse periods for bat- tery-power conservation. When the shutdown pin (pin 1) is pulled high, all linear amplifiers will be deactivated to mute the amplifier outputs. And The G1422 enters an extra low current consumption state, I DD is smaller than 2 µA. Shutdown pin should never be left unconnected, this floating condition will cause the amplifier operations unpredictable. Optimizing DEPOP Operation Circuitry has been implemented in the G1422 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 gener- ated at the two ends of t he speaker. To avoid the popping heard, the bypass capacitor should be cho- sen promptly, 1/(C Bx100kΩ) ≦ 1/(C I*(RI+RF)). Where 100kΩ is the output impedance of the mid-rail generator, CB is the mid-rail bypass capacitor, C I is the input coupling capacitor, R I is the input imped- ance, 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 theG1422 is shown on Fig- ure D. The PNP transistor limits the voltage drop across the 225k Ω by slewing the internal node slowly when power is applied. At start-up, the volt- age 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 trans istor is conducting), fol- lowed by the expected ex ponential ramp of an R-C circuit. Bypass VDD 100 kΩ 100 kΩ 225 kΩ Figure D Bypass VDD 100 kΩ 100 kΩ 225 kΩ Figure D
Ver: 1.2 Jun 29, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1422Global Mixed-mode Technology Inc.
Package Information
TSSOP-20 (FD) Package Note: 1. JEDCE outline: MP-153 AC/MO-153 ACT (thermally enhanced variations only) 2. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.15 per side. 3. Dimension “E1” does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.25 per side. 4. Dimension “b” does not include dambar protrusion. Allowable dambar protrusion shall be 0.08mm total in ex- cess of the “b” dimension at maximum material conditions. Dambar cannot be located on the lower radius of the foot. Minimum space between protrusion and adjacent lead is 0.07mm. 5. Dimensions “D” and “E1” to be determined at datum plane “H”. DIMENSION IN MM DIMENSION IN INCH SYMBOLS MIN NOM MAX MIN NOM MAX E 6.40 BSC 0.252 BSC e 0.65 BSC 0.026 BSC Taping Specification PACKAGE Q’TY/BY REEL TSSOP-20 (FD) 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. Feed Direction Typical TSSOP Package Orientation Feed Direction Typical TSSOP Package Orientation E1 E D b L θ e 0.05 A
0.127 TYP
C H E1 E D b L θ e 0.05 A C H