G1420

G1420 GMT | Alldatasheet

Document overview

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Technical content

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

Applications

„ Stereo Power Amplifiers for Notebooks or Desktop Computers „ Multimedia Monitors „ Stereo Power Amplifiers for Portable Audio Systems General Description G1420 is a stereo audio power amplifier in 24pin TSSOP thermal pad package. It can drive 1.8W 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, 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 en- hances the hardware designing flexibility.

Ordering Information

(Pb free) TEMP. RANGE PACKAGE G1420F31U G1420F31Uf -40°C to +85°C TSSOP-24 (FD) Note: F3: TSSOP-24 (FD) U: Tape & Reel Pin Configuration ROUT+ RLINEIN RHPIN RBYPASS RVDD NC HP/LINE ROUT- SE/BTL GND/HS LOUT+ LLINEIN LHPIN LBYPASS LVDD SHUTDOWN MUTE OUT LOUT- MUTE IN G1420 GND/HS TSSOP-24 (FD) TJ NC Thermal Pad Top View Bottom View GND/HSGND/HS Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation. ROUT+ RLINEIN RHPIN RBYPASS RVDD NC HP/LINE ROUT- SE/BTL GND/HS LOUT+ LLINEIN LHPIN LBYPASS LVDD SHUTDOWN MUTE OUT LOUT- MUTE IN G1420 GND/HS TSSOP-24 (FD) TJ NC Thermal Pad Top View Bottom View GND/HSGND/HS 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 G1420Global 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 CONDITIONS MIN TYP MAX UNIT Stereo BTL --- 7 13 VDD =3.3V Stereo SE --- 3.5 8 Stereo BTL --- 8 16 Supply Current I DD VDD = 5V Stereo SE --- 4 10 mA DC Differential Output Voltage V O(DIFF) V DD = 5V,Gain = 2 --- 5 50 mV Stereo BTL 8 16 Supply Current in Mute Mode IDD(MUTE) V DD = 5V Stereo SE --- 4 10 mA IDD in Shutdown I SD V DD = 5V --- 2 5 µA (AC Operation Characteristics, VDD = 5.0V, TA=+25°C, RL = 4Ω, unless otherwise noted) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT THD = 1%, BTL, RL = 4Ω --- 1.8 --- THD = 1%, BTL, RL = 8Ω --- 1.12 --- THD = 10%, BTL, RL = 4Ω --- 2 --- THD = 10%, BTL, RL = 8Ω --- 1.4 --- W THD = 10%, SE, RL L = 8Ω --- 400 --- Output power (each channel) see Note P (OUT) mW PO = 1.6W, BTL, RL = 4Ω --- 500 --- PO = 1W, BTL, RL = 8Ω --- 150 --- PO = 75mW, SE, RL = 32Ω --- 20 --- 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 --- 60 --- ° Power supply ripple rejection PSRR f = 120Hz --- 75 --- dB Mute attenuation --- 85 --- dB Channel-to-channel output separation f = 1kHz --- 82 --- dB Line/HP 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: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc. (AC Operation Characteristics, VDD = 3.3V, TA=+25°C, RL = 4Ω, unless otherwise noted) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT THD = 1%, BTL, RL = 4Ω --- 0.8 --- THD = 1%, BTL, RL = 8Ω --- 0.5 --- THD = 10%, BTL, RL = 4Ω --- 1 --- THD = 10%, BTL, RL = 8Ω --- 0.6 --- W THD = 10%, SE, RL L = 8Ω --- 180 --- Output power (each channel) see Note P (OUT) mW PO = 1.6W, BTL, RL = 4Ω --- 270 --- PO = 1W, BTL, RL = 8Ω --- 100 --- PO = 75mW, SE, RL = 32Ω --- 20 --- 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 --- 60 --- ° Power supply ripple rejection PSRR f = 120Hz --- 75 --- dB Mute attenuation --- 85 --- dB Channel-to-channel output separation f = 1kHz --- 80 --- dB Line/HP 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: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc. Recommended Minimum Footprint 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0 0.2 0.4 0.6 0.8 Output Pow er(W) Power Dissipation(W) V DD=5V SE Each Channel RL=4Ω RL=8Ω RL=32Ω 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16 Output P ow er (W) Power Dissipation(W) V DD=3.3V SE Each Channel RL=4Ω RL=8Ω RL=32Ω Figure 53 Figure 54 Power Dissipation vs Output Power Power Dissipation vs Output Power TSSOP-24 (FD)

Ver: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc. Pin Description PIN NAME I/O FUNCTION 1,12,13,24 GND/HS Ground connection for circui try, directly connected to thermal pad. 2 TJ O Source a current inversely to the j unction temperature. This pin should be left uncon- nected during normal operation. For more in formation, see the junction temperature measurement section of this document. 3 LOUT+ O Left channel + output in BTL mode, + output in SE mode. 4 LLINE IN I Left channel line input, selected when HP/ pin is held low. 5 LHP IN I Left channel headphone input, se lected when HP/pin is held high. 6 LBYPASS Connect to voltage divider for left channel internal mid-supply bias. 7 LVDD I Supply voltage input for left c hannel and for primary bias circuits.

8 SHUTDOWN I Shutdown mode control signal inpu t, places entire IC in shutdown mode when held

high, IDD = 5µA. 9 MUTE OUT O Follows MUTE IN pin, provides buffered output. 10 LOUT- O Left channel - output in BTL mode, high impedance state in SE mode. 11 MUTE IN I Mute control si gnal input, hold low for normal operation, hold high to mute. 14 SE/ BTL I Mode control signal input, hold low fo r BTL mode, hold high for SE mode. 15 ROUT- O Right channel - output in BT L mode, high impedance state in SE mode.

16 HP/ LINE I MUX control input, hold high to select headphone inputs (5,20), hold low to select line

inputs (4,21). 17,23 NC 18 RVDD I Supply voltage input for right channel. 19 RBYPASS Connect to voltage divider fo r right channel internal mid-supply bias. 20 RHP IN I Right channel headphone input, sel ected when HP/pin is held high. 21 RLINE IN I Right channel line input, selected when HP/pin is held low. 22 ROUT+ O Right channel + output in BTL mode, + output in SE mode. Thermal Pad 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 G1420Global Mixed-mode Technology Inc. Block Diagram Parameter Measurement Information LEFT MUX MUTEIN RF RI CI CB 4.7µF LLINEIN LHPIN LBYPASS SHUTDOWN HP/LINE SE/BTL LVDD LOUT- LOUT+ RL 4/8/32ohm BTL Mode Test Circuit AC source LEFT MUX MUTEIN RF RI CI CB 4.7µF LLINEIN LHPIN LBYPASS SHUTDOWN HP/LINE SE/BTL LVDD LOUT- LOUT+ RL 4/8/32ohm BTL Mode Test Circuit AC source LEFT MUX _ 3 LLINEIN LHPIN LBYPASS 18RVDD LOUT- LOUT+ RIGHT MUXRHPIN RLINEIN 22ROUT+ ROUT- 7LVDD BIAS CIRCUITS MODES CONTROL CIRCUITS 2TJ SE/BTL HP/LINE SHUTDOWN RBYPASS MUTEIN MUTEOUT 20k 20k LEFT MUX _ 3 LLINEIN LHPIN LBYPASS 18RVDD LOUT- LOUT+ RIGHT MUXRHPIN RLINEIN 22ROUT+ ROUT- 7LVDD BIAS CIRCUITS MODES CONTROL CIRCUITS 2TJ SE/BTL HP/LINE SHUTDOWN RBYPASS MUTEIN MUTEOUT 20k 20k20k

Ver: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc. Parameter Measurement Information (Continued) LEFT MUX MUTEIN RF RI CI CB 4.7µF LLINEIN LHPIN LBYPASS SHUTDOWN HP/LINE SE/BTL LVDD LOUT- LOUT+ RL 32ohm SE Mode Test Circuit VDD AC source LEFT MUX MUTEIN RF RI CI CB 4.7µF LLINEIN LHPIN LBYPASS SHUTDOWN HP/LINE SE/BTL LVDD LOUT- LOUT+ RL 32ohm SE Mode Test Circuit VDD AC source

Ver: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc. Application Circuits Logical Truth Table INPUTS OUTPUT AMPLIFIER STATES SE/BTL HP/ LINE Mute In Shutdown Mute Out Input L/R Out+ L/R Out- Mode X X ---- High ---- X ---- ---- Mute Low X High ---- High X VDD/2 VDD/2 Mute High X High ---- High X VDD/2 ---- Mute Low Low Low Low Low L/R Line BTL Output BTL Output BTL Low High Low Low Low L/R HP BTL Output BTL Output BTL High Low Low Low Low L/R Line SE Output ---- SE High High Low Low Low L/R HP SE Output ---- SE GND/HS NC ROUT+ RLINEIN RHPIN LVDD RVDD NC HP/LINE ROUT- SE/BTL GND/HS R 100KΩ 1KΩ PHONOJACK COUTR CFLRFL AUDIO SOURCE CILRIL R 100KΩCSR 4.7µF 1KΩ COUTR GND/HS TJ LOUT+ LLINEINRIR LHPIN LBYPASS RBYPASS SHUTDWON MUTE OUT LOUT- MUTE IN GND/HS CIR AUDIO SOURCE RFL 20KΩ CFR G1420 1 24 2 23 3 22 4 21 12 13 1411 10 15 91 6 205 10KΩ1µF 4.7µF 220µF 0.1µF 4.7µF 220µF 1µF 10KΩ 20KΩ GND/HS NC ROUT+ RLINEIN RHPIN LVDD RVDD NC HP/LINE ROUT- SE/BTL GND/HS R 100KΩ 1KΩ PHONOJACK COUTR CFLRFL AUDIO SOURCE CILRIL R 100KΩCSR 4.7µF 1KΩ COUTR GND/HS TJ LOUT+ LLINEINRIR LHPIN LBYPASS RBYPASS SHUTDWON MUTE OUT LOUT- MUTE IN GND/HS CIR AUDIO SOURCE RFL 20KΩ CFR G1420 1 24 2 23 3 22 4 21 12 13 1411 10 15 91 6 205 10KΩ1µF 4.7µF 220µF 0.1µF 4.7µF 220µF 1µF 10KΩ 20KΩ

Ver: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc.

Application Information

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) = -(R F(HP)/RI(HP)) BTL Gain(LINE) = -2(R F(LINE)/RI(LINE)) To achieve headphones and speakers listening parity, (RF(LINE/RI(LINE)) is suggested to be 5 times of (R F(HP)/ RI(HP)). The ratio of (R F(HP)/RI(HP)) can be determined by the applications. When the optimum distortion per- formance into the headphones (clear sound) is impor- tant, gain of –1 ((R F(HP) / RI(HP)) = 1) is suggested. Single Ended Mode Operation G1420 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 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 capaci- tor 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 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 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: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc. MUTE and SHUTDOWN Mode Operations G1420 implements the mute and shutdown mode operations to reduce supply current, I DD, to the ab- solute 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, I DD is smaller than 5 µA. If pulling mute-in pin (pin 11) high, it will force the activated linear ampli- fier 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 be- tween 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 Circuitry has been implemented in G1420 to mini- mize the amount of popping heard at power-up and when coming out of shutdown mode. Popping oc- curs whenever a voltage step is applied to the speaker and making the differential voltage gener- ated at the two ends of the speaker. To avoid the popping heard, the bypass capacitor should be chosen promptly, 1/(C Bx100kΩ) ≦ 1/(C I*(RI+RF)). Where 100k Ω is the output impedance of the mid-rail generator, C B is the mid-rail bypass ca- pacitor, CI is the input coupling capacitor, R I is the input impedance, R F is the gain setting impedance which is on the feedback path. C B is the most im- portant capacitor. Besides it is used to reduce the popping, C B can also determine the rate at which the amplifier starts up dur ing 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 circ uit down. So the capacitor sees a lower effective voltage, and thus the charg- ing is slower. This appears as a linear ramp (while the PNP transistor is c onducting), followed by the expected exponential ramp of an R-C circuit. Junction Temperature Measurement Characterizing a PCB layout with respect to thermal impedance is very difficult, as it is usually impossi- ble to know the junction temperature of the IC. G1420 TJ (pin 2) sources a current inversely pro- portional to the junction temperature. Typically TJ sources–120 µA for a 5V supply at 25 °C. And the slope is approximately 0.22 µA/°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 con- sumption. Temperature sensing circuit is shown on Figure E. Bypass VDD 100 kΩ 100 kΩ 50 kΩ Figure D Bypass VDD 100 kΩ 100 kΩ 50 kΩ Figure D TJ VDD R R Figure E TJ VDD R R Figure E

Ver: 1.5 Aug 04, 2005 TEL: 886-3-5788833 http://www.gmt.com.tw G1420Global Mixed-mode Technology Inc.

Package Information

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 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/REEL TSSOP-24 (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 A C L θ e Note 5 E1 E D b A C L θ e Note 5