G1438 Global Mixed-mode Technology Inc. 2W Stereo Audio Amplifier with DC Volume Control and Selectable Gain Features General Description The G1438 is a stereo audio power amplifier in both 28pin TSSOP and TQFN thermal pad package. It can deliver 2.0W 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, G1438 supports the Bridge-Tied Load (BTL) mode for driving the speakers, Single-End (SE) mode for driving the headphone. For the low current consumption applications, the Shutdown mode is supported to disable the G1438 when it is idle. The current consumption can be reduced below 2µA. 0dB ~-78dB Internal DC Volume Gain Setting Embedded Depop Circuitry Integrated Output Power at 1% THD+N, VDD=5V --2.0W/CH (typical) into a 4Ω Load --1.2W/CH (typical) into a 8Ω Load Bridge-Tied Load (BTL), Single-Ended (SE) PC-Beep Input Selectable Internal/External Gain Setting Shutdown Control Available Thermal Shutdown Protection Surface-Mount Power Package 28-Pin TSSOP-P / 28pin TQFN Available The internal DC volume gain setting is ranged from 0dB to -78dB. We can activate the internal DC volume control by setting the Mode pin high, and setting the Vol value to get the expected DC volume gain. Applications Stereo Power Amplifiers for Notebooks or Desktop Computers Multimedia Monitors Stereo Power Amplifiers for Portable Audio Systems The G1438 is with the flexible for the user to select the internal embedded gain setting or external gains through the gain_sel pin. Setting the gain_sel pin low is to activate the internal gain settings, setting high for external gains. Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Pb free) G1438F4U G1438R6U G1438 1438 -40°C to +85°C -40°C to +85°C TSSOP-28 (FD) TQFN5X5-28 Note: F4: TSSOP-28 (FD) U: Tape & Reel R6 : TQFN5X5-28 VDD Left Out+ GND/HS Left Dock Left In 18 17 16 15 Left Out- 19 Left Gain2 21 G1438 20 Pin Configuration GND/HS 1 28 Shutdown 2 27 VDD Gain Select 3 26 Right Out- Left Gain1 22 14 Beep In Mode 4 25 Right Gain2 GND/HS 23 13 Right In Mute 5 24 Right Gain1 HP Sense 24 12 Right Dock VDD 6 23 GND/HS 25 DC Vol 7 22 Bypass Bypass GND/HS Right Out+ Thermal Pad Thermal Pad 11 GND 26 10 DC Vol Left Out+ Bottom View TSSOP-28 (FD) 7 Top View VDD 15 Mode GND/HS 14 5 Left Out- 16 6 17 Shutdown Mute Gain Select VDD 8 4 9 GND/HS 27 28 3 Right Gain1 Right Gain2 Right Out+ GND/HS Left Gain1 Left Gain2 Right In 10 Beep In 11 Left In 12 Left Dock 13 2 HP Sense 1 21 20 19 18 VDD 8 9 Right Out- GND Right Dock G1438 TQFN5X5-28 Note: Recommend connecting the Thermal Pad to the GND for excellent power dissipation. TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 1.1 Nov 12, 2008 1