Freescale公司的 SGTL5000是集成了耳机放大器的低功耗立体声CODEC,具有线输入,麦克风输入,线输出,耳机输出和数字I/O.模拟输入的ADC的SNR为 85 dB,线输出的SNR为100 dB,器件的工作电压为1.62 - 3.6V,主要用在手持媒体播放器(PMP),GPS单元和智能手机.本文介绍了SGTL5000主要特性,框图, 应用框图,几种典型应用电路以及评估板KITSGTL5000EVBE主要特性,方框图和电路图.
The SGTL5000 is a Low Power Stereo Codec with Headphone Amp from Freescale, and is designed to provide a complete audio solution for portable products needing line-in, mic-in, line-out, headphone-out, and digital I/O. Deriving it’s architecture from best in class, Freescale integrated products that are currently on the market. The SGTL5000 is able to achieve ultra low power with very high performance and functionality, all in one of the smallest footprints available. Target markets include portable media players, GPS units, and smart phones.
Features such as capless headphone design and an internal PLL, help lower overall system cost.

SGTL5000主要特性:
Analog Inputs
• Stereo Line In - Support for external analog input
• Stereo Line In - Codec bypass for low power
• MIC bias provided (5.0 x 5.0 mm QFN, 3.0 x 3.0 mm QFN TA2)
• Programmable MIC gain
• ADC - 85 dB SNR (-60 dB input) and -73 dB THD+N (VDDA = 1.8 V)Analog Outputs
• HP Output - Capless design
• HP Output - 45 mW max into 16 ohm load @ 3.3 V
• HP Output - 100 dB SNR (-60 dB input) and -80 dB THD+N (VDDA = 1.8 V, 16 ohm load, DAC to headphone)
• Line Out - 100 dB SNR (-60 dB input) and -85 dB THD+N (VDDIO = 3.3 V) Digital I/O
• I2S port to allow routing to Application Processor Integrated Digital Processing
• Freescale Surround, Freescale Bass, tone control/ parametric equalizer/graphic equalizer Clocking/Control
• PLL allows input of an 8.0 MHz to 27 MHz system clock - Standard audio clocks are derived from PLL
Power Supplies
• Designed to operate from 1.62 to 3.6 volts

图1.SGTL5000简化框图

图2.SGTL5000简化应用框图

图3.20 QFN封装的SGTL5000 典型应用电路

图4.20 QFN封装的SGTL5000 最低功耗应用电路

图5.32 QFN封装的SGTL5000 最低功耗应用电路

图6.32 QFN封装的SGTL5000 最低功耗应用电路(2)

SGTL5000评估板KITSGTL5000EVBE
The KITSGTL5000EVBE Evaluation board supports the SGTL5000, which is a Low Power Stereo Codec with Headphone Amp from Freescale, and is designed to provide a complete audio solution for portable products needing line-in, mic-in, line-out, headphone-out, and digital I/O.

评估板KITSGTL5000EVBE主要特性:
SGTL5000 Audio Codec
LINEIN RCA analog input jack
LINEOUT RCA analog output jack
Selectable mini-jack or onboard microphone input
Stereo headphone mini-jack analog output, with optional capless design circuitry
Two-row headers for buffered I2S digital input/output
Support for onboard or external MCLK source
USB to I2C/SPI communication port
5V input voltage through either internal LDO regulators, or external individual supplies

图7.评估板KITSGTL5000EVBE外形图

图8.评估板KITSGTL5000EVBE框图

图9.评估板KITSGTL5000EVBE电路图(1)

图10.评估板KITSGTL5000EVBE电路图(2)

图11.评估板KITSGTL5000EVBE电路图(3)

图12.评估板KITSGTL5000EVBE电路图(4)

图13.评估板KITSGTL5000EVBE电路图(5)

图14.评估板KITSGTL5000EVBE电路图(6)

图15.评估板KITSGTL5000EVBE电路图(7)