TWR-AUDIO-SGTL Freescale Semiconductor, TWR-AUDIO-SGTL Datasheet - Page 39

• Manufacturer Part Number: TWR-AUDIO-SGTL
• Description: TWR SYS Audio Board
• Manufacturer: Freescale Semiconductor
• Series: Kinetisr

Specifications of TWR-AUDIO-SGTL

• Kit Contents: TWR-AUDIO-SGTL Featuring SGTL5000 Low Power Stereo Codec, Printed Quick Start Guide
• Mcu Supported Families: K20, K50, MCF51Jx
• Kit Features: SGTL5000 Low Power Stereo Codec With Headphone
• Rohs Compliant: Yes
• Design Resources: TWR-AUDIO-SGTL Schematics
• Accessory Type: Module, Audio with CODEC
• Description/function: Audio CODECs
• Mounting Style: Press Fit
• Product: Audio Modules
• Features: SGTL5000 Low Power Stereo Codec With Headphone Amplifier, Stereo Line-in / Line-out On 3.5mm Jack
• Lead Free Status / Rohs Status: Details
• For Use With/related Products: Freescale Tower System

the bandgap reference bias voltage and currents.
Table 26. CHIP_REF_CTRL 0x0028
Analog Integrated Circuit Device Data
Freescale Semiconductor
BITS
15:9
The
15
8:4
3:1
0
Table 26, CHIP_REF_CTRL 0x0028
14
SMALL_POP
BIAS_CTRL
VAG_VAL
FIELD
RSVD
13
RSVD
12
RW
RW
RW
RW
RO
11
RESET
0x0
0x0
0x0
0x0
10
register controls
Reserved
Analog Ground Voltage Control
These bits control the analog ground voltage in 25 mV steps. This should usually be
set to VDDA/2 or lower for best performance (maximum output swing at minimum
THD). This VAG reference is also used for the DAC and ADC voltage reference. So
changing this voltage scales the output swing of the DAC and the output signal of the
ADC.
0x00 = 0.800 V
0x1F = 1.575 V
Bias control
These bits adjust the bias currents for all of the analog blocks. By lowering the bias
current a lower quiescent power is achieved. It should be noted that this mode can
affect performance by 3-4 dB.
0x0 = Nominal
0x1-0x3=+12.5%
0x4=-12.5%
0x5=-25%
0x6=-37.5%
0x7=-50%
VAG Ramp Control
Setting this bit slows down the VAG ramp from ~200 to ~400 ms to reduce the startup
pop, but increases the turn on/off time.
0x0 = Normal VAG ramp
0x1 = Slow down VAG ramp
9
8
7
VAG_VAL
6
DEFINITION
5
4
FUNCTIONAL DEVICE OPERATION
3
PROGRAMMING EXAMPLES
BIAS_CTRL
2
1
SGTL5000
0
39