Absolute Value Without SAR
124
SNIU028A – February 2016 – Revised April 2016
Copyright © 2016, Texas Instruments Incorporated
Front End
3.5
Absolute Value Without SAR
It is also possible to get absolute value data from the EADC without using SAR mode. For accurate data
in this case, the Error ADC has to be within range of the EADC DAC setting.
Vabs = Ve Veadc
If EADC averaging is used, the average EADC value will be used to calculate the absolute value.
3.6
EADC Modes
There are several other front end modes for different applications.
The complete list is as follows:
•
0 = Standard mode, EADC samples based on sample triggers from DPWM module (Default)
•
1 = Averaging Mode, configured by AVG_MODE_SEL
•
2 = Non-continuous SAR Mode
•
3 = Continuous SAR Mode
•
4 = Reserved
•
5 = Digital Peak Current Mode
•
6 = Constant Power/Constant Current Control Mode (CPCC module controls switching between
Standard Mode and Non-Continuous SAR Mode)
•
7 = Constant Power/Constant Current Control 2 Mode (CPCC module controls switching between
Standard mode and Continuous SAR Mode)
3.7
Front End Control Registers
Registers for Front End Control modules 0-2 are identical in their bit definitions.
3.7.1 Ramp Control Register (RAMPCTRL)
Address 0x0008_0000 – Front End Control 2 Ramp Control Register
Address 0x000B_0000 – Front End Control 1 Ramp Control Register
Address 0x000E_0000 – Front End Control 0 Ramp Control Register
Figure 3-9. Ramp Control Register (RAMPCTRL)
29
16
SYNC_FET_RAMP_START
R/W-00 0000 0000 0000
15
13
12
11
10
9
8
Reserved
RAMP_SAT
_EN
RAMP_COMP
_INT_EN
RAMP_DLY
_INT_EN
PREBIAS_INT
_EN
PCM_START
_SEL
R-00
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
7
6
5
4
3
2
1
0
SYNC_FET
_EN
MASTER_SEL
SLAVE_COMP
_EN
SLAVE_DELAY
_EN
CONTROL_EN
FIRMWARE
_START
RAMP_EN
R/W-0
R/W-00
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 3-3. Ramp Control Register (RAMPCTRL) Register Field Descriptions
Bit
Field
Type
Reset
Description
29-16
SYNC_FET
_RAMP_START
R/W
00 0000
0000
0000
Provides the starting value for the SyncFET Ramp with a resolution of High
Frequency Oscillator Period/bit
15-13
Reserved
R
00