SN8P2977
8-Bit Micro-Controller with Regulator, PGIA, 24-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 105
Version 1.7
13.3 Voltage Regulator
SN8P2977 is built in voltage regulators, which can provide a stable 2.4V/2.8V/3.2V (pin AVDDR) and
0.75V/1.0V1.5V/2.0V (pin AVE+) with maximum 10mA current driving capacity. Register VREG can enable or disable
AVDDR and AVE output voltage. Because the power of PGIA and ADC are came from AVDDR, turn on AVDDR
(AVDDRENB = 1) first before enabling PGIA and ADC. The AVDDR voltage was regulated from VDD.
13.3.1
Voltage Regulator Control Register
090H
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
VREG
BGRENB
-
AVENB
AVESEL1
AVESEL0 AVDDRENB AVDDRSEL1 AVDDRSEL0
R/W
R/W
-
R/W
R/W
R/W
R/W
R/W
R/W
After Reset
0
-
0
1
0
0
0
1
Bit7:
BGRENB:
Band Gap Reference voltage enable control bit
0 = Disable Band Gap Reference Voltage
1 = Enable Band Gap Reference Voltage
Bit5:
AVENB:
Regulator (AVE) voltage Enable control bit.
0 = Disable Regulator and AVE Output voltage.
1 = Enable Regulator and AVE Output voltage.
Note:
※
When AVE enable & AVE set 1.5V/2.0V, AVE pin have to connect 1uf capacitors to ground.
Bit[4:3]:
AVESEL[1:0]:
Regulator (AVE) voltage output voltage control bit.
00 = AVE 0.75V. (Sink only)
01 = AVE 1.0V. (Sink only)
10 = AVE 1.5V. (Drive only)
11 = AVE 2.0V. (Drive only)
Bit2:
AVDDRENB:
Regulator (AVDDR) voltage Enable control bit.
0 = Disable Regulator and AVDDR Output voltage.
1 = Enable Regulator and AVDDR Output voltage.
Bit[1:0]:
AVDDRSEL[1:0]:
Regulator (AVDDR) voltage output voltage control bit.
00 = Reserved.
01 = AVDDR 2.4V.
10 = AVDDR 2.8V.
11 = AVDDR 3.2V.
Note_1: Band Gap Reference voltage must be enable (FBRGEN), before following function accessing:
(Reference AMPM1 and AMPM2 register for detail information)
(1)Regulators of AVDDR.
(2)PGIA Function.
(3)ADC Function.
(4)Low Battery Detection Function.
Note_2: All current consumptions from AVE+.(ex. Load cell or AVDDR will NOT double.)
Note_3: PGIA can work in Normal, Slow or Green Mode, when high clock is still running (STPHX=0).
Note_4: Add 10ms delay time after enabling each regulators, AVDDR/AVE to avoid VDD drop in CR2032
battery application.