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SLOS758G – DECEMBER 2011 – REVISED MARCH 2020
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Detailed Description
Copyright © 2011–2020, Texas Instruments Incorporated
6.14.1.2.8 Regulator and I/O Control Register (0x0B)
describes the bit fields of the Regulator and I/O Control register. This register controls the
three voltage regulators.
Default Value:
0x87, set at POR = H or EN = L
Table 6-26. Regulator and I/O Control Register (0x0B)
BIT NO.
BIT NAME
FUNCTION
DESCRIPTION
B7
auto_reg
0 = Manual system
1 = Automatic system
Automatic system settings:
VDD_RF = VIN – 250 mV
VDD_A = VIN – 250 mV
VDD_X = VIN – 250 mV, but not higher than 3.4 V
Manual system settings:
See B2 to B0
B6
en_ext_pa
Support for external power
amplifier
Internal peak detectors are disabled, receiver inputs (RX_IN1 and
RX_IN2) accept externally demodulated subcarrier. At the same
time, the ASK/OOK pin becomes modulation output for external TX
amplifier.
B5
io_low
1 = Enable low peripheral
communication voltage
When B5 = 1, maintains the output driving capabilities of the I/O
pins connected to the level shifter under low-voltage operation.
Should be set 1 when VDD_I/O voltage is 1.8 V to 2.7 V.
B4
Unused
No function
Default is 0.
B3
Unused
No function
Default is 0.
B2
vrs2
Voltage set. B2 is the MSB.
vrs3_5 = L:
VDD_RF, VDD_A, VDD_X range is 2.7 V to 3.4 V.
See
,
, and
B1
vrs1
B0
vrs0
Table 6-27. Supply Regulator Setting, Manual 5-V System
REGISTER
OPTION BITS SETTING IN CONTROL REGISTER
ACTION
B7
B6
B5
B4
B3
B2
B1
B0
00
1
5-V system
0B
0
Manual regulator setting
0B
0
1
1
1
VDD_RF = 5 V, VDD_A = 3.5 V, VDD_X = 3.4 V
0B
0
1
1
0
VDD_RF = 4.9 V, VDD_A = 3.5 V, VDD_X = 3.4 V
0B
0
1
0
1
VDD_RF = 4.8 V, VDD_A = 3.5 V, VDD_X = 3.4 V
0B
0
1
0
0
VDD_RF = 4.7 V, VDD_A = 3.5 V, VDD_X = 3.4 V
0B
0
0
1
1
VDD_RF = 4.6 V, VDD_A = 3.5 V, VDD_X = 3.4 V
0B
0
0
1
0
VDD_RF = 4.5 V, VDD_A = 3.5 V, VDD_X = 3.4 V
0B
0
0
0
1
VDD_RF = 4.4 V, VDD_A = 3.5 V, VDD_X = 3.4 V
0B
0
0
0
0
VDD_RF = 4.3 V, VDD_A = 3.5 V, VDD_X = 3.4 V
