SI4708-C Datasheet, PDF (27/40 Pages) Silicon Laboratories – BROADCAST FM RADIO TUNER FOR PORTABLE APPLICATIONS

Si4708/09-C
Register 07h. Test 1
Bit D15
D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Name Reserved AHIZEN
Reserved
Type R/W
R/W
R/W
Reset value = 0x0100
Bit
Name
Function
15
Reserved Always write to zero.
14
AHIZEN
Audio High-Z Enable.
0 = Disable (default).
1 = Enable.
Setting AHIZEN maintains a dc bias of 0.5 x V_IO on the LOUT and ROUT pins to pre-
vent the ESD diodes from clamping to the V_IO or GND rail in response to the output
swing of another device. Register 07h containing the AHIZEN bit must not be written
during the powerup sequence and high-Z only takes effect when in powerdown and
V_IO is supplied. Bits 13:0 of register 07h must be preserved as 0x0100 while in pow-
erdown and as 0x3C04 while in powerup.
13:0
Reserved If written, these bits should be read first and then written with their pre-existing values.
Do not write during powerup.
Register 08h. Test 2
Bit D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Name
Reserved
Type
R/W
Reset value = 0x0000
Bit
Name
Function
15:0
Reserved If written, these bits should be read first and then written with their pre-existing values.
Do not write during powerup.
Rev. 1.2
27