MAX2120_10 Datasheet, PDF (12/21 Pages) Maxim Integrated Products – Complete, Direct-Conversion Tuner for DVB-S and Free-to-Air Applications

Complete, Direct-Conversion Tuner for DVB-S
and Free-to-Air Applications
Table 7. VCO Register
BIT NAME
BIT LOCATION (0 = LSB)
VCO[4:0]
7–3
VAS
2
ADL
1
ADE
0
DEFAULT
11001
FUNCTION
Controls which VCO is activated when using manual VCO
programming mode. This also serves as the starting point for
the VCO autoselect mode.
VCO Autoselection (VAS) Circuit
1
0 = Disable VCO selection must be program through I²C
1 = Enable VCO selection controlled by autoselection circuit
Enables or disables the VCO tuning voltage ADC latch when
0
the VCO autoselect mode (VAS) is disabled.
0 = Disables the ADC latch
1 = Latches the ADC value
Enables or disables VCO tuning voltage ADC read when the
0
VCO autoselect mode (VAS) is disabled.
0 = Disables ADC read
1 = Enables ADC read
Table 8. Lowpass Filter Register
BIT NAME
BIT LOCATION (0 = LSB)
LPF[7:0]
7–0
DEFAULT
01001011
FUNCTION
Sets the baseband lowpass filter 3dB corner frequency. 3dB
corner frequency = 4MHz + (LPF[7:0] - 12) x 290kHz.
Table 9. Control Register
BIT NAME
BIT LOCATION (0 = LSB)
STBY
7
X
6
PWDN
5
X
4
BBG[3:0]
3–0
DEFAULT
0
X
0
X
0000
FUNCTION
Software standby control.
0 = Normal operation
1 = Disables the signal path and frequency synthesizer, leaving
only the 2-wire bus, crystal oscillator, XTALOUT buffer, and
XTALOUT buffer divider active
Don’t care.
Factory use only.
0 = Normal operation; other value is not tested.
Don’t care.
Baseband gain setting (1dB typical per step).
0000 = Minimum gain (0dB)
…
1111 = Maximum gain (15dB typical)
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