Rainbow Electronics MAX3580 - Manual (Page 13)

MAX3580
Direct-Conversion TV Tuner
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Register Descriptions
N-Divider Integer (Register Address 0x00)
N<7:0>: VCO Integer-N Divider Ratio
N-Divider Frac2 (Register Address 0x01)
MP: Minimum CP Pulse Width. Always set to 0
(factory use only).
LI1, LI0; CP Linearity Control. Always set to 00
(factory use only).
INT: Integer Mode ON/OFF. Set to 0 for normal
operation.
F<19:16>: MSB of Main Divider Fractional Divide Ratio
N-Divider Frac1, Frac0
(Register Address 0x02, 0x03)
F<15:0> 16 LSB of Main Divider Fractional Divide
Ratio
Tracking Filter Series Capacitor
(Register Address 0x04)
TFS<7:4>: Tracking Filter Parallel Capacitor.
TFS<3:0>: Tracking Filter Series Capacitor.
See the RF tracking filter description in the
Applications
Information section.
Tracking Filter Parallel Capacitor and VCO Control
(Register Address 0x05)
VCO_DIV1, VCO_DIV0: VCO Post Divider
00 = Divide by 4 use for RF frequencies of 540 to
868 MHz
01 = Divide by 8 use for RF frequencies of 470 to
550 MHz
10 = Divide by 16 use for RF frequencies of 170 to
230 MHz
11 = Divide by 32 is not used
RFS: RF Input Select
0 = RFIN2 selected
1 = RFIN selected
TF_BS: Tracking Filter Band Select
1 = VHF band
0 = UHF band
TFP<4:0>: Tracking Filter Shunt Capacitor
See the RF tracking filter description in the
Applications
Information section.
PLL Configuration (Register Address 0x06)
LF_DIV2, LF_DIV1, LF_DIV0: Prescaler for Internal
Low Frequency Clocks
000 - 110 = Divided by 8 to 14 for REF crystal fre-
quencies of 15MHz to 28MHz
111 = Divide by 2 for REF crystal frequencies of
4MHz
ADLY1, ADLY0: VCO Autotuner Delay Selection
CPS: Charge-Pump Current Mode
0 = Controlled by ICP bit
1 = Controlled by VCO autotuner
ICP: Charge-Pump Current
0 = 600µA
1 = 1200µA
RDIV: PLL Reference Divider Ratio
0 = Divide by 1
1 = Divide by 2
Test Functions (Register Address 0x07)
CP_TST<2:0>: Charge-Pump Test Modes
000 = Normal operation
100 = Low impedance*
101 = Source
110 = Sink
111 = High impedance
LD_MUX: Lock-Detector Mode
000 = Normal operation: high = PLL locked,
low = unlocked
001 = Monitor N-divider output, post-divided by 2
010 = Monitor R-divider output*
011 = Modulator test vector output
(factory use only)
1XX = Bias current trim (factory use only)
* Not production tested.