L64704 LSI Logic Corporation, L64704 Datasheet - Page 28

• Manufacturer Part Number: L64704
• Description: Satellite Decoder Technical Manual 5/97
• Manufacturer: LSI Logic Corporation

2.5
Carrier
Synchronizer
Loop Controls
2-6
PLLVDD
PLLVSS
Carrier Synchronizer Loop controls are used to synchronize the I/Q
Down Converter circuitry. Carrier Synchronizer Loop controls are dis-
cussed in
CAR_DCLKP/N
CAR_PED[1:0]
CAR_VCO1P/N
CAR_VCO2P/N
L64704 Signal Definitions
Section 5.6, “Carrier Synchronizer.”
PLL Power
Power supply pin for the PLL module. This pin is normally
connected to the system power (V
PLL Ground
Power supply pin for the PLL module. This pin is normally
connected to the system ground plane.
VCO Prescaler Input
The CAR_DCLK pins are differential inputs for the pre-
scaled (divided) Carrier VCO clock (typically = VCO
frequency / 32).
Carrier Phase Error Detector
These pins are the 2-bit outputs from the Phase Error
Detector. You use the CAR_PED outputs for carrier loop
implementation in combination with an external digital to
analog converter. It should be used when operating at
rates less than 5 Mbaud.
Carrier Loop VCO Control 1
When CAR_OUT_SEL (Group 4, APR 33) is set to 0,
these pins are the Positive/Negative
puts that control the carrier VCO frequency.
CAR_VCO1P/N feed external RC circuit number 1. A
LOW output decreases the carrier VCO frequency. A
HIGH output increases the carrier VCO frequency. A high
impedance level maintains the carrier VCO frequency.
When CAR_OUT_SEL is set to 1, these pins carry the
CAR_PED.2 and CAR_PED.3 signals.
Carrier Loop VCO Control 2
When CAR_OUT_SEL (Group 4, APR 33) is set to 0,
these pins are the Positive/Negative
puts that control the carrier VCO frequency.
CAR_VCO2P/N feed external RC circuit number 2. A
LOW output decreases the carrier VCO frequency. A
DD
) plane.
modulated out-
modulated out-
Output
Output
Output
Input
Input
Input