ISG4042EU-T Datasheet, PDF (7/8 Pages) SIRENZA MICRODEVICES – 5V CATV MODEM RF TUNER AND TRANSMITTER

ISG4042EU-T
PROGRAMMING INFORMATION FOR RX
There are four 22-bit words needed to program the RX. PLL2 has the following words.
LSB
MSB
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 0 0 R2
1 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 1 0 0 1 0 N2
PLL1 has the following words.
LSB
MSB
0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 R1
1 1 A A A A A A A B B B B B B B B B B B 0 0 N1
[ ] Where N =
Tune Frequency (MHz) + 1100
0.25
and
[ ^{B = N – Mod N}
64
64
A = N – 64 (B)
They should be entered using the serial data input timing diagram below.
Serial Data Input Timing
DATA N20: MSB N19
(R20: MSB) (R19)
N10 N9
C2
(R10) (R9) (R8) (C2)
C1: LSB
(C1: LSB)
CLOCK
tCWL
LE
OR
tCS
tCH
LE
tES
tCWH
tEW
Rx Timing Characteristics
SYMBOLS
PARAMETERS
VOH
VOL
tCS
tCH
tCWH
tCWL
tES
tEW
High-Level Output Voltage
Low-Level Output Voltage
Data to Clock Set Up Time
Data to Clock Hold Time
Clock Pulse Width High
Clock Pulse Width Low
Clock to Load Enable Set Up Time
Load Enable Pulse Width
VALUE
UNITS
MIN
TYP
MAX
4.1
V
0.4
V
50
ns
10
ns
50
ns
50
ns
50
ns
50
ns
Notes:
1. Parenthesis data indicates programmable reference divider data.
2. Data shifted into register on clock rising edge.
3. Data is shifted in MSB first.
4. Pin 6 LD_TX held high.
Test Conditions:
The Serial Data Input Timing is tested using a symmetrical waveform around VCC/2. The test
waveform has an edge rate of 0.6V/ns with amplitudes of 2.2 V @ VCC = 2.7 V and 2.6 V @ VCC
= 5.5 V.
303 S. Technology Court, Broomfield, CO 80021
303-327-3030
7
www.sirenza.com
REV. A
4/1/2005