TDA8261TW Philips Semiconductors, TDA8261TW Datasheet - Page 8

• Manufacturer Part Number: TDA8261TW
• Description: Satellite Zero-IF QPSK/8PSK downconverter with PLL synthesizer
• Manufacturer: Philips Semiconductors

Philips Semiconductors
P
The programmable address bits MA1 and MA0 offer the
possibility of having up to four TDA8260TW devices in the
same system. The relationship between the voltage
applied on pin AS and the value of bits MA1 and MA0 is
given in Table 3.
Table 3 I
P
Program bytes PD1 and PD2 contain the fifteen bits
N14 to N0 that set the main divider ratio. The ratio
N = N14
O
The mode of operation is set using bits T2, T1 and T0 in
control byte CD1; see Table 4.
Table 4 Mode selection
Note
1. Status at power-on: the tuning voltage output is
2004 Dec 02
0 to 0.1V
open-circuit
0.4V
0.9V
ROGRAMMABLE ADDRESS
ROGRAMMABLE MAIN DIVIDER RATIO
PERATING AND TEST MODES
T2
Satellite Zero-IF QPSK/8PSK
downconverter with PLL synthesizer
0
0
0
0
1
1
1
1
released and pin VT is in the high-impedance mode.
CC
CC
V
T1
to 0.6V
to V
0
0
1
1
0
0
1
1
AS
CC
2
2
C-bus address selection
14
CC
+ N13
T0
0
1
0
1
0
1
0
1
CC
normal operation
POR state = CP sink
1
CP sink
normal operation
2
CP off
CP source
/
2
2
f
13
ref
TEST MODE
f
DIV
MA1
+...+ N1
0
0
1
1
2 + N0.
(1)
off
f
1
f
f
2
f
f
XTAL
XTAL
XTAL
XTAL
XTAL
MA0
/
2
XTOUT
0
1
0
1
f
ref
f
DIV
8
R
Five reference divider ratios allow to adjust the
comparison frequency to different values, depending on
the compromise which has to be found between step size
and phase noise. The reference divider ratios and the
corresponding comparison frequencies are programmed
using bits R2, R1 and R0, as described in Table 5.
Table 5 Reference divider ratio
C
Four values of charge pump current can be chosen using
bits C1 and C0, according to Table 6.
Table 6 Typical charge pump current
R2
EFERENCE DIVIDER
HARGE PUMP CURRENT
0
0
0
0
1
1
1
1
C1
0
0
1
1
R1
0
0
1
1
0
0
1
1
C0
0
1
0
1
R0
0
1
0
1
0
1
0
1
DIVIDER RATIO
not allowed
not allowed
not allowed
I
CP
16
32
2
4
8
(ABSOLUTE VALUE)
1320 A
2320 A
420 A
900 A
TDA8261TW
Product specification
COMPARISON
FREQUENCY
not allowed
not allowed
not allowed
500 kHz
250 kHz
125 kHz
2 MHz
1 MHz