Atmel ATR4262M1 - Manual (Page 9)

9
4994BS–AUDR–05/08
ATR4262M1 [Preliminary]
10. Double Tuner Application
Figure 10-1. Double Tuner Operation
10.1 Two-Wire Interface-Bus Address Modes
To allow programming of both ICs (e.g., double tuner), SCL and SDA can be connected to both
ICs.
There are two different modes for ENABLE. For example, the ENABLE pin of the master IC is
not connected (open mode). Only a capacitor to ground is required to avoid oscillations of the
ENABLE pin. To program the master IC for open mode, the address byte C2h must be used.
The ENABLE pin of the other IC (slave) has to be set to high. The applied voltage for high mode
should be in the range of 2.5V to 5.3V. Address byte C0h is used as the slave in this case.
Another possibility is the use of separate ENABLE lines which can be controlled by a
microcontroller.
VCOBUF
ATR4262M1
VTUNE
or DAC
25
27 or
18
ATR4262M1
100 pF
VCOBUF
SW2
SDA
12
25
REF2
REF1
REF2
REF1
REF
CLK1
10 nF*
REF
CLK2
Master Slave
SCL
10 nF
ENABLE ENABLE
ENABLE1 SDA ENABLE2 SCL
5V
(high)
270 pF*
1 µH*
IFOUT1 IFOUT2
IFOUT1 IFOUT2 IFOUT1 IFOUT2
34 35
32
31 31
18
19
17
SDA
SCL 19
32
17
10,11
10 nF*
270 pF*
1 µH*
IFOUT1 IFOUT2
34 35
*) optional