SI2107-D-FM Silicon Laboratories Inc, SI2107-D-FM Datasheet - Page 34

• Manufacturer Part Number: SI2107-D-FM
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2107-D-FM

• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Lead Free Status / Rohs Status: Compliant

Si2107/08/09/10
When the tone format select bit, TFS, is programmed to
use an external oscillator, the TT bit directly controls the
output of the TGEN pin, and the TR bit directly reflects
the input of the TDET pin. In this mode, the tone
direction control bit, TDIR, directly controls the output of
the DRC pin.
6.8. On-Chip LNB DC-DC Step-Up
In addition to the LNB signaling controller present on all
device versions, Si2108 and Si2110 devices contain an
internal supply controller circuit. This internal dc-dc
controller can be enabled via register bit LNB_EN. The
internal circuit requires the connection of an external
circuit with a specified bill-of-materials, and this
combination generates the selected LNB voltage with
superimposed one-way or two-way LNB signaling
communications. Si2108/10 devices include short-
circuit protection, overcurrent protection, and a step-up
dc-dc controller to implement a low-cost LNB power
supply using minimal external components. The
34
End of continuous
tone (if present)
Controller (Si2108/10 Only)
> 15ms
Change of voltage
(if required)
reply requested)
1st message (no
> 25ms
Figure 21. LNB Signaling Sequence
(reply requested)
2nd message
Rev. 1.0
required circuit for DiSEqC1.x operation is illustrated in
Figure 9 on page 14. A circuit for DiSEqC2.x operation
is shown in Figure 6 on page 12.
When the LNB supply circuit is populated, the Si2108/
10 detects a connection to ground on the ISEN pin via
R10 during reset and configures the LNB pins for dc-dc
converter control instead of providing the interfaces to
an external LNB supply regulator discussed in the
previous section. See Table 17.
Pin
< 150ms
10
12
Table 17. LNB Pin Configuration
7
9
8
Reply to 2nd
message
Connected
> 15ms
VSEN
LNB2
LNB1
PWM
ISEN
LNB Supply Circuit
Tone Burst
> 15ms
Start of continuous
tone (if present)
Unconnected
TGEN
TDET
DRC
DCS
NC