znbg3115 Zetex Semiconductors plc., znbg3115 Datasheet - Page 11
![no-image](/images/no-image-200.jpg)
znbg3115
Manufacturer Part Number
znbg3115
Description
Znbg3115 - Fet Bias Controller With Polarization Switch And Tone Detection
Manufacturer
Zetex Semiconductors plc.
Datasheet
1.ZNBG3115.pdf
(15 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
znbg3115Q16TC
Manufacturer:
ZETEX
Quantity:
20 000
APPLICATIONS INFORMATION(cont)
The following block diagram shows the main section of an LNB designed for use with the Astra series of satellites.
The ZNBG3115/16 is the core bias and control element of this circuit. The ZNBG provides the negative rail, FET
bias control, polarisation switch control, tone detection and band switching with the minimum of external
components. Compared to other discrete component solutions the ZNBG circuit reduces component count and
overall size required.
Tone detection and band switching is provided on the ZNBG3115/16 devices. The following diagrams describes
how this feature operates in an LNB and the external components required. The presence or absence of a 22kHz
tone applied to pin F
L
oscillator applications, selected by pin L
switch between -2.6V (disabled) and 0V (enabled). Referring to Figures 2 and 3 wiring pin L
source (e.g. a potential divider across V
force the L
Tone Detection Function
Note 1: 0 volts in typical LNB applications but ependent on extenal circuits.
ISSUE 2 - JUNE 2006
Single Universal LNB Block Diagram
B
L
G
V
. The L
OV
OSC
ND
B
B
and H
and H
B
B
outputs are designed to be compatible with both MMIC and discrete (bipolar or FET) local
outputs to provide the required oscillator supply, V
F
22kHz
—
22kHz
—
IN
IN
enables one of two outputs, L
ZNBG3115/16
L
Disabled
Enabled
Disabled
Enabled
B
OV
CC
. Referring to Figure 1 wiring pin L
and ground set to the required oscillator supply voltage, V
B
and H
11
H
Enabled
Disabled
Enabled
Disabled
B
B
. A tone present enables H
OSC
Regulator
, when enabled and 0V when disabled.
L
-3 volts
G
Note 1
V
OV
B
OSC
ND
to ground will force L
B
ZNBG3115
ZNBG3116
and tone absent enables
OV
to a positive voltage
H
G
-3 volts
V
Note 1
OSC
B
ND
B
and H
OSC
) will
B
to