A8286SETTR-TB ALLEGRO [Allegro MicroSystems], A8286SETTR-TB Datasheet - Page 12

• Manufacturer Part Number: A8286SETTR-TB
• Description: Dual LNB Supply and Control Voltage Regulator
• Manufacturer: ALLEGRO [Allegro MicroSystems]

A8286
Control Registers
All main functions of the A8286 are controlled through the
I
A8286 contains numerous control options, as well as featuring
two channels, it is necessary to have four Control registers. Each
2
C™-compatible interface via the 8-bit Control registers. As the
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
VSEL
VSEL
VSEL
VSEL
ODTx
ENBx
I0
I1
Table 2. Control Registers with Address (I1, I0) = 00 and 01
Bit
0
1
2
3
4
5
6
7
(I
2
3
0
1
2
x
C™-Compatible Write Register)
x
x
x
(Address: I1, I0 = 00)
These three bits provide incremental control over the voltage on the LNBx output.
The available voltages provide the necessary levels for all the common standards
plus the ability to add line compensation in increments of 333 mV. The voltage levels are
defined in table 4, Output Voltage Amplitude Selection.
Switches between the low level and high level output voltages on the LNBx output. 0 selects
the low level voltage and 1 selects the high level. The low-level center voltage is 12.709 V
nominal and the high level is 18.042 V nominal. These may be increased in steps of 333 mV
using the VSEL
Enables the overcurrent disable timer. When set to 1, and an overcurrent occurs for longer
than the detection time, the LNBx ouput on the channel is disabled. It is highly recom-
mended that the ODT function be enabled at all times. (When set to 0, if an overcurrent
occurs, the LNBx output will operate in current limit indefinitely.)
Enables the LNBx output. When set to 1 the LNBx output is switched on. When set to 0,
the LNBx output is disabled.
Address
Address
Channel 1
Dual LNB Supply and Control Voltage Regulator
VSEL
VSEL
VSEL
VSEL
ODT1
ENB1
I0
I1
0
1
2
3
1
1
1
1
2
x, VSEL
Name
1
(Address: I1, I0 = 01)
x and VSEL
Channel 2
VSEL
VSEL
VSEL
VSEL
ODT2
ENB2
I0
I1
0
0
1
2
3
x control register bits.
register contains up to 6 bits of data (bit 0 to bit 5), followed by
2 bits for the register address (bit 6 and bit 7). The power-up
states for the control functions are all 0s.
and the settings for output voltage:
2
2
2
2
The following tables define the control bits for each address
See table 4, Output Voltage
Amplitude Selection
0: LNBx = Low range
1: LNBx = High range
0: Overcurrent disable time off
1: Overcurrent disable time on
(setting ODT on at all times is
recommended)
0: Disable LNBx Output
1: Enable LNBx Output
Address Bit
Channel 1: 0
Channel 2: 1
Address Bit
Channel 1: 0
Channel 2: 0
Setting
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
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