Texas Instruments Evaluation Board for the LMP7312 LMP7312MAEVAL/NOPB LMP7312MAEVAL/NOPB 데이터 시트
제품 코드
LMP7312MAEVAL/NOPB
2
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7
3
1
2
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(5
5
1
6
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3
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)
Hardware Setup
REGISTER PROGRAMMING SETUP
In order to use the on board SPI commands
generator to program the LMP7312 the following
jumpers need to be configured as follows:
generator to program the LMP7312 the following
jumpers need to be configured as follows:
J1
open
J2
open
J3
open
J6
short pin1 to pin 2
In order to use a microcontroller to program the
LMP7312 the following jumpers need to be
configured as follows:
LMP7312 the following jumpers need to be
configured as follows:
J1
short
J2
short
J3
short
J6
short pin2 to pin 3
Connect the external microcontroller to J7.
Refer to Table 3 for J7 pin out.
Refer to Table 3 for J7 pin out.
POWER SUPPLY SETUP
When the LMP7312 is programmed through the
onboard SPI command generator, a 5V supply is
needed to power the eval board:
onboard SPI command generator, a 5V supply is
needed to power the eval board:
•
Connect a +5V supply to the +Vs and GND
banana plugs
When the LMP7312 is programmed through a
microcontroller:
microcontroller:
•
Connect a +5V supply between +Vs and GND
banana plugs
•
Connect a supply (2.7V – 5.5V) that matches
microcontroller voltage range between +VIO
and GND banana plugs
and GND banana plugs
SOURCE SETUP
Attenuation input pair
If signal source impedance matching is desired,
solder the resistors R8 and R9 of appropriate
value.
If signal source impedance matching is desired,
solder the resistors R8 and R9 of appropriate
value.
Amplification input pair
The 50
The 50
Ω
shunt resistor (R1) between the inputs
needs to be removed if the amplification input
pair is not used as a current loop receiver.
pair is not used as a current loop receiver.
OUTPUT CONFIGURATION
The LMP7312 is able to work in both single
ended and differential output mode. The selection
of the output is made through the Vocm (output
common mode voltage) pin.
ended and differential output mode. The selection
of the output is made through the Vocm (output
common mode voltage) pin.
Differential mode
•
Open jumper J4
•
Short pin1 and pin2 of J5
•
Connect a supply in the range between 1V
and 5V to the +Vocm and GND banana plugs
Single ended mode
•
Short jumper J4
•
Short pin2 and pin3 of J5
•
Connect a supply in the range between 0V
and 5V between VR and GND banana plugs
COMPONENTS
If the device is configured in the differential output
mode
mode
,
the series resistances R2 and R3, RLd
and the capacitance CLd can be changed in
order to build a first order low pass filter with
desired bandwidth. In this configuration the
capacitance CLs and the resistance RLs should
be removed.
If the device is configured in the single-ended
output mode, the series resistance R3, RLs and
capacitance CLs can be changed in order to build
a first order low pass filter with desired
bandwidth. In this configuration the capacitance
CLd and the resistance RLd should be removed.
If the value of the shunt resistance R1 does not fit
the application needs, replace it as needed
order to build a first order low pass filter with
desired bandwidth. In this configuration the
capacitance CLs and the resistance RLs should
be removed.
If the device is configured in the single-ended
output mode, the series resistance R3, RLs and
capacitance CLs can be changed in order to build
a first order low pass filter with desired
bandwidth. In this configuration the capacitance
CLd and the resistance RLd should be removed.
If the value of the shunt resistance R1 does not fit
the application needs, replace it as needed
Using the Board
INPUT AND OUTPUT SIGNALS
Attenuation mode
Connect a signal at +IN_LS and –IN_LS BNC;
refer to the Datasheet for the allowed amplitude
according to the set gain.
Amplification mode
Connect a signal at +IN_CL and –IN_CL banana;
refer to the Datasheet for the allowed amplitude
according to the set gain.
Connect a signal at +IN_LS and –IN_LS BNC;
refer to the Datasheet for the allowed amplitude
according to the set gain.
Amplification mode
Connect a signal at +IN_CL and –IN_CL banana;
refer to the Datasheet for the allowed amplitude
according to the set gain.
PROGRAMMING THE LMP7312
The register in the LMP7312 can be programmed
using switches S1 and S2. S2 consists of five
switches
using switches S1 and S2. S2 consists of five
switches
labeled
B0,
B1,
B2,
B3,
B4,
corresponding to the five bits of the LMP7312
register. If the switch is up a “0” is programmed to
the corresponding bit. S1 is used to load the data
into the register of the LMP7312.
For example, to load the gain of 0.384V/V set S2
as follows:
Gain_1
register. If the switch is up a “0” is programmed to
the corresponding bit. S1 is used to load the data
into the register of the LMP7312.
For example, to load the gain of 0.384V/V set S2
as follows:
Gain_1
– Down 1
Gain_0
– Up
0
EN_CL
– Up
0
Null_SW – Up
0
HiZ
– Up
0
Then Push the switch S1 to load the data into the
register of the LMP7312.
Table 1 shows the allowed register values.
register of the LMP7312.
Table 1 shows the allowed register values.