MAX1365 Datasheet, PDF (14/25 Pages) Maxim Integrated Products – Stand-Alone, 4.5-/3.5-Digit Panel Meters with 4-20mA Output

Stand-Alone, 4.5-/3.5-Digit Panel Meters
with 4–20mA Output
SEGDP
SEGG
SEGF
SEGE
SEGD
SEGC
SEGB
SEGA
A B C D E F G DP A B C D E F G DP
DIGIT 1
A
F _GB
E
C
DP
D
Figure 4. 2-Digit Common-Cathode Configuration
DIGIT 2
A
FGB
E
C
DP
D
DIGIT 4 (MSD)
DIGIT 3
DIGIT 2
DIGIT 1
DIGIT 0 (LSD)
DATA
Figure 5. LED Voltage Waveform
T_ON
INTERDIGIT BLANKING TIME
T
43210432104
MSD
LSD
Current Output
The MAX1365/MAX1367 feature a 4–20mA (0 to 16mA)
current output for driving remote panel meters, data log-
gers, and process controllers in industrial applications.
The DAC output is proportional to the input of the ADC
and LED display. In the simplest configuration, connect
DAC_VOUT directly to CONV_IN to have the current out-
put (4–20mA or 0 to 16mA) follow the analog inputs.
Custom signal conditioning can be inserted between
DAC_VOUT and CONV_IN, or CONV_IN can be driven
independently by a voltage source if desired. See
Figures 11–14 for the transfer functions of the DAC and
V/I converter.
Note: The MAX1365/MAX1367 expect a 6kΩ (typ)
source impedance from the external voltage source
driving CONV_IN.
Current Offset
Set EN_I high for a current span of 4–20mA. Set EN_I low
for a current span of 0 to 16mA. See Table 5 for current
output.
Unipolar Mode
Set EN_BPM low to engage unipolar operation. In
unipolar mode, the current output at 4-20OUT (4–20mA
or 0 to 16mA) maps the analog input voltage (0 to 2V or
0 to 200mV). Negative voltages at the analog input
result in a 4mA or 0mA output, depending on the EN_I
setting. See Table 5 for current output. See Figures 12
and 13.
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