MAX1366ECM-T Maxim Integrated, MAX1366ECM-T Datasheet - Page 14

• Manufacturer Part Number: MAX1366ECM-T
• Description: LED Display Drivers
• Manufacturer: Maxim Integrated

Specifications of MAX1366ECM-T

• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C

Microcontroller-Interface, 4.5-/3.5-Digit Panel
Meters with 4–20mA Output
Figure 2. Segment Connection for the MAX1366 (4.5 Digits)
clock source for best 50Hz/60Hz rejection perfor-
mance. Other external clock frequencies allow for cus-
tom conversion rates. A 2.4576MHz clock signal
reduces the conversion rate and the LED update rate
by a factor of two while keeping good 50Hz/60Hz noise
rejection. The MAX1366/MAX1368 operate with an
external clock source of up to 5.05MHz.
The MAX1366/MAX1368 contain an internal charge pump
to provide the negative supply voltage for the internal
analog input/reference buffers. The bipolar input range of
the analog input/reference buffers allows this device to
accept negative inputs with high source impedances.
Connect a 0.1µF capacitor from NEGV to GND.
The MAX1366 has a 4.5-digit common-cathode display
driver, and the MAX1368 has a 3.5-digit common-cath-
ode display driver.
Figures 2 and 3
standard seven-segment LED display. The LED update
rate is 2.5Hz.
The MAX1366/MAX1368 automatically display the results
of the ADC, if desired. The MAX1366/MAX1368 also
allow independent control of the LED driver through the
serial interface, allowing for data processing of the ADC
result before showing the result on the LED. Additionally,
each LED segment can be individually controlled (see
the LED Segment-Display Register sections).
14
Figure 3. Segment Connection for the MAX1368 (3.5 Digits)
F
______________________________________________________________________________________
DIGIT 4
D
A
G
F
DIGIT 4
D
G
A
C
B
DP
F
E
DIGIT 3
C
B
show the connection schemes for a
G
D
A
DP
F
E
B
DIGIT 3
C
DP
G
D
A
E
F
DIGIT 2
B
C
A
G
D
DP
LED Driver (Table 1)
E
F
C
B
DIGIT 2
DP
A
G
D
E
F
DIGIT 1
C
B
A
G
D
DP
Charge Pump
F
E
B
C
DIGIT 1
DP
A
G
D
F
E
DIGIT 0
B
C
A
G
D
DP
C
B
DP
Figure 4
tion for two digits. In common-cathode configuration,
the cathodes of all LEDs in a digit are connected
together. Each segment driver of the MAX1366/
MAX1368 connects to its corresponding LED’s anodes.
For example, segment driver SEGA connects to all LED
segments designated as A. Similar configurations are
used for other segment drivers.
The MAX1366/MAX1368 use a multiplexing scheme to
drive one digit at a time. The scan rate is fast enough to
make the digits appear to be lit.
data-timing diagram for the MAX1366/MAX1368 where
t is the display scan period (typically around 1/512Hz
or 1.9531ms). t
time each digit is on and is calculated as follows:
The MAX1366/MAX1368 allow for full decimal-point
control and feature leading-zero suppression.
Use the DPON, DPSET1, and DPSET2 bits in the con-
trol register to set the value of the decimal point
2 and
underrange display is shown in
The MAX1366/MAX1368 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.
Table 1. LED Priority Table
X = Don’t care.
SEG_SEL
1
0
0
0
0
3). The MAX1366/MAX1368 overrange and
shows a typical common-cathode configura-
t
SPI/ADC
ON
X
1
0
0
0
ON
=
5
t
in
=
Figure 5
1 95312
HOLD
.
X
X
1
0
0
5
Decimal-Point Control
PEAK
ms
Table
denotes the amount of
X
X
X
1
0
=
Figure 5
390 60
Current Output
LED segment
registers
LED display register
(user written)
LED display register
Peak register
ADC result register
DISPLAY VALUES
4.
.
µ
FORM
s
shows the
(Tables