MAX1498ECJ+ Maxim Integrated Products, MAX1498ECJ+ Datasheet - Page 13

• Manufacturer Part Number: MAX1498ECJ+
• Description: IC ADC 4 1/2DIG W/LED DVR 32TQFP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1498ECJ+

• Number Of Bits: 4.5 Digit
• Sampling Rate (per Second): 5
• Number Of Converters: 1
• Power Dissipation (max): 1.65W
• Voltage Supply Source: Analog and Digital
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 5. Two-Digit Common-Cathode Configuration
Figure 6. LED Voltage Waveform—MAX1447/MAX1498
Figure 7. LED Voltage Waveform—MAX1496
SEGDP
SEGG
SEGD
SEGC
SEGB
SEGA
SEGF
SEGE
A
B
C
F
E
DIGIT 1
D
G
D
A
______________________________________________________________________________________
E
B
C
F
DP
DIGIT 3 (MSD)
DIGIT 4 (MSD)
DIGIT 0 (LSD)
DIGIT 0 (LSD)
G
DIGIT 2
DIGIT 1
DIGIT 3
DIGIT 2
DIGIT 1
DP
DATA
DATA
3.5- and 4.5-Digit, Single-Chip ADCs
A
B
C
MSD
E
MSD
T
F
T
ON
3
ON
4
DIGIT 2
D
A
G
D
2
3
E
C
B
T
F
DP
1
T
2
G
LSD
0
1
DP
LSD
3
0
2
4
Figure 5 shows a typical common-cathode configura-
tion for two digits. In common-cathode configuration,
the cathodes of all LEDs in a digit are connected
together. Each segment driver of the MAX1447/
MAX1496/MAX1498 connects to its corresponding
LED’s anodes. For example, segment driver SEGA con-
nects to all LED segments designated as A. Similar
configurations are used for other segment drivers.
The MAX1447/MAX1496/MAX1498 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. Figures 6 and
7 show data-timing diagrams for the MAX1447/
MAX1496/MAX1498, where T is the display scan period
(typically around 1/512Hz or 1.9531ms for the
MAX1447/MAX1498, and 1/640Hz or 1.5625ms for the
MAX1496). T
of time each digit is on and is calculated as follows:
T
T
1
ON
ON
3
=
=
0
2
T
T
5
4
=
=
3
1
1 95312
1 5625
.
.
ON
2
0
with LED Drivers
4
5
in Figures 6 and 7 denotes the amount
ms
1
4
ms
=
=
390 60
390 60
.
.
µ
µ
s MAX
s MAX
(
(
1496
1447
)
/
MAX
1498
13
)