MAX1495CCJ+ Maxim Integrated Products, MAX1495CCJ+ Datasheet - Page 18

• Manufacturer Part Number: MAX1495CCJ+
• Description: IC ADC 4.5 DGT LCD DVR 32-TQFP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1495CCJ+

• Display Type: LCD
• Configuration: 7 Segment + 2 Annunciators
• Digits Or Characters: A/D 4.5 Digits
• Current - Supply: 980µA
• Voltage - Supply: 2.7 V ~ 5.25 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 32-LQFP
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Interface: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
offers enhanced offset calibration on demand. Connect
HOLD to DV
bration.
The MAX1491/MAX1493/MAX1495 feature peak detec-
tion circuitry. When activated (PEAK connected to DV
the devices display only the highest voltage measured to
the LCD. First, the current ADC result is displayed. Then
the new ADC conversion result is compared to this value.
If the new value is larger than the previous peak value,
the new value is displayed. If the new value is less than
the previous peak value, the display remains unchanged.
Connect PEAK to GND to clear the peak value and dis-
able the peak function. The peak function is only valid for
the -19,487 to +19,999 range for the MAX1493/
MAX1495 and -1217 to +1999 for the MAX1491.
The MAX1491/MAX1493/MAX1495 feature data HOLD
circuitry. When activated (HOLD connected to DV
the devices hold the current reading on the LCD.
The MAX1491/MAX1493/MAX1495 feature a low-battery
detection input. When the voltage at LOWBATT drops
below 2.048V (typ), the LOWBATT segment of the LCD
turns on.
Connect the differential inputs of the MAX1491/
MAX1493/MAX1495 to the bridge network of the strain
gauge. In Figure 13, the analog supply voltage powers
the bridge network and the MAX1491/MAX1493/
MAX1495 along with its reference voltage. The
MAX1491/MAX1493/MAX1495 handle an analog input
voltage range of ±200mV or ±2V full scale. The ana-
log/reference inputs of the part allow the analog input
range to have an absolute value anywhere between
-2.2V and +2.2V.
To measure 4–20mA signals, connect a shunt resistor
across AIN+ and AIN- to create the ±2V or ±200mV
input voltage (see Figure 14).
Table 4. LCD Priority Table
18
HOLD
DV
GND
GND
______________________________________________________________________________________
DD
DD
for 2s to perform enhanced offset cali-
PEAK
DV
Strain Gauge Measurement
GND
X
DD
4–20mA Measurement
Latest ADC result
Current value
DISPLAYS
Peak value
Low Battery
Peak
Hold
DD
DD
),
),
Figure 13. Strain-Gauge Application with the MAX1491/MAX1493/
MAX1495
Figure 14. 4–20mA Measurement
DUMMY
ACTIVE
GAUGE
GAUGE
4–20mA
0.1µF
R
REF
0.1µF
R
R
R
0.1µF
0.1µF
0.1µF
0.1µF
0.1µF
4.7µF
REF+
REF-
AIN+
AIN-
AV
R = 100
DD
ANALOG SUPPLY
MAX1491
MAX1493
MAX1495
10
FERRITE
GND
Ω
BEAD
Ω
for ±200mV RANGE
for ±2V RANGE
AIN+
AIN-
INTREF
DV
V
DD
NEG
0.1µF
MAX1491
MAX1493
MAX1495
±1.8.8.8.8
0.1µF
4.7µF