Datasheet

MAX1447/MAX1496/MAX1498
3.5- and 4.5-Digit, Single-Chip ADCs
with LED Drivers
_______________________________________________________________________________________ 9
Pin Description
PIN
MAX1496
MAX1447/
MAX1498
NAME
FUNCTION
1
31
VNEG
-2.5V Charge-Pump Voltage Output. Connect a 0.1µF capacitor to GND.
232REF-
Negative Reference Voltage Input. For internal-reference operation, connect REF- to GND.
For external-reference operation, bypass REF- to GND with a 0.1µF capacitor and set V
REF-
from -2.2V to +2.2V, provided V
REF+
> V
REF-
.
31REF+
Positive Reference Voltage Input. For internal-reference operation, connect a 4.7µF
capacitor from REF+ to GND. For external-reference operation, bypass REF+ to GND with a
0.1µF capacitor and set V
REF+
from -2.2V to +2.2V, provided V
REF+
> V
REF-
.
42AIN+
Positive Analog Input. Positive side of fully differential analog input. Bypass AIN+ to GND
with a 0.1µF or greater capacitor.
53AIN-
Negative Analog Input. Negative side of fully differential analog input. Bypass AIN- to GND
with a 0.1µF or greater capacitor.
64ISET
Segment Current Controller. Connect to ground through a resistor to set the segment
current. See Table 5 for current selection.
75GND Ground
8—V
DD
Analog and Digital Circuit Supply Voltage. Connect V
DD
to a +2.7V to +5.25V power supply.
Bypass V
DD
to GND with a 0.1µF capacitor and a 4.7µF capacitor.
98
INTREF
Internal-Reference Logic Input. Connect to GND to select external-reference mode. Connect
to DV
DD
for the MAX1447/MAX1498 and V
DD
for the MAX1496 to select the internal-
reference mode.
10 9
RANGE
Range Logic Input. RANGE controls the fully differential analog input range. Connect to
GND for the ±2V input range. Connect to DV
DD
(MAX1447/MAX1498) or V
DD
(MAX1496) for
the ±200mV input range.
11 10
DPSET1
Decimal-Point Logic-Input 1. Controls the decimal point of the LED. See the Decimal-Point
Control section.
12 11
DPSET2
Decimal-Point Logic-Input 2. Controls the decimal point of the LED. See the Decimal-Point
Control section.
13 12
PEAK
Peak Logic Input. Connect to DV
DD
(MAX1447/MAX1498) or V
DD
(MAX1496) to display the
highest ADC value on the LED. Connect to GND to disable the peak function.
14 13
HOLD
Hold Logic Input. Connect to DV
DD
(MAX1447/MAX1498) or V
DD
(MAX1496) to hold the
current ADC value on the LED. Connect to GND to update the LED at a rate of 2.5Hz and
disable the hold function. For the MAX1447, only placing the device into hold mode initiates
an offset mismatch calibration. Assert HOLD high for a minimum of 2s to ensure the
completion of offset mismatch calibration.
15 14 DIG0 Digit 0 Driver
16 15 DIG1 Digit 1 Driver
17 16
GLED
Ground for LED Display Digit Driver
18 17 DIG2 Digit 2 Driver