Datasheet
MAX1447/MAX1496/MAX1498
3.5- and 4.5-Digit, Single-Chip ADCs
with LED Drivers
_______________________________________________________________________________________ 5
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
LED DRIVERS (Table 5)
LED Supply Voltage V
LED
2.70 5.25
V
LED Shutdown Supply Current I
SHDN
LED driver shutdown mode 10 µA
LED Supply Current I
LED
Seven segments and decimal point on,
R
ISET
= 25kΩ
176
180 mA
MAX1447/MAX1498
512
Display Scan Rate f
OSC
MAX1496
640
Hz
Segment Current Slew Rate
∆I
SEG
/∆t
25
mA/µs
DIG_ Voltage Low V
DIG
I
DIG_
= 176mA
0.178 0.300
V
Segment Drive Source Current
Matching
∆I
SEG
3 ±10 %
Segment Drive Source Current I
SEG
V
LED
- V
SEG
= 0.6V, R
ISET
= 25kΩ
16.0 21.5 25.5
mA
Interdigit Blanking Time 4µs
ELECTRICAL CHARACTERISTICS (continued)
(AV
DD
= DV
DD
= V
DD
= +2.7V to +5.25V, GND = 0, V
LED
= +2.7V to +5.25V, GLED = 0, V
REF+
- V
REF-
= 2.048V (external reference),
C
REF+
= C
REF-
= 0.1µF, C
VNEG
= 0.1µF. Internal clock mode, unless otherwise noted. All specifications are at T
A
= T
MIN
to T
MAX
.
Typical values are at T
A
= +25°C, unless otherwise noted.)
Note 1: Integral nonlinearity is the deviation of the analog value at any code from its theoretical value after nulling the gain error and
offset error.
Note 2: Offset calibrated.
Note 3: Offset nulled.
Note 4: Drift error is eliminated by recalibration at the new temperature.
Note 5: The input voltage range for the analog inputs is given with respect to the voltage on the negative input of the differential pair.
Note 6: V
AIN
+ or V
AIN
- = -2.2V to +2.2V. V
REF
+ or V
REF
- = -2.2V to +2.2V. All input structures are identical. Production tested on
AIN+ and REF+ only.
Note 7: Power-supply currents are measured with all digital inputs at either GND or DV
DD
.
Note 8: Measured at DC by changing the power-supply voltage from 2.7V to 5.25V and measuring the effect on the conversion
error with external reference. PSRR at 50Hz and 60Hz exceeds 120dB with filter notches at 50Hz and 60Hz (Figure 2).
Note 9: LED drivers are disabled.