MAX1497 Maxim, MAX1497 Datasheet - Page 29

• Manufacturer Part Number: MAX1497
• Description: 3.5- and 4.5-Digit / Single-Chip ADCs with LED Drivers and C Interface
• Manufacturer: Maxim

For a 28-pin PDIP package, VLED - V
have the following condition to ensure it operates safe-
ly:
The MAX1499 TQFP package can operate safely for all
supply voltages provided V
Integral nonlinearity (INL) is the deviation of the values
on an actual transfer function from a straight line. This
straight line is either a best-straight-line fit or a line
drawn between the end points of the transfer function,
once offset and gain errors have been nullified. INL for
the MAX1497/MAX1499 is measured using the end-
point method.
VLED - V
TOP VIEW
3.5- and 4.5-Digit, Single-Chip ADCs with LED
DIODE
0.8V < VLED - V
DOUT
VNEG
SCLK
REF+
REF-
AIN+
GND
AIN-
CLK
EOC
V
I
DIN
SET
CS
DD
VLED - V
= [571mW - (5.25V x 2mA) - 5.25V x
1.080mA] / [(127 / 128) x 25.5mA x 8]
______________________________________________________________________________________
10
11
12
13
14
1
2
3
4
5
6
7
8
9
SSOP/PDIP
MAX1497
DIODE
DIODE
DIODE
= 2.80V
32-Pin TQFP Package
> 1.5V.
28
27
26
25
24
23
22
21
20
19
18
17
16
15
< 3.18V
SEGDP
SEGG
SEGF
VLED
SEGE
SEGD
SEGC
SEGB
SEGA
DIG3
DIG2
GLED
DIG1
DIG0
Definitions
DIODE
should
INL
Drivers and µC Interface
Differential nonlinearity (DNL) is the difference between
an actual step width and the ideal value of ±1 LSB. A
DNL error specification of less than ±1 LSB guarantees
no missing codes and a monotonic transfer function.
Rollover error is defined as the absolute-value differ-
ence between a near positive full-scale reading and
near negative full-scale reading. Rollover error is tested
by applying a full-scale positive voltage, swapping
AIN+ and AIN-, and adding the results.
Ideally, with AIN+ connected to AIN-, the MAX1497/
MAX1499 digital ADC result is 0000h. Zero input read-
ing is the measured deviation from the ideal 0x0000
and the actual measured point.
Gain error is the amount of deviation between the mea-
sured full-scale transition point and the ideal full-scale
transition point.
TOP VIEW
DV
AV
REF+
AIN+
AIN-
GND
CLK
I
SET
DD
DD
1
2
3
4
5
7
8
6
32
9
10
31
11
30
MAX1499
TQFP
Pin Configurations
29
12
13
28
Zero Input Reading
27
14
15
26
Rollover Error
16
25
Gain Error
24 SEGE
23 SEGD
22
21
20
19
18
17
SEGC
SEGB
SEGA
DIG4
DIG3
DIG2
DNL
29