Rainbow Electronics MAX1499 User Manual
General Description
The MAX1497/MAX1499 low-power, 3.5- and 4.5-digit,
analog-to-digital converters (ADCs) with integrated lightemitting diode (LED) drivers operate from a single 2.7V
to 5.25V power supply. They include an internal reference, a high-accuracy on-chip oscillator, and a multiplexed LED display driver. An internal charge pump
generates the negative supply needed to power the
integrated input buffers for single-supply operation. The
ADC is configurable for either a ±2V or ±200mV input
range and it outputs its conversion results to an LED
and/or to a microcontroller (µC). Microcontroller
communication is possible through an SPI™-/QSPI™/MICROWIRE™-compatible serial interface. The
MAX1497 is a 3.5-digit (±1999 count) device and the
MAX1499 is a 4.5-digit (±19,999 count) device.
The MAX1497/MAX1499 do not require external precision integrating capacitors, autozero capacitors, crystal
oscillators, charge pumps, or other circuitry required
with dual-slope ADCs (commonly used in panel meter
circuits).
These devices also feature on-chip buffers for the differential signal and reference inputs, allowing direct
interface with high-impedance signal sources. In addition, they use continuous internal offset-calibration and
offer >100dB rejection of 50Hz and 60Hz line noise.
Other features include data hold and peak detection,
overrange and underrange detection, and a user-programmable low-battery monitor.
The MAX1499 is available in a 32-pin, 7mm ✕7mm
TQFP package and the MAX1497 is available in 28-pin
SSOP and 28-pin PDIP packages. All devices in this
family operate over the -40°C to +85°C extended temperature range.
Applications
Digital Panel Meters
Hand-Held Meters
Digital Voltmeters
Digital Multimeters
Features
♦ High Resolution
MAX1499: 4.5 Digits (±19,999 Count)
MAX1497: 3.5 Digits (±1999 Count)
♦ Sigma-Delta ADC Architecture
No Integrating Capacitors Required
No Autozeroing Capacitors Required
>100dB of Simultaneous 50Hz and 60Hz
Rejection
♦ Operate from a Single 2.7V or 5.25V Supply
♦ Selectable Input Range of ±200mV or ±2V
♦ Selectable Voltage Reference: Internal 2.048V or
External
♦ Internal High-Accuracy Oscillator Needs No
External Components
♦ Automatic Offset Calibration
♦ Low Power (Exclude LED Driver Current)
Maximum 664µA Operating Current
Maximum 268µA Shutdown Current
♦ Small 32-Pin, 7mm x 7mm TQFP Package (4.5
Digits), 28-Pin SSOP Package (3.5 Digits)
♦ Also Available in a PDIP Package (3.5 Digits)
♦ Multiplexed LED Drivers
Resistor-Programmable Segment Current
♦ SPI-/QSPI-/MICROWIRE-Compatible Serial
Interface
♦ Extended Temperature Range (-40°C to +85°C)
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
19-3054; Rev 1a; 2/04
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
PART
TEMP RANGE
PIN-
RESOLUTION
(DIGITS)
MAX1497EAI*
28 SSOP 3.5
MAX1497EPI
28 PDIP 3.5
MAX1499ECJ
32 TQFP 4.5
Pin Configurations appear at end of data sheet.
*Future product—contact factory for availability.
SPI/QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
PACKAGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
AVDDto GND (MAX1499).........................................-0.3V to +6V
DV
DD
to GND (MAX1499) ........................................-0.3V to +6V
AIN+, AIN- to GND (MAX1499) ...........VNEG to (AV
DD
to +0.3V)
REF+, REF- to GND (MAX1499)......... VNEG to (AV
DD
to +0.3V)
LOWBATT to GND (MAX1499) ................-0.3V to (AV
DD
+ 0.3V)
CLK,
EOC, CS, DIN, SCLK,
DOUT to GND (MAX1499).......................-0.3V to (DV
DD
+ 0.3V)
VNEG to GND (MAX1499) .......................-2.6V to (AV
DD
+ 0.3V)
LED_EN to GND (MAX1499)....................-0.3V to (DV
DD
+ 0.3V)
ISET to GND (MAX1499)..........................-0.3V to (AV
DD
+ 0.3V)
V
DD
to GND (MAX1497)...........................................-0.3V to +6V
AIN+, AIN- to GND (MAX1497)..............VNEG to (V
DD
to +0.3V)
REF+, REF- to GND (MAX1497) ........... VNEG to (V
DD
to +0.3V)
CLK, EOC, CS, DIN, SCLK,
DOUT to GND (MAX1497)..........................-0.3V to (V
DD
+ 0.3V)
VNEG to GND (MAX1497)..........................-2.6V to (V
DD
+ 0.3V)
ISET to GND (MAX1497) ............................-0.3V to (V
DD
+ 0.3V)
VLED to GLED..........................................................-0.3V to +6V
GLED to GND........................................................-0.3V to +0.3V
SEG_ to GLED..........................................-0.3V to (VLED + 0.3V)
DIG_ to GLED ..........................................-0.3V to (VLED + 0.3V)
DIG_ Sink Current .............................................................300mA
DIG_ Source Current...........................................................50mA
SEG_ Sink Current ..............................................................50mA
SEG_ Source Current..........................................................50mA
Maximum Current Input into Any Other Pin ........................50mA
Continuous Power Dissipation (T
A
= +70°C)
32-Pin TQFP (derate 20.7mW/°C above +70°C).....1652.9mW
28-Pin SSOP (derate 9.5mW/°C above +70°C) ...........762mW
28-Pin PDIP (derate 14.3mW/°C above +70°C)......1142.9mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(AVDD= DVDD= VDD= +2.7V to +5.25V, GND = 0, GLED = 0, V
LED
= +2.7V to +5.25V, 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 TA= T
MIN
to T
MAX
.
Typical values are at T
A
= +25°C, unless otherwise noted.)
PARAMETER
CONDITIONS
UNITS
DC ACCURACY
MAX1499
Noise-Free Resolution
MAX1497
Count
2.000V range ±1
Integral Nonlinearity (Note 1) INL
200mV range ±1
Count
Range Change Ratio
(V
AIN+
- V
AIN-
= 0.100V) on 200mV range
(V
AIN+
- V
AIN-
= 0.100V) on 2.0V range
Ratio
Rollover Error
V
AIN+
- V
AIN-
= full scale
V
AIN-
- V
AIN+
= full scale
±1
Count
Output Noise 10
µV
P-P
Offset Error (Zero Input Reading)
Offset VIN = 0 (Note 2) -0 0
Reading
Gain Error (Note 3)
%FSR
Offset Drift (Zero Reading Drift) VIN = 0 (Note 4) 0.1
µV/°C
Gain Drift ±1
ppm/°C
INPUT CONVERSION RATE
External-Clock Frequency
MHz
External-Clock Duty Cycle 40 60 %
Internal clock 5
Conversion Rate
External clock, f
CLK
= 4.9152MHz 5
Hz
SYMBOL
MIN TYP MAX
-19,999 +19,999
-1999 +1999
10:1
-0.5 +0.5
4.9152
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
_______________________________________________________________________________________ 3
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ANALOG INPUTS (AIN+, AIN-) (bypass to GND with 0.1µF or greater capacitors)
RANGE bit = 0
AIN Input Voltage Range (Note 5)
RANGE bit = 1
AIN Absolute Input Voltage
Range to GND
V
Internal clock mode, 50Hz and 60Hz ±2%
Normal-Mode 50Hz and 60Hz
Rejection (Simultaneously)
External clock mode, 50Hz and 60Hz ±2%,
f
CLK
= 4.9152MHz
dB
Common-Mode 50Hz and 60Hz
Rejection (Simultaneously)
CMR
dB
Common-Mode Rejection CMR At DC
dB
Input Leakage Current 10 nA
Input Capacitance 10 pF
Average Dynamic Input Current
(Note 6) -20 +20 nA
LOW-BATTERY VOLTAGE MONITOR (LOWBATT) (MAX1499 only)
LOWBATT TripThreshold
V
LOWBATT Leakage Current 10 pA
Hysteresis 20 mV
INTERNAL REFERENCE (REF- = GND, INTREF bit = 1) (bypass REF+ to GND with a 4.7µF capacitor)
REF Output Voltage V
REF
AVDD = V
DD
= 5V
V
REF Output Short-Circuit Current
1mA
REF Output Temperature
Coefficient
AVDD = V
DD
= 5V 40
ppm/°C
Load Regulation I
SOURCE
= 0 to 300µA, I
SINK
= 0 to 30µA 6
mV/µA
Line Regulation 50
µV/V
0.1Hz to 10Hz 25
Noise Voltage
10Hz to 10kHz
µV
P-P
EXTERNAL REFERENCE (INTREF bit = 0) (bypass REF+ and REF- to GND with 0.1µF or greater capacitors)
REF Input Voltage Differential (V
REF+
- V
REF-
)
Absolute REF+, REF- Input
Voltage to GND
V
Internal clock mode, 50Hz and 60Hz ±2%
Normal-Mode 50Hz and 60Hz
Rejection (Simultaneously)
External clock mode, 50Hz and 60Hz ±2%,
f
CLK
= 4.9152MHz
dB
Common-Mode 50Hz and 60Hz
Rejection (Simultaneously)
CMR
dB
Common-Mode Rejection CMR At DC
dB
Input Leakage Current 10 nA
ELECTRICAL CHARACTERISTICS (continued)
(AVDD= DVDD= VDD= +2.7V to +5.25V, GND = 0, GLED = 0, V
LED
= +2.7V to +5.25V, 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 TA= T
MIN
to T
MAX
.
Typical values are at T
A
= +25°C, unless otherwise noted.)
TC
VREF
For 50Hz and 60Hz ±2%, R
For 50Hz and 60Hz ±2%, R
SOURCE
SOURCE
< 10kΩ 150
< 10kΩ 150
-2.0 +2.0
-0.2 +0.2
-2.2 +2.2
100
120
100
2.048
2.007 2.048 2.089
400
2.048
-2.2 +2.2
100
120
100
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
4 _______________________________________________________________________________________
PARAMETER
CONDITIONS
UNITS
Input Capacitance 10 pF
Average Dynamic Input Current (Note 6) -20 +20 nA
CHARGE PUMP
Output Voltage VNEG C
VNEG
= 0.1µF
V
DIGITAL INPUTS (SCLK, DIN, CS, CLK)
Input Current I
IN
VIN = 0 or DVDD = V
DD
-10 +10 µA
MAX1499
0.3 x
Input Low Voltage V
INL
MAX1497
0.3 x
V
DD
V
MAX1499
0.7 x
Input High Voltage V
INH
MAX1497
0.7 x
V
Input Hysteresis V
HYS
DVDD = VDD = 3.0V
mV
DIGITAL OUTPUTS (DOUT, EOC)
Output Low Voltage V
OL
I
SINK
= 1mA 0.4 V
I
SOURCE
= 200µA, M AX 1499
0.8 x
Output High Voltage V
OH
I
SOURCE
= 200µA, M AX 1497
0.8 x
V
Tri-State Leakage Current I
L
DOUT only -1 +1 µA
Tri-State Output Capacitance C
OUT
DOUT only 15 pF
POWER SUPPLY (Note 10)
VDD Voltage V
DD
MAX1497
V
AVDD Voltage AV
DD
MAX1499
V
DVDD Voltage DV
DD
MAX1499
V
Power-Supply Rejection V
DD
PSRR (Note 7) 80 dB
Power-Supply Rejection AV
DD
(Note 7) 80 dB
Power-Supply Rejection DV
DD
(Note 7)
dB
VDD = 5.25V
744
VDD = 3.3V
663VDD Current (Notes 8, 9) I
VDD
Standby mode
325
µA
AVDD = 5.25V 640
AVDD = 3.3V 600
AVDD Current (Notes 8, 9) I
AVDD
Standby mode 305
µA
ELECTRICAL CHARACTERISTICS (continued)
(AVDD= DVDD= VDD= +2.7V to +5.25V, GND = 0, GLED = 0, V
LED
= +2.7V to +5.25V, 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 TA= T
MIN
to T
MAX
.
Typical values are at T
A
= +25°C, unless otherwise noted.)
SYMBOL
MIN TYP MAX
-2.60 -2.42 -2.30
DV
DD
V
DD
200
DV
DD
V
DD
DV
DD
2.70 5.25
PSRR
PSRR
A
D
2.70 5.25
2.70 5.25
100
664
618
268
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
_______________________________________________________________________________________ 5
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DVDD = 5V 320
DVDD = 3.3V 180DVDD Current (Notes 8, 9) I
DVDD
Standby mode 20
µA
LED Drivers Bias Current From AV
DD
or V
DD
µA
LED DRIVERS (Table 6)
LED Supply Voltage V
LED
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
mA
MAX1499
Display Scan Rate f
OSC
MAX1497
Hz
Segment Current Slew Rate
25
mA/µs
DIG_ Voltage Low V
DIG
I
DIG_
= 176mA
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 20
mA
Interdigit Blanking Time 4µs
ELECTRICAL CHARACTERISTICS (continued)
(AVDD= DVDD= VDD= +2.7V to +5.25V, GND = 0, GLED = 0, V
LED
= +2.7V to +5.25V, 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 TA= T
MIN
to T
MAX
.
Typical values are at T
A
= +25°C, unless otherwise noted.)
∆I
/∆t
SEG
120
2.70 5.25
176
512
640
0.178 0.300
25.5
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
6 _______________________________________________________________________________________
TIMING CHARACTERISTICS (Notes 11, 12, Figure 8)
(AVDD= DVDD= VDD= +2.7V to +5.25V, GND = 0, GLED = 0, V
LED
= +2.7V to +5.25V, 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 TA= T
MIN
to T
MAX
.
Typical values are at T
A
= +25°C, unless otherwise noted.)
PARAMETER
CONDITIONS
UNITS
SCLK Operating Frequency f
SCLK
0 4.2
MHz
SCLK Pulse-Width High t
CH
ns
SCLK Pulse-Width Low t
CL
ns
DIN to SCLK Setup t
DS
50 ns
DIN to SCLK Hold t
DH
0ns
CS Fall to SCLK Rise Setup t
CSS
50 ns
SCLK Rise to CS Rise Hold t
CSH
0ns
SCLK Fall to DOUT Valid t
DO
C
LOAD
= 50pF, Figures 13, 14
ns
CS Rise to DOUT Disable t
TR
C
LOAD
= 50pF, Figures 13, 14
ns
CS Fall to DOUT Enable t
DV
C
LOAD
= 50pF, Figures 13, 14
ns
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. See OFFSET_CAL1 and OFFSET_CAL2 (MAX1499 only) in the On-Chip Registers section.
Note 3: Offset nulled.
Note 4: Offset 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: 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 8: CLK and SCLK are disabled.
Note 9: LED drivers are disabled.
Note 10: Power-supply currents are measured with all digital inputs at either GND, DV
DD
, or VDDand with the device in internal-clock mode.
Note 11: All input signals are specified with t
RISE
= t
FALL
= 5ns (10% to 90% of DVDD) and are timed from a voltage level of 50% of
DV
DD
, unless otherwise noted.
Note 12: See the serial-interface timing diagrams.
SYMBOL
MIN TYP MAX
100
100
120
120
120
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
_______________________________________________________________________________________ 7
Typical Operating Characteristics
(AV
DD
= DVDD= VDD= +2.7V to +5.25V, V
LED
= +2.7V to +5.25V, GND = 0, GLED = 0, external reference mode, REF+ = 2.048V,
REF- = GND, C
REF+
= C
REF-
= 0.1µF, RANGE bit = 1, internal clock mode, C
VNEG
= 0.1µF. TA= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE (MAX1499)
MAX1497/99 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
4.754.253.753.25
100
200
300
400
500
600
700
0
2.75 5.25
ANALOG SUPPLY
DIGITAL SUPPLY
SUPPLY CURRENT
vs. SUPPLY VOLTAGE (MAX1497)
MAX1497/99 toc02
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
4.744.233.723.21
450
500
550
600
650
700
400
2.70 5.25
SUPPLY CURRENT
vs. TEMPERATURE (MAX1499)
MAX1497/99 toc03
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
605040302010
100
200
300
400
500
600
700
0
070
ANALOG SUPPLY
DIGITAL SUPPLY
SUPPLY CURRENT
vs. TEMPERATURE (MAX1497)
MAX1497/99 toc04
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
6035-15 10
610
640
630
620
650
660
670
680
690
700
600
-40 85
SHUTDOWN CURRENT
vs. TEMPERATURE (MAX1499)
MAX1497/99 toc05
TEMPERATURE (°C)
SHUTDOWN CURRENT (µA)
605040302010
50
100
150
200
250
300
0
070
ANALOG SUPPLY
DIGITAL SUPPLY
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE (MAX1499)
MAX1497/99 toc07
SUPPLY VOLTAGE (V)
SHUTDOWN CURRENT (µA)
4.754.253.753.25
50
100
150
200
250
300
0
2.75 5.25
ANALOG SUPPLY
DIGITAL SUPPLY
SHUTDOWN CURRENT
vs. SUPPLY VOLTAGE (MAX1497)
MAX1497/99 toc08
SUPPLY VOLTAGE (V)
SHUTDOWN CURRENT (µA)
4.744.233.723.21
50
150
100
200
250
300
350
0
2.70 5.25
MAX1499
OFFSET ERROR vs. SUPPLY VOLTAGE
MAX1497/99 toc09
SUPPLY VOLTAGE (V)
OFFSET ERROR (LSB)
4.754.253.753.25
-0.11
-0.06
-0.01
0.04
0.09
0.14
0.19
-0.16
2.75 5.25
SHUTDOWN CURRENT
vs. TEMPERATURE (MAX1497)
MAX1497/99 toc06
TEMPERATURE (°C)
SHUTDOWN CURRENT (µA)
6035-15 10
50
150
100
200
250
300
350
0
-40 85
INTERNAL REFERENCE VOLTAGE
vs. TEMPERATURE
MAX1497/99 toc16
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
605040302010
2.046
2.045
2.047
2.049
2.048
2.051
2.050
2.053
2.052
2.054
2.044
070
INTERNAL REFERENCE VOLTAGE
vs. ANALOG SUPPLY VOLTAGE
MAX1497/99 toc17
SUPPLY VOLTAGE (V)
REFERENCE VOLTAGE (V)
4.754.253.753.25
2.045
2.046
2.047
2.048
2.049
2.050
2.044
2.75 5.25
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
8 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(AV
DD
= DVDD= VDD= +2.7V to +5.25V, V
LED
= +2.7V to +5.25V, GND = 0, GLED = 0, external reference mode, REF+ = 2.048V,
REF- = GND, C
REF+
= C
REF-
= 0.1µF, RANGE bit = 1, internal clock mode, C
VNEG
= 0.1µF. TA= +25°C, unless otherwise noted.)
MAX1499
OFFSET ERROR vs. TEMPERATURE
MAX1497/99 toc10
TEMPERATURE (°C)
OFFSET ERROR (LSB)
605010 20 30 40
-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
-0.2
070
MAX1499
GAIN ERROR vs. SUPPLY VOLTAGE
MAX1497/99 toc11
SUPPLY VOLTAGE (V)
GAIN ERROR (% FULL SCALE)
4.754.253.25 3.75
-0.08
-0.04
-0.06
-0.02
0
0.02
0.04
0.06
0.08
-0.10
2.75 5.25
MAX1499
GAIN ERROR vs. TEMPERATURE
MAX1497/99 toc12
TEMPERATURE (°C)
GAIN ERROR (% FULL SCALE)
605030 402010
-0.09
-0.08
-0.07
-0.06
-0.05
-0.04
-0.03
-0.02
-0.01
0
-0.10
070
MAX1499
(±200mV INPUT RANGE) INL vs. OUTPUT CODE
MAX1497/99 toc13
OUTPUT CODE
INL (COUNTS)
10,0000-10,000
-0.5
0
0.5
1.0
-1.0
-20,000 20,000
MAX1499
(±2V INPUT RANGE) INL vs. OUTPUT CODE
MAX1497/99 toc14
OUTPUT CODE
INL (COUNTS)
10,0000-10,000
-0.5
0
0.5
1.0
-1.0
-20,000 20,000
NOISE DISTRIBUTION
MAX1497/99 toc15
NOISE (LSB)
PERCENTAGE OF UNITS (%)
0.80.70.60.50.40.30.20.10-0.1
5
10
15
20
25
0
-0.2
DATA OUTPUT RATE
vs. TEMPERATURE
MAX1497/99 toc18
TEMPERATURE (°C)
DATA OUTPUT RATE (Hz)
6035-15 10
4.92
4.98
4.96
4.94
5.00
5.02
5.04
5.06
5.08
5.10
4.90
-40 85
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
_______________________________________________________________________________________ 9
Typical Operating Characteristics (continued)
(AV
DD
= DVDD= VDD= +2.7V to +5.25V, V
LED
= +2.7V to +5.25V, GND = 0, GLED = 0, external reference mode, REF+ = 2.048V,
REF- = GND, C
REF+
= C
REF-
= 0.1µF, RANGE bit = 1, internal clock mode, C
VNEG
= 0.1µF. TA= +25°C, unless otherwise noted.)
DATA OUTPUT RATE
vs. SUPPLY VOLTAGE
MAX1497/99 toc19
SUPPLY VOLTAGE (V)
DATA OUTPUT RATE (Hz)
4.744.233.21 3.72
4.995
4.990
4.985
5.000
5.005
5.010
5.015
5.020
4.980
2.70 5.25
OFFSET ERROR
vs. COMMON-MODE VOLTAGE
MAX1497/99 toc20
COMMON-MODE VOLTAGE (V)
OFFSET ERROR (LSB)
1.51.0-1.5 -1.0 -0.5 0 0.5
-0.15
-0.10
-0.05
0
0.05
0.10
0.15
0.20
-0.20
-2.0 2.0
SEGMENT CURRENT
vs. SUPPLY VOLTAGE
MAX1497/99 toc23
SUPPLY VOLTAGE (V)
SEGMENT CURRENT (µA)
4.744.233.723.21
5
10
15
20
25
30
0
2.70 5.25
R
ISET
= 25kΩ
V
NEG
STARTUP SCOPE SHOT
MAX1497/99 toc21
20ms/div
2V/div
1V/div
V
DD
V
NEG
CHARGE-PUMP OUTPUT VOLTAGE
vs. ANALOG SUPPLY VOLTAGE
MAX1497/99 toc22
SUPPLY VOLTAGE (V)
V
NEG
VOLTAGE (V)
4.754.253.753.25
-2.48
-2.46
-2.44
-2.42
-2.40
-2.50
2.75 5.25
MAX1497/MAX1499
3.5- and 4.5-Digit, Single-Chip ADCs with LED
Drivers and µC Interface
10 ______________________________________________________________________________________
Pin Description
PIN
MAX1497
NAME FUNCTION
131VNEG -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.
64I
SET
Segment Current Controller. Connect to ground through a resistor to set the segment
current. See Table 6 for segment current selection.
75GND Ground
8—V
DD
Analog and Digital Circuit Supply Voltage. Connect VDD to a +2.7V to +5.25V power
supply. Bypass V
DD
to GND with a 0.1µF and a 4.7µF capacitor.
98CLK
External Clock Input. When the EXTCLK register bit is set to one, CLK is the master clock
input (frequency = 4.9152MHz) for the modulator and the filter. When the EXTCLK
register bit is reset to zero, the internal clock is used. Connect CLK to GND or DV
DD
(MAX1499) or V
DD
(MAX1497) when the internal oscillator is used.
10 9 EOC
Active-Low End-of-Conversion Logic Output. A logic low at EOC indicates that a new
ADC result is available in the ADC result register.
11 10 CS Active-Low Chip Select Input. Forcing CS low activates the serial interface.
12 11 DIN
Serial Data Input. Data present at DIN is shifted into the internal registers in response to
a rising edge at SCLK when CS is low.
13 12 SCLK
Serial Clock Input. Apply an external clock to SCLK to facilitate communication through
the serial bus. SCLK may idle high or low.
14 13 DOUT
Serial Data Output. DOUT presets serial data in response to register queries. Data shifts
out on the falling edge of SCLK. DOUT goes high impedance when CS is high.
15 14 DIG0 Digit 0 Driver
16 15 DIG1 Digit 1 Driver
17 16 GLED Ground for LED-Display Segment Driver
18 17 DIG2 Digit 2 Driver
19 18 DIG3 Digit 3 Driver
20 20 SEGA Segment A Driver
21 21 SEGB Segment B Driver
22 22 SEGC Segment C Driver
23 23 SEGD Segment D Driver
24 24 SEGE Segment E Driver
MAX1499
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