Rainbow Electronics MAX111 User Manual

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

________________________________________________________________

Maxim Integrated Products

General Description

The MAX110/MAX111 analog-to-digital converters (ADCs) use an internal auto-calibration technique to achieve 14-bit resolution plus overrange, with no external components. Operating supply current is only 550µA (MAX110) and reduces to 4µA in power-down mode, making these ADCs ideal for high-resolution battery-powered or remote-sensing applications. A fast serial interface simplifies signal routing and opto-isolation, saves microcontroller pins, and offers compatibility with SPI™, QSPI™, and MICROWIRE™. The MAX110 operates with ±5V supplies, and converts differential analog signals in the -3V to +3V range. The MAX111 operates with a single +5V supply and converts differential analog signals in the ±1.5V range, or singleended signals in the 0V to +1.5V range.

Internal calibration allows for both offset and gain-error correction under microprocessor (µP) control. Both devices are available in space-saving 16-pin DIP and SO packages, as well as an even smaller 20-pin SSOP package.

________________________Applications

Process Control Weigh Scales Panel Meters Data-Acquisition Systems Temperature Measurement

____________________________Features

♦ Single +5V Supply (MAX111) ♦ Two Differential Input Channels ♦ 14-Bit Resolution Plus Sign and Overrange ♦ 0.03% Linearity (MAX110)

0.05% Linearity (MAX111)

♦ Low Power Consumption:

550µA (MAX110) 640µA (MAX111) 4µA Shutdown Current

♦ Up to 50 Conversions/sec ♦ 50Hz/60Hz Rejection ♦ Auto-Calibration Mode ♦ No External Components Required ♦ 16-Pin DIP/SO, 20-Pin SSOP

Ordering Information

19-0283; Rev 5; 11/98

Typical Operating Circuit

Pin Configurations

IN1+

IN1-

REF+ REF-

RCSEL

SCLK

DIN

DOUT

IN2+ IN2-

+5V

-5V (0V)

FROM µC

MAX110 MAX111

( ) ARE FOR MAX111

(AGND)

PART

MAX110ACPE

MAX110BCPE MAX110ACWE 0°C to +70°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

16 Plastic DIP 16 Plastic DIP

16 Wide SO MAX110BCWE 0°C to +70°C 16 Wide SO MAX110ACAP 0°C to +70°C 20 SSOP MAX110BCAP 0°C to +70°C 20 SSOP

EVALUATION KIT

AVAILABLE

MAX110BC/D 0°C to +70°C Dice*

Ordering Information continued at end of data sheet.

Contact factory for dice specifications.

SPI and QSPI are trademarks of Motorola, Inc. MICROWIRE is a trademark of National Semiconductor Corp.

Pin Configurations continued at end of data sheet.

INL(%)

±0.03 ±0.05 ±0.03 ±0.05 ±0.03 ±0.05 ±0.05

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 1-800-835-8769.

TOP VIEW

IN1+ REF-

REF+

3 4

RCSEL

XCLK

6 7

SCLK

BUSY

( ) ARE FOR MAX111

MAX110 MAX111

DIP/SO

IN1-

IN2+

IN2-

V GND

DIN

DOUT

(AGND)

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

VDDto GND ...........................................................................+6V

to GND (MAX110)..............................................+0.3V to -6V

AGND to DGND.....................................................-0.3V to +0.3V

IN1+

, V

IN1-

......................................(VDD+ 0.3V) to (VSS- 0.3V)

IN2+

, V

IN2-

......................................(VDD+ 0.3V) to (VSS- 0.3V)

REF+

, V

REF-

....................................(VDD+ 0.3V) to (VSS- 0.3V)

Digital Inputs and Outputs .........................(V

+ 0.3V) to -0.3V

Continuous Power Dissipation

16-Pin Plastic DIP (derate 10.53mW/°C above +70°C).....842mW

16-Pin Wide SO (derate 9.52mW/°C above +70°C) ......762mW

20-Pin SSOP (derate 8.00mW/°C above +70°C) ...........640mW

16-Pin CERDIP (derate 10.00mW/°C above +70°C)......800mW

Operating Temperature Ranges

MAX11_ _C_ _......................................................0°C to +70°C

MAX11_ _E_ _...................................................-40°C to +85°C

MAX11_BMJE.................................................-55°C to +125°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

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.

ELECTRICAL CHARACTERISTICS—MAX110

(VDD= 5V ±5%, VSS= -5V ±5%, f

XCLK

= 1MHz, ÷ 2 mode (DV2 = 1), 81,920 CLK cycles/conv, V

REF+

= 1.5V, V

REF-

= -1.5V,

TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

LSB

nA500

CONDITIONS

IN+

, I

IN-

Input Bias Current

(Note 3) pF10

-0.83 x V

REF

≤ VIN≤ 0.83 x V

REF

-V

REF

≤ VIN≤ V

REF

-0.83 x V

REF

≤ VIN≤ 0.83 x V

REF

Input Capacitance

-V

REF

≤ VIN≤ V

REF

2.25 2.25

IN+

IN-

Absolute Input Voltage Range

V-V

REF

Differential Input Voltage Range

ppm

Power-Supply Rejection

ppm/°C8

Full-Scale Error Temperature Drift

±0.1

µV/°C

0.003

Offset Error Temperature Drift

(Note 6)

UNITSMIN TYP MAXSYMBOLPARAMETER

mV±4Offset Error

±0.018

±0.03 ±0.06

±0.015 ±0.03

±0.04

IN+

= V

IN-

= 0V

MAX110BC/E

MAX110AC/E

After gain calibration (Note 5)

After offset null

VSS= -5V, VDD= 4.75V to 5.25V VDD= 5V, VSS= -4.75V to -5.25V

(Notes 3, 4) ±2DNLDifferential Nonlinearity

ppm/V6CMRR

Common-Mode Rejection Ratio

-2.5V ≤ (V

IN+

= V

IN-

) ≤ 2.5V

Uncalibrated

-8 0

Full-Scale Error

Uncalibrated

0.02

-V

REF

≤ VIN≤ V

REF

-0.83 x V

REF

≤ VIN≤ 0.83 x V

REF

%FSRINL

Relative Accuracy (Notes 3, 5–7)

±0.1

±0.05

MAX110BM

(Note 2)

14 + POL

+ OFL

RESResolution Bits

No-Missing-Codes Resolution

(Note 3)

13 + POL

+ OFL

Bits

ACCURACY (Note 1)

ANALOG INPUTS

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS—MAX110 (continued)

(VDD= 5V ±5%, VSS= -5V ±5%, f

XCLK

= 1MHz, ÷ 2 mode (DV2 = 1), 81,920 CLK cycles/conv, V

REF+

= 1.5V, V

REF-

= -1.5V,

TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

V4.75 5.25V

Positive Supply Voltage

0.8V

V-4.75 -5.25V

Negative Supply Voltage

µA

Input Low Voltage

550 950

780

Positive Supply Current

VDD= 5.25V, VSS= -5.25V

320 650

Performance guaranteed by supply rejection test Performance guaranteed by supply rejection test

pF10

0.4

VDD- 0.5

Output High Voltage

Input Capacitance

XCLK

= 500kHz,

continuous-conversion mode

µA

µAI

Negative Supply Current

VDD= 5.25V, VSS= -5.25V

±1

20.48

410I

LKG

Input Leakage Current

XCLK unloaded, continuous-conversion mode, RC oscillator operational (Note 9)

XCLK

= 500kHz,

continuous-conversion mode

(Note 3)

µA±10I

LKG

Leakage Current

pF10Output Capacitance

µA

0.05 2

Digital inputs at 0V or 5V

Power-Down Current

DOUT, BUSY, VDD= 4.75V, I

SOURCE

= 1.0mA

VDD= 5.25V, VSS= -5.25V, V

XCLK

= 0V, PD = 1

OUT

= 5V or 0V

(Note 3)

10,240 clock-cycles/conversion

DOUT, BUSY, I

SINK

= 1.6mA

CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

204.80

CONV

Synchronous Conversion Time (Note 7)

102,400 clock-cycles/conversion

MHz0.25 1.25f

OSC

Oversampling Clock Frequency

(Note 8)

V2.4V

Input High Voltage

V0 3.0V

REF

Differential Reference Input Voltage Range

pF10

Reference Input Capacitance

(Note 3)

0.4

Output Low Voltage

XCLK, I

SINK

= 200µA

VDD- 0.5

XCLK, VDD= 4.75V, I

SOURCE

= 200µA

nA500

REF+

REF-

Reference Input Current V

REF+

= 2.5V, V

REF-

= 0V

2.25 2.25

REF+

REF-

Absolute Reference Input Voltage Range

CONVERSION TIME

DIGITAL OUTPUTS (DOUT, BUSY, and XCLK when RCSEL = VDD)

POWER REQUIREMENTS (all digital inputs at 0V or 5V)

REFERENCE INPUTS

DIGITAL INPUTS (CS, SCLK, DIN, and XCLK when RCSEL = 0V)

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS—MAX111

(VDD= 5V ±5%, f

XCLK

= 1MHz, ÷ 2 mode (DV2 = 1), 81,920 CLK cycles/conv, V

REF+

= 1.5V, V

REF-

= 0V, TA= T

MIN

to T

MAX

unless otherwise noted. Typical values are at TA= +25°C.)

LSB

nA500

CONDITIONS

IN+

, I

IN-

Input Bias Current

(Note 3) pF10

-0.667 x V

REF

≤ VIN≤ 0.667 x V

REF

-V

REF

≤ VIN≤ V

REF

-0.667 x V

REF

≤ VIN≤ 0.667 x V

REF

Input Capacitance

-V

REF

≤ VIN≤ V

REF

V0V

- 3.2

IN+

IN-

Absolute Input Voltage Range

V-V

REF

Differential Input Voltage Range

-V

REF

≤ VIN≤ V

REF

ppm15VDD= 4.75V to 5.25VPower-Supply Rejection

%FSRINL

ppm/°C8

Full-Scale Error Temperature Drift

Relative Accuracy, Differential Input (Notes 3, 5–7)

(Notes 3, 4)

±0.25

±2

±0.2

±0.20

DNLDifferential Nonlinearity

(Note 6)

UNITSMIN TYP MAXSYMBOL

ppm/V6

(Note 2)

PARAMETER

14 + POL

+ OFL

RESResolution

CMRR

mV±4Offset Error

Common-Mode Rejection Ratio

10mV ≤ (V

IN+

= V

IN-

) ≤ 2.0V

Bits

No-Missing-Codes Resolution

±0.10

(Note 3)

-8 0

±0.05 ±0.10

Full-Scale Error

Uncalibrated

±0.03 ±0.05

MAX111BM

13 + POL

+ OFL

Bits

±0.18

IN+

= V

IN-

= 0V

MAX111BC/E

MAX111AC/E

After gain calibration (Note 5)

VIN≤ 0.667 x V

REF

0V ≤ VIN≤ V

REF

VIN≤ 0.667 x V

REF

0V ≤ VIN≤ V

REF

0V ≤ VIN≤ V

REF

VIN≤ 0.667 x V

REF

%FSRINL

Relative Accuracy, Single-Ended Input (IN- = GND)

±0.25 ±0.15

±0.10

±0.1

±0.06

MAX111BM

±0.18

MAX111BC/E

MAX111AC/E

ACCURACY (Note 1)

ANALOG INPUTS

-0.667 x V

REF

≤ VIN≤ 0.667 x V

REF

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

_______________________________________________________________________________________ 5

ELECTRICAL CHARACTERISTICS—MAX111 (continued)

(VDD= 5V ±5%, f

XCLK

= 1MHz, ÷ 2 mode (DV2 = 1), 81,920 CLK cycles/conv, V

REF+

= 1.5V, V

REF-

= 0V, TA= T

MIN

to T

MAX

unless otherwise noted. Typical values are at TA= +25°C.)

V4.75 5.25V

Positive Supply Voltage

0.4

0.8V

204.80

Output Low Voltage

µA

Input Low Voltage

640 1200

CONV

Synchronous Conversion Time (Note 7)

102,400 clock-cycles/conversion

XCLK, I

SINK

= 200µA

pF10

Reference Input Capacitance

MHz0.25 1.25

OSC

Oversampling Clock Frequency

(Note 8)

V2.4V

Input High Voltage

(Note 3)

V0 1.5V

REF

960

Supply Current VDD= 5.25V

Differential Reference Input Voltage Range

Performance guaranteed by supply rejection test

500

REF+

REF-

Reference Input Current

pF10

REF+

= 1.5V, V

REF-

= 0V

0.4

V0V

- 3.2

REF+

REF-

VDD- 0.5

Output High Voltage

Input Capacitance

Absolute Reference Input Voltage Range

VDD- 0.5

XCLK

= 500kHz,

continuous-conversion mode

µA±1

XCLK, VDD= 4.75V, I

SOURCE

= 200µA

20.48

410

LKG

Input Leakage Current

XCLK unloaded, continuous-conversion mode, RC oscillator operational (Note 9)

(Note 3)

µA±1I

LKG

Leakage Current

pF10Output Capacitance

µA

Digital inputs at 0V or 5V

Power-Down Current

DOUT, BUSY, VDD= 4.75V, I

SOURCE

= 1.0mA

VDD= 5.25V, V

XCLK

= 0V, PD = 1

OUT

= 5V or 0V

(Note 3)

10,240 clock-cycles/conversion

DOUT, BUSY, I

SINK

= 1.6mA

CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

CONVERSION TIME

DIGITAL OUTPUTS (DOUT, BUSY, and XCLK when RCSEL = VDD)

POWER REQUIREMENTS (all digital inputs at 0V or 5V)

REFERENCE INPUTS

DIGITAL INPUTS (CS, SCLK, DIN, and XCLK when RCSEL = 0V)

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

6 _______________________________________________________________________________________

Note 10: Timing specifications are guaranteed by design. All input control signals are specified with tr= tf= 5ns

(10% to 90% of +5V) and timed from a +1.6V voltage level.

Note 1: These specifications apply after auto-null and gain calibration. Performance at power-supply tolerance limits is guaranteed

by power-supply rejection tests. Tests are performed at V

= 5V and VSS= -5V (MAX110).

Note 2: 32,768 LSBs cover an input voltage range of ±V

REF

(15 bits). An additional bit (OFL) is set for VIN> V

REF

Note 3: Guaranteed by design. Not subject to production testing. Note 4: DNL is less than ±2 counts (LSBs) out of 2

counts (±14 bits). The major source of DNL is noise, and this can be further

improved by averaging.

Note 5: See

3-Step Calibration

section in text.

Note 6: V

REF

= (V

REF+

- V

REF-

), VIN= (V

IN1+

- V

IN1-

) or (V

IN2+

- V

IN2-

). The voltage is interpreted as negative when the voltage at

the negative input terminal exceeds the voltage at the positive input terminal.

Note 7: Conversion time is set by control bits CONV1–CONV4. Note 8: Tested at clock frequency of 1MHz with the divide-by-2 mode (i.e. oversampling clock of 500kHz). See

Typical Operating

Characteristics

section for the effect of other clock frequencies. Also read the

Clock Frequency

section.

Note 9: This current depends strongly on C

XCLK

(see

Applications Information

section).

TIMING CHARACTERISTICS (see Figure 6)

(VDD= 5V, VSS= -5V (MAX110), TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.)

MHz

1.1 3.0MAX11_ BM

RC Oscillator Frequency

1.3 2.8MAX11_ _C/E

2.0TA= +25°C

PARAMETER SYMBOL MIN TYP MAX UNITS

CS to SCLK Hold Time (Note 10)

CSH

0 ns

DIN to SCLK Setup Time (Note 10)

100

DIN to SCLK Hold Time (Note 10)

0 ns

100

60 80

CS to SCLK Setup Time (Note 10)

CSS

100

120

SCLK, XCLK Pulse Width (Note 10)

160

03580 0 100

Data Access Time (Note 10)

0 120

0 60 100 0 120

SCLK to DOUT Valid Delay (Note 10)

0 140

35 80

Bus Relinquish Time (Note 10)

120

MAX11_ BM

MAX11_ _C/E

TA= +25°C

MAX11_ BM

MAX11_ _C/E

CONDITIONS

MAX11_ _C/E

MAX11_ BM

TA= +25°C

MAX11_ BM

TA= +25°C

LOAD

= 50pF

TA= +25°C

LOAD

= 50pF

MAX11_ _C/E

TA= +25°C

MAX11_ BM

TA= +25°C

MAX11_ _C/E/M

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

_______________________________________________________________________________________

-0.10

-0.05

0.05

0.10

-4 -2 0 2 4

MAX110 RELATIVE ACCURACY

(-V

REF

< VIN < V

REF

)

MAX110 toc01

VIN (V)

RELATIVE ACCURANCY (%FSR)

-40°C ≤ TA ≤ +85°C RANGE OF INL VALUES (200 PIECE SAMPLE SIZE)

-0.10

-0.05

0.05

0.10

-4 -2 0 2 4

MAX110 RELATIVE ACCURACY (-0.83 V

REF

< V

< 0.83 V

REF

)

MAX110 toc02

VIN (V)

RELATIVE ACCURANCY (%FSR)

-40°C ≤ TA ≤ +85°C RANGE OF INL VALUES (200 PIECE SAMPLE SIZE)

0.07

0.06

0.05

MAX110-TOC03

0.02

0.01

0 0.25 0.50 0.75 1.00 1.25

0.04

0.03

OSC

(MHz)

RELATIVE ACCURACY (%FSR)

÷1 MODE

÷2 MODE

÷ 4 MODE

VDD = 4.75V V

= -4.75V

= +85°C

MAX110 RELATIVE ACCURACY vs.

OVERSAMPLING FREQUENCY (f

OSC

)

0.10

MAX110-TOC04

0.04

0.02

-50

-25

0 25 50 75 100

0.08

0.06

TEMPERATURE (°C)

RELATIVE ACCURACY (%FSR)

MAX110 RELATIVE ACCURACY

vs. TEMPERATURE

MAX110-TOC05

0 0.25 0.50 0.75 1.00 1.25

OSC

(MHz)

POWER DISSIPATION (mW)

÷ 4 MODE

÷ 2 MODE

÷ 1 MODE

MAX110 POWER DISSIPATION vs.

OVERSAMPLING FREQUENCY (f

OSC

)

VDD = 5.25V V

= 0V

= -40°C

__________________________________________Typical Operating Characteristics

(MAX110, VDD= 5V, VSS= -5V, V

REF+

= 1.5V, V

REF-

= -1.5V, differential input (V

IN+

= -V

IN-

), f

XCLK

= 1MHz, ÷ 2 mode (DV2 = 1),

81,920 clocks/conv, TA = +25°C, unless otherwise noted.)

MAX110/MAX111

Low-Cost, 2-Channel, ±14-Bit Serial ADCs

8 _______________________________________________________________________________________

____________________________Typical Operating Characteristics (continued)

(MAX111, VDD= 5V, V

REF+

= 1.5V, V

REF-

= 0V, differential input (V

IN+

= -V

IN-

), f

XCLK

= 1MHz, ÷ 2 mode (DV2 = 1),

81,920 clocks/conv, TA = +25°C, unless otherwise noted.)

0.14

0.12

0.1

MAX110-TOC08

0.04

0.02

0 0.25

0.50

0.75

1.00

0.08

0.06

OSC

(MHz)

RELATIVE ACCURACY (%FSR)

÷4 MODE

÷2 MODE

÷ 1 MODE

= 4.75V

= +85°C

MAX111 RELATIVE ACCURACY vs.

OVERSAMPLING FREQUENCY (f

OSC

)

0.10

MAX110-TOC09

0.04

0.02

-50

-25

0 25 50 75 100

0.08

0.06

TEMPERATURE (°C)

RELATIVE ACCURACY (%FSR)

MAX111 RELATIVE ACCURACY

vs. TEMPERATURE

MAX110-TOC10

0 0.25 0.50 0.75 1.00 1.25

OSC

(MHz)

POWER DISSIPATION (mW)

÷ 4 MODE

÷ 2 MODE

÷ 1 MODE

MAX111 POWER DISSIPATION vs.

OVERSAMPLING FREQUENCY (f

OSC

)

VDD = 5.25V V

= 0V

= -40°C

0.10

0.05

-0.05

-0.10

MAX110-TOC6

(V)

-2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0

MAX111 RELATIVE ACCURACY

(-0.667V

REF

< VIN < 0.667V

REF

)

RELATIVE ACCURACY (%FSR)

0.10

0.05

-0.05

-0.10

MAX110-TOC7

(V)

-2.0 -1.5 -1.0 -0.5 0 0.5 1.0 1.5 2.0

MAX111 RELATIVE ACCURACY

(-V

REF

< VIN < V

REF

)

RELATIVE ACCURACY (%FSR)

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