Rainbow Electronics MAX1143 User Manual

General Description

The MAX1142/MAX1143 are 200ksps, 14-bit ADCs.
These serially interfaced ADCs connect directly to
SPI™, QSPI™, and MICROWIRE™ devices without
external logic. They combine an input scaling network,
internal track/hold, a clock, +4.096V reference, and
three general-purpose digital output pins (for external
multiplexer or PGA control) in a 20-pin SSOP package.

The excellent dynamic performance (SINAD ≥ 81dB),

high-speed (200ksps), and low power (7.5mA) of these
ADCs, make them ideal for applications such as indus­trial process control, instrumentation, and medical
applications. The MAX1142 accepts input signals of 0
to +12V (unipolar) or ±12V (bipolar), while the
MAX1143 accepts input signals of 0 to +4.096V (unipo­lar) or ±4.096V (bipolar). Operating from a single
+4.75V to +5.25V analog supply and a +4.75V to
+5.25V digital supply, power-down modes reduce cur­rent consumption to 1mA at 10ksps and further reduce
supply current to less than 20µA at slower data rates.
A serial strobe output (SSTRB) allows direct connection
to the TMS320-family of digital signal processors. The
MAX1142/MAX1143 user can select either the internal
clock, or an external serial-interface clock for the ADC
to perform analog-to-digital conversions.

The MAX1142/MAX1143 feature internal calibration cir­cuitry to correct linearity and offset errors. On-demand
calibration allows the user to optimize performance.
Three user-programmable logic outputs are provided
for the control of an 8-channel MUX or a PGA.

Applications

Industrial Process Control

Industrial I/O Modules

Data-Acquisition Systems

Medical Instruments

Portable and Battery-Powered Equipment

Features

♦ 200ksps (Bipolar) and 150ksps (Unipolar)

Sampling ADC

♦ 14-Bits, No Missing Codes
♦ 1LSB INL Guaranteed
♦ 81dB (min) SINAD
♦ +5V Single-Supply Operation
♦ Low Power Operation, 7.5mA (Unipolar Mode)
♦ 2.5µA Shutdown Mode
♦ Software-Configurable Unipolar & Bipolar Input

Ranges

0 to +12V and ±12V (MAX1142)
0 to +4.096V and ±4.096V (MAX1143)
Internal or External Reference

♦ Internal or External Clock
♦ SPI/QSPI/MICROWIRE-Compatible Wire Serial

Interface

♦ Three User-Programmable Logic Outputs
♦ Small 20-Pin SSOP Package

MAX1142/MAX1143

14-Bit ADC, 200ksps, +5V Single-Supply

with Reference

________________________________________________________________

Maxim Integrated Products

1

Pin Configuration

19-2037; Rev 0; 5/01

Ordering Information

Functional Diagram appears at end of data sheet.
Typical Application Circuit appears at end of data sheet.

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

Ordering Information continued at end of data sheet.

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

MAX1142ACAP 0°C to +70°C 20 SSOP ±1

MAX1142BCAP 0°C to +70°C 20 SSOP ±2

PIN-

PACKAGE

(LSB)

TOP VIEW

1

REF

2

REFADJ

3

AGND

4

AV

DD

DGND

SHDN

P2

P1

P0

SSTRB

MAX1142

5

MAX1143

6

7

8

9

10 DOUT

SSOP

20

AIN

19

AGND

CREF

18

17

CS

16

DIN

15

DV

DD

DGND

14

SCLK

13

12

RST

11

INL

MAX1142/MAX1143

14-Bit ADC, 200ksps, +5V Single-Supply
with Reference

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 AGND, DVDDto DGND .............................-0.3V to +6V

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

AIN to AGND.....................................................................±16.5V

REFADJ, CREF, REF to AGND.................-0.3V to (AV

DD

+ 0.3V)

Digital Inputs to DGND.............................................-0.3V to +6V

Digital Outputs to DGND .........................-0.3V to (DV

DD

+ 0.3V)
Continuous Power Dissipation (T

A

= +70°C)

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

Operating Temperature Ranges

MAX114_CAP ......................................................0°C to +70°C

MAX114_EAP....................................................-40°C to +85°C

Storage Temperature Range .............................-60°C to +150°C

Junction Temperature......................................................+150°C

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

ELECTRICAL CHARACTERISTICS

(AVDD= DVDD= +5V ±5%, f

SCLK

= 4.8MHz, external clock (50% duty cycle), 24 clocks/conversion (200ksps), bipolar input, external

V

REF

= +4.096V, V

REFADJ

= AVDD, C

REF

= 2.2µF, C

CREF

= 1µF, TA = T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DC ACCURACY (Note 1)

Resolution 14 Bits

Relative Accuracy (Note 2) INL

Differential Nonlinearity DNL Unipolar Mode ±1 LSB

Transition Noise 0.34 LSB RMS

Offset Error

Gain Error (Note 3)

Offset D r i ft ( Bi p ol ar and U ni p ol ar ) Excluding reference drift ±1 ppm/
G ai n D r i ft ( Bi p ol ar and U ni p ol ar ) Excluding reference drift ±1 ppm/

DYNAMIC SPECIFICATIONS (5kHz sine-wave input, 200ksps, 4.8MHz clock, bipolar input mode).
(MAX1142, 24Vp-p. MAX1143, 8.192Vp-p)

SINAD

SNR

THD

SFDR

ANALOG INPUT

Input Range

Unipolar Mode MAX114_A ±1

Unipolar ±4
Bipolar ±6
Unipolar ±0.2
Bipolar ±0.3

f

= 5kHz 81

IN

f

= 100kHz 82

IN

f

= 5kHz 82

IN

f

= 100kHz 82

IN

f

= 5kHz -88

IN

f

= 100kHz 91

IN

f

= 5kHz 90

IN

f

= 100kHz 95

IN

MAX1142

MAX1143

MAX114_B ±2

Unipolar 0 12

Bipolar -12 12

Unipolar 0 4.096

Bipolar - 4.096 4.096

LSB

mV

%FSR

dB

dB

dB

dB

V

o

C

o

C

MAX1142/MAX1143

14-Bit ADC, 200ksps, +5V Single-Supply

with Reference

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(AVDD= DVDD= +5V ±5%, f

SCLK

= 4.8MHz, external clock (50% duty cycle), 24 clocks/conversion (200ksps), bipolar input, external

V

REF

= +4.096V, V

REFADJ

= AVDD, C

REF

= 2.2µF, C

CREF

= 1µF, TA = T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Input Impedance

Input Capacitance 32 pF

CONVERSION RATE

Internal Clock Frequency 4 MHz

Aperture Delay t

Aperture Jitter t

MODE 1 (24 External Clock Cycles per Conversion)

External Clock Frequency f

Sample Rate f

Conversion Time (Note 4)

MODE 2 (Internal Clock Mode)

External Clock Frequency
(Data Transfer Only)

Conversion Time SSTRB Low Pulse Width 4 6 µs

Acquisition Time

MODE 3 (32 External Clock Cycles per Conversion)

External Clock Frequency f

Sample Rate f

Conversion Time (Note 4)

INTERNAL REFERENCE

Output Voltage V

REF Short Circuit Current 24 mA

Output Tempco ±20 ppm/

Capacitive Bypass at REF 0.47 10 µF

Maximum Capacitive Bypass at
REFADJ

REFADJ Output Voltage 4.096 V

REFADJ Input Range For small adjustments from 4.096V ±100 mV

AD

AJ

SCLK

= f

S

t

CONV+ACQ

24 / f

/24

SCLK

=

SCLK Bipolar 5 240

MAX1142

MAX1143

Unipolar 7.5 10.0

Bipolar 5.9 7.9

Unipolar 100 1000

Bipolar 3.4 4.5

Unipolar 0.1 3

Bipolar 0.1 4.8

Unipolar 4.17 125

Bipolar 4.17 200

Unipolar 8 240

10 ns

50 ps

Unipolar 1.82

Bipolar 1.14

SCLK

= f

S

SCLK

t

CONV+ACQ

32 / f

SCLK

REF

Unipolar or Bipolar 0.1 4.8 MHz

/32 Unipolar or Bipolar 3.125 150 ksps

=

Unipolar or Bipolar 6.67 320 µs

4.056 4.096 4.136 V

10 µF

8 MHz

kΩ

MHz

ksps

µs

µs

o

C

MAX1142/MAX1143

14-Bit ADC, 200ksps, +5V Single-Supply
with Reference

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(AVDD= DVDD= +5V ±5%, f

SCLK

= 4.8MHz, external clock (50% duty cycle), 24 clocks/conversion (200ksps), bipolar input, external

V

REF

= +4.096V, V

REFADJ

= AVDD, C

REF

= 2.2µF, C

CREF

= 1µF, TA = T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

REFADJ Buffer Disable
Threshold

Buffer Voltage Gain 1 V/V

EXTERNAL REFERENCE (Reference buffer disabled. Reference applied to REF)

Input Range (Notes 5 and 6) 3.0 4.096 4.2 V

Input Current

DIGITAL INPUTS

Input High Voltage V

Input Low Voltage V

Input Leakage I

Input Hysteresis V

Input Capacitance C

DIGITAL OUTPUTS

Output High Voltage V

Output Low Voltage V

Three-State Leakage Current I

Three-State Output
Capacitance

POWER SUPPLIES

Analog Supply (Note 7) AV

Digital Supply (Note 7) DV

Analog Supply Current I

Digital Supply Current I

Power Supply Rejection Ratio
(Note 8)

IH

IL

IN

HYST

IN

OH

OL

L

DD

DD

To power-down the internal reference

V

= 4.096V, f

REF

V

= 4.096V, f

REF

In power-down, f

AVDD -

0.5V

= 4.8MHz 250

SCLK

= 0 230

SCLK

= 0 0.1

SCLK

2.4 V

VIN = 0 or DV

I

SOURCE

I

= 5mA 0.4

SINK

I

= 16mA 0.8

SINK

CS = DV

CS = DV

DD

= 0.5mA

DD

DD

DV

0.5

DD

-

4.75 5 5.25 V

4.75 5 5.25 V

0.2 V

10 pF

10 pF

Unipolar Mode 5 8

ANALOG

DIGITAL

PSRR AV

Bipolar Mode 8.5 11
SHDN = 0, or softw are power -down mode

0.3 10 µA

Unipolar or Bipolar Mode 2.5 3.5 mA
SHDN = 0, or softw are power -down mode

= DVDD = 4.75V to 5.25V, 72 dB

DD

2.2 10 µA

AVDD -

0.1V

0.8 V

±1 µA

±10 µA

V

µA

V

V

mA

MAX1142/MAX1143

14-Bit ADC, 200ksps, +5V Single-Supply

with Reference

_______________________________________________________________________________________ 5

Note 1: Tested at AV

DD

= DV

DD

= +5V, bipolar input mode.

Note 2: Relative accuracy is the deviation of the analog value at any code from its theoretical value after the gain error and offset

error have been nulled.

Note 3: Offset nulled.
Note 4: Conversion time is defined as the number of clock cycles multiplied by the clock period, clock has 50% duty cycle.

Includes the acquisition time.

Note 5: ADC performance is limited by the converter’s noise floor, typically 300µVp-p.
Note 6 When an external reference has a different voltage than the specified typical value, the full scale of the ADC will scale

proportionally.

Note 7: Electrical characteristics are guaranteed from AV

DD(MIN)

= DV

DD(MIN)

to AV

DD(MAX)

= DV

DD(MAX)

. For operations beyond

this range, see the

Typical Operating Characteristics

. For guaranteed specifications beyond the limits, contact

the factory.

Note 8: Defined as the change in positive full-scale caused by a ±5% variation in the nominal supply voltage.

TIMING CHARACTERISTICS (Figures 5 and 6)

(AVDD= DVDD= +5V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted.)

Acquisition Time t

DIN to SCLK Setup t

DIN to SCLK Hold t

SCLK to DOUT Valid t

CS Fall to DOUT Enable t
CS Rise to DOUT Disable t
CS to SCLK Rise Setup t
CS to SCLK Rise Hold t

SCLK High Pulse Width t

SCLK Low Pulse Width t

SCLK Fall to SSTRB t

CS Fall to SSTRB Enable t
CS Rise to SSTRB Disable t

SSTRB Rise to SCLK Rise t
RST Pulse Width t

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNIT

ACQ

DS

DH

DO

DV

TR

CSS

CSH

CH

CL

SSTRB

SDV

STR

SCK

RS

C

LOAD

C

LOAD

C

LOAD

C

LOAD

C

LOAD

Internal clock mode 0 ns

1.14 µs

50 ns

0 ns

70 ns

= 50pF 80 ns

= 50pF 80 ns

100 ns

0 ns

80 ns

80 ns

= 50pF 80 ns

= 50pF, External clock mode 80 ns

= 50pF, External clock mode 80 ns

208 ns

MAX1142/MAX1143

14-Bit ADC, 200ksps, +5V Single-Supply
with Reference

6 _______________________________________________________________________________________

Typical Operating Characteristics

(MAX1142/MAX1143, AVDD= DVDD= +5V , f

SCLK

= 4.8MHz, external clock (50% duty cycle), 24-clocks/conversion (200ksps), bipo-

lar input, external REF = +4.096V, 0.22µF bypassing on REFADJ, 2.2µF on REF, 1µF on CREF, TA= 25°C, unless otherwise noted.)

-1.0

-0.6

-0.8

-0.2

-0.4

0.2

0

0.4

0.8

0.6

1.0

1 3433

5149

6865

1717 8581

10297

12013

13729

15445

INTEGRAL NONLINEARITY

vs. DIGITAL OUTPUT CODE

MAX1142 toc01

DIGITAL OUTPUT CODE

INTEGRAL NONLINEARITY (LSB)

-1.0

-0.5

0.5

0

1.0

1 3263

4894

6525

81561632

9787

11418

13049

14680

1631

DIFFERENTIAL NONLINEARITY

vs. DIGITAL OUTPUT CODE

MAX1142 toc02

DIGITAL OUTPUT CODE

DIFFERENTIAL NONLINEARITY (LSB)

9.5

10.1

9.9

9.7

10.5

10.3

11.3

11.1

10.9

10.7

11.5

-40 -20 0 20 40 60 80

TOTAL SUPPLY CURRENT

vs. TEMPERATURE

MAX1142/3 toc03

TEMPERATURE (°C)

TOTAL SUPPLY CURRENT (mA)

A: AVDD, DVDD = +4.75V
B: AVDD, DVDD = +5.00V
C: AVDD, DVDD = +5.25V

C

B

A

-4

0

-1

-2

-3

OFFSET VOLTAGE

vs. TEMPERATURE

MAX1142/3 toc04

TEMPERATURE (°C)

OFFSET VOLTAGE (V)

-40 20 40-20 0 60 80

A: AVDD, DVDD = +4.75V
B: AV

DD

, DVDD = +5.00V

C: AV

DD

, DVDD = +5.25V

A

B

C

GAIN ERROR vs.

TEMPERATURE

MAX1142/3 toc05

GAIN ERROR (% FULL SCALE)

0

0.04

0.03

0.02

0.01

TEMPERATURE (°C)

-40 20 40-20 0 60 80

A: AVDD, DVDD = +4.75V
B: AV

DD

, DVDD = +5.00V

C: AV

DD

, DVDD = +5.25V

A

B

C

0.01

0.1

1

10

100

TOTAL SUPPLY CURRENT vs.

CONVERSION RATE (USING SHUTDOWN)

MAX1142/3 toc06

CONVERSION RATE (ksps)

TOTAL SUPPLY CURRENT (mA)

0 100 10001 10