Rainbow Electronics MAX1273 User Manual

General Description

The MAX1272/MAX1273 multirange 12-bit data-acquisition systems (DAS) operate with a single 5V supply. The software-programmable analog input accepts a variety of voltage ranges: ±10V, ±5V, 0 to 10V, 0 to 5V for the MAX1272; ±V

REF

, ±V

REF

/ 2, 0 to V

REF

, 0 to V

REF

/ 2 for the MAX1273. The software-selectable extended analog input range increases the effective dynamic range to 14 bits and provides the flexibility to interface 4–20mA powered sensors directly to a single 5V system. In addition, the MAX1272 provides fault protection to ±12V. Other features include a 5MHz track/hold (T/H) bandwidth, 87ksps throughput rate, and internal (4.096V) or external (2.40V to 4.18V) reference.

The MAX1272/MAX1273 serial interfaces connect directly to SPI™/QSPI™/MICROWIRE™-compatible devices without any external logic.

Four software-programmable power-down modes (delayed standby, immediate standby, delayed full powerdown, and immediate full power-down) provide low-current shutdown between conversions. In standby mode, the internal reference buffer remains active, thus eliminating startup delay.

The MAX1272/MAX1273 are available in 8-pin PDIP and µMAX packages. Both devices are available in the commercial (0°C to +70°C) or extended (-40°C to +85°C) temperature range.

Applications

Industrial Control Systems

Data-Acquisition Systems

Robotics

Automatic Testing

Battery-Powered Instruments

Medical Instruments

Features

♦ Four Software-Selectable Input Ranges

MAX1272: 0 to 10V, 0 to 5V, ±10V, ±5V MAX1273: 0 to V

REF

, 0 to V

REF

/ 2, ±V

REF

±V

REF

/ 2

♦ 12-Bit Resolution, No Missing Codes

♦ 5V Single-Supply Operation

♦ SPI/QSPI/MICROWIRE-Compatible 3-Wire

Interface

♦ 87ksps Sampling Rate

♦ ±12V Fault-Protected Analog Input (MAX1272)

♦ Internal (4.096V) or External (2.4V to 4.18V)

Reference

♦ Low Power

1.5mA at 87ksps

0.4mA at 10ksps

0.2mA at 1ksps

♦ Four Power-Down Modes

♦ 8-Pin µMAX and PDIP Packages

MAX1272/MAX1273

Fault-Protected, 12-Bit ADCs

with Software-Selectable Input Range

________________________________________________________________ Maxim Integrated Products 1

Pin Configuration

Ordering Information

19-2921; Rev 0; 7/03

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

PINPACKAGE

INL

(LSB)

MAX1272CPA

±1

MAX1272CUA

8 µMAX ±1

MAX1272EPA

±1

MAX1272EUA

8 µMAX ±1

MAX1273CPA

±1

MAX1273CUA

8 µMAX ±1

MAX1273EPA

±1

MAX1273EUA

8 µMAX ±1

SPI and QSPI are trademarks of Motorola, Inc.

MICROWIRE is a trademark of National Semiconductor Corp.

Typical Application Circuit appears at end of data sheet.

0°C to +70°C 8 Plastic DIP 0°C to +70°C

-40°C to +85°C 8 Plastic DIP

-40°C to +85°C 0°C to +70°C 8 Plastic DIP 0°C to +70°C

-40°C to +85°C 8 Plastic DIP

-40°C to +85°C

TOP VIEW

SCLK

MAX1272 MAX1273

PDIP/µMAX

87DOUT

CSDIN

REF

AINGND

MAX1272/MAX1273

Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range

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.

VDDto GND..............................................................-0.3V to +6V

AIN to GND (MAX1272) ...................................................... ±12V

AIN to GND (MAX1273) ........................................................ ±6V

DOUT, CS, DIN, SCLK, REF to GND..........-0.3V to (V

+ 0.3V)

Maximum Current into Any Pin............................................50mA

Continuous Power Dissipation (T

= +70°C)

8-Pin Plastic DIP (derate 9.1mW/°C above +70°C) ......727mW

8-Pin µMAX (derate 4.5mW/°C above +70°C) ..............362mW

Operating Temperature Ranges

MAX127_ C_ _ .....................................................0°C to +70°C

MAX127_ E_ _...................................................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

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

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

ELECTRICAL CHARACTERISTICS

(VDD= 4.75V to 5.25V, unipolar/bipolar input range, external reference mode, V

REF

= 4.096V, C

REF

= 1.0µF, f

SCLK

= 1.4MHz,

50% duty cycle, C

LOAD

= 50pF, TA= T

MIN

to T

MAX

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

ACCURACY (Note 1)

Resolution 12 Bits

Integral Nonlinearity INL ±0.3 ±1.0 LSB

Differential Nonlinearity DNL No missing codes over temperature ±0.35 ±1.00 LSB

Offset Error

Gain Error (Note 2)

Gain Error Temperature Coefficient (Note 2)

DYNAMIC SPECIFICATIONS (10kHz sine-wave input, ±10V

Signal-to-Noise + Distortion Ratio SINAD 69 72 dB

Total Harmonic Distortion THD Up to the 5th harmonic -87 -78 dB

Spurious-Free Dynamic Range SFDR 80 88 dB

Aperture Delay t

Aperture Jitter t

ANALOG INPUT

T/H Acquisition Time t

PARAMETERS SYMBOL CONDITIONS MIN TYP MAX UNITS

ACQ

Unipolar ±5

Bipolar ±10

Unipolar ±10

Bipolar ±10

Unipolar ±3

Bipolar ±5

(MAX1272), or ±4.096V

P-P

(MAX1273), f

SAMPLE

15 ns

<50 ps

= 87ksps)

2.85 µs

LSB

ppm/°C

MAX1272/MAX1273

Fault-Protected, 12-Bit ADCs

with Software-Selectable Input Range

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 4.75V to 5.25V, unipolar/bipolar input range, external reference mode, V

REF

= 4.096V, C

REF

= 1.0µF, f

SCLK

= 1.4MHz,

50% duty cycle, C

LOAD

= 50pF, TA= T

MIN

to T

MAX

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

Small-Signal Bandwidth BW

Input Voltage Range (Tables 2, 3)

Input Current I

Input Capacitance 40 pF

INTERNAL REFERENCE

REF Output Voltage V

REF Output Tempco TC V

Output Short-Circuit Current REF shorted to GND 40 mA

Load Regulation 0 to 0.5mA output current 0.7 10 mV

Capacitive Bypass at REF 1µF

REFERENCE INPUT (Reference buffer disabled, reference input applied to REF)

Input Voltage Range 2.40 4.18 V

PARAMETERS SYMBOL CONDITIONS MIN TYP MAX UNITS

REF

-3dB

REF

±10V (MAX1272) or ±V range

±5V (MAX1272) or ±V range

0 to 10V (MAX1272) or 0 to V range

0 to 5V (MAX1272) or 0 to V (MAX1273) range

MAX1272

Unipolar

MAX1273

MAX1272

Bipolar

MAX1273

MAX1272

Unipolar

MAX1273

MAX1272

Bipolar

MAX1273

MAX127_ C ±15

MAX127_ E ±30

(MAX1273)

REF

/ 2 (MAX1273)

REF

RNG = 1 0 10

RNG = 0 0 5

RNG = 1 0 V

RNG = 0 0 V

RNG = 1 -10 +10

RNG = 0 -5 +5

RNG = 1 -V

RNG = 0 -V

0 to 10V range -10 +860

0 to 5V range -10 +430

0 to V

±10V range -1400 +860

±5V range -720 +430

±V

REF

±V

REF

(MAX1273)

/ 2

range -10 +10

REF

/ 2 range -10 +10

REF

range -1400 +10

/ 2 range -720 +10

4.036 4.096 4.156 V

REF

/ 2 +V

REF

2.5

1.25

REF

/ 2

REF

/ 2

MHz

µA

ppm/°C

MAX1272/MAX1273

Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 4.75V to 5.25V, unipolar/bipolar input range, external reference mode, V

REF

= 4.096V, C

REF

= 1.0µF, f

SCLK

= 1.4MHz,

50% duty cycle, C

LOAD

= 50pF, TA= T

MIN

to T

MAX

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

Input Current V

POWER REQUIREMENTS

Supply Voltage V

Supply Current (Internal Reference Mode)

Supply Current (External Reference Mode)

Power-Supply Rejection Ratio (Note 3)

TIMING

Clock Frequency Range f

T/H Acquisition Time t

Conversion Time t

Throughput Rate 87.5 ksps

Internal Reference Settling Time REF bypass capacitor initially discharged 2 ms

Device Power-Up Time External reference mode 10 µs

DIGITAL INPUTS (DIN, SCLK, and CS)

Input High-Threshold Voltage V

Input Low-Threshold Voltage V

Input Hysteresis V

Input Leakage Current I

Input Capacitance C

DIGITAL OUTPUT (DOUT)

Output Voltage Low V

Output Voltage High V

Three-State Leakage Current I

Three-State Output Capacitance C

PARAMETERS SYMBOL CONDITIONS MIN TYP MAX UNITS

PSRR

SCLK

ACQ

CONV

HYS

OUT

Converting 400 850

= 4.096V

REF

Converting

Standby power-down mode 400 700

Full power-down mode 1

Converting

Standby power-down mode 200 450

Full power-down mode 1

External reference = 4.096V ±0.3 ±1.0

Internal reference ±0.5

(Note 4) 2.85 µs

(Note 4) 8.57 µs

VIN = 0 to V

= 10mA 0.4

SINK

= 16mA 0.6

SINK

CS = V CS = V

SOURCE

= 0.5mA

Standby power-down mode

Full power-down mode 1

Bipolar 2.4 4

Unipolar 2.2 3

Bipolar 1.5 2.5

Unipolar 1.2 2.0

4.75 5 5.25 V

0.1 1.4 MHz

0.8 V

0.2 V

-10 +10 µA

15 pF

- 0.5

-10 +10 µA

15 pF

510

2.4 V

µA

LSB

MAX1272/MAX1273

Fault-Protected, 12-Bit ADCs

with Software-Selectable Input Range

_______________________________________________________________________________________ 5

TIMING CHARACTERISTICS

(VDD= 4.75V to 5.25V, unipolar/bipolar input range, external reference mode, V

REF

= 4.096V, C

REF

= 1.0µF, f

SCLK

= 1.4MHz,

50% duty cycle, C

LOAD

= 50pF, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Figures 1 and 4)

Note 1: Accuracy specifications tested at VDD= 5V. Performance at power-supply tolerance limit is guaranteed by power-supply

rejection test.

Note 2: Offset error nulled. The ideal last-code transition is (FS - 1.5 LSB). Note 3: PSRR measured at full scale. Tested at ±10V (MAX1272) and ±4.096V (MAX1273) input ranges. Note 4: Acquisition and conversion times are dependent on the clock speed.

Typical Operating Characteristics

(Typical operating circuit, BIP = RNG = 1, VDD= 5V, external reference mode, V

REF

= 4.096V, C

REF

= 1.0µF, f

SCLK

= 1.4MHz,

50% duty cycle, 87ksps, T

= +25°C, unless otherwise noted.)

CONVERTING SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX1272/73 toc01

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

5.205.155.05 5.104.85 4.90 4.95 5.004.80

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

4.75 5.25

INTERNAL REFERENCE

EXTERNAL REFERENCE

AIN

= 0

CONVERTING SUPPLY CURRENT

vs. TEMPERATURE

MAX1272/73 toc02

TEMPERATURE (°C)

SUPPLY CURRENT (mA)

6035-15 10

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

-40 85

AIN

= 0

INTERNAL REFERENCE

EXTERNAL REFERENCE

STANDBY SUPPLY CURRENT

vs. TEMPERATURE

MAX1272/73 toc03

TEMPERATURE (°C)

STANDBY SUPPLY CURRENT (mA)

603510-15

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-40 85

AIN

= 0

INTERNAL REFERENCE

EXTERNAL REFERENCE

PARAMETERS SYMBOL CONDITIONS MIN TYP MAX UNITS

DIN to SCLK Setup t

DIN to SCLK Hold t

SCLK Fall to Output Data Valid t

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

SCLK Pulse Width High t

SCLK Pulse Width Low t

CSS

CSH

100 ns

0ns

20 250 ns

100 ns

0ns

200 ns

MAX1272/MAX1273

Fault-Protected, 12-Bit ADCs with Software-Selectable Input Range

6 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(Typical operating circuit, BIP = RNG = 1, VDD= 5V, external reference mode, V

REF

= 4.096V, C

REF

= 1.0µF, f

SCLK

= 1.4MHz,

50% duty cycle, 87ksps, T

= +25°C, unless otherwise noted.)

STANDBY SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX1272/73 toc04

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

5.205.155.05 5.104.85 4.90 4.95 5.004.80

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

4.75 5.25

AIN

= 0

INTERNAL REFERENCE

EXTERNAL REFERENCE

FULL POWER-DOWN

SUPPLY CURRENT vs. TEMPERATURE

MAX1272/73 toc05

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

603510-15

-40 85

AIN

= 0

INTERNAL/EXTERNAL REFERENCE

FULL POWER-DOWN SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX1272/73 toc06

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

5.205.155.05 5.104.85 4.90 4.95 5.004.80

4.75 5.25

AIN

= 0

INTERNAL/EXTERNAL REFERENCE

NORMALIZED INTERNAL REFERENCE

VOLTAGE vs. TEMPERATURE

MAX1272/73 toc07

TEMPERATURE (°C)

NORMALIZED INTERNAL REFERENCE VOLTAGE

6035-15 10

0.9970

0.9975

0.9980

0.9985

0.9990

0.9995

1.0000

1.0005

0.9960

0.9965

-40 85

NORMALIZED INTERNAL REFERENCE

VOLTAGE vs. SUPPLY VOLTAGE

MAX1272/73 toc08

SUPPLY VOLTAGE (V)

NORMALIZED INTERNAL REFERENCE VOLTAGE

5.205.155.05 5.104.85 4.90 4.95 5.004.80

0.9992

0.9994

0.9996

0.9998

1.0000

1.0002

1.0004

1.0006

1.0008

1.0010

0.9990

4.75 5.25

DNL vs. CODE

MAX1272/73 toc09

CODE

DNL (LSB)

358430722048 25601024 1536512

-0.8

-0.6

-0.4

-0.2

0.2

0.4

0.6

0.8

1.0

-1.0 0 4096

INL vs. CODE

MAX1272/73 toc10

CODE

INL (LSB)

358430722048 25601024 1536512

-0.8

-0.6

-0.4

-0.2

0.2

0.4

0.6

0.8

1.0

-1.0 0 4096

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