Rainbow Electronics MAX44252 User Manual

19-6000; Rev 0; 10/11

MAX44251/MAX44252

20V, Ultra-Precision, Low-Noise Op Amps

General Description

The MAX44251/MAX44252 are 20V, ultra-precision, lownoise, low-drift amplifiers that offer near-zero DC offset and drift through the use of patented autocorrelating zeroing techniques. This method constantly measures and compensates the input offset, eliminating drift over time and temperature and the effect of 1/f noise. These dual and quad devices feature rail-to-rail outputs, operate from a single 2.7V to 20V supply, and consume only

1.15mA per channel, while providing 5.9nV/√Hz inputreferred voltage noise. The ICs are unity-gain stable with a gain-bandwidth product of 10MHz.

With excellent specifications such as offset voltage of 6µV (max), drift of 19nV/°C (max), and 123nV

0.1Hz to 10Hz, the ICs are ideally suited for applications requiring ultra-low noise and DC precision such as interfacing with pressure sensors, strain gauges, precision weight scales, and medical instrumentation.

The ICs are available in 8-pin SOT23, 8-pin µMAXM, and 14-pin SOIC packages and are rated over the

-40°C to +125°C temperature range.

Ordering Information appears at end of data sheet.

Functional Diagrams appear at end of data sheet.

For related parts and recommended products to use with this part, refer to www.maxim-ic.com/MAX44251.related.

noise in

P-P

Benefits and Features

S 2.7V to 20V Power-Supply Range

S Integrated EMI Filter

S 6µV Input Offset Voltage (max) at Room

Temperature

S TCVOS of 19nV/°C (max) S Low 5.9nV/√Hz Input-Referred Voltage Noise

S 123nV

in 0.1Hz to 10Hz

P-P

S Fast 400ns Settling Time

S 10MHz Gain-Bandwidth Product

S Rail-to-Rail Output

S High Accuracy Enables Precision Signal Chain

Acquisition

Applications

Strain Gauges Pressure Transducers Medical Instrumentation Precision Instrumentation Load Cell and Bridge Transducer Amplification

Typical Operating Circuit

3.3V

20V

MAX44251

1.5V

R

20V

BUFFER

MAX44251

V

IN+

V

IN-

V

DD

MAX11211

V

SS

V

REF

OUTPUT

20V

R

G

BUFFER

50R

20V

BUFFER

G

MAX44251

R

µMAX is a registered trademark of Maxim Integrated Products, Inc.

�� Maxim Integrated Products 1

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

3V

V

R

C

1

OUT

1

MAX6126

V

DD

MICRO-

PROCESSOR

MAX44251/MAX44252

20V, Ultra-Precision, Low-Noise Op Amps

ABSOLUTE MAXIMUM RATINGS

Supply Voltage (VDD to VSS).................................-0.3V to +22V

All Other Pins ..................................(VSS - 0.3V) to (VDD + 0.3V)

Short-Circuit Duration to Either Supply Rail ............................ 1s

Continuous Input Current (any pin) ................................. ±20mA

Differential Input Voltage ...................................................... ±6V

Maximum Power Dissipation (TA = +70°C)

SOT23 (derate 9.1 mW/°C above +70°C) ...................727mW

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

SOIC (derate 8.3 mW/°C above +70°C) ..................666.7mW

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.

PACKAGE THERMAL CHARACTERISTICS (Note 1)

SOT23

Junction-to-Ambient Thermal Resistance (ΘJA) ....... 196°C/W

Junction-to-Case Thermal Resistance (ΘJC) ...............70°C/W

µMAX

Junction-to-Ambient Thermal Resistance (ΘJA) ........221°C/W

Junction-to-Case Thermal Resistance (ΘJC) ...............42°C/W

Operating Temperature Range ........................ -40°C to +125NC

Junction Temperature .....................................................+150NC

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

Lead Temperature (soldering, 10s) .............................. +300NC

Soldering Temperature (reflow) .................................... +260NC

SOIC

Junction-to-Ambient Thermal Resistance (ΘJA) ........120°C/W

Junction-to-Case Thermal Resistance (ΘJC) ...............37°C/W

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-

layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.

ELECTRICAL CHARACTERISTICS

(VDD = 10V, VSS = 0V, V at +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLY

Supply Voltage Range V

Power-Supply Rejection Ratio (Note 3)

Quiescent Current per Amplifier I

Power-Up Time t

DC SPECIFICATIONS

Input Common-Mode Range V

Common-Mode Rejection Ratio (Note 3)

IN+

= V

= VDD/2, RL = 10kI to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are

IN-

DD

PSRR VDD = 2.7V to 20V, VCM = 0V 140 145 dB

DD

ON

CM

CMRR

Guaranteed by PSRR 2.7 20 V

RL = J

Guaranteed by CMRR test

TA = +25NC, VCM = -0.05V to (VDD -

1.5V)

-40NC < TA < +125NC

TA = +25NC

-40NC < TA < +125NC

VSS -

0.05

133 140

130

1.15 1.55

1.75

25

VDD -

1.5

mA

Fs

V

dB

�� Maxim Integrated Products 2

MAX44251/MAX44252

20V, Ultra-Precision, Low-Noise Op Amps

ELECTRICAL CHARACTERISTICS (continued)

(VDD = 10V, VSS = 0V, V at +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Input Offset Voltage (Note 3) V

Input Offset Voltage Drift (Note 3)

Input Bias Current (Note 3) I

Input Offset Current (Note 3) I

Open-Loop Gain (Note 3) A

Output Short-Circuit Current To VDD or V

Output Voltage Low V

Output Voltage High V

AC SPECIFICATIONS

Input Voltage-Noise Density e

Input Voltage Noise 0.1Hz < f < 10Hz 123 nV

Input Current-Noise Density i

Input Capacitance C

Gain-Bandwidth Product GBW 10 MHz

Phase Margin PM CL = 20pF 60 Degrees

Slew Rate SR AV = 1V/V, V

Capacitive Loading C

Total Harmonic Distortion THD

Settling Time To 0.01%, V

IN+

= V

= VDD/2, RL = 10kI to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are

IN-

3 6

7

5 19

200 1300

2400

400 pA

12 25

45 85

18 37

71 135

2 pF

8

TC V

OS

VOL

OS

B

OL

OH

N

IN

L

TA = +25NC

-40NC < TA < +125NC

OS

TA = +25NC

-40NC < TA < +125NC

250mV P V P VDD - 250mV, RL = 10kI to VDD/2

V

- V

OUT

VDD - V

SS

OUT

SS

TA = +25NC

-40NC < TA < +125NC

145 154

136

Noncontinuous 96 mA

RL = 10kI to VDD/2

RL = 2kI to VDD/2

RL = 10kI to VDD/2

RL = 2kI to VDD/2

f = 1kHz 5.9

f = 1kHz 0.6

= 2V

OUT

P-P

No sustained oscillation, AV = 1V/V 500 pF

V

= 2V

OUT

AV = +1V/V, RL = 10kI to VDD/2

,

P-P

f = 1kHz -124

f = 20kHz -119

= 2V step, AV = -1V/V 400 ns

OUT

nV/NC

mV

nV/√Hz

pA/√Hz

V/Fs

FV

pA

dB

P-P

dB

�� Maxim Integrated Products 3

MAX44251/MAX44252

20V, Ultra-Precision, Low-Noise Op Amps

ELECTRICAL CHARACTERISTICS

(VDD = 3.3V, VSS = 0V, V are at +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLY

Quiescent Current per Amplifier I

Power-Up Time t

DC SPECIFICATIONS

Input Common-Mode Range V

Common-Mode Rejection Ratio (Note 3)

Input Offset Voltage (Note 3) V

Input Offset Voltage Drift (Note 3)

Input Bias Current (Note 3) I

Input Offset Current (Note 3) I

Open-Loop Gain (Note 3) A

Output Short-Circuit Current To VDD or V

Output Voltage Low V

Output Voltage High V

AC SPECIFICATIONS

Input Voltage-Noise Density e

Input Voltage Noise 0.1Hz < f < 10Hz 123 nV

Input Current-Noise Density i

Input Capacitance C

Gain-Bandwidth Product GBW 10 MHz

IN+

= V

= VDD/2, RL = 10kI to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values

IN-

DD

ON

CM

CMRR

OS

TC V

B

OS

VOL

OL

OH

N

IN

RL = J

Guaranteed by CMRR test

TA = +25NC, VCM = -0.05V to (VDD -

1.5V)

-40NC < TA < +125NC

TA = +25NC

-40NC < TA < +125NC

OS

TA = +25NC

-40NC < TA < +125NC

250mV P V P VDD - 250mV, RL = 10kI to VDD/2

V

- V

OUT

SS

VDD - V

OUT

f = 1kHz 6.2

f = 1kHz 0.3

TA = +25NC

-40NC < TA < +125NC

OUT

TA = +25NC

-40NC < TA < +125NC

Noncontinuous 58 mA

SS

RL = 10kI to VDD/2

RL = 2kI to VDD/2

RL = 10kI to VDD/2

RL = 2kI to VDD/2

VSS -

0.05

120 129

117

136 151

133

1.1 1.5

1.65

25

VDD -

1.5

3 5.5

6.5

8 18

200 1100

1200

400 pA

5 22

17 42

9 22

29 52

2 pF

nV/NC

nV/√Hz

pA/√Hz

mA

Fs

V

dB

FV

pA

dB

mV

P-P

�� Maxim Integrated Products 4

MAX44251/MAX44252

02

20V, Ultra-Precision, Low-Noise Op Amps

ELECTRICAL CHARACTERISTICS (continued)

(VDD = 3.3V, VSS = 0V, V at +25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Phase Margin PM CL = 20pF 60 Degrees

Slew Rate SR AV = 1V/V, V

Capacitive Loading C

Total Harmonic Distortion THD

IN+

= V

= VDD/2, RL = 10kI to VDD/2, TA = -40°C to +125°C, unless otherwise noted. Typical values are

IN-

= 1V

OUT

No sustained oscillation, AV = 1V/V 500 pF

L

V

OUT

= 1V

P-P

,

AV = +1V/V,

, 10% to 90% 5

P-P

f = 1kHz -124

VCM = VDD/4, RL = 10kI to VDD/2

f = 20kHz -100

V/Fs

dB

Settling Time To 0.01%, V

= 1V step, AV = -1V/V 200 ns

OUT

Note 2: All devices are 100% production tested at TA = +25°C. Temperature limits are guaranteed by design. Note 3: Guaranteed by design.

Typical Operating Characteristics

(VDD = 10V, VSS = 0V, outputs have RL = 10kI to VDD/2. TA = +25NC, unless otherwise specified.)

OFFSET VOLTAGE HISTOGRAM

25

20

15

10

FREQUENCY (%)

5

0

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

OFFSET VOLTAGE (µV)

MAX44251 toc01

INPUT OFFSET VOLTAGE DRIFT HISTOGRAM

16

14

12

10

8

6

FREQUENCY (%)

4

2

0

-0.00100.001

OFFSET VOLTAGE DRIFT (µV/°C)

0.002

0.003

0.004

0.005

MAX44251 toc02

0.006

SUPPLY CURRENT vs. SUPPLY VOLTAGE

1.4

TA = +125°C

1.2

1.0

0.8

0.6

SUPPLY CURRENT (mA)

0.4

0.2

TA = +25°C

0

SUPPLY VOLTAGE (V)

TA = 0°C

SUPPLY CURRENT

TA = +85°C

TA = -40°C

PER AMPLIFIER

2015105

MAX44251 toc03

5

�� Maxim Integrated Products 5