MAXIM MAX9636, MAX9637, MAX9638 User Manual

19-5228; Rev 2; 1/11

EVALUATION KIT

AVAILABLE

3V/5V Low-Power, Low-Noise, CMOS,

General Description

The MAX9636/MAX9637/MAX9638 are single-supply,
CMOS input op amps featuring wide bandwidth at low
quiescent current, making them suitable for a broad
range of battery-powered applications such as portable
medical instruments, portable media players, and smoke
detectors. A combination of extremely low input bias
currents, low input current noise and low input voltage
noise allows interface to high-impedance sources such
as photodiode and piezoelectric sensors. These devices
are also ideal for general-purpose signal processing
functions such as filtering and amplification in a broad
range of portable, battery-powered applications.

The ICs feature a maximized ratio of gain bandwidth
(GBW) to supply current. The devices operate from a
single 2.1V to 5.5V supply at a typical quiescent supply
current of 36µA. For additional power conservation, the
MAX9636 and MAX9638 offer a low-power shutdown
mode that reduces supply current to 1µA and places the
amplifiers’ outputs into a high-impedance state.

The ICs are specified over the automotive operating tem­perature range (-40°C to +125°C). The single is offered
in a space-saving, 6-pin SC70 package, while the dual is
offered in tiny, 8-pin SC70 and 10-pin UTQFN packages.

Rail-to-Rail I/O Op Amps

MAX9636/MAX9637/MAX9638

Features

S Low Input Voltage-Noise Density: 38nV/√Hz
S Low Input Current-Noise Density: 0.9fA/√Hz

S Ultra-Low 0.1pA Bias Current

S Low 36µA Quiescent Current

S 1µA Quiescent Current in Shutdown

S Wide 1.5MHz Bandwidth

S Single-Supply Operation VDD = 2.1V to 5.5V

S Available in Tiny 6-Pin SC70, 8-Pin SC70, and

10-Pin UTQFN Packages

S -40°C to +125°C Operating Temperature Range

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX9636AXT+ -40NC to +125NC 6 SC70
MAX9637AXA+ -40NC to +125NC 8 SC70
MAX9638AVB+ -40NC to +125NC 10 UTQFN

+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.

Applications

Portable Medical Instruments

Piezoelectric Transducer Amplifiers

Smoke Detectors

Battery-Powered Devices

General-Purpose Signal Conditioning

Notebooks

Portable Media Players

_______________________________________________________________ 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/5V Low-Power, Low-Noise, CMOS,
Rail-to-Rail I/O Op Amps

ABSOLUTE MAXIMUM RATINGS

VDD, SHDN to VSS ..................................................-0.3V to +6V

IN+, IN-, OUT ....................................GND - 0.3V to VDD + 0.3V

Continuous Input Current (any pins) ............................... Q20mA

Output Short Circuit to VDD or VSS Duration .......................... 5s

Thermal Limits (Note 1)
Multiple Layer PCB
Continuous Power Dissipation (TA = +70NC)

6-Pin SC70 (derate 3.1mW/°C above +70NC) ............245mW

BJA ....................................................................... 326.5°C/W

BJC .........................................................................115°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.

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

(VDD = 3.3V, VSS = 0V, V
at TA = +25NC, unless otherwise noted.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DC CHARACTERISTICS

Input Voltage Range V

MAX9636/MAX9637/MAX9638

Input Offset Voltage V

Input Offset Voltage Drift
(Note 3)

Input Bias Current (Note 3) I

Common-Mode Rejection Ratio CMRR

Open-Loop Gain A

Output Short-Circuit Current I

Output Voltage Low V

Output Voltage High V

Output Leakage in Shutdown

IN+

= V

= VCM = VDD/2, RL = 10kI to VDD/2, SHDN = VDD, TA = -40NC to +125NC. Typical values are

IN-

, V

IN+

OS

TCV

OL

SC

OL

OH

Guaranteed by CMRR

IN-

TA = +25NC 0.01 2.2
TA = -40NC to +125NC 3.5

MAX9636 only 7

OS

MAX9637, MAX9638 only 10
TA = +25NC ±0.1 ±0.8
TA = -40NC to +85NC ±50

B

TA = -40NC to +125NC ±800

VSS < VCM <
(VDD - 1.4V)

(VSS - 0.1V) < VCM < (VDD + 0.1V) 58 77
V

= 0.25V from rails 104 124

OUT

V

= 0.4V from rails, RL = 600I 100 120

OUT

Short to VDD 55
Short to VSS 40

V

OUT

VDD - V

OUT

SHDN = VSS, V
MAX9638 only)

8-Pin SC70 (derate 3.1mW/NC above +70NC) .............245mW

BJA ......................................................................... 326°C/W

BJC .........................................................................115NC/W

10-Pin UTQFN (derate 7mW/NC above +70NC) ........558.7mW

BJA ...................................................................... 143.2NC/W

BJC .........................................................................20.1NC/W

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

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

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

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

V

-

SS

0.1

TA = +25NC 72 86
TA = -40NC to +125NC 68

RL = 10kI 0.014 0.03
RL = 600I 0.044 0.08
RL = 10kI 0.019 0.04
RL = 600I 0.057 0.1

OUT

= 0V to V

(MAX9636,

DD

0.01 1 FA

V

+

DD

0.1

V

mV

FV/NC

pA

dB

dB

mA

V

V

2

3V/5V Low-Power, Low-Noise, CMOS,

Rail-to-Rail I/O Op Amps

ELECTRICAL CHARACTERISTICS (continued)

(VDD = 3.3V, VSS = 0V, V
at TA = +25NC, unless otherwise noted.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

AC CHARACTERISTICS

Input Voltage Noise Density e
Input Voltage Noise 0.1Hz ≤ f ≤ 10Hz 5 FV
Input Current Noise Density I
Input Capacitance C
Gain Bandwidth GBW 1.5 MHz
Slew Rate SR 0.9 V/Fs
Capacitive Loading C

Distortion THD

Settling Time To 0.1%, V

Crosstalk

POWER-SUPPLY CHARACTERISTICS

Power-Supply Range V

Power-Supply Rejection Ratio PSRR

Quiescent Current I

Shutdown Supply Current I

Shutdown Input V

Shutdown Input V

Shutdown Input Bias Current
(Note 3)

Turn-On Time t

Power-Up Time t

Note 2: All devices are 100% production tested at TA = +25NC. Temperature limits are guaranteed by design.
Note 3: Parameter is guaranteed by design.

IN+

= V

= VCM = VDD/2, RL = 10kI to VDD/2, SHDN = VDD, TA = -40NC to +125NC. Typical values are

IN-

f = 1kHz 38 nV/√Hz

N

f = 1kHz 0.9 fA/√Hz

N

IN

LOAD

DD

DD

DD_SHDNVSHDN

I

SHDN

ON

UP

No sustained oscillations 300 pF
f = 10kHz, VO = 2V

f = 10kHz, VO = 2V
VDD = 5.5V

f = 1kHz (MAX9637, MAX9638) 100

f = 10kHz (MAX9637, MAX9638) 80

Guaranteed by PSRR 2.1 5.5 V

V

IN+

VDD - VSS = 2.1V
to 5.5V

Per amplifier

Over the power-supply range (MAX9636,

IL

MAX9638 only)

Over the power-supply range (MAX9636,

IH

MAX9638 only)

MAX9636, MAX9638 only 1 100 nA

V

SHDN

only)

VDD = 0V to 3.3V 18 Fs

, AV = 1V/V -68

P-P

, AV = 1V/V,

P-P

= 2V step, AV = 1V/V 11.5 Fs

OUT

= V

= VSS,

IN-

P V

(MAX9636, MAX9638 only) 1 FA

IL

= 0V to 3V (MAX9636, MAX9638

TA = +25NC 72 100

TA = -40NC to +125NC 69

TA = +25NC 36 55
TA = -40NC to +125NC 60

1.4 V

2 pF

-74

0.5 V

60 Fs

dB

dB

dB

FA

MAX9636/MAX9637/MAX9638

P-P

3

3V/5V Low-Power, Low-Noise, CMOS,

OUTPUT VOLTAGE HIGH (mV)

Rail-to-Rail I/O Op Amps

Typical Operating Characteristics

(VDD = 3.3V, VSS = 0V, V
TA = +25NC, unless otherwise noted.)

OFFSET VOLTAGE HISTOGRAM

20

18

16

14

12

10

8

6

PERCENT OCCURANCE (%)

4

2

0

OFFSET VOLTAGE (mV)

IN+

= V

= VCM = VDD/2, RL = 10kI to VDD/2, SHDN = VDD, TA = -40NC to +125NC. Typical values are at

IN-

OFFSET VOLTAGE THERMAL

COEFFICIENT HYSTOGRAM

40

35

MAX9636 toc01

30

25

20

15

PERCENT OCCURANCE (%)

10

5

0

0.90.7 1.00.80.1 0.2 0.3 0.4 0.5 0.60

0

OFFSET VOLTAGE THERMAL COEFFICIENT (µV/°C)

1.00.1 0.2 0.3 0.5 0.70.6 0.80.4 0.9

500

450

MAX9636 toc02

400

350

300

250

200

OFFSET VOLTAGE (µV)

150

100

50

0

INPUT OFFSET VOLTAGE

vs. COMMON-MODE VOLTAGE

TA = -40°C

TA = 0°C

TA = +25°C

TA = +85°C

TA = +125°C

-0.5
COMMON-MODE VOLTAGE (V)

3.53.02.0 2.50.5 1.0 1.50

4.0

MAX9636 toc03

INPUT OFFSET VOLTAGE

vs. SUPPLY VOLTAGE V

400

380

360

340

320

MAX9636/MAX9637/MAX9638

TA = 0°C

300

TA = +25°C

280

OFFSET VOLTAGE (µV)

260

240

220

200

0 6

TA = +85°C

TA = +125°C

SUPPLY VOLTAGE (V)

OUTPUT VOLTAGE LOW vs. SINK CURRENT

= 3.3V

V

250

200

150

100

OUTPUT VOLTAGE LOW (mV)

TA = +25°C

50

0

0 12

DD

T

A

TA = +85°C

TA = -40°C

SINK CURRENT (mA)

CM

TA = -40°C

= +125°C

= VDD/2

TA = 0°C

600

400

MAX9636 toc04

200

0

-200

INPUT BIAS CURRENT (pA)

-400

54321

-600

-0.5 4.0

OUTPUT VOLTAGE LOW vs. SINK CURRENT

350

300

MAX9636 toc07

250

200

150

100

OUTPUT VOLTAGE LOW (mV)

50

108642

0

INPUT BIAS CURRENT

vs. COMMON-MODE VOLTAGE

TA = +25°C

TA = +85°C

TA = +125°C

COMMON-MODE VOLTAGE (V)

VDD = 5V

TA = +125°C

TA = +85°C

TA = +25°C

TA = 0°C

TA = -40°C

0 25

SINK CURRENT (mA)

OUTPUT VOLTAGE LOW vs. SINK CURRENT

= 2.1V

V

500

450

MAX9636 toc05

400

350

300

250

200

150

OUTPUT VOLTAGE LOW (mV)

100

50

3.53.02.52.01.51.00.50

0

0 12

DD

TA = +125°C

MAX9636 toc06

TA = +85°C

TA = +25°C

TA = 0°C

TA = -40°C

108642

SINK CURRENT (mA)

OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT

= 2.1V, VOH = VDD - V

V

1200

1000

MAX9636 toc08

800

600

400

200

2015105

DD

TA = +85°C

TA = +25°C

0

0 10

SOURCE CURRENT (mA)

TA = -40°C

OUT

MAX9636 toc09

TA = +125°C

TA = 0°C

987654321

4

3V/5V Low-Power, Low-Noise, CMOS,

OUTPUT VOLTAGE HIGH (mV)

OPEN-LOOP GAIN (dB)

Rail-to-Rail I/O Op Amps

Typical Operating Characteristics (continued)

(VDD = 3.3V, VSS = 0V, V
TA = +25NC, unless otherwise noted.)

OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT

= 3.3V, VOH = VDD - V

V

2000

1800

1600

1400

1200

1000

800

600

OUTPUT VOLTAGE HIGH (mV)

400

200

DD

TA = +85°C

TA = +25°C

0

0 35

SOURCE CURRENT (mA)

IN+

TA = +125°C

TA = -40°C

= V

= VCM = VDD/2, RL = 10kI to VDD/2, SHDN = VDD, TA = -40NC to +125NC. Typical values are at

IN-

OUTPUT VOLTAGE HIGH vs. SOURCE CURRENT

OUT

TA = 0°C

302515 20105

MAX9636 toc10

1200

1000

800

600

400

200

= 5V, VOH = VDD - V

V

DD

TA = +85°C

TA = +25°C

TA = 0°C

0

SOURCE CURRENT (mA)

OUT

TA = +125°C

TA = -40°C

MAX9636 toc11

454035302520151050 50

SUPPLY CURRENT vs. SUPPLY VOLTAGE

45

43

TA = +85°C

41

39

37

35

33

31

SUPPLY CURRENT (µA)

29

TA = -40°C

27

25

2.0 6.0

TA = +125°C

TA = +25°C

TA = 0°C

SUPPLY VOLTAGE (V)

PER AMPLIFIER

5.55.04.0 4.53.0 3.52.5

MAX9636/MAX9637/MAX9638

MAX9636 toc12

140

120

100

80

60

40

20

0

-20

-40

-60

0.001 10,000

100

90

80

70

60

50

40

30

20

POWER-SUPPLY REJECTION RATIO (dB)

10

0

0.01 10,000

OPEN-LOOP GAIN AND PHASE

vs. FREQUENCY

GAIN

PHASE

FREQUENCY (kHz)

1001 100.10.01

MAX9636 toc13

1000

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

10001001010.1

FREQUENCY (kHz)

180

135

90

45

0

-45

-90

-135

-180

MAX9636 toc16

COMMON-MODE REJECTION RATIO

vs. FREQUENCY

0

-10

-20

-30

-40

-50

CMRR (dB)

PHASE (DEG)

-60

-70

-80

-90

0.01 10,000
FREQUENCY (kHz)

DC POWER-SUPPLY REJECTION RATIO

vs. TEMPERATURE

100

98

96

94

92

90

88

86

84

82

DC POWER-SUPPLY REJECTION RATIO (dB)

80

-50 125
TEMPERATURE (°C)

DC COMMON-MODE REJECTION RATIO

vs. TEMPERATURE

100

98

MAX9636 toc14

96

94

92

90

88

86

84

82

DC COMMON-MODE REJECTION RATIO (dB)

10001001010.1

80

-50 125
TEMPERATURE (°C)

MAX9636 toc15

1007525 500-25

INPUT VOLTAGE NOISE vs. FREQUENCY

300

250

MAX9636 toc17

200

150

100

INPUT VOLTAGE NOISE (nV/√Hz)

50

0

1007525 500-25

0.01 100
FREQUENCY (kHz)

1010.1

MAX9636 toc18

5