Datasheet OPA2338EA-3K, OPA2338UA, OPA337EA-250, OPA337UA, OPA338UA Datasheet (Burr Brown)

1

®

OPA337, OPA2337
OPA338, OPA2338

®

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: [phone]

Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: [phone] • Immediate Product Info: [phone]

PDS-1410C

© 1997 Burr-Brown Corporation PDS-1410D Printed in U.S.A. June, 2000

FEATURES

●

Micro

SIZE PACKAGES:
SOT23-5
SOT23-8

● SINGLE-SUPPLY OPERATION

● RAIL-TO-RAIL OUTPUT SWING

● FET-INPUT: IB = 10pA max

● HIGH SPEED:

OPA337: 3MHz, 1.2V/µs (G = 1)
OPA338: 12.5MHz, 4.6V/µs (G = 5)

● OPERATION FROM 2.5V to 5.5V

● HIGH OPEN-LOOP GAIN: 120dB

● LOW QUIESCENT CURRENT: 525µA/amp

● SINGLE AND DUAL VERSIONS

DESCRIPTION

The OPA337 and OPA338 series rail-to-rail output CMOS
operational amplifiers are designed for low cost and minia­ture applications. Packaged in the new SOT23-8, the
OPA2337EA and OPA2338EA are Burr-Brown’s smallest
dual op amps. At 1/4 the size of a conventional SO-8 surface
mount, they are ideal for space-sensitive applications.

Utilizing advanced CMOS technology, OPA337 and
OPA338 op amps provide low bias current, high-speed
operation, high open-loop gain, and rail-to-rail output
swing. They operate on a single supply with operation as
low as 2.5V while drawing only 525µA quiescent current.
In addition, the input common-mode voltage range in­cludes ground—ideal for single-supply operation.

The OPA337 series is unity-gain stable. The OPA338
series is optimized for gains greater than or equal to five.
They are easy to use and free from phase inversion and
overload problems found in some other op amps. Excel­lent performance is maintained as the amplifiers swing to
their specified limits. The dual versions feature completely
independent circuitry for lowest crosstalk and freedom
from interaction, even when overdriven or overloaded.

Micro

SIZE, Single-Supply

CMOS OPERATIONAL AMPLIFIERS

Micro

Amplifier

™

Series

APPLICATIONS

● BATTERY-POWERED INSTRUMENTS

● PHOTODIODE PRE-AMPS

● MEDICAL INSTRUMENTS

● TEST EQUIPMENT

● AUDIO SYSTEMS

● DRIVING ADCs

● CONSUMER PRODUCTS

1
2
3
4

8
7
6
5

V+
Out B
–In B
+In B

Out A

–In A
+In A

V–

OPA2337, OPA2338

8-Pin DIP

(1)

, SO-8, SOT23-8

A

B

1
2
3
4

8
7
6
5

NC
V+
Output
NC

NC
–In
+In

V–

OPA337, OPA338

8-Pin DIP

(1)

, SO-8, MSOP-8

(1)

1
2
3

5

4

V+

–In

Out

V–

+In

OPA337, OPA338

SOT23-5

NOTE: (1) DIP AND MSOP-8 versions for OPA337, OPA2337 only.

SPICE Model available at www.burr-brown.com

For most current data sheet and other product

information, visit www.burr-brown.com

OPA337

OPA2337

OPA338

OPA2338

G = 1 STABLE G ≥ 5 STABLE

SINGLE DUAL SINGLE DUAL

PACKAGE OPA337 OPA2337 OPA338 OPA2338

SOT23-5 ✔✔
SOT23-8 ✔✔

MSOP-8 ✔

SO-8 ✔✔ ✔✔

DIP-8 ✔✔

OPA337

OPA2337

OPA2338

2

®

OPA337, OPA2337
OPA338, OPA2338

SPECIFICATIONS: VS = 2.7V to 5.5V

At TA = +25°C, and RL = 25kΩ connected to VS/2, unless otherwise noted.
Boldface limits apply over the specified temperature range, –40°C to +85°C, V

S

= 5V.

The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.

OPA337NA, EA, UA, PA

OPA2337EA, UA, PA

OPA338NA, UA

OPA2338EA, UA

PARAMETER CONDITION MIN TYP

(1)

MAX UNITS

OFFSET VOLTAGE

Input Offset Voltage V

OS

±0.5 ±3mV

T

A

= –40°C to +85°C ±3.5 mV

vs Temperature dV

OS

/dT ±2 µV/°C

vs Power Supply Rejection Ratio PSRR V

S

= 2.7V to 5.5V 25 125 µV/V

T

A

= –40°C to +85°C VS = 2.7V to 5.5V 125 µV/V

Channel Separation (dual versions) dc 0.3 µV/V

INPUT BIAS CURRENT

Input Bias Current I

B

±0.2 ±10 pA

T

A

= –40°C to +85°C See Typical Curve

Input Offset Current I

OS

±0.2 ±10 pA

NOISE

Input Voltage Noise, f = 0.1Hz to 10Hz 6 µVp-p
Input Voltage Noise Density, f = 1kHz e

n

26 nV/√Hz

Current Noise Density, f = 1kHz i

n

0.6 fA/√Hz

INPUT VOLTAGE RANGE

Common-Mode Voltage Range V

CM

TA = –40°C to +85°C –0.2 (V+) – 1.2 V

Common-Mode Rejection Ratio CMRR –0.2V < V

CM

< (V+) – 1.2V 74 90 dB

T

A

= –40°C to +85°C –0.2V < V

CM

< (V+) – 1.2V 74 dB

INPUT IMPEDANCE

Differential 10

13

|| 2 Ω || pF

Common-Mode 10

13

|| 4 Ω || pF

OPEN-LOOP GAIN

Open-Loop Voltage Gain A

OLRL

= 25kΩ, 125mV < VO < (V+) – 125mV 100 120 dB

T

A

= –40°C to +85°C RL = 25kΩ, 125mV < VO < (V+) – 125mV 100 dB

R

L

= 5kΩ, 500mV < VO < (V+) – 500mV 100 114 dB

T

A

= –40°C to +85°C RL = 5kΩ, 500mV < VO < (V+) – 500mV 100 dB

OPA337 FREQUENCY RESPONSE

Gain-Bandwidth Product GBW V

S

= 5V, G = 1 3 MHz

Slew Rate SR V

S

= 5V, G = 1 1.2 V/µs

Settling Time: 0.1% V

S

= 5V, 2V Step, CL = 100pF, G = 1 2 µs

0.01% V

S

= 5V, 2V Step, CL = 100pF, G = 1 2.5 µs

Overload Recovery Time V

IN

• G = V

S

2 µs

Total Harmonic Distortion + Noise THD+N V

S

= 5V, VO = 3Vp-p, G = 1, f = 1kHz 0.001 %

OPA338 FREQUENCY RESPONSE

Gain-Bandwidth Product GBW V

S

= 5V, G = 5 12.5 MHz

Slew Rate SR V

S

= 5V, G = 5 4.6 V/µs

Settling Time: 0.1% V

S

= 5V, 2V Step, CL = 100pF, G = 5 1.4 µs

0.01% V

S

= 5V, 2V Step, CL = 100pF, G = 5 1.9 µs

Overload Recovery Time V

IN

• G = V

S

0.5 µs

Total Harmonic Distortion + Noise THD+N V

S

= 5V, VO = 3Vp-p, G = 5, f = 1kHz 0.0035 %

OUTPUT

Voltage Output Swing from Rail

(2)

RL = 25kΩ, AOL ≥ 100dB 40 125 mV

T

A

= –40°C to +85°C RL = 25kΩ, AOL ≥ 100dB 125 mV

R

L

= 5kΩ, AOL ≥ 100dB 150 500 mV

T

A

= –40°C to +85°C RL = 5kΩ, AOL ≥ 100dB 500 mV

Short-Circuit Current I

SC

±9mA

Capacitive Load Drive C

LOAD

See Typical Curve

POWER SUPPLY

Specified Voltage Range V

S

TA = –40°C to +85°C 2.7 5.5 V

Minimum Operating Voltage 2.5 V
Quiescent Current (per amplifier) I

Q

IO = 0 0.525 1 mA

T

A

= –40°C to +85°C IO = 0 1.2 mA

3

®

OPA337, OPA2337
OPA338, OPA2338

PACKAGE SPECIFIED

DRAWING TEMPERATURE PACKAGE ORDERING TRANSPORT

PRODUCT DESCRIPTION PACKAGE NUMBER RANGE MARKING NUMBER

(1)

MEDIA

OPA337 Series

OPA337NA Single, G = 1 Stable 5-Lead SOT23-5 331 –40 °C to +85°C C37 OPA337NA/250 Tape and Reel

"" """"OPA337NA/3K Tape and Reel

OPA337EA Single, G = 1 Stable MSOP-8 337 –40 °C to +85°C G37 OPA337EA/250 Tape and Reel

"" """"OPA337EA/2K5 Tape and Reel

OPA337PA Single, G = 1 Stable 8-Pin DIP 006 –40°C to +85°C OPA337PA OPA337PA Rails
OPA337UA Single, G = 1 Stable SO-8 Surface Mount 182 –40°C to +85°C OPA337UA OPA337UA Rails

"" """"OPA337UA/2K5 Tape and Reel

OPA2337EA Dual, G = 1 Stable 8-Lead SOT23-8 348 –40°C to +85°C A7 OPA2337EA/250 Tape and Reel

"" """"OPA2337EA/3K Tape and Reel

OPA2337PA Dual, G = 1 Stable 8-Pin DIP 006 –40°C to +85°C OPA2337PA OPA2337PA Rails
OPA2337UA Dual, G = 1 Stable SO-8 Surface Mount 182 –40°C to +85°C OPA2337UA OPA2337UA Rails

"" """"OPA2337UA/2K5 Tape and Reel

OPA338 Series

OPA338NA Single, G ≥ 5 Stable 5-Lead SOT23-5 331 –40°C to +85°C A38 OPA338NA/250 Tape and Reel

"" """"OPA338NA/3K Tape and Reel

OPA338UA Single, G

≥ 5 Stable SO-8 Surface Mount 182 –40°C to +85°C OPA338UA OPA338UA Rails

"" """"OPA338UA/2K5 Tape and Reel

OPA2338EA Dual, G

≥ 5 Stable 8-Lead SOT23-8 348 –40°C to +85°C A8 OPA2338EA/250 Tape and Reel

"" """"OPA2338EA/3K Tape and Reel

OPA2338UA Dual, G

≥ 5 Stable SO-8 Surface Mount 182 –40°C to +85°C OPA2338UA OPA2338UA Rails

"" """"OPA2338UA/2K5 Tape and Reel

NOTES: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500 pieces
of “OPA2337UA/2K5” will get a single 2500-piece Tape and Reel.

SPECIFICATIONS: VS = 2.7V to 5.5V (Cont.)

At TA = +25°C, and RL = 25kΩ connected to VS/2, unless otherwise noted.
Boldface limits apply over the specified temperature range, –40°C to +85°C, V

S

= 5V.

OPA337NA, EA, UA, PA

OPA2337EA, UA, PA

OPA338NA, UA

OPA2338EA, UA
PARAMETER CONDITION MIN TYP MAX UNITS
TEMPERATURE RANGE

Specified Range –40 +85 °C
Operating Range –55 +125 °C
Storage Range –55 +125 °C
Thermal Resistance

θ

JA

SOT23-5 Surface Mount 200 °C/W
SOT23-8 Surface Mount 200 °C/W
MSOP-8 150 °C/W
SO-8 Surface Mount 150 °C/W
8-Pin DIP 100 °C/W

NOTES: (1) V

S

= 5V. (2) Output voltage swings are measured between the output and negative and positive power supply rails.

ELECTROSTATIC
DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.

ESD damage can range from subtle performance degrada­tion to complete device failure. Precision integrated circuits
may be more susceptible to damage because very small
parametric changes could cause the device not to meet its
published specifications.

Supply Voltage ................................................................................... 5.5V

Input Voltage

(2)

.................................................. (V–) –0.5V to (V+) +0.5V

Input Current

(2)

................................................................................. 10mA

Output Short Circuit

(3)

.............................................................. Continuous

Operating Temperature .................................................. –55 °C to +125°C

Storage Temperature ..................................................... –55°C to +125°C

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

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

NOTES: (1) Stresses above these ratings may cause permanent damage.
Exposure to absolute maximum ratings for extended periods may degrade
device reliability. (2) Input signal voltage is limited by internal diodes
connected to power supplies. See text. (3) Short circuit to ground, one
amplifier per package.

ABSOLUTE MAXIMUM RATINGS

(1)

PACKAGE/ORDERING INFORMATION

4

®

OPA337, OPA2337
OPA338, OPA2338

TYPICAL PERFORMANCE CURVES

At TA = +25°C, VS = +5V, and RL = 25kΩ connected to VS/2, unless otherwise noted.

OPEN-LOOP GAIN/PHASE vs FREQUENCY

Frequency (Hz)

Open-Loop Gain (dB)

Phase (°)

160
140
120
100

80
60
40
20

0

–20

1 10 100 10k1k 100k 10M1M

OPA337
OPA338

G

φ

0

–45

–90

–135

–180

CHANNEL SEPARATION vs FREQUENCY

Frequency (Hz)

Channel Separation (dB)

140

130

120

110

100

90

80

100 10k1k 1M100k

Dual Versions

INPUT BIAS CURRENT

vs INPUT COMMON-MODE VOLTAGE

Common-Mode Voltage (V)

Input Bias Current (pA)

0.5

0.4

0.3

0.2

0.1

0

–0.1

–1 210543

INPUT BIAS CURRENT vs TEMPERATURE

Temperature (°C)

Input Bias Current (pA)

100

10

1

0.1

0.01
–75 –50 –25 0 25 50 75 100 125

POWER SUPPLY REJECTION RATIO AND

COMMON-MODE REJECTION RATIO vs FREQUENCY

Frequency (Hz)

PSRR, CMRR (dB)

100

90
80
70
60
50
40
30
20
10

1 10 100 1k 10k 100k 1M 10M

+PSRR

–PSRR

CMRR

INPUT VOLTAGE AND CURRENT NOISE

SPECTRAL DENSITY vs FREQUENCY

Frequency (Hz)

Voltage Noise (nV√Hz)

1k

100

10

1

0.1

1k

100

10

1

0.1

1 10 100 1k 10k 100k 1M

Current Noise (fA√Hz)

Voltage Noise

Current Noise

5

®

OPA337, OPA2337
OPA338, OPA2338

TYPICAL PERFORMANCE CURVES (Cont.)

At TA = +25°C, VS = +5V, and RL = 25kΩ connected to VS/2, unless otherwise noted.

MAXIMUM OUTPUT VOLTAGE vs FREQUENCY

Frequency (Hz)

Output Voltage (Vp-p)

6

5

4

3

2

1

0

10k 100k 100M1M 10M

Maximum output

voltage without slew

rate-induced distortion.

OPA337

OPA338

TOTAL HARMONIC DISTORTION + NOISE

vs FREQUENCY

Frequency (Hz)

THD+N (%)

0.1

0.01

0.001

0.0001
20 100 1k 10k 20k

G = +10, RL = 5kΩ, 25kΩ

G = +5, RL = 5kΩ, 25kΩ

RL = 25kΩ

RL = 5kΩ

G = +1

VO = 3Vp-p

OPA337
OPA338

AOL, CMRR, PSRR vs TEMPERATURE

Temperature (°C)

A

OL

, CMRR (dB)

PSRR (dB)

140

130

120

110

100

90

80

130

120

110

100

90

80

70

–75 –50 –25 0 25 50 75 100 125

PSRR

CMRR

A

OL

QUIESCENT CURRENT AND SHORT-CIRCUIT CURRENT

vs TEMPERATURE

Temperature (°C)

Quiescent Current (µA)

600

550

500

450

400

350

300

12

11

10

9

8

7

6

Short-Circuit Current (mA)

–75 –50 –25 0 25 50 75 100 125

–I

SC

+I

SC

I

Q

OUTPUT VOLTAGE SWING vs OUTPUT CURRENT

Output Current (mA)

Output Voltage (V)

2.5

2.0

1.5

1.0

0.5
0

–0.5
–1.0
–1.5
–2.0
–2.5

0 ±3±2±1 ±6 ±7 ±8±5±4

125°C

Sinking

Sourcing

25°C

VS = ±2.5V

R

L

Tied to Ground

–55°C

–55°C

QUIESCENT AND SHORT-CIRCUIT CURRENT

vs SUPPLY VOLTAGE

Supply Voltage (V)

Quiescent Current (µA)

Short-Circuit Current (mA)

700

650

600

550

500

450

400

±12

±10

±8

±6

±4

±2

0

2.5 4.03.53.0 5.55.04.5

+I

SC

–I

SC

I

Q

6

®

OPA337, OPA2337
OPA338, OPA2338

TYPICAL PERFORMANCE CURVES (Cont.)

At TA = +25°C, VS = +5V, and RL = 25kΩ connected to VS/2, unless otherwise noted.

SMALL-SIGNAL STEP RESPONSE

C

L

= 100pF, VS = +5V

1µs/div

50mV/div

LARGE-SIGNAL STEP RESPONSE

C

L

= 100pF, VS = +5V

2µs/div

500mV/div

OFFSET VOLTAGE DRIFT

PRODUCTION DISTRIBUTION

Percent of Amplifiers (%)

Offset Voltage Drift (µV/°C)

30

25

20

15

10

5

0

Typical distribution
of packaged units

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

OFFSET VOLTAGE

PRODUCTION DISTRIBUTION

Percent of Amplifiers (%)

Offset Voltage (mV)

–3.0

–2.5

–2.0

–1.5

–1.0

–0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

25

20

15

10

5

0

Typical distribution
of packaged units.

OPA337

G = 1

OPA338

G = 5

OPA337

G = 1

OPA338

G = 5

SETTLING TIME vs CLOSED-LOOP GAIN

Closed-Loop Gain (V/V)

Settling Time (µs)

100

10

1

11k10 100

0.01%

OPA337

0.1%

OPA338

SMALL-SIGNAL OVERSHOOT vs LOAD CAPACITANCE

Load Capacitance (pF)

Overshoot (%)

60

50

40

30

20

10

0

10 10k100 1k

OPA337

(G = ±1)

OPA337

(G = ±10)

OPA338

(G = ±50)

OPA338

(G = ±5)

7

®

OPA337, OPA2337
OPA338, OPA2338

APPLICATIONS INFORMATION

The OPA337 series and OPA338 series are fabricated on a
state-of-the-art CMOS process. The OPA337 series is unity­gain stable. The OPA338 series is optimized for gains
greater than or equal to five. Both are suitable for a wide
range of general purpose applications. Power supply pins
should be bypassed with 0.01µF ceramic capacitors.

OPERATING VOLTAGE

The OPA337 series and OPA338 series can operate from a
+2.5V to +5.5V single supply with excellent performance.
Unlike most op amps which are specified at only one supply
voltage, these op amps are specified for real-world applica­tions; a single limit applies throughout the +2.7V to +5.5V
supply range. This allows a designer to have the same
assured performance at any supply voltage within the speci­fied voltage range. Most behavior remains unchanged
throughout the full operating voltage range. Parameters
which vary significantly with operating voltage are shown in
typical performance curves.

FIGURE 2. Input Current Protection for Voltages Exceeding

the Supply Voltage.

5kΩ

OPA337

10mA max

+5V

V

IN

V

OUT

I

OVERLOAD

0

3V

V

OUT

, G = +1
(limited by input
common-mode
range)

–3V

V

OUT

, G = –1
(not limited by
input common­mode range.)

G = ±1

OPA337, VIN = ±3V Greater Than VS = ±2.5V

FIGURE 1. OPA337—No Phase Inversion with Inputs

Greater than the Power Supply Voltage.

INPUT VOLTAGE

The input common-mode range extends from (V–) – 0.2V to
(V+) – 1.2V. For normal operation, inputs should be
limited to this range. The absolute maximum input voltage
is 500mV beyond the supplies. Inputs greater than the
input common-mode range but less than maximum input
voltage, while not valid, will not cause any damage to the
op amp. Furthermore, if input current is limited the inputs
may go beyond the power supplies without phase inver­sion (Figure 1) unlike some other op amps.

Normally, input currents are 0.2pA. However, large inputs
(greater than 500mV beyond the supply rails) can cause
excessive current to flow in or out of the input pins.
Therefore, as well as keeping the input voltage below the
maximum rating, it is also important to limit the input
current to less than 10mA. This is easily accomplished
with an input resistor as shown in Figure 2.

USING THE OPA338 IN LOW GAINS

The OPA338 series is optimized for gains greater than or
equal to five. It has significantly wider bandwidth (12.5MHz)
and faster slew rate (4.6V/µs) when compared to the OPA337
series. The OPA338 series can be used in lower gain con­figurations at low frequencies while maintaining its high
slew rate with the proper compensation.

Figure 3 shows the OPA338 in a unity-gain buffer configu­ration. At dc, the compensation capacitor C1 is effectively
“open” resulting in 100% feedback (closed-loop gain = 1).
As frequency increases, C1 becomes lower impedance and
closed-loop gain increases, eventually becoming 1 + R2/R

1

(in this case five, which is equal to the minimum gain
required for stability).

The required compensation capacitor value can be deter­mined from the following equation:

C1 = 1/(2πfCR1)

Since fC may shift with process variations, it is recom­mended that a value less than fC be used for determining C1.
With fC = 1MHz and R1 = 2.5kΩ, the compensation capaci­tor is about 68pF.

The selection of the compensation capacitor C1 is important.
A proper value ensures that the closed-loop circuit gain is
greater than or equal to five at high frequencies. Referring to
the “Open-Loop Gain vs Frequency” plot in the Typical
Performance Curves section, the OPA338 gain line (dashed
in the curve) has a constant slope (–20dB/decade) up to
approximately 3MHz. This frequency is referred to as fC.
Beyond fC the slope of the curve increases, suggesting that
closed-loop gains less than 5 are not appropriate.

FIGURE 3. Compensation of OPA338 for Unity-Gain Buffer.

C1 =

1

2πf

CR1

R

1

2.5kΩ

C

1

68pF

R

2

10kΩ

OPA338

V

IN

V

OUT

Where fC is the frequency at which closed-loop
gains less than five are not appropriate—see text.

Improved slew rate (4.6V/µs) versus

OPA337 (1.2V/µs) in unity gain.

8

®

OPA337, OPA2337
OPA338, OPA2338

Figure 4 shows a compensation technique using an inverting
configuration. The low frequency gain is set by the resistor
ratio while the high frequency gain is set by the capacitor
ratio. As with the noninverting circuit, for frequencies above
fC the gain must be greater than the recommended minimum
stable gain for the op amp.

The capacitor values shown are the nearest standard values.
Capacitor values may need to be adjusted slightly to opti­mize performance. For more detailed information, consult
the OPA686 product data sheet.

Figure 5 shows the large-signal transient response using the
circuit given in Figure 4. As shown, the OPA338 is stable in
low gain applications and provides improved slew rate
performance when compared to the OPA337.

FIGURE 4. Inverting Compensation Circuit of OPA338 for

Low Gain.

500mV/div

OPA338

2µs/div

FIGURE 5. G = 2, Slew-Rate Comparison of OPA338 and

OPA337.

OPA337

Resistors R1 and R2 are chosen to set the desired dc signal
gain. Then the value for C2 is determined as follows:

C2 = 1/(2πfCR2)

C1 is determined from the desired high frequency gain (GH):

C1 = (GH – 1) • C

2

For a desired dc gain of 2 and high frequency gain of 10, the
following resistor and capacitor values result:

R1 = 10kΩ C1 = 150pF
R2 = 5kΩ C2 = 15pF

TYPICAL APPLICATION

Figure 6 shows the OPA2337 in a typical application. The
ADS7822 is a 12-bit, micro-power sampling analog-to­digital converter available in the tiny MSOP-8 package. As
with the OPA2337, it operates with a supply voltage as
low as +2.7V. When used with the miniature SOT23-8
package of the OPA2337, the circuit is ideal for space­limited and low power applications. In addition, OPA2337’s
high input impedance allows large value resistors to be
used which results in small physical capacitors, further
reducing circuit size. For further information, consult the
ADS7822 product data sheet.

C2 = , C1 = (GH –1) • C

2

1

2πf

CR2

C

1

150pF

OPA338

V

IN

V

OUT

R

1

5kΩ

R

2

10kΩ

Where GH is the high frequency gain,

G

H

= 1 + C1/C

2

Improved slew rate versus OPA337
(see Figure 5).

C

2

15pF

9

®

OPA337, OPA2337
OPA338, OPA2338

FIGURE 6. Low Power, Single-Supply, Speech Bandpass Filtered Data Acquisition System.

1/2

OPA2337E

1/2

OPA2337E

ADS7822

12-Bit A/D

C

3

V

+

GND

3

18

4

5

6

7

–IN

+IN

2

C

2

33pF

DCLOCK

Serial
Interface

1000pF

R

1

1.5kΩ

R

4

20kΩ

R

5

20kΩ

R

6

100kΩ

R

8

150kΩ

R

9

510kΩ

R

7

51kΩ

D

OUT

V

REF

V+ = +2.7V to 5V

CS/SHDN

C

1

1000pF

Electret

Microphone

(1)

G = 100

Passband 300Hz to 3kHz

R

3

1MΩ

R

2

1MΩ

NOTE: (1) Electret microphone
with internal transistor (FET)
powered by R

1

.

FIGURE 7. Recommended SOT23-5 and SOT23-8 Solder Footprints.

0.035

(0.889)

0.10

(2.54)

0.018

(0.457)

0.026

(0.66)

SOT23-8

(Package Drawing #348)

Refer to end of data sheet or Appendix C of Burr-Brown IC Data Book for

tolerances and detailed package drawing. For further information on solder

pads for surface-mount packages, consult Application Bulletin AB-132.

SOT23-5

(Package Drawing #331)

0.035

(0.889)

0.10

(2.54)

0.0375

(0.9525)

0.0375

(0.9525)

0.075

(1.905)

0.027

(0.686)