Datasheet OPA2349EA, OPA2349UA, OPA349NA-3K, OPA349NA, OPA349UA-2K5 Datasheet (Burr Brown)

1µA, Rail-to-Rail, CMOS

OPERATIONAL AMPLIFIERS

FEA TURES

● LOW SUPPLY CURRENT: 1µA

● GAIN-BANDWIDTH: 70kHz

● UNITY GAIN STABLE

● LOW INPUT BIAS CURRENT: 10pA

● WIDE SUPPLY RANGE: 1.8V to 5.5V

● INPUT RANGE 200mV BEYOND RAILS

● OUTPUT SWINGS TO 150mV OF RAILS

● OUTPUT DRIVE CURRENT: 20mA

● OPEN-LOOP GAIN: 90dB

● SOT23

Micro

PACKAGES

APPLICATIONS

● BATTERY PACKS AND POWER SUPPLIES

● PORTABLE PHONES/PAGERS/CAMERAS

● SOLAR-POWERED SYSTEMS

● SMOKE/GAS/FIRE DETECTION SYSTEMS

● REMOTE SENSORS

● PCMCIA CARDS

● DRIVING A/D CONVERTERS

●

Micro

POWER FILTERS

DESCRIPTION

The OPA349 and OPA2349 are ultra-low power op­erational amplifiers that provide 70kHz bandwidth
with only 1µA quiescent current. These rail-to-rail
input and output amplifiers are specifically designed
for battery powered applications. Unlike some
micropower op amps, these parts are unity-gain stable
and require no external compensation. The OPA349’s
low input bias current allows the use of large source
and feedback resistors. The input common-mode volt­age range extends 200mV beyond the power supply
rails and the output swings to within 150mV of the
rails, maintaining wide dynamic range.

OPA349 can be operated with power supplies from

1.8V to 5.5V with little change in performance, guar­anteeing continuing superior performance even in low
battery situations.

OPA349 comes in the miniature SOT23-5, SO-8 sur­face mount and PDIP-8

(1)

packages. OPA2349 dual is
also available in the SOT23 (8-lead SOT23-8), as well
as the SO-8 surface mount packages. These tiny pack­ages are ideal for use in high-density applications,
such as PCMCIA cards, battery packs and portable
instruments.

All models are specified for the commercial tempera­ture range, 0°C to +70°C.

®

OPA349

OPA2349

© 2000 Burr-Brown Corporation PDS-1568A Printed in U.S.A. June, 2000

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]

For most current data sheet and other product

information, visit www.burr-brown.com

1
2
3

5

4

V+

–In

Out

V–

+In

OPA349

SOT23-5

1
2
3
4

8
7
6
5

NC
V+
Out
NC

NC
–In
+In

V–

OPA349

SO-8, PDIP-8

(1)

NOTE: (1) Available Q4 2000.

1
2
3
4

8
7
6
5

V+
Out B
–In B
+In B

Out A

–In A
+In A

V–

OPA2349

SOT23-8, SO-8

OPA349

OPA349

OPA2349

2

OPA349

®

PARAMETER CONDITION MIN TYP MAX UNITS
OFFSET VOLTAGE

Input Offset Voltage V

OS

VS = 5V, VCM = 2.5V ±2 ±10 mV

Drift dV

OS

/dT ±10 µV/°C

vs Power Supply PSRR V

S

= 1.8V to 5.5V, VCM = (V–) + 0.3V 350 1000 µV/V

Channel Separation, dc (Dual version) R

L

= 100kΩ 10 µV/V

INPUT VOLTAGE RANGE

Common-Mode Voltage Range V

CM

(V–) – 0.2 (V+) + 0.2 V

Common-Mode Rejection Ratio CMRR V

S

= +5V, –0.2V < VCM < 3.5V 52 72 dB

V

S

= +5V, –0.2V < VCM < 5.2V 48 60 dB

INPUT BIAS CURRENT

Input Bias Current I

B

±1 ±10 pA

Input Offset Current I

OS

±1 ±10 pA

INPUT IMPEDANCE

Differential 10

13

|| 2 Ω || pF

Common-Mode 10

13

|| 4 Ω || pF

NOISE

Input Voltage Noise, f = 0.1Hz to 10Hz 8 µVp-p
Input Voltage Noise Density, f = 1kHz e

n

300 nV/√Hz

Current Noise Density, f = 1kHz i

n

4 fA/√Hz

OPEN-LOOP GAIN

Open-Loop Voltage Gain

RL = 1MΩ, VS = +5.5V, +0.3V < VO < +5.2V

74 90 dB

Open-Loop Voltage Gain A

OLRL

= 10kΩ, VS = +5.5V, +0.35V < VO < +5.15V

74 90 dB

OUTPUT

Voltage Output Swing from Rail R

L

= 1MΩ, VS = +5.5V, AOL > 74dB 150 300 mV

R

L

= 10kΩ, VS = +5.5V, AOL > 74dB 200 350 mV
Output Current ±8mA
Short-Circuit Current I

SC

±25 mA

FREQUENCY RESPONSE C

L

= 10pF
Gain-Bandwidth Product GBW G = +1 70 kHz
Slew Rate SR V

S

= +5V, G = +1 0.02 V/µs

Settling Time, 0.1% t

S

VS = 5V, 1V Step 65 µs

0.01% V

S

= 5V, 1V Step 80 µs

Overload Recovery Time V

IN

• Gain = V

S

5 µs

POWER SUPPLY

Specified Voltage Range V

S

1.8 5.5 V
Operating Voltage Range 1.8 5.5 V
Quiescent Current (per amplifier) I

Q

IO = 0 1 2 µA

TEMPERATURE RANGE

Specified Range 0 +70 °C
Storage Range –65 +150 °C
Thermal Resistance

θ

JA

°C/W
SOT23-5 Surface Mount 200 °C/W
SOT23-8 Surface Mount 200 °C/W
SO-8 Surface Mount 150 °C/W
PDIP-8 100 °C/W

OPA349NA, UA, PA

OPA2349EA, UA

SPECIFICATIONS: VS = +1.8V to +5.5V

Boldface limits apply over the specified temperature range, TA = 0°C to +70°C

At TA = +25°C, RL = 1MΩ connected to VS/2, unless otherwise noted.

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.

3

®

OPA349

Supply Voltage, V+ to V– ................................................................... 5.5V

Signal Input Terminals, Voltage

(2)

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

Current

(2)

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

Output Short Circuit

(3)

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

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

Storage Temperature .....................................................–65°C to +150°C

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

Lead Temperature (soldering, 3s) ................................................... 300°C

NOTES: (1) Stresses above these ratings may cause permanent damage.
Exposure to absolute maximum conditions for extended periods may de­grade device reliability. These are stress ratings only, and functional opera­tion of the device at these, or any other conditions beyond those specified,
is not implied. (2) Input terminals are diode-clamped to the power supply
rails. Input signals that can swing more than 0.5V beyond the supply rails
should be current-limited to 10mA or less. (3) Short circuit to ground, one
amplifier per package.

ABSOLUTE MAXIMUM RATINGS

(1)

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.

PACKAGE/ORDERING INFORMATION

PACKAGE SPECIFIED
DRAWING TEMPERATURE PACKAGE ORDERING TRANSPORT

PRODUCT PACKAGE NUMBER RANGE MARKING NUMBER

(1)

MEDIA

Single

OPA349NA SOT23-5 331 0°C to +70°C A49 OPA349NA/ 250 Tape and Reel

"""""OPA349NA/3K Tape and Reel

OPA349UA SO-8 182 0°C to +70°C OPA349UA OPA349UA Rails

"""""OPA349UA/2K5 Tape and Reel

OPA349PA

(2)

PDIP-8 006 0 °C to +70°C OPA349PA OPA349PA Rails

Dual

OPA2349EA SOT23-8 348 0°C to +70°C C49 OPA2349EA/250 Tape and Reel

"""""OPA2349EA/3K Tape and Reel

OPA2349UA SO-8 182 0°C to +70°C OPA2349UA OPA2349UA Rails

"""""OPA2349UA/2K5 Tape and Reel

NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /3K indicates 3000 devices per reel). Ordering 3000 pieces of
“OPA2349EA/3K” will get a single 3000-piece Tape and Reel. (2) OPA349PA (DIP) available Q4 2000.

4

OPA349

®

TYPICAL PERFORMANCE CURVES

At TA = +25°C, VS = 5V, unless otherwise noted.

COMMON-MODE REJECTION RATIO vs FREQUENCY

Frequency (Hz)

CMRR (dB)

70

60

50

40

30

20

10

0

10 100 1k 10k 100k

CHANNEL SEPARATION vs FREQUENCY

Frequency (Hz)

Channel Separation (dB)

100

90
80
70
60
50
40
30
20
10

0

10 100 1k 10k 100k

INPUT VOLTAGE NOISE DENSITY

Frequency (Hz)

Voltage Noise (nV/√Hz)

1000

400

100

10 100 1k 10k

OFFSET VOLTAGE DRIFT

PRODUCTION DISTRIBUTION

Population

Offset Voltage Drift

–30 –25 –20 –15 –10 –5 0 5 10 15 20 25 30 35 40

POWER SUPPLY REJECTION RATIO vs FREQUENCY

Frequency (Hz)

PSRR (dB)

100

90
80
70
60
50
40
30
20
10

0

10 100 1k 10k 100k

+PSRR

–PSRR

OPEN-LOOP GAIN AND PHASE vs FREQUENCY

Frequency (Hz)

Gain (dB)

Phase (°)

100

90
80
70
60
50
40
30
20
10

0

0

45

90

135

180

1 10 100 1k 10k 100k 1M0.1

5

®

OPA349

TYPICAL PERFORMANCE CURVES (Cont.)

At TA = +25°C, unless otherwise noted.

OUTPUT VOLTAGE vs OUTPUT CURRENT

Output Current (mA)

Output Voltage (V)

V+

(V+)–1

(V+)–2

(V+)+2

(V–)+1

V–

012345678

Sourcing Current

Sinking Current

0°C to +70°C

0°C to +70°C

MAXIMUM OUTPUT VOLTAGE vs FREQUENCY

Frequency (Hz)

Output Voltage (Vp-p)

6

5

4

3

2

1

0

100 1k 10k 100k

VS = +5.5V

VS = +5V

VS = +2.5V

VS = +1.8V

100µs/div

LARGE-SIGNAL STEP RESPONSE

G = 1, R

L

= 1MΩ

1V/div

40µs/div

SMALL-SIGNAL STEP RESPONSE

G = 1, R

L

= 1MΩ, CL = 20pF

50mV/div

100µs/div

SMALL-SIGNAL STEP RESPONSE

G = 1, R

L

= 1MΩ, CL = 500pF

50mV/div

QUIESCENT CURRENT vs TEMPERATURE

Temperature (°C)

Quiescent Current (µA)

16
14
12
10

8
6
4
2
0

–75 –50 –25 0 25 50 75 100 125

OPA2349

(per channel)

OPA349

6

OPA349

®

FIGURE 2. Simplified Schematic.

FIGURE 1. AC-Coupled Amplifier.

V

BIAS1

V

BIAS2

VIN+

VIN–

Class AB

Control

Circuitry

V

O

V–

(Ground)

V+

Reference

Current

APPLICATIONS INFORMATION

OPA349 series op amps are unity gain stable and can operate
on a single supply, making them highly versatile and easy to
use. Power supply pins should be by passed with 0.01µF
ceramic capacitors.

OPA349 series op amps are fully specified and guaranteed
from +1.8V to +5.5V. Parameters that vary significantly with
operating voltages or temperature are shown in the Typical
Performance Curves.

The ultra low quiescent current of the OPA349 requires
careful applications circuit techniques to achieve low overall
current consumption. Figure 1 shows an ac-coupled ampli­fier biased with a voltage divider. Resistor values must be
very large to minimize current. The large feedback resistor

value reacts with input capacitance and stray capacitance to
produce a pole in the feedback network. A feedback capaci­tor may be required to assure stability and limit overshoot or
gain peaking. Check circuit performance carefully to assure
that biasing and feedback techniques meet your signal and
quiescent current requirements.

RAIL-TO-RAIL INPUT

The input common-mode voltage range of the OPA349 series
extends 200mV beyond the supply rails. This is achieved with
a complementary input stage—an N-channel input differen­tial pair in parallel with a P-channel differential pair (see
Figure 2). The N-channel pair is active for input voltages close
to the positive rail, typically (V+) – 1.3V to 200mV above the
positive supply, while the P-channel pair is on for inputs from
200mV below the negative supply to approximately (V+) –

1.3V. There is a small transition region, typically (V+) – 1.5V
to (V+) – 1.1V, in which both pairs are on. This 400mV
transition region can vary 300mV with process variation.
Thus, the transition region (both stages on) can range from
(V+) – 1.8V to (V+) – 1.4V on the low end, up to (V+) – 1.2V
to (V+) – 0.8V on the high end. Within the 400mV transition
region PSRR, CMRR, offset voltage, offset drift, and THD
may be degraded compared to operation outside this region.
For more information on designing with rail-to-rail input op
amps, see Figure 3 “Design Optimization with Rail-to-Rail
Input Op Amps.”

V

OUT

OPA349

G = 11

C

F

3pF

+1.8 to 5.5V

R

3

2M

R

4

2M

R

5

10M

R

1

10M

R

2

10M

10nF

CF may be required
for best stability or to
reduce frequency
peaking—see text.

7

®

OPA349

R

V

IN

V

CM

V

OUT

R

FIGURE 3. Design Optimization.

In most applications, operation is within the range of only
one differential pair. However, some applications can
subject the amplifier to a common-mode signal in the
transition region. Under this condition, the inherent mis­match between the two differential pairs may lead to
degradation of the CMRR and THD. The unity-gain buffer
configuration is the most problematic—it will traverse
through the transition region if a sufficiently wide input

DESIGN OPTIMIZATION WITH RAIL-TO-RAIL INPUT OP AMPS

swing is required. A design option would be to configure
the op amp as a unity-gain inverter as shown below and
hold the noninverting input at a set common-mode voltage
outside the transition region. This can be accomplished
with a voltage divider from the supply. The voltage divider
should be designed such that the biasing point for the
noninverting input is outside the transition the region.

COMMON-MODE REJECTION

The CMRR for the OPA349 is specified in two ways so the
best match for a given application may be used. First, the
CMRR of the device in the common-mode range below the
transition region (VCM < (V+) – 1.5V) is given. This specifi­cation is the best indicator of the capability of the device when
the application requires use of one of the differential input
pairs. Second, the CMRR at VS = 5V over the entire common­mode range is specified.

RAIL-TO-RAIL OUTPUT

A class AB output stage with common-source transistors is
used to achieve rail-to-rail output.

Loads that connect to single supply ground (or the V- supply
pin) can cause the op amp to oscillate if the output voltage

is driven to the low limit (Figure 4). Similarly, loads that can
cause current to flow out of the output pin when the output
voltage is near V– can cause oscillations. The op amp will
recover to normal operation a few milliseconds after the
output is driven positively out of the rail.

Some op amp applications can produce this condition even
without a load connected to V– The integrator in Figure 4a
shows an example. Assume that the output ramps nega­tively, and saturates near 0V. Any negative-going step at
VIN will produce a positive output current pulse through R1
and C1. This may incite the oscillation. Diode, D1, prevents
the input step from pulling output current when the output is
saturated at the rail, thus preventing the oscillation.

FIGURE 4. Output Driven to Negative Rail.

V

O

V

IN

V+

OPA349

0V

a) b)

R

L

1V

(No Load)

V

IN

V+

2V

0V

OPA349

0V

C

1

1nF

R

1

1M

D1

1N4148