BURR-BROWN UAF42 User Manual

UNIVERSAL ACTIVE FIL TER

UAF42

UAF42

UAF42

FEATURES

● VERSATILE—

LOW-PASS, HIGH-PASS
BAND-PASS, BAND-REJECT

● SIMPLE DESIGN PROCEDURE

● ACCURATE FREQUENCY AND Q —

INCLUDES ON CHIP 1000pF

±0.5%

CAPACITORS

DESCRIPTION

The UAF42 is a universal active filter which can be
configured for a wide range of low-pass, high-pass,
and band-pass filters. It uses a classical state-variable
analog architecture with an inverting amplifier and
two integrators. The integrators include on-chip 1000pF
capacitors trimmed to 0.5%. This solves one of the
most difficult problems of active filter design—
obtaining tight tolerance, low-loss capacitors.

A DOS-compatible filter design program allows easy
implementation of many filter types such as
Butterworth, Bessel, and Chebyshev. A fourth, un­committed FET-input op amp (identical to the other

APPLICATIONS

● TEST EQUIPMENT

● COMMUNICATIONS EQUIPMENT

● MEDICAL INSTRUMENTATION

● DATA ACQUISITION SYSTEMS

● MONOLITHIC REPLACEMENT FOR UAF41

three) can be used to form additional stages, or for
special filters such as band-reject and Inverse
Chebyshev.

The classical topology of the UAF42 forms a time­continuous filter, free from the anomalies and switch­ing noise associated with switched-capacitor filter
types.

The UAF42 is available in 14-pin plastic DIP and
SOL-16 surface-mount packages, specified for the –
25°C to +85°C temperature range.

SBFS002

High-Pass

Out

R

R

In

1

In

2

R

In

3

R = 50kΩ ±0.5%

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©

1990 Burr-Brown Corporation PDS-1070H Printed in U.S.A. January, 1998

Band-Pass

1000pF

R

NOTE: (1) ±0.5%

Out

(1)

GND

Low-Pass

1000pF

Out

(1)

V+

V–

SPECIFICATIONS

ELECTRICAL

At TA = +25°C, VS = ±15V, unless otherwise noted.

UAF42AP, AU
PARAMETER CONDITIONS MIN TYP MAX UNITS
FILTER PERFORMANCE

Frequency Range, fn 0 to 100 kHz
Frequency Accuracy f = 1kHz 1 %
vs Temperature 0.01 %/°C
Maximum Q 400 —
Maximun (Q • Frequency) Product 500 kHz
Q vs Temperature (f

Q Repeatability (f
Offset Voltage, Low-Pass Output ±5mV

O

(f

O

O

Resistor Accuracy 0.5 1% %

OFFSET VOLTAGE

(1)

Input Offset Voltage ±0.5 ±5mV
vs Temperature ±3 µV/°C
vs Power Supply V

INPUT BIAS CURRENT

(1)

= ±6 to ±18V 80 96 dB

S

Input Bias Current VCM = 0V 10 50 pA
Input Offset Current V

NOISE

Input Voltage Noise

Noise Density: f = 10Hz 25 nV/√Hz

f = 10kHz 10 nV/√Hz

Voltage Noise: BW = 0.1 to 10Hz 2 µVp-p

Input Bias Current Noise

Noise Density: f = 10kHz 2 fA/√Hz

INPUT VOLTAGE RANGE

(1)

Common-Mode Input Range ±11.5 V
Common-Mode Rejection V

INPUT IMPEDANCE

(1)

Differential 1013 || 2 Ω || pF
Common-Mode 10

OPEN-LOOP GAIN

(1)

Open-Loop Voltage Gain VO = ±10V, RL = 2kΩ 90 126 dB

FREQUENCY RESPONSE

(1)

Slew Rate 10 V/µs
Gain-Bandwidth Product G = +1 4 MHz
Total Harmonic Distortion G = +1, f = 1kHz 0.0004 %

(1)

OUTPUT

Voltage Output RL = 2kΩ±11 ±11.5 V
Short Circuit Current ±25 mA

POWER SUPPLY

Specified Operating Voltage ±15 V
Operating Voltage Range ±6 ±18 V
Current ±6 ±7mA

TEMPERATURE RANGE

Specification –25 +85 °C
Operating –25 +85 °C
Storage –40 +125 °C
Thermal Resistance,

θ

JA

✻ Same as specification for UAF42AP.
NOTES: (1) Specifications apply to uncommitted op amp, A

. The three op amps forming the filter are identical to A4 but are tested as a complete filter.

4

4

• Q) < 10

5

• Q) < 10

5

• Q) < 10

= 0V 5 pA

CM

= ±10V 80 96 dB

CM

0.01 %/°C

0.025 %/°C
2%

13

|| 6 Ω || pF

100 °C/W

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.

UAF42

2

PIN CONFIGURATION

Top View

Low-Pass V

V

V
Auxiliary Op Amp, +In
Auxiliary Op Amp, –In

Auxiliary Op Amp, V

Bandpass V

O

IN3

IN2

O

O

Plastic DIP, P

1
2
3
4
5
6
7

14

Frequency Adj

13

High-Pass V

12

V

IN1

11

Ground

10

V+

9

V–

8

Frequency Adj

2

O

1

ABSOLUTE MAXIMUM RATINGS

Power Supply Voltage ....................................................................... ±18V

Input Voltage............................................................................. ±V

Output Short Circuit .................................................................Continuous

Operating Temperature:

Plastic DIP, P; SOIC, U ................................................. –40°C to +85°C

Storage Temperature:

Plastic DIP, P; SOIC, U ............................................... –40°C to +125°C

Junction Temperature:

Plastic DIP, P; SOIC, U .............................................................. +125°C

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

S

±0.7V

U Package

SOL-16, 16-Pin SOIC

Low-Pass V

NC
V
V

Auxiliary Op Amp, +In
Auxiliary Op Amp, –In

Auxiliary Op Amp, V

Bandpass V

NOTE: NC: No Connection. For best

performance connect all “NC” pins to

ground to minimize inter-lead capacitance.

1

O

2
3

IN3

4

IN2

5
6
7

O

8

O

16

Frequency Adj

15

NC

14

High-Pass V

13

V

IN1

12

Ground

11

V+

10

V–

9

Frequency Adj

2

O

1

PACKAGE/ORDERING INFORMATION

PACKAGE

DRAWING TEMPERATURE

PRODUCT PACKAGE NUMBER

UAF42AP Plastic 14-pin DIP 010 –25°C to +85°C
UAF42AU SOL-16 211 –25°C to +85°C

NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix C of Burr-Brown IC Data Book.

(1)

RANGE

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.

3

UAF42

APPLICATIONS INFORMATION

The UAF42 is a monolithic implementation of the proven
state-variable analog filter topology. Pin-compatible with
the popular UAF41 Analog Filter, it provides several
improvements.

Slew Rate of the UAF42 has been increased to 10V/µs
versus 1.6V/µs for the UAF41. Frequency • Q product of
the UAF42 has been improved, and the useful natural
frequency extended by a factor of four to 100kHz. FET­input op amps on the UAF42 provide very low input bias
current. The monolithic construction of the UAF42 provides
lower cost and improved reliability.

DESIGN PROGRAM

Application Bulletin AB-035 and a computer-aided design
program, available from Burr-Brown, make it easy to design
and implement many kinds of active filters. The DOS­compatible program guides you through the design process
and automatically calculates component values.

Low-pass, high-pass, band-pass and band-reject (notch)
filters can be designed. The program supports the three most
commonly used all-pole filter types: Butterworth, Chebyshev
and Bessel. The less-familiar Inverse Chebyshev is also
supported, providing a smooth passband response with ripple
in the stop-band.

With each data entry, the program automatically calculates
and displays filter performance. This allows a spreadsheet­like “what if” design approach. For example, you can quickly
determine, by trial and error, how many poles are required
for a desired attenuation in the stopband. Gain/phase plots
may be viewed for any response type.

The basic building element of the most commonly used filter
types is the second-order section. This section provides a
complex-conjugate pair of poles. The natural frequency, ω
and Q of the pole pair determines the characteristic response
of the section. The low-pass transfer function is

2

VO(s)

VI(s)

ALPω

=

2

+ s ωn/Q + ω

s

n

2

n

(1)

The high-pass transfer function is

2

VHP(s)

VI(s)

=

AHPs

2

+ s ωn/Q + ω

s

2

n

(2)

The band-pass transfer function is

V

(s)

BP

VI(s)

ABP(ωn/Q) s

=

2

s

+ s ωn/Q + ω

2

n

(3)

A band-reject response is obtained by summing the low-pass
and high-pass outputs, yielding the transfer function

V

BR

VI(s)

(s)

=

ABR(s2 +ω

2

+ s ωn/Q + ω

s

2

)

n

2

n

(4)

The most commonly used filter types are formed with one or
more cascaded second-order sections. Each section is de­signed for ω

and Q according to the filter type (Butterworth,

n

Bessel, Chebyshev, etc.) and cutoff frequency. While tabu­lated data can be found in virtually any filter design text, the
design program eliminates this tedious procedure.

Second-order sections may be non-inverting (Figure 1) or
inverting (Figure 2). Design equations for these two basic
configurations are shown for reference. The design program
solves these equations, providing complete results, includ­ing component values.

,

n

UAF42

4

LP OutBP OutHP Out

R

F1

13 8 7 14

R

1

50kΩ

R

2

2

50kΩ

C

1

1000pF

R

F2

112

C

2

1000pF

50kΩ

R

V

G

IN

3

R

Q

A

1

R

4

50kΩ

A

2

A

3

UAF42

11

NOTE: If R
gain-setting resistor by connecting V

= 50kΩ, you can eliminate the external

G

to pin 2. Pin numbers are for DIP

IN

package. SOL-16 pinout
is different.

Design Equations

R

1

1 +

R

=

R

G

R

=

R

R

=

R

2

1

1

1

+

+

R

R

2

A

1

4
G

R

G

Q

4

R

2

1 +

R

=

LP

R

G

1

1

1

1

+

+

R

R

R

G

Q

4

1. ω

2. Q =

3. QA

n2

=

LP

R1 R

R4 (RG + RQ)

1 +

1 +

= QA

R

2

F1 RF2 C1 C2

R

G RQ

R

2

R

1

R

1

HP

R

2

= A

4. A

LP

F1 C1
F2 C2

F1 C1
F2 C2

1/2

5. A

HP

1/2

6. A

BP

R2 R
R1 R

R1 R

BP

R2 R

FIGURE 1. Non-Inverting Pole-Pair.

5

UAF42

LP OutBP OutHP Out

R

V

IN

G

R

F1

13 8 7 14

R

1

50kΩ

R

2

2

50kΩ

C

1

1000pF

R

F2

112

C

2

1000pF

50kΩ

A

3

R

Q

1

R

4

50kΩ

A

2

A

3

UAF42

11
NOTE: If R
Q-setting resistor by connecting pin 2 to ground.

= 50kΩ, you can eliminate the external

Q

Pin numbers are for DIP
package. SOL-16 pinout
is different.

Design Equations

1. ω

n2

=

R1 R

F1 RF2 C1 C2

R

2

4. A

R

1

=

LP

R

G

2. Q =

3. QA

1 +

= QA

LP

FIGURE 2. Inverting Pole-Pair.

R

4

R

Q

HP

1

1

1

+

+

R

R

1

2

R

1

= A

BP

R

2

1

R

G

R1 R
R2 R

R

R1 R2 R

F1 C1
F2 C2

F1 C1

1/2

F2 C2

1/2

5. A

6. A

BP

R

=

HP

R

=

1 +

R

2
1

2

A

=

LP

R

G

R

4

R

Q

1

1

1

1

+

R

G

+

R

R

R

1

2

G

UAF42

6

PACKAGE OPTION ADDENDUM

www.ti.com

28-Nov-2005

PACKAGING INFORMATION

Orderable Device Status

(1)

Package

Type

Package
Drawing

Pins Package

Qty

Eco Plan

UAF42AP ACTIVE PDIP N 14 25 TBD Call TI Level-NA-NA-NA

UAF42AP-1 OBSOLETE PDIP N 14 TBD Call TI Call TI

UAF42AU ACTIVE SOIC DW 16 48 Pb-Free

UAF42AU-1 OBSOLETE SOIC DW 16 TBD Call TI Call TI

UAF42AUE4 ACTIVE SOIC DW 16 48 Pb-Free

(1)

The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in

a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.

(2)

Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS & no Sb/Br) - please check

http://www.ti.com/productcontent for the latest availability information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements

for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)

(RoHS)

(RoHS)

(2)

Lead/Ball Finish MSL Peak Temp

CU NIPDAU Level-3-260C-168 HR

CU NIPDAU Level-3-260C-168 HR

(3)

(3)

MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder

temperature.

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Addendum-Page 1

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