Datasheet TC911BCPA, TC911BCOA, TC911ACPA, TC911ACOA Datasheet (TelCom Semiconductor)

AUTO-ZEROED OPERATIONAL AMPLIFIERS

FEATURES

■ First Monolithic Chopper-Stabilized Amplifier

With On-Chip Nulling Capacitors

■ Offset Voltage .................................................... 5µV

■ Offset Voltage Drift .................................. 0.05µV/°C

■ Low Supply Current ...................................... 350µA

■ High Common-Mode Rejection .................... 116dB

■ Single Supply Operation.......................4.5V to 16V

■ High Slew Rate............................................. 2.5V/µs

■ Wide Bandwidth............................................1.5MHz

■ High Open-Loop Voltage Gain

(RL = 10 kΩ) .................................................... 120dB

■ Low Input Voltage Noise

(0.1 Hz to 1 Hz).......................................... 0.65µV

P-P

■ Pin Compatible With ICL7650

■ Lower System Parts Count

ORDERING INFORMATION

Maximum

Temperature Offset

Part No. Package Range Voltage

TC911ACOA 8-Pin SOIC 0°C to +70°C15µV
TC911ACPA 8-Pin 0°C to +70°C15µV

Plastic DIP
TC911BCOA 8-Pin SOIC 0°C to +70°C30µV
TC911BCPA 8-Pin 0°C to +70°C30µV

Plastic DIP

FUNCTIONAL BLOCK DIAGRAM

V

SS

V CORRECTION AMPLIFIER

OS

*

*

MAIN
AMPLIFIER

–INPUT

+INPUT

V

DD

47

2

A

3

+

–

+

–

GENERAL DESCRIPTION

The TC911 CMOS auto-zeroed operational amplifier is
the first complete monolithic chopper-stabilized amplifier.
Chopper operational amplifiers like the ICL7650/7652 and
LTC1052 require user-supplied, external offset compensa­tion storage capacitors. External capacitors are not re-
quired with the TC911. Just as easy to use as the conven­tional OP07 type amplifier, the TC911 significantly reduces
offset voltage errors. Pinout matches the OP07/741/7650
8-pin mini-DIP configuration.

Several system benefits arise by eliminating the exter­nal chopper capacitors: lower system parts count, reduced
assembly time and cost, greater system reliability, reduced
PC board layout effort and greater board area utilization.
Space savings can be significant in multiple-amplifier de­signs.

Electrical specifications include 15µV maximum offset
voltage, 0.15µV/°C maximum offset voltage temperature
coefficient. Offset voltage error is five times lower than the
premium OP07E bipolar device. The TC911 improves off­set drift performance by eight times.

The TC911 operates from dual or single power sup­plies. Supply current is typically 350µA. Single 4.5V to 16V
supply operation is possible, making single 9V battery
operation possible. The TC911 is available in 2 package
types: 8-pin plastic DIP and SOIC.

PIN CONFIGURATION (SOIC and DIP)

1

NC

2

– INPUT

3

+ INPUT

A

B

B

+

–

TC911ACPA
TC911BCPA

V

4

SS

INTERNAL

OSCILLATOR

(f 200 Hz)

≈

OSC

TC911

LOW IMPEDANCE
OUTPUT BUFFER

1

8

NC
V

7

DD

6

OUTPUT
NC

5

NC = NO INTERNAL CONNECTION

6

OUTPUT

NC
– INPUT
+ INPUT

V

2
3

SS

4

TC911A
TC911B

TC911ACOA
TC911BCOA

8
7
6
5

NC
V

DD

OUTPUT
NC

1

2

3

4

5

6

7

*

NOTE: Internal capacitors. No external capacitors required.

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8

TC911/A/B-7 9/11/96

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TC911A
TC911B

AUTO-ZEROED MONOLITHIC

OPERA TIONAL AMPLIFIERS

ABSOLUTE MAXIMUM RATINGS*

Package Power Dissipation (TA = ≤ 70°C)

Plastic DIP ......................................................730mW

Total Supply Voltage (VDD to VSS) ........................... +18V

Input Voltage ........................ (V

+ 0.3V) to (VSS – 0.3V)

DD

Current into Any Pin .................................................10mA

While Operating................................................100µA

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

Lead Temperature (Soldering, 10 sec) .................+300°C

Operating Temperature Range

Plastic SOIC ...................................................470mW

*Static-sensitive device. Unused devices should be stored in conductive
material. Stresses above 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
above those indicated in the operational sections of the specifications is not
implied.

C Device ................................................ 0°C to +70°C

ELECTRICAL CHARACTERISTICS: V

= ±5V, TA = +25°C, unless otherwise indicated.

S

TC911A TC911B

Symbol Parameter Test Conditions

V

OS

TCV

I

B

IOSAverage Input TA = +25°C — 5 20 — 10 40 pA

e

N

CMRR Common-Mode VSS ≤ VCM ≤ VDD – 2.2 110 116 — 105 110 — dB

CMVR Common-Mode V

A

OL

V

OUT

BW Closed Loop Closed Loop Gain = +1 — 1.5 — — 1.5 — MHz

SR Slew Rate RL = 10 kΩ, CL = 50 pF — 2.5 — — 2.5 — V/µs
PSRR Power Supply ±3.3V to ±5.5V 112 — — 105 — — dB

V

S

I

S

NOTES: 1. Characterized; not 100% tested.

Input Offset Voltage TA = +25°C — 5 15 — 15 30 µV
Average Temperature 0°C ≤ TA ≤ +70°C — 0.05 0.15 — 0.1 0.25 µV/°C

OS

Coefficient of Input –25°C ≤ T

≤ +85°C — 0.05 0.15 — 0.1 0.25 µV/°C

A

Offset Voltage (Note 1)
Average Input Bias TA = +25°C — — 70 — — 120 pA

Current 0°C ≤ T

≤ +70°C——3——4nA

A

–25°C ≤ TA ≤ +85°C——4 ——6nA

Offset Current TA = +85°C——1——1nA
Input Voltage Noise 0.1 to 1 Hz, RS ≤ 100Ω — 0.65 — — 0.65 — µV

0.1 to 10 Hz, RS ≤ 100Ω —11— — 11—µV

Rejection Ratio

Voltage Range
Open-Loop Voltage

RL = 10 kΩ, V

OUT

= ±4V

Gain
Output Voltage Swing RL = 10 kΩ VSS + 0.3 — VDD – 0.9 VSS + 0.3 — VDD – 0.9 V

Bandwidth

Rejection Ratio
Operating Supply Split Supply ±3.3 — ± 8 ±3.3 — ±8V

Voltage Range Single Supply 6.5 — 16 6.5 — 16 V
Quiescent Supply VS = ±5V — 350 600 — — 800 µA

Current

Min Typ Max Min Typ Max Unit

P-P
P-P

SS

—V

115 120 — 110 120 — dB

– 2 V

DD

SS

—V

DD

– 2 V

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TELCOM SEMICONDUCTOR, INC.

AUTO-ZEROED MONOLITHIC
OPERA TIONAL AMPLIFIERS

TYPICAL CHARACTERISTICS

Supply Current vs. ± Supply Voltage

700

TA = +25°C

600

500

400

Supply Current vs. Temperature

450

400

350

VS = ±5V

35

30

25

20

Input Offset Voltage vs.
Common-Mode Voltage

VS = ±5V
T

= +25°C

A

1

TC911A
TC911B

2

300

200

SUPPLY CURRENT (µA)

100

0

2345678

50
40
30
20

10

0
–10
–20

CLOSED-LOOP GAIN (dB)

–30
–40

10k

± SUPPLY VOLTAGE (V)

Gain and Phase vs. Frequency

VS = ±5V
T

= +25°C

PHASE

GAIN

100k 1M 10M

FREQUENCY (Hz)

A

R

= 10 k

L

300

250

SUPPLY CURRENT (µA)

200

–100

225
180

Ω

135
90
45
0

PHASE (deg)

–45
–90
–135

–180

–50 0 50 100 150

AMBIENT TEMPERATURE (°C)

Large Signal Output

Switching Waveform

INPUT VERTICAL
SCALE = 2 V/DIV

OUTPUT
VERTICAL
SCALE
= 1 V/DIV

0V

HORIZONTAL SCALE = 2 µs/DIV

RL = 10 kΩ

= +25°C

T

A

15

10

5

INPUT OFFSET VOLTAGE (µV)

0

–5–4–3–2–101234

–6

INPUT COMMON-MODE VOLTAGE (V)

Output Voltage Swing vs.

Load Resistance

5.8

= +25°C

T

A

VS = ±5V

5.0

4.2

3.4

2.6

± OUTPUT VOLTAGE (V)

1.8

1.0
100

1k 10k 100k

LOAD RESISTANCE (Ω)

3

4

–SWING

+SWING

5

1M

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6

7

8

3-265

TC911A
TC911B

AUTO-ZEROED MONOLITHIC

OPERA TIONAL AMPLIFIERS

Pin Compatibility

The CMOS TC911 is pin compatible with the industry
standard ICL7650 chopper-stabilized amplifier. The ICL7650
must use external 0.1µF capacitors connected at pins 1 and

8. With the TC911, external offset voltage error cancel-
ing capacitors are not required. On the TC911 pins 1, 8
and 5 are not connected internally. The ICL7650 uses pin 5
as an optional output clamp connection. External chopper
capacitors and clamp connections are not necessary with
the TC911. External circuits connected to pins 1, 8 and 5 will
have no effect. The TC911 can be quickly evaluated in
existing ICL7650 designs. Since external capacitors are not
required, system part count, assembly time, and total sys­tem cost are reduced. Reliability is increased and PC board
layout eased by having the error storage capacitors inte­grated on the TC911 chip.

The TC911 pinout matches many existing op amps:
741, LM101, LM108, OP05–OP08, OP-20, OP-21, ICL7650
and ICL7652. In many applications operating from +5V
supplies the TC911 offers superior electrical performance
and can be a functional pin-compatible replacement. Offset
voltage correction potentiometers, compensation capaci­tors, and chopper-stabilization capacitors can be removed
when retrofitting existing equipment designs.

Thermocouple Errors

Heating one joint of a loop made from two different
metallic wires causes current flow. This is known as the
Seebeck effect. By breaking the loop, an open circuit voltage

J = J

3

4

J = J
J = J

NO TEMPERATURE DIFFERENTIAL

2

5

AND SAME METALLIC CONNECTION

1

6

J

3

J

2

J

1

PACKAGE
PIN

(Seebeck voltage) can be measured. Junction temperature
and metal type determine the magnitude. Typical values are

0.1µV/°C to 10µV/°C. Thermal-induced voltages can be
many times larger than the TC911 offset voltage drift. Unless
unwanted thermocouple potentials can be controlled, sys­tem performance will be less than optimum.

Unwanted thermocouple junctions are created when
leads are soldered or sockets/connectors are used. Low
thermo-electric coefficient solder can reduce errors. A 60%
Sn/36% Pb solder has 1/10 the thermal voltage of common
64% Sn/36% Pb solder at a copper junction.

The number and type of dissimilar metallic junctions in
the input circuit loop should be balanced. If the junctions are
kept at the same temperature, their summation will add to
zero-canceling errors (Figure 1).

Shielding precision analog circuits from air currents —
especially those caused by power dissipating components
and fans — will minimize temperature gradients and ther­mocouple-induced errors.

Avoiding Latch-Up

Junction-isolated CMOS circuits inherently contain a
parasitic p-n-p-n transistor circuit. Voltages exceeding the
supplies by 0.3V should not be applied to the device pins.
Larger voltages can turn the p-n-p-n device on, causing
excessive device power supply current and excessive power
dissipation. TC911 power supplies should be established at
the same time or before input signals are applied. If this is not
possible input current should be limited to 0.1mA to avoid
triggering the p-n-p-n structure.

Overload Recovery

The TC911 recovers quickly from the output saturation.
Typical recovery time from positive output saturation is
20msec. Negative output saturation recovery time is typi­cally 5msec.

J

J

4

J

5

J

2

+–+–

–

V

J

3

3

+

+

J

4

–

Figure 1. Unwanted Thermocouple Errors Eliminated by
Reducing Thermal Gradients and Balancing Junctions

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V = V + V + V – V – V – V = 0

T123456

V

4

V

2

V

5

+–+–

J

5

6

J

1

V

1

V

6

J

6

V = 0

T

TELCOM SEMICONDUCTOR, INC.

AUTO-ZEROED MONOLITHIC
OPERA TIONAL AMPLIFIERS

TYPICAL APPLICATIONS

1

TC911A
TC911B

10-Volt Precision Reference

2

6.4 kΩ

+15V

TC911

73

+

6

–

4

0.1 µF

3.6 kΩ

Programmable Gain Amplifier With Input Multiplexer

18 kΩ

6.4V

V = 10V

OUT

TEMP
OUT

V

REF

V = V

OUT

OUT

dT

K = 1 +

+9V

REF02

ADJ

TEMP

=

[

R

2

R X R

3

Thermometer Circuit

R

1

2

R + R

3

R X R

3

R + R

R X R

3

1
1

d (V )d V

1 + R

[ ( )

1 + R

( )]

2

1

R

13
1

–

+

3

–

]

TEMP
dT

TC911

R

2

V

[

REF

K (2.1 mV/°C)

≈

2

3

V

OUT

R

2

]

R

1

4

5

+5V –5V GND +5V –5V

IN

1

IN

2

IN

3

IN

4

INPUT

CHANNEL

SELECT

68HC11

TELCOM SEMICONDUCTOR, INC.

IC1b

A1A2A3A4WR

IC1a, b, = Quad Analog Switch

GAIN

SELECT

IC1b

+

–

+5V –5V 1

WR

LATCH

A1A2A3A

TC911

V

OUT

10X 100 1000XXX

18 kΩ

99 kΩ 999 kΩ

6

7

GND

4

2 kΩ

1 kΩ 1 kΩ

8

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