SGS-THOMSON Microelectronics TC1026CEOA, TC1026 Datasheet

A

UA

OA

SOP

C

TC1026

Linear Building Block – Low Power Comparator with

Op Amp and Voltage Reference

Features

• Combines Low-Power OpAmp, Comparator and
Voltage Reference in a Single Package

• Optimized for Single Supply Operation

• SmallPackages:8-PinMSOP,8-PinSOIC,
8-Pin PDI P

• Ultra Low Input Bias Current: Less than 100pA

• Low Quiescent Current: 12µA(Typ.)

• Rail-to-Rail Inputs and Outputs

•OperatesDowntoV

=1.8V,Min

DD

Applications

• Power Management Circuits

• Battery Operated Equipment

• Consumer Products

Device Selection Table

Part Number Package

TC1026CEPA 8-Pin PDIP -40°C to +85°C

TC1026CEUA 8-Pin MSOP -40°C to +85°C
TC1026CEOA 8-Pin SOIC -40°C to +85°C

Temperature

Range

Package Types

General Description

The TC1026 is a mixed-function device combining a
general-purpose op amp, comparator and voltage
reference in a single 8-pin package. This increased
integration allows the user to r eplace two or three
packages, which saves space, lowers supply current
and increases system performance.

Both the op amp and comparatorhaverail-to-rail inputs
and outputs which allows operation from low supply
voltages with large input and output swings. The
TC1026 is optimized for low voltage (V

=1.8V),low

DD

supply current (12µA typ) operation.
Packaged in a space-saving 8-Pin MSOP, the TC1026

consumes half the board area of an 8-Pin SOIC and is
ideal for applications requiring high integration, small
size and low power. It is also available i n 8-Pin SOIC
and 8-Pin PDIP packages.

Functional Block Diagram

AMPOUT

AMPIN-

AMPIN+

-

AMP

TC1026

+

+

CMP

1

2

3

8

V

DD

7

CMPOUT

-

6

REF (CMPIN-)

8-Pin PDIP

-Pin M

4

V

SS

Voltage

Reference

5

CMPIN+

-Pin SOI

V

AMPOUT

AMPIN

AMPIN+

V

SS



2002 Microchip TechnologyInc. DS21725B-page 1

TC1026CEP
TC1026CE
TC1026CE

8

DD

CMPOUT

7

REF (CMPIN)

6

CMPIN+

5

TC1026

1.0 ELECTRICAL
CHARACTERISTICS

*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

ABSOLUTE MAXIMUM RATINGS*

Supply Voltage......................................................6.0V

operation sections of the specifications is not implied.
Exposure to Absolute Maximum Rating conditions for
extended periods may affectdevice reliability.

Package Power Dissipation:

8-Pin PDIP ...............................................730 mW

8-Pin SOIC...............................................470 mW

8-Pin MSOP .............................................320 mW

Voltage on Any Pin..........(V

– 0.3V) to (VDD+0.3V)

SS

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

Operating Temperature Range.............-40°C to +85°C

StorageTemperature Range..............-55°C to +150°C

TC1026 ELECTRICAL SPECIFICATIONS

Electrical Characteristics: Typical values apply at 25°C and VDD=3.0V;TA= -40° to +85°C, and VDD= 1.8V to 5.5V,unless

otherwise specified.

Symbol Parameter Min Typ Max Units Test Conditions

V

DD

I

Q

Op Amp

A

VOL

V

ICMR

V

OS

I

B

V

OS (DRIF T)

GBWP Gain-Bandwidth Product — 90 — kHz V

SR Slew Rate — 35 — mV/µsec CL= 100pF

V

OUT

CMRR Common Mode Rejection Ratio 66 — — dB T

PSRR Power Supply Rejection Ratio 80 — — dB TA=25°C,VCM=V

I

SRC

I

SINK

En Input Noise Voltage — 10 — µVpp 0.1Hz to 10Hz
en Input Noise Voltage Density — 125 — nV/√Hz

Comparator

V

IR

V

OS

I

B

V

OH

V

OL

Supply Voltage 1.8 — 5.5 V
Supply Current — 12 18 µA All outputs unloaded

LargeSignal Voltage Gain — 100 — V/mV RL=10kΩ, VDD=5V
CommonModeInputRange VSS–0.2 — VDD+0.2 V
Input Offset Voltage ±100

±0.3

±500
±1.5

µVmVVDD=3V,VCM=1.5V,TA=25°C

T

= -40°C to 85°C

A

Input Bias Current -100 50 100 pA TA=25°C,VCM=VDDto V
Input Offset Voltage Drift — ±4 — µV/°C VDD=3V,VCM=1.5V

= 1.8V to 5.5V;

DD

V

O=VDD

R

L

Gain = 1
V

IN=VSS

to V

SS

=1MΩ to GND

to V

DD

Output Signal Swing VSS+0.05 — VDD–0.05 V RL=10kΩ

=25°C,VDD=5V

A

V

CM=VDD

VDD=1.8Vto5V

Output Source Current 3 — — mA VIN+=VDD,VIN-=V

OutputShorted to V
VDD=1.8V,Gain=1

OutputSInkCurrent — 125 — nV/Hz IN+ = VSS,IN-=V

OutputShorted to V
VDD=1.8V,Gain=1

to V

SS

SS

SS

SS

DD

DD

1kHz

Input Voltage Range VSS–0.2 — VDD+0.2 V
Input Offset Voltage -5

-5

—
—

+5
+5

mV VDD=3V,TA=25°C

T

= -40°C to 85°C

A

Input Bias Current –– — ±100 pA TA=25°C,IN+=VDDto V
OutputHighVoltage VDD–0.3 — — V RL=10kΩ to V
OutputLowVoltage — — 0.3 V RL=10kΩ to V

SS
DD

SS

SS

DS21725B-page 2



2002 Microchip TechnologyInc.

TC1026

TC1026 ELECTRICAL SPECIFICATIONS (C ONTINUED)

Electrical Characteristics: Typical values apply at 25°C and VDD=3.0V;TA= -40° to +85°C, and VDD= 1.8V to 5.5V,unless

otherwise specified.

Symbol Parameter Min Typ Max Units Test Conditions

PSRR Power Supply Rejection Ratio 60 — — dB T

I

SRC

I

SINK

t

PD1

t

PD2

Output Source Current 1 — — mA IN+ = V

OutputSink Current 2 — — mA IN+ = V

Response Time — 4 — µsec 100mV Overdrive, CL= 100pF
Response Time — 6 — µsec 10mV Overdrive, CL= 100pF

Voltage Reference

V

REF

I

REF(SOURCE)

I

REF(SINK)

C

L(REF)

Reference Voltage 1.176 1.200 1.221 V
Source Current 50 — — µA
Sink Current 50 — — µA
Load Capacitance — — 100 pF

=25°C

A

V

=1.8Vto5V

DD

DD

OutputShortedtoV
VDD=1.8V

SS

OutputShortedtoV
VDD=1.8V

SS

DD



2002 Microchip TechnologyInc. DS21725B-page 3

TC1026

2.0 PIN DESCRIPTION

The description of t he pins are listed in Table 2-1.

TABLE 2-1: PIN FUNCTION TABLE

Pin No.

(8-Pin PDIP)

(8-Pin MSOP)

(8-Pin SOIC)

1 AMPOUT Op amp output.
2 AMPIN- Inverting op amp input.
3 AMPIN+ Non-inverting op amp input.
4V
5 CMPIN+ Non-inverting comparator input.
6 REF(CMPIN) Invertingcomparator input and voltage reference output voltage.
7 CMPOUT Comparator output.
8V

Symbol Description

SS

DD

Negative power supply.

Positive power supply.

DS21725B-page 4



2002 Microchip TechnologyInc.

TC1026

3.0 DETAILED DESCRIPTION

The TC1026 i s one of a series of very low power,linear
building block products targeted at low voltage, single
supply applications. The TC1026 minimum operating
voltageis 1.8V, and typicalsupplycurrentis only 12µA.
It combines a comparator, an op amp and a voltage
reference in a single package.

3.1 Comparator

The TC1026 contains one comparator. The compara­tor’s input range extends beyond both supply voltages
by 200mV and the outputs will swing to within several
millivolts of the supplies depending on the load current
beingdriven.Theinvertinginputisinternallyconnected
to the output of the reference.

The c omparator exhibitspropagation delay and supply
current which are largely independent of supply
voltage. The low i nput bias current and offset voltage
make it suitable for high impedance precision
applications.

3.2 Operational Amplifier

The TC1026 contains one rail-to-rail op amp. The
amplifier’s i nput range extends beyond both supplies
by 200mV and the outputs will swing to within several
millivolts of the supplies depending on the load current
being driven.

The amplifier design is such that large signal gain, slew
rate and bandwidth are largely independent of supply
voltage.Thelowinput bias current and offsetvoltageof
the TC1026 make it suitable for precisionapplications.

3.3 Voltage Reference

A 2.0% tolerance, internally biased, 1.20V bandgap
voltage reference is included i n the TC1026. It has a
push-pull output capable of sourcing and sinking at
least 50µA.

4.0 TYPICAL APPLICATIONS

The TC1026 lends itself to a wide variety of
applications,particularlyin battery powered systems. It
typically finds application in power management,
processor supervisory and interface circuitry.

4.1 External Hysteresis (Comparator)

Hysteresis can be set externally with three resistors
using positive f eedback techniques (see Figure 4-1).
The design procedure for setting external comparator
hysteresisis as follows:

1. Choose the feedback resistor R
input bias current of the comparator is at most
100pA, the current through R
100nA (i.e., 1000 times the input bias current)
and retain excellent accuracy. The current
through R
R

where VRis a stable reference voltage.

C

at the comparator’s trip point is VR/

C

2. Determinethehysteresis voltage (V
the upper and lower thresholds.

3. Calculate R

as follows:

A

EQUATION 4-1:

V

HY



=

-----------

C



V

DD

RAR

4. Choose the rising threshold voltage for V
(V

).

THR

5. Calculate R

as follows:

B

EQUATION 4-2:

V

THR

1

1



–

-------



R

-----------------------------------------------------------=

R

B



---------------------



VRRA×

6. Verify the t hreshold voltages with these
formulas:

V

rising:

SRC

.Sincethe

C

canbesetto

C

HY

1

–

------­R

A

C

)between

SRC

EQUATION 4-3:

V

V

SRC

THR

falling:

VR()RA()




------­R

1

A

1



-------

++=



R

B

1



-------



R

C

EQUATION 4-4:

RAVDD×



V



2002 Microchip TechnologyInc. DS21725B-page 5

THF

V

THR

--------- ------------- ---

–=



R

C

TC1026

FIGURE 4-1: CO MPARATOR

EXTERNAL HYSTERESIS
CONFIGURATION

R

C

V

SRC

TC1026

R

A

R

B

V

DD

+

–

TC1026

Comparator

V

R

V

OUT

4.2 Precision Battery Monitor

Figure 4-2 is a precision battery low/battery dead
monitoring circuit. Typically, the battery low output
warns the user that a battery dead condition i s
imminent. Battery dead typically initiates a forced
shutdown to prevent operation at low internal supply
voltages(whichcan cause unstable system operation).

The circuit of Figure 4-2 uses two TC1026 devices and
only six external resistors. AMP 1 is a simple buffer
whileCMPTR1 and CMPTR2 provideprecisionvoltage
detection using V
R4 set the detection threshold for BATT LOW
resistors R1and R3 set the detection threshold for
BATT FAIL

. The component values shown assert
BATT LOW
(typical). Total current consumed by this circuit is
typically 28µA at 3V. Resistors R5 and R6 provide
hysteresis for comparators CMPTR1 and CMPTR2,
respectively.

as a reference. Resistors R2 and

R

while

at 2.2V (typical) and BATT FAIL at 2.0V

4.3 Voice Band Receive Filter

The majority of spectral energy for human voices is in
a 2.7kHz frequency band from 300Hz to 3kHz. To
properly recover a voice signal in applications such as
radios, c ellular phones and voice pagers, a low-power
bandpass filter that is matched to the human voice
spectrum can be implemented using Microchip’s
CMOS op amps. Figure 4-3 shows a unity-gain multi­pole Butterworth filter with ripple less than 0.15dB in
thehumanvoiceband.Thelower3dBcut-off frequency
is 70Hz (single-orderresponse),whilethe upper cut-off
frequency is 3.5kHz (fourth-order response).

4.4 Supervisory Audio Tone (SAT)
Filter for Cellular

Supervisory Audio Tones (SAT) provide a reliable
transmission path between cellular subscriber units
and base stations. The SAT tone functions much like
the current/voltage used in land l ine telephone systems
to indicate that a phone is off the hook. The SAT tone
may be one of three frequencies: 5970, 6000 or
6030Hz. A loss of SAT implies that channel conditions
are impaired, and if SAT is interrupted for more than 5
seconds, a cellular call is terminated.

Figure 4-4 shows a high Q (30) first order SAT
detection bandpass filter using Microchip’s CMOS op
amp architecture. This circuit nulls all frequencies
except the three SAT tones of interest.

DS21725B-page 6



2002 Microchip TechnologyInc.