TC7652
Low Noise, Chopper Stabilized Operational Amplifier
Features
•
•
•
•
•
•
•
•
Low Offset Over Temperature Range: 10µV
Ultra Low Long Term Drift: 150nV/Month
Low Temperature Drift: 100nV/
°
C
Low DC Input Bias Current: 15pA
High Gain, CMRR and PSRR: 110dB Min
Low Input Noise Voltage: 0.2µV
p-p
(DC to 1Hz)
Internally Compensated for Unity Gain Operation
Clamp Circuit for Fast Overload Recovery
General Description
The TC7652 is a lower noise version of the TC7650,
sacrificing some input specifications (bias current and
bandwidth) to achieve a 10x reduction in noise. All the
other benefits of the chopper technique are present,
(i.e, freedom from offset adjust, drift and reliability prob-
lems from external trim components). Like the TC7650,
the TC7652 requires only two noncritical external caps
for storing the chopped null potentials. There are no
significant chopping spikes, internal effects or over-
range lockup problems.
Applications
•
•
•
•
•
Instrumentation
Medical Instrumentation
Embedded Control
Temperature Sensor Amplifier
Strain Gage Amplifier
Device Selection Table
Part Number
TC7652CPA
TC7652CPD
Package
8-Pin Plastic DIP
14-Pin Plastic DIP
Temperature
Range
0°C to +70°C
0°C to +70°C
Package Type
8-Pin DIP
C
A
1
8 C
B
7
-Input 2
+Input 3
V
SS
4
TC7652CPA
V
DD
6 Output
5 Output
Clamp
14-Pin DIP
C
B
1
C
A
2
NC 3
-Input 4
+Input 5
NC 6
V
SS
7
14 INT/EXT
EXT CLK
13 In
12 INT CLK
Out
11 V
DD
10 Output
9
8
Output
Clamp
C
RETN
TC7652CPD
NC = No Internal Connection
(May Be Used As Input Guard)
2002 Microchip Technology Inc.
DS21464B-page 1
©
TC7652
Functional Block Diagram
TC7652
14-Pin DIP Only
Output Clamp
(Not On "Z" Pinout)
Output Clamp
Circuit
Oscillator
INT/EXT
EXT CLK IN
CLK OUT
Main
Amplifier
Inputs
NULL
A
B
Output
C
B
Intermod
Comparator
B
B
NULL
Amplifier
A
NULL
NOTE 1:
For 8-pin DIP connect to V
SS
, or to C
RET
on "Z" pinout.
C
RETN
(1)
V
SS
B
A
C
A
©
DS21464B-page 2
2002 Microchip Technology Inc.
TC7652
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 indi-
cated in the operation sections of the specifications is not
implied. Exposure to Absolute Maximum Rating conditions
for extended periods my affect device reliability.
ABSOLUTE MAXIMUM RATINGS*
Total Supply Voltage (V
DD
to V
SS
) .......................+18V
Input Voltage .................... (V
DD
+0.3V) to (V
SS
– 0.3V)
Voltage on Oscillator Control Pins...............V
DD
to V
SS
Duration of Output Short Circuit ..................... Indefinite
Current Into Any Pin............................................ 10mA
While Operating (Note
1)............................
100µA
Package Power Dissipation (T
A
< 70°C)
8-Pin Plastic DIP ....................................... 730mW
14-Pin Plastic DIP ..................................... 800mW
Storage Temperature Range .............. -65°C to +150°C
Operating Temperature Range
C Device .......................................... 0°C to +70°C
I Device ......................................... -25°C to +85°C
TC7652 ELECTRICAL SPECIFICATIONS
Electrical Characteristics:
V
DD
= +5V, V
SS
= -5V, T
A
= +25°C, unless otherwise indicated.
Symbol
V
OS
TCV
OS
V
OS
/DT
I
BIAS
Parameter
Input Offset Voltage
Average Temperature Co-efficient of
Input Offset Voltage
Offset Voltage vs Time
Input Bias Current (CLK On)
Min
—
—
—
—
—
—
—
—
—
—
—
120
±4.7
—
-4.3
120
120
—
—
—
—
—
—
5
Typ
±2
0.01
150
30
100
250
15
35
100
25
10
12
Max
±5
0.05
—
100
—
1000
30
—
1000
150
—
—
—
—
+3.5
—
—
1.5
5
—
—
—
—
16
Units
µV
µV/°C
nV/mo
pA
Test Conditions
T
A
= +25°C
0°C < T
A
< +70°C
T
A
= +25°C
0°C < T
A
< +70°C
-25°C < T
A
< +85°C
T
A
= +25°C
0°C < T
A
< +70°C
-25°C < T
A
< +85°C
I
BIAS
Input Bias Current (CLK Off)
pA
I
OS
R
IN
OL
V
OUT
CMVR
MRR
PSRR
e
N
I
N
GBW
SR
V
DD
, V
SS
Input Offset Current
Input Resistance
Large Signal Voltage Gain
Output Voltage Swing
(Note
2)
Common Mode Voltage Range
Common Mode Rejection Ratio
Power Supply
Input Noise Voltage
Input Noise Current
Unity Gain Bandwidth
Slew Rate
Overshoot
Operating Supply Range
pA
Ω
dB
V
V
dB
dB
µV
P-P
µV
P-P
pA/
√Hz
MHz
V/µsec C
L
= 50pF, R
L
= 10kΩ
%
V
CMVR = -4.3V to +3.5V
±3V to ±8V
R
S
= 100Ω, DC to 1Hz
DC to 10Hz
f = 10Hz
R
L
= 10kΩ, V
OUT
= ±4V
R
L
= 10kΩ
R
L
= 100kΩ
150
±4.85
±4.95
—
140
140
0.2
0.7
0.01
0.4
1
15
—
Note 1:
Limiting input current to 100µA is recommended to avoid latch-up problems. Typically 1mA is safe however, this is not
guaranteed.
2:
Output clamp not connected. See typical characteristics curves for output swing versus clamp current characteristics.
3:
See “Output Clamp” under detailed description.
2002 Microchip Technology Inc.
DS21464B-page 3
©
TC7652
TC7652 ELECTRICAL SPECIFICATIONS
(CONTINUED)
Electrical Characteristics:
V
DD
= +5V, V
SS
= -5V, T
A
= +25°C, unless otherwise indicated.
Symbol
I
S
f
CH
Parameter
Supply Current
Internal Chopping Frequency
Clamp ON Current (Note
3)
Clamp OFF Current (Note
3)
Min
—
100
25
—
Typ
1
275
100
1
Max
3
—
—
—
Units
mA
Hz
µA
pA
Test Conditions
No Load
Pins 12 – 14 Open (DIP)
R
L
= 100kΩ
-4V
≤
V
OUT
< +10V
Note 1:
Limiting input current to 100µA is recommended to avoid latch-up problems. Typically 1mA is safe however, this is not
guaranteed.
2:
Output clamp not connected. See typical characteristics curves for output swing versus clamp current characteristics.
3:
See “Output Clamp” under detailed description.
©
DS21464B-page 4
2002 Microchip Technology Inc.
TC7652
2.0
PIN DESCRIPTIONS
The descriptions of the pins are listed in Table 2-1.
TABLE 2-1:
PIN FUNCTION TABLE
Symbol
Description
Nulling capacitor pins
Inverting Input
Non-inverting Input
Negative Power Supply
Output Voltage Clamp
Output
Positive Power Supply
No internal connection
Capacitor current return pin
Internal Clock Output
External Clock Input
Select Internal or External Clock
Pin Number
8-pin DIP
1,8
2
3
4
5
6
7
—
—
—
—
—
14-pin DIP
2,1
4
5
7
9
10
11
3,6
8
12
13
14
C
A
, C
B
-INPUT
+INPUT
V
SS
OUTPUT
CLAMP
OUTPUT
V
DD
NC
C
RETN
INT CLK OUT
EXT CLK IN
INT/EXT
2002 Microchip Technology Inc.
DS21464B-page 5
©
