1
TC7650
CHOPPER-STABILIZED OPERATIONAL AMPLIFIER
FEATURES
Low Input Offset Voltage ......................... 0.7
µ
V Typ
Low Input Offset Voltage Drift ......... 0.05
µ
V/
°
C Max
Low Input Bias Current ............................ 10pA Max
High Impedance Differential CMOS Inputs .... 10
12
Ω
High Open-Loop Voltage Gain ................ 120dB Min
Low Input Noise Voltage ............................ 2.0
µ
Vp-p
High Slew Rate .......................................... 2.5V/
µ
sec
Low-Power Operation ..................................... 20mW
Output Clamp Speeds Recovery Time
Compensated Internally for Stable Unity Gain
Operation
s
Direct Replacement for ICL7650
s
Available in 8-Pin Dip and 14-Pin Dip
s
s
s
s
s
s
s
s
s
s
GENERAL DESCRIPTION
The TC7650 CMOS chopper-stabilized operational
amplifier practically removes offset voltage error terms
from system error calculations. The 5µV maximum V
OS
specification, for example, represents a 15 times improve-
ment over the industry-standard OP07E. The 50nV/°C off-
set drift specification is over 25 times lower than the OP07E.
The increased performance eliminates V
OS
trim proce-
dures, periodic potentiometer adjustment and the reliability
problems caused by damaged trimmers.
The TC7650 performance advantages are achieved
without the additional manufacturing complexity and cost
incurred with laser or "zener zap" V
OS
trim techniques.
The TC7650 nulling scheme corrects both DC V
OS
errors and V
OS
drift errors with temperature. A nulling
amplifier alternately corrects its own V
OS
errors and the main
amplifier V
OS
error. Offset nulling voltages are stored on two
user-supplied external capacitors. The capacitors connect
to the internal amplifier V
OS
null points. The main amplifier
input signal is never switched. Switching spikes are not
present at the TC7650 output.
The 14-pin dual-in-line package (DIP has an external
oscillator input to drive the nulling circuitry for optimum noise
performance. Both the 8 and 14-pin DIPs have an output
voltage clamp circuit to minimize overload recovery time.
PIN CONFIGURATIONS
8-Pin DIP
C
A
1
8 C
B
7 V
DD
TC7650CPA
6 OUTPUT
5 CLAMP
2
3
4
5
6
7
ORDERING INFORMATION
Part No.
TC7650CPA
TC7650CPD
Package
8-Pin Plastic DIP
14-Pin Plastic DIP
Temperature
Range
0°C to +70°C
0°C to +70°C
Max
V
OS
5µV
5µV
FUNCTIONAL BLOCK DIAGRAM
OUTPUT
CLAMP
OUTPUT CLAMP
CIRCUIT
MAIN
AMPLIFIER
INPUTS
NULL
A
B
OSCILLATOR
14-PIN DIP ONLY
INT/EXT
EXT CLK IN
CLK OUT
(–) INPUT 2
(+) INPUT 3
V
SS
4
OUTPUT
CEXT
14-Pin DIP
C
B
1
14 INT/EXT
EXT CLK
13 INPUT
12 INT CLK
OUTPUT
TC7650CPD
11 V
DD
10 OUTPUT
9
OUTPUT
CLAMP
INTERMOD
COMPENSATION
B
B
NULL
AMPLIFIER
A
NULL
* FOR 8-PIN DIP, CONNECT TO V .
SS
TC7650
B
A
CEXT
C
A
2
NC
(GUARD)
(–) INPUT
(+) INPUT
NC
(GUARD)
V
SS
3
4
5
6
7
*CRET
8 C
RETN
NC = NO INTERNAL CONNECTION
TC7650-5 9/11/96
8
3-273
TELCOM SEMICONDUCTOR, INC.
TELCOM [ TELCOM SEMICONDUCTOR, INC ]
