PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
INA330
SBOS260 – NOVEMBER 2002
www.ti.com
DESCRIPTION
The INA330 is a precision amplifier designed for thermoelec-
tric cooler (TEC) control in optical networking applications. It
is optimized for use in 10kΩ thermistor-based temperature
controllers. The INA330 provides thermistor excitation and
generates an output voltage proportional to the difference in
resistances applied to the inputs. It uses only one precision
resistor plus the thermistor, thus providing an alternative to
the traditional bridge circuit. This new topology eliminates the
need for two precision resistors while maintaining excellent
accuracy for temperature control applications.
An excitation voltage is applied to the thermistor (R
THERM
)
and precision resistor (R
SET
), creating currents I
1
and I
2
. The
current conveyor circuit produces an output current, I
O
, equal
to I
1
– I
2
, which flows through the external gain-setting
resistor. A buffered voltage output proportional to I
O
is also
provided.
The INA330 offers excellent long-term stability, and very low
1/f noise throughout the life of the product. The low offset
results in a 0.009°C temperature error from –40°C to +85°C.
It comes in MSOP-10 packaging and operates with supply
voltages from +2.7V to +5.5V. It is specified over the indus-
trial temperature range, –40°C to +85°C, with operation from
–40°C to +125°C.
FEATURES
● OPTIMIZED FOR PRECISION 10kΩ
THERMISTOR APPLICATIONS
● LOW OFFSET OVER TEMPERATURE:
0.009°C Temperature Error, –40°C to +85°C
● EXCELLENT LONG-TERM STABILITY
● VERY LOW 1/f NOISE: (0.01Hz to 10Hz)
(Peak-to-Peak Equivalent to 0.0001°C)
● WIDE OUTPUT SWING: Within 10mV of Rails
● SUPPLY RANGE: Single +2.7V to +5.5V
●
micro
PACKAGE: MSOP-10
● REQUIRES ONLY ONE PRECISION RESISTOR
Copyright © 2002, Texas Instruments Incorporated
THERMISTOR SIGNAL AMPLIFIER
FOR TEMPERATURE CONTROL
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
APPLICATIONS
● THERMISTOR-BASED TEMPERATURE
CONTROLLERS FOR OPTICAL NETWORKING
● HIGH ACCURACY FOR TEC APPLICATIONS
● LASER TEMPERATURE CONTROL
D/A
Converter
2
3
10
1
95
4
V+
V
2
V
EXCITE
1V
V
1
6
Enable High = On
Low = Off
8
7
I
1
I
2
R
SET
10kΩ
R
G
200kΩ
Thermistor
R
THERM
= 10kΩ
C
FILTER
500pF
I
O
= I
1
– I
2
V
O
V
REF
2.5V
PID CONTROLLER
INA330 In A Temperature Control Loop
V
ADJUST
= +2.5V
I
N
A
3
3
0
