Datasheet

MAX1968/MAX1969
Power Drivers for Peltier TEC Modules
______________________________________________________________________________________ 15
Applications Information
The MAX1968/MAX1969 typically drive a thermoelectric
cooler inside a thermal control loop. TEC drive polarity
and power are regulated based on temperature informa-
tion read from a thermistor, or other temperature-mea-
suring device to maintain a stable control temperature.
Temperature stability of 0.01°C can be achieved with
carefully selected external components.
There are numerous ways to implement the thermal
loop. Figures 1 and 2 show a design that employs preci-
sion op amps, along with a DAC or potentiometer to set
the control temperature. The loop may also be imple-
mented digitally, using a precision A/D to read the ther-
mistor or other temperature sensor, a microcontroller to
implement the control algorithm, and a DAC (or filtered
PWM signal) to send the appropriate signal to the
MAX1968/MAX1969 CTLI input. Regardless of the form
taken by the thermal control circuitry, all designs are
similar in that they read temperature, compare it to a
set-point signal, and then send an error-correcting sig-
nal to the MAX1968/MAX1969 that moves the tempera-
ture in the appropriate direction.
Pin Configuration
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
MAXV
MAXIP
MAXIN
COMP
PGND1
LX1
OS1
PGND1
LX1
PV
DD
1
LX1
PV
DD
1
SHDN
CS
OS2
ITEC
FREQ
PV
DD
2
LX2
PV
DD
2
LX2
PGND2
LX2
PGND2
REF
CTLI
GND
V
DD
TSSOP-EP
TOP VIEW
MAX1968
MAX1969
NOTE: GND IS CONNECTED TO THE UNDERSIDE METAL SLUG.
Revision History
Pages changed at Rev 2: 1, 9, 15, 16
Chip Information
TRANSISTOR COUNT: 2959
PROCESS: BiCMOS