MAX1978 Maxim, MAX1978 Datasheet - Page 10

• Manufacturer Part Number: MAX1978
• Description: Integrated Temperature Controllers for Peltier Modules
• Manufacturer: Maxim

Integrated Temperature
Controllers for Peltier Modules
10
28, 31, 33
27, 30
32, 34
PIN
23
24
36
37
38
39
40
41
44
45
46
47
48
______________________________________________________________________________________
PGND1
MAXIN
PV
MAXIP
NAME
COMP
AOUT
MAXV
FREQ
ITEC
CTLI
AIN-
OS1
V
REF
LX1
CS
DD
DD
1
Undedicated Chopper-Stabilized Amplifier Inverting Input
Undedicated Chopper-Stabilized Amplifier Output
Power 1 Inputs. Must be same voltage as V
Bypass to PGND1 with a 10µF ceramic capacitor.
Inductor 1 Connection. Connect all LX1 pins together. Connect LX1 to LX2 when using the MAX1979.
Power Ground 1. Internal synchronous-rectifier ground connections. Connect all PGND pins together at
power ground plane.
Switching-Frequency Select. Low = 500kHz, high = 1MHz.
TEC Current Monitor Output. The ITEC output voltage is a function of the voltage across the TEC current-
sense resistor. V
Current-Control Loop Compensation. For most designs, connect a 10nF capacitor from COMP to GND.
Maximum Positive TEC Current. Connect MAXIP to REF to set default positive current limit +150mV / R
Maximum Negative TEC Current. Connect MAXIN to REF to set default negative current limit
-150mV / R
Maximum Bipolar TEC Voltage. Connect an external resistive divider from REF to GND to set the maximum
voltage across the TEC. The maximum TEC voltage is 4
Analog Supply Voltage Input. Bypass to GND with a 10µF ceramic capacitor.
TEC Current-Control Input. Sets differential current into the TEC. Center point is 1.50V (no TEC current).
Connect to INTOUT when using the thermal control loop. I
R
1.5V Reference Voltage Output. Bypass REF to GND with a 1µF ceramic capacitor.
Current-Sense Input. The current through the TEC is monitored between CS and OS1. The maximum TEC
current is given by 150mV / R
Output Sense 1. OS1 senses one side of the differential TEC voltage. OS1 is a sense point, not a power
output.
SENSE
). When (V
SENSE
ITEC
. Connect MAXIN to GND when using the MAX1979.
CLTI
= 1.50V + (V
- V
REF
) > 0, V
SENSE
OS1
OS2
and is bipolar for the MAX1978. The MAX1979 TEC current is unipolar.
- V
> V
CS
DD
)
OS1
✕
. Connect all PV
8.
> V
FUNCTION
CS
.
✕
V
TEC
MAXV
Pin Description (continued)
DD
= (V
.
1 inputs together at the V
OS1
- V
CS
) / R
SENSE
= (V
DD
CTLI
power plane.
- 1.50) / (10
SENSE
.
✕