MAX1968_07 Datasheet, PDF (9/16 Pages) Maxim Integrated Products – Power Drivers for Peltier TEC Modules

Power Drivers for Peltier TEC Modules
Pin Description
PIN NAME
1
V_DD Analog Supply Voltage Input
2
GND Analog Ground
FUNCTION
TEC Current Control Input. Sets differential current into the TEC. Center point is 1.50V (no TEC current).
3
CTLI The current is given by:
I_TEC = (V_OS1 - V_CS) / R_SENSE = (V_CTLI - 1.50) / (10 x R_SENSE). When (V_CTLI - V_REF) > 0, V_OS2 > V_OS1 > V_CS.
4
REF 1.50V Reference Output. Bypass REF to GND with a 1µF ceramic capacitor.
5, 7
6, 8, 10
9, 11
12
13
14
PGND2
LX2
PV_DD2
FREQ
ITEC
OS2
Power Ground 2. Internal synchronous rectifier ground connections. Connect all PGND pins together at
power ground plane.
Inductor Connection. Connect all LX2 pins together. For MAX1969, connect LX1 and LX2 pins together.
Power 2 Inputs. Must be same voltage as V_DD. Connect all PV_DD2 inputs together at the V_DD power plane.
Switching Frequency Select. High = 1MHz, Low = 500kHz.
TEC Current Monitor Output. The ITEC output voltage is a function of the voltage across the TEC current-
sense resistor. V_ITEC = 1.50V + (V_OS1 - V_CS) x 8.
Output Sense 2. OS2 senses one side of the differential TEC voltage. OS2 is a sense point, not a power
output. For MAX1969, connect OS2 to GND.
15
OS1
16
CS
17
SHDN
18, 20 PVDD1
19, 21, 23 LX1
Output Sense 1. OS1 senses one side of the differential TEC voltage. OS1 is a sense point, not a power
output.
Current-Sense Input. The current through the TEC is monitored between CS and OS1. The maximum TEC
current is given by 150mV / R_SENSE and is bipolar.
Shutdown Control Input. Active-low shutdown control.
Power 1 Inputs. Must be same voltage as V_DD. Connect all PV_DD1 inputs together at the V_DD power plane.
Inductor Connection. Connect all LX1 pins together. For MAX1969, connect all LX1 and LX2 pins together.
22, 24
PGND1
Power Ground 1. Internal synchronous rectifier ground connections. Connect all PGND pins together at
power ground plane.
25
COMP Current Control-Loop Compensation. For most designs connect a 0.01µF capacitor from COMP to GND.
26
MAXIN
Maximum Negative TEC Current. Connect MAXIN to REF to set default negative current limit
-150mV / R_SENSE. For MAX1969, connect MAXIN to MAXIP.
27
MAXIP
Maximum Positive TEC Current. Connect MAXIP to REF to set default positive current limit +150mV / R_SENSE.
(See the Setting Max Positive and Negative TEC Current section).
28
MAXV
Maximum Bipolar TEC Voltage. Connect an external resistive-divider from REF to GND to set the maximum
voltage. The maximum TEC voltage is 4 x V_MAXV.
—
EP
Exposed Pad. Internally connected to GND. Connect to a large ground plane to maximize thermal
performance.
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