MAX1968_15 Datasheet, PDF (1/16 Pages) Maxim Integrated Products – Power Drivers for Peltier TEC Modules

MAX1968/MAX1969
EVALUATION KIT AVAILABLE
Power Drivers for Peltier TEC Modules
General Description
The MAX1968/MAX1969 are highly integrated and cost-
effective, high-efficiency, switch-mode drivers for Peltier
thermoelectric cooler (TEC) modules. Both devices
utilize direct current control to eliminate current surges
in the TEC. On-chip FETs minimize external components
while providing high efficiency. A 500kHz/1MHz switch-
ing frequency and a unique ripple cancellation scheme
reduce component size and noise.
The MAX1968 operates from a single supply and pro-
vides bipolar ±3A output by biasing the TEC between
the outputs of two synchronous buck regulators.
Bipolar operation allows for temperature control without
“dead zones” or other nonlinearities at low load
currents. This arrangement ensures that the control
system does not hunt when the set point is very close
to the natural operating point, requiring a small amount
of heating or cooling. An analog control signal precisely
sets the TEC current. The MAX1969 provides unipolar
output up to 6A. Reliability is optimized with settable
limits for both TEC voltage and current, with indepen-
dently set limits for heating and cooling current. An
analog output also monitors TEC current.
The MAX1968/MAX1969 are available in a low-profile
28-pin TSSOP-EP package and is specified over the
-40°C to +85°C temperature range. The thermally
enhanced TSSOP-EP package with exposed metal pad
minimizes operating junction temperature. An evalua-
tion kit is available to speed designs.
Applications
Fiber Optic Laser Modules
WDM, DWDM Laser Diode Temperature Control
Fiber Optic Network Equipment
EDFA Optical Amplifiers
Telecom Fiber Interfaces
ATE
Biotech Lab Equipment
Benefits and Features
• High Accuracy and Adjustability Improves System
Performance by Optimizing TEC Operation
• Direct Current Control Prevents TEC Current Surges
• Ripple Cancellation for Low Noise
• No Dead-Zone or Hunting at Low-Output Current
• 1% Accurate Voltage Reference
• Adjustable TEC Voltage Limit
• Separately Adjustable Heating and Cooling Current
Limits
• ITEC Output Provides Proportional Voltage to TEC
Current for Monitoring
• High-Efficiency Switch-Mode Design
• On-Chip Power MOSFETs Improve Efficiency While
Reducing External Components
• 500kHz/1MHz Switching Frequency
• Choose from ±3A Output Current (MAX1968) or 6A
Output Current (MAX1969)
• Thermally Enhanced TSSOP-EP Package Minimizes
Operating Junction Temperature
Ordering Information
PART
MAX1968EUI
MAX1969EUI
*EP = Exposed pad.
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
28 TSSOP-EP*
28 TSSOP-EP*
Typical Operating Circuit
TEC
3V TO
CURRENT- 5.5V
CONTROL
SIGNAL
CTLI
V_DD
COMP
LX2
GND OS2
PV_DD1 PV_DD2
MAX1968
OS1
CS
PGND1
PGND2
LX1
TEC
Pin Configuration and Functional Diagram appear at end
of data sheet.
19-2447; Rev 3; 5/15