EVALUATION KIT AVAILABLE Power Drivers for Peltier TEC Modules MAX1968/MAX1969 General Description Benefits and Features The MAX1968/MAX1969 are highly integrated and cost- High Accuracy and Adjustability Improves System effective, high-efficiency, switch-mode drivers for Peltier Performance by Optimizing TEC Operation thermoelectric cooler (TEC) modules. Both devices Direct Current Control Prevents TEC Current Surges utilize direct current control to eliminate current surges Ripple Cancellation for Low Noise in the TEC. On-chip FETs minimize external components No Dead-Zone or Hunting at Low-Output Current while providing high efficiency. A 500kHz/1MHz switch- 1% Accurate Voltage Reference ing frequency and a unique ripple cancellation scheme Adjustable TEC Voltage Limit reduce component size and noise. Separately Adjustable Heating and Cooling Current The MAX1968 operates from a single supply and pro- Limits vides bipolar 3A output by biasing the TEC between ITEC Output Provides Proportional Voltage to TEC the outputs of two synchronous buck regulators. Current for Monitoring Bipolar operation allows for temperature control without High-Efficiency Switch-Mode Design dead zones or other nonlinearities at low load On-Chip Power MOSFETs Improve Efficiency While currents. This arrangement ensures that the control Reducing External Components system does not hunt when the set point is very close 500kHz/1MHz Switching Frequency to the natural operating point, requiring a small amount Choose from 3A Output Current (MAX1968) or 6A of heating or cooling. An analog control signal precisely sets the TEC current. The MAX1969 provides unipolar Output Current (MAX1969) output up to 6A. Reliability is optimized with settable Thermally Enhanced TSSOP-EP Package Minimizes limits for both TEC voltage and current, with indepen- Operating Junction Temperature dently set limits for heating and cooling current. An analog output also monitors TEC current. Ordering Information The MAX1968/MAX1969 are available in a low-profile 28-pin TSSOP-EP package and is specified over the PART TEMP RANGE PIN-PACKAGE -40C to +85C temperature range. The thermally MAX1968EUI -40C to +85C 28 TSSOP-EP* enhanced TSSOP-EP package with exposed metal pad MAX1969EUI -40C to +85C 28 TSSOP-EP* minimizes operating junction temperature. An evalua- tion kit is available to speed designs. *EP = Exposed pad. Applications Typical Operating Circuit Fiber Optic Laser Modules WDM, DWDM Laser Diode Temperature Control 3V TO TEC CURRENT- 5.5V Fiber Optic Network Equipment CONTROL SIGNAL EDFA Optical Amplifiers Telecom Fiber Interfaces ATE V CTLI PV 1PV 2 Biotech Lab Equipment DD DD DD PGND1 PGND2 COMP MAX1968 LX1 LX2 GND OS2 OS1 CS TEC Pin Configuration and Functional Diagram appear at end of data sheet. 19-2447 Rev 3 5/15Power Drivers for Peltier TEC Modules MAX1968/MAX1969 Absolute Maximum Ratings V to GND..............................................................-0.3V to +6V Peak LX Current (MAX1968) (Note 1).................................4.5A DD Peak LX Current (MAX1969) (Note 1)....................................+9A SHDN, MAXV, MAXIP, MAXIN, CTLI, Continuous Power Dissipation (T = +70C) A FREQ to GND .......................................................-0.3V to +6V 28-Pin TSSOP-EP (derate 23.8mW/C above +70C).....1.9W COMP, OS1, OS2, CS, REF, Operating Temperature Range ...........................-40C to +85C ITEC to GND...........................................-0.3V to (V + 0.3V) DD Maximum Junction Temperature .....................................+150C PV 1, PV 2 to GND...............................-0.3V to (V + 0.3V) DD DD DD Storage Temperature Range .............................-65C to +150C PV 1, PV 2 to V -0.3V to +0.3V DD DD DD .................................................. Lead Temperature (soldering 10s) ..................................+300C PGND1, PGND2 to GND .......................................-0.3V to +0.3V COMP, REF, ITEC Short to GND ...................................Indefinite Note 1: LX has internal clamp diodes to PGND and PV . Applications that forward bias these diodes should take care not to DD exceed the ICs package power dissipation limits. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Electrical Characteristics (V = PV 1 = PV 2 = SHDN = 5V, PGND1 = PGND2 = FREQ = GND, CTLI = MAXV = MAXIP = MAXIN = REF, C = 1F, DD DD DD REF C = 0.1F, L = 3.3H, C = C = 1F, I < 3A (MAX1968), I < 6A (MAX1969), T = 0C to +85C, unless COMP LX CS OS2 TEC RMS TEC RMS A otherwise noted. Typical values are at T = +25C.) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Supply Range V 3.0 5.5 V DD V = 5V, I = 0 to 3A, DD TEC -4.3 +4.3 V = V - V (MAX1968) OUT OS1 OS2 V = 5V, I = 0 to 6A, DD TEC 4.3 V = V (MAX1969) OUT OS1 Output Voltage Range V V OUT V = 3V, I = 0 to 3A, DD TEC -2.3 +2.3 V = V - V (MAX1968) OUT OS1 OS2 V = 3V, I = 0 to 6A, DD TEC 2.3 V = V (MAX1969) OUT OS1 MAX1968 3 Maximum TEC I A TEC(MAX) Current MAX1969 6 Reference Voltage V V = 3V to 5.5V, I = 150A 1.485 1.500 1.515 V REF DD REF Reference Load V V = 3V to 5.5V, I = +10A to -1mA 1.2 5 mV REF DD REF Regulation V = V 140 150 160 MAXI REF V < V OS1 CS V = V /3 40 50 60 Current-Sense MAXI REF mV Threshold Accuracy V = V 140 150 160 MAXI REF V > V OS1 CS V = V /3 40 50 60 MAXI REF Switch-Fault Reset 50 150 250 mV Voltage V = 5V, I = 0.5A 0.04 0.07 DD NFET On-Resistance R DS(ON-N) V = 3V, I = 0.5A 0.06 0.08 DD V = 5V, I = 0.5A 0.06 0.10 DD PFET On-Resistance R DS(ON-P) V = 3V, I = 0.5A 0.09 0.12 DD V = V = 5V, T = +25C 0.02 10 LX DD A NFET Leakage I A LEAK(N) V = V = 5V, T = +85C 1 LX DD A www.maximintegrated.com Maxim Integrated 2