link to page 10 link to page 10 LTM4663 APPLICATIONS INFORMATION VLDR VOLTAGE REACH TEC VOLTAGE VOLTAGE CLK LIMIT AND INTERNAL LIMIT SOFT-START VPWM HEATING TEC VOLTAGE BUILDS UP VREF VB 10k VLIM/SD 10µA DISABLE RV SW OPEN = VVLIM_COOL SW CLOSED = V DISCHARGE SOFT-START VLIM_HEAT PREBIAS BEGINS 4663 F04 TIME Figure 4. TEC Voltage Limit Setting 4663 F03 Figure 3. Soft-Start Profile in Cooling Mode The maximum TEC voltage in the cooling mode can be MAXIMUM TEC VOLTAGE LIMIT calculated as: The maximum voltage of the TEC driver in the LTM4663 R V V can be programmed individually by applying a resistor LIM_COOL = 2 • 2.5V • 10k +RV (RV) from VLIM/SD pin to GNDA. The voltage limiter oper- ates bidirectionally and allows the cooling limit to be dif- The maximum TEC voltage in the heating mode can be ferent from the heating limit. calculated as: As shown in Figure 4, the internal current sink circuitry ⎛ R 10k •R ⎞ V V –10µA • V connected to V LIM_HEAT = 2 • 2.5V • LIM/SD draws a current when the LTM4663 ⎝⎜ 10k +RV 10k +RV ⎠⎟ drives the TEC in a heating direction, which lowers the voltage at VLIM/SD. The current sink is not active when See Table 2 for the list of Typical TEC Voltage Limit the TEC is driven in a cooling direction; therefore, the settings. TEC heating voltage limit is always lower than the cooling voltage limit. Table 2. Example of Typical TEC Voltage Limit SettingBOTTOMMAX TEC VOLTAGEMAX TEC VOLTAGERESISTOR RV(COOLING MODE)(HEATING MODE)(kΩ)(V)(V) OPEN 5 –4.8 90.9 4.5 –4.32 40.2 4 –3.84 23.2 3.5 –3.35 15 3 –2.88 10 2.5 –2.4 6.65 2 –1.92 4.22 1.5 –1.42 2.49 1 –0.96 Rev. 0 10 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Typical Performance Characteristics Pin Functions Block Diagram Decoupling Requirements Operation Applications Information Typical Applications Package Description Package Photo Package Description Design Resources Related Parts