DEMO MANUAL DC705A LTC4053EMSE-4.2 Lithium-Ion Linear Battery Charger with Thermal Regulation Description Demonstration circuit DC705 is a complete constant- C/10 trickle charge for deeply discharged batteries current, constant-voltage battery charger designed to Auto recharge when battery voltage drops below pre- charge one Lithium-Ion cell. The LTC 4053EMSE-4.2 used set threshold on this demo circuit features an internal P-channel power Input power OK LED indicator (ACPR) MOSFET with a unique thermal feedback loop that reduces the output current under high ambient temperature and/or C/10 charge LED indicator (CHRG) high power dissipation conditions. This feature allows the Fault LED indicator for out of temp range (FAULT) charger to provide higher charge currents under normal conditions and still provide safe charging under abnormal Small surface mount components are used to minimize conditions such as high ambient temperature, high input board space and height with the circuitry occupying ap- voltage or low battery voltage. The IC is available in a 10-pin proximately 0.15 square inches of board space with a MSOP thermally enhanced package featuring an exposed height of 0.054 inches (1.4mm). bottom-side metal pad for soldering to the PC board. Table 1. Typical Demo Board Specifications Other features include: Input Voltage Range V 4.25V to 7V (Upper Range Limited IN by PC Board Dissipation) Preset float voltage of 4.2V 1% Output Voltage V (Constant 4.2V 1% BAT Voltage Mode) 1A and 0.5A constant current selected by a jumper Output Current I (Constant 1A 8%, 0.5A 8% (Selected by BAT Capable of charging directly from USB power Current Mode) Jumper) Current Monitor Output 1.5V 5% at Full Current 3-hour charge termination timer. This timer can be set Output Current I (Trickle Current 100mA 20%, 50mA 20% BAT for other time periods through a capacitor change. For Mode) instance, you may want to use a much shorter period C/10 CHRG LED Threshold Level 100mA 20%, 50mA 25% (on the order of 30 seconds) when evaluating the board Circuit Board Temperature in 60C to 70C with a battery simulator instead of a real Li-Ion battery. Thermal Feedback Mode Trickle Charge Threshold Voltage 2.457V Charge current monitor output can be used for gas Battery Drain Current with V < 1A gauging IN Removed Manual shutdown Design files for this circuit board are available at Low battery drain current when input supply is removed DEMO MANUAL DC705A Quick s p D To save time, we recommend using a battery simulator SETup (described in Table 2 and Figure 1) If an actual rechargeable Refer to Table 2 and Figure 1 for equipment requirements Li-Ion battery is used, keep the DC resistance between the and proper setup. charger and the battery to a minimum, as this will affect 1. Set jumper JP1 to the RUN position (lower position). the charge current in the constant voltage mode. 2. Set jumper JP2 to the lower position, which programs Table 2. Test Equipment Required for Demo Board Evaluation the constant charge current to 1A. Lab power supply for input power 0 to 7V, 1.2A Digital voltmeter for measuring input 3 1/2 digits 3. Set the input power supply to 0V, and then connect it voltage (V ) IN to the V and GND pins of the demo board. IN Digital voltmeter for measuring battery 4 1/2 digits, resolution to voltage (V ) 1mV 4. Set the battery simulator to 0V, and then connect it to BAT Digital voltmeter for measuring PROG pin 3 1/2 digits, resolution to the BAT and GND pins. voltage (current monitor) 1mV 5. Connect the digital voltmeters as shown in the setup Digital voltmeter for measuring voltage 100mV range across current sense resistor (I ) diagram to measure V , V(current monitor), charge BAT IN voltage (V ) and the charge current (I ). 4.2V rechargeable Li-Ion cell or battery 600mA/Hr to 1.3A/Hr BAT BAT simulator Battery Simulator Consists of: Power supply with coarse and fine output 0 to 5V, 2.5A voltage adjust controls Power resistor (preload for power supply) 2, 10W Current sense resistor for measuring 0.1, 1%, 1W charge current Current sense resistor for measuring 1k, 1%, 0.5W battery drain current dc705af 2 ure roce tart