LTC4101 PIN FUNCTIONSILIM (Pin 13): An external resistor is connected between this ITH (Pin 19): Control Signal of the Inner Loop of the Current pin and GND. The value of the external resistor programs Mode PWM. Higher ITH corresponds to higher charging the range and resolution of the programmed charger current in normal operation. A 0.0015μF capacitor to GND current. This is a digital, not an analog, function. fi lters out PWM ripple. Typical full-scale output current is 40μA. Nominal voltage range for this pin is 0V to 3V. VLIM (Pin 14): An external resistor is connected between this pin and GND. The value of the external resistor IDC (Pin 20): Bypass to GND with a 0.068μF Capacitor. programs the range and resolution of the charging CSP (Pin 21): Current Amplifi er CA1 Input. This pin voltage. This is a digital, not an analog, function. and the BAT pin measure the voltage across the sense THB (Pin 15): SafetySignal Force/Sense Pin to Smart resistor, RSENSE, to provide the instantaneous current Battery. See description of operation for more detail. The signals required for both peak and average current mode maximum allowed combined capacitance on THA, THB and operation. SafetySignal is 1nF (see Figure 4). A series resistor 54.9k BAT (Pin 22): Battery Sense Input and the Negative Refer- needs to be connected between this pin and the battery’s ence for the Current Sense Resistor. A bypass capacitor SafetySignal for this circuit to work correctly. of at least 10μF is required. THA (Pin 16): SafetySignal Force/Sense Pin to Smart CLN (Pin 23): Negative Input to the Input Current Limiting Battery. See description of operation for more detail. The Circuit Block. If no current limit function is desired, connect maximum allowed combined capacitance on THA, THB this pin to CLP. The threshold is set at 100mV below the and SafetySignal is 1nF (see Figure 4). A series resistor voltage at the CLP pin. When used to limit supply current, 1130Ω needs to be connected between this pin and the a fi lter is needed to fi lter out the switching noise. battery’s SafetySignal for this circuit to work correctly. CLP (Pin 24): Positive Input to the Input Current Limiting VDD (Pin 17): Power Supply Input for the LTC4101 Digital Circuit Block. This pin also serves as a power supply for Circuitry. Bypass this pin with 0.1μF. Typically between the IC. 3.3V and 5VDC. VSET (Pin 18): Tap Point of the Programmable Resistor Divider, which Provides Battery Voltage Feedback to the Charger. 4101fa 8