Datasheet LTC4013 (Analog Devices) - 8

LTC4013
PIN FUNCTIONS INFET (Pin 1):
Input PowerPath MOSFET Gate Drive. An
TMR (Pin 10):
Timer Capacitor Pin. A capacitor from this internal charge pump provides turn-on drive for this pin. pin to ground sets the time the charger spends in various This pin should be connected to the gate of an external charging stages. The equalization timeout is a ratio of this N-channel MOSFET to prevent battery discharge when time, either 1/4 or 1/8 of the absorption time, depending DCIN is less than the battery voltage. on the MODE pins settings. The low battery timeout period
DCIN (Pin 2):
Input Supply Pin. This pin is used to sense is 1/8 of the absorption time. the input voltage to determine whether to enable the
MODE1, MODE2 (Pins 11, 12):
Charge Algorithm Control INFET charge pump. It also supplies power to the INFET Pins. See Table 1. The LTC4013 supports 2, 3 and 4-stage charge pump. lead-acid as well as Li-Ion charging algorithms with and
MPPT, FBOC (Pins 3, 4):
Maximum Power Point Tracking without termination. The MODE pins are tri-state and should (MPPT) Regulation Loop Set-Point Pins. The input voltage be strapped to INTVCC, ground or left floating. regulation loop regulates charge current, providing maxi-
CLKOUT (Pin 13):
Oscillator Frequency Output Pin. This mum power charging in the presence of a power limited logic output is roughly 180 degrees out of phase with the source such as a solar panel. A resistor divider is placed switching regulator's oscillator. from the input supply to MPPT, FBOC and ground. These
SYNC (Pin 14):
Frequency Synchronization Pin. This pin pins are used to program the input voltage regulation loop allows the switching frequency to be synchronized to an as a percentage of the input open circuit voltage. If the external clock. The R input voltage falls below the programmed percentage of T resistor should be chosen to oper- ate the internal clock 20% slower than the SYNC pulse the open-circuit voltage, the MPPT loop will reduce charge frequency. Ground SYNC when not in use. current to maintain the target maximum power point volt- age at DCIN. If the input voltage regulation feature is not
RT (Pin 15):
Switching Regulator Frequency Control Pin. A used, connect FBOC to INTVCC. mandatory resistor from RT to ground sets the switching frequency between 200kHz and 1MHz.
ENAB (Pin 5):
Precision Threshold Enable Pin. The enable threshold is 1.22V (rising), with 170mV of hysteresis. In
ITH (Pin 16):
Compensation Control Pin. This pin is used shutdown, all charging functions are disabled and input to compensate the switching regulator’s constant-current supply current is reduced. control loop.
ISMON (Pin 6):
Charge Current Monitor Pin. The voltage
NTC (Pin 17):
Thermistor Input Pin. With the use of on this pin is twenty times the differential voltage between an external NTC thermistor, the NTC pin can be used SENSE and BAT and can be used to monitor charge current. to develop a temperature dependent charge voltage for lead-acid batteries. NTC pin voltages above 3.3V disable
STAT0, STAT1 (Pins 7, 8):
Open drain outputs that indicate the NTC function. The NTC function is not suitable for the charger status. These pins can sink 5mA, enabling them Lithium Ion batteries and should be disabled by strapping to drive an LED. Specific states are detailed in Table 2. NTC to INTVCC.
LB (Pin 9):
Low Battery Level Control Pin. A precision
FB (Pin 18):
Constant-Voltage Feedback Pin. This pin 20µA current sourced from LB to an external resistor sets provides feedback for regulating battery voltage during the detection voltage for a deeply discharged battery. If FB the constant-voltage phase of charging. A resistor divider stays below LB for 1/8 of the absorption timeout period, from the battery to this pin sets the constant-voltage charging is stopped. Charging is reinitiated with an ENAB charging level. pin toggle, a power cycle or by swapping out the battery. 4013fa 8