Datasheet LTC4001-1 (Analog Devices) - 6
| Manufacturer | Analog Devices |
| Description | 2A Synchronous Buck Li-Ion Charger |
| Pages / Page | 20 / 6 — PIN FUNCTIONS. NTC (Pin 11):. SS (Pin 14):. TIMER (Pin 15):. PROG (Pin … |
| File Format / Size | PDF / 236 Kb |
| Document Language | English |
PIN FUNCTIONS. NTC (Pin 11):. SS (Pin 14):. TIMER (Pin 15):. PROG (Pin 12):. BATSENS (Pin 16):. Exposed Pad (Pin 17):. IDET (Pin 13):
Model Line for this Datasheet
Text Version of Document
LTC4001-1
PIN FUNCTIONS NTC (Pin 11):
Input to the NTC (Negative Temperature
SS (Pin 14):
Soft-Start/Compensation. Provides soft-start Coeffi cient) Thermistor Temperature Monitoring Circuit. function and compensation for the fl oat voltage control Under normal operation, tie a thermistor from the NTC pin loop and compensation for the charge current control to the GNDSENS pin and a resistor of equal value from loop. Tie a soft-start/compensation capacitor between NTC to VIN. When the voltage on this pin is above 0.74VIN this pin and GNDSENS. (Cold, 0°C) or below 0.29VIN (Hot, 50°C), charging is
TIMER (Pin 15):
Timer Capacitor. The timer period is set disabled and the CHRG pin blinks. When the voltage on by placing a capacitor, C NTC comes back between 0.74V TIMER, to GNDSENS. Set CTIMER IN and 0.29VIN, the timer to: continues where it left off and charging resumes. There is approximately 3°C of temperature hysteresis associated CTIMER = Time (Hrs) • 0.0733 (μF) with each of the input comparators. If the NTC function where time is the desired charging time. is not used connect the NTC pin to GNDSENS. This will disable all of the NTC functions. NTC should never be Connect this pin to IDET to disable the timer. Connect this pulled above V pin to GNDSENS to end battery charging when I IN. BAT drops below the IDET charge rate threshold.
PROG (Pin 12):
Charge Current Program. The RPROG resistor connects from this pin to GNDSENS, setting the
BATSENS (Pin 16):
Battery Sense Input. An internal resistor current: divider sets the fi nal fl oat voltage at this pin. The resistor divider is disconnected in sleep mode or when RPROG = 1.110k I EN = H to reduce the battery drain current. Connect this BAT(AMPS) pin to the positive battery terminal. where IBAT is the high rate battery charging current.
Exposed Pad (Pin 17):
Ground. This pin must be soldered
IDET (Pin 13):
Charge Rate Detection Threshold. Connect- to the PCB ground (PGND) for electrical contact and rated ing a resistor, R thermal performance. IDET to GNDSENS programs the charge rate detection threshold. If RIDET = RPROG, CHRG provides an IBAT/10 indication. For other thresholds see the Applica- tions Information section. 40011fa 6
PIN FUNCTIONS NTC (Pin 11):
Input to the NTC (Negative Temperature
SS (Pin 14):
Soft-Start/Compensation. Provides soft-start Coeffi cient) Thermistor Temperature Monitoring Circuit. function and compensation for the fl oat voltage control Under normal operation, tie a thermistor from the NTC pin loop and compensation for the charge current control to the GNDSENS pin and a resistor of equal value from loop. Tie a soft-start/compensation capacitor between NTC to VIN. When the voltage on this pin is above 0.74VIN this pin and GNDSENS. (Cold, 0°C) or below 0.29VIN (Hot, 50°C), charging is
TIMER (Pin 15):
Timer Capacitor. The timer period is set disabled and the CHRG pin blinks. When the voltage on by placing a capacitor, C NTC comes back between 0.74V TIMER, to GNDSENS. Set CTIMER IN and 0.29VIN, the timer to: continues where it left off and charging resumes. There is approximately 3°C of temperature hysteresis associated CTIMER = Time (Hrs) • 0.0733 (μF) with each of the input comparators. If the NTC function where time is the desired charging time. is not used connect the NTC pin to GNDSENS. This will disable all of the NTC functions. NTC should never be Connect this pin to IDET to disable the timer. Connect this pulled above V pin to GNDSENS to end battery charging when I IN. BAT drops below the IDET charge rate threshold.
PROG (Pin 12):
Charge Current Program. The RPROG resistor connects from this pin to GNDSENS, setting the
BATSENS (Pin 16):
Battery Sense Input. An internal resistor current: divider sets the fi nal fl oat voltage at this pin. The resistor divider is disconnected in sleep mode or when RPROG = 1.110k I EN = H to reduce the battery drain current. Connect this BAT(AMPS) pin to the positive battery terminal. where IBAT is the high rate battery charging current.
Exposed Pad (Pin 17):
Ground. This pin must be soldered
IDET (Pin 13):
Charge Rate Detection Threshold. Connect- to the PCB ground (PGND) for electrical contact and rated ing a resistor, R thermal performance. IDET to GNDSENS programs the charge rate detection threshold. If RIDET = RPROG, CHRG provides an IBAT/10 indication. For other thresholds see the Applica- tions Information section. 40011fa 6
