link to page 13 LTC4007 TYPICAL PERFORMANCE CHARACTERISTICSEfficiency at 19VDC VINEfficiency at 12.6V with 15VDC VIN 100 100 16.8V 95 95 12.6V 90 90 85 85 EFFICIENCY (%) EFFICIENCY (%) 80 80 75 75 0.50 1.00 1.50 2.00 2.50 3.00 0.50 1.00 1.50 2.00 2.50 3.00 CHARGE CURRENT (A) CHARGE CURRENT (A) 4007 G10 4007 G11 PIN FUNCTIONSDCIN (Pin 1): External DC Power Source Input. Bypass this conditioning error, or that charger operation is suspended pin with at least 0.01µF. See "Applications Information". due to the thermistor exceeding allowed values. A pull-up CHG (Pin 2): Charge Status Output. When the battery is resistor is required if this function is used. The pin is being charged, the CHG pin is pulled low by an internal capable of sinking at least 100µA. N-channel MOSFET. Internal 10µA pull-up to 3.5V. If GND (Pin 6): Ground for Low Power Circuitry. VLOGIC is greater than 3.3V, add an external pull-up. The 3C4C (Pin 7): Select 3-cell or 4-cell float voltage by timer charge termination can be defeated by forcing this connecting this pin to GND or open, respectively. Internal pin below 1V (or connecting it to GND). 14µA pull-up to 5.3V. This pin can also be driven with ACP (Pin 3): Open-Drain output to indicate if the AC open-collector/drain logic levels. High: 4 cell. Low: 3 cell. adapter voltage is adequate for charging. This pin is pulled LOBAT (Pin 8): Low-Battery Indicator. Active low digital low by an internal N-channel MOSFET if DCIN is below output. Internal 10µA pull-up to 3.5V. If the battery voltage BAT. A pull-up resistor is required. The pin is capable of is below 2.5V/cell (or 2.44V/cell for 4.1V chemistry sinking at least 100µA. batteries) LOBAT will be low. The pin is capable of sinking RT (Pin 4): Timer Resistor. The timer period is set by at least 100µA. If VLOGIC is greater than 3.3V, add an placing a resistor, RRT , to GND. This resistor is always external pull-up. required. NTC (Pin 9): A thermistor network is connected from NTC The timer period is tTIMER = (1hour • RRT/154K). to GND. This pin determines if the battery temperature is If this resistor is not present, the charger will not start. safe for charging. The charger and timer are suspended and the FAULT pin is driven low if the thermistor indicates FAULT (Pin 5): Active low open-drain output that indicates a temperature that is unsafe for charging. The thermistor charger operation has stopped due to a low-battery function may be disabled with a 300k to 500k resistor from DCIN to NTC. Rev D 6 For more information www.analog.com Document Outline Description Typical Application Absolute Maximum Ratings Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Typical Application Related Parts Features Applications Typical Application Description Absolute Maximum Ratings Order Information Electrical Characteristics Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Test Circuit Operation Applications Information Package Description Revision History Typical Application Related Parts