Datasheet LTC1960 (Analog Devices) - 8

LTC1960
PIN FUNCTIONS (G/UHF) Input Power Related Battery Charging Related SCN (Pin 4/Pin 30):
PowerPath Current Sensing Negative
VSET (Pin 13/Pin 1):
The Tap Point of a Programmable Input. This pin should be connected directly to the “bottom” Resistor Divider Which Provides Battery Voltage Feedback (output side) of the sense resistor, RSC, in series with the to the Charger. A capacitor from CSN to VSET and from three PowerPath switch pairs, for detecting short-circuit VSET to GND provide necessary compensation and filtering current events. Also powers LTC1960 internal circuitry for the voltage loop. when all other sources are absent.
ITH (Pin 14/Pin 2):
The Control Signal of the Inner Loop of
SCP (Pin 5/Pin 31):
PowerPath Current Sensing Positive the Current Mode PWM. Higher ITH voltage corresponds to Input. This pin should be connected directly to the “top” higher charging current in normal operation. A capacitor (switch side) of the sense resistor, RSC, in series with the of at least 0.1µF to GND filters out PWM ripple. Typical three PowerPath switch pairs, for detecting short-circuit full-scale output current is 30µA. Nominal voltage range current events. for this pin is 0V to 2.4V.
GDCO (Pin 6/Pin 32):
DCIN Output Switch Gate Drive.
ISET (Pin 15/Pin 3):
A capacitor from ISET to ground is Together with GDCI, this pin drives the gate of the P-channel required to filter higher frequency components from the switch in series with the DCIN input switch. delta-sigma IDAC.
GDCI (Pin 7/Pin 33):
DCIN Input Switch Gate Drive.
CSN (Pin 22/Pin 11):
Current Amplifier CA1 Input. Con- Together with GDCO, this pin drives the gate of the nect this to the common output of the charger MUX P-channel switch connected to the DCIN input. switches.
GB1O (Pin 8/Pin 34):
BAT1 Output Switch Gate Drive.
CSP (Pin 23/Pin 12):
Current Amplifier CA1 Input. This Together with GB1I, this pin drives the gate of the P-channel pin and the CSN pin measure the voltage across the switch in series with the BAT1 input switch. sense resistor, RSNS, to provide the instantaneous cur-
GB1I (Pin 9/Pin 35):
BAT1 Input Switch Gate Drive. rent signals required for both peak and average current Together with GB1O, this pin drives the gate of the P-channel mode operation. switch connected to the BAT1 input.
COMP1 (Pin 25/Pin 14):
The Compensation Node for the
GB2O (Pin 10/Pin 36):
BAT2 Output Switch Gate Drive. Amplifier CL1. A capacitor is required from this pin to GND Together with GB2I, this pin drives the gate of the P-channel if input current amplifier CL1 is used. At input adapter switch in series with the BAT2 input switch. current limit, this node rises to 1V. By forcing COMP1 low, amplifier CL1 will be defeated (no adapter current limit).
GB2I (Pin 11/Pin 37):
BAT2 Input Switch Gate Drive. COMP1 can source 10µA. Together with GB2O, this pin drives the gate of the P-channel switch connected to the BAT2 input.
BGATE (Pin 27/Pin 16):
Drives the bottom external MOSFET of the battery charger buck converter.
CLP (Pin 24/Pin 13):
The Positive Input to the Supply Current Limiting Amplifier CL1. The threshold is set at
SW (Pin 30/Pin 19):
PWM switch node connected to source 100mV above the voltage at the DCIN pin. When used of the top external MOSFET switch. Used as reference for to limit supply current, a filter is needed to filter out the top gate driver. switching noise.
BOOST (Pin 31/Pin 20):
Supply to Topside Floating Driver. The bootstrap capacitor is returned to this pin. Voltage swing at this pin is from a diode drop below VCC to (DCIN + VCC). Rev. C 8 For more information www.analog.com Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Test Circuit Timing Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts