The LT 1620 simplifies the design of high performance, controlled current battery charging circuits when used in conjunction with a current mode PWM controller IC. The LT1620 regulates average output current independent of input and output voltage variations.
Output current can be easily adjusted via a programming voltage applied to the LT1620’s PROG pin. Most current mode PWM controllers have limited output voltage range because of common mode limitations on the current sense inputs. The LT1620 overcomes this restriction by providing a level-shifted current sense signal, allowing a 0V to 32V output voltage range. The 16-pin version of the LT1620 contains a programmable low charging current flag output.
This output flag can be used to signal when a Li-Ion battery charging cycle is nearing completion. The LT1621 incorporates two fully independent current control circuits for dual loop applications.
Power Supply Voltage: VCC ..........................– 0.3V to 7V
Programming Voltage:
PROG, PROG2 ............ –0.3V to VCC + 0.3V (7V Max)
IOUT, SENSE, AVG, AVG2,
MODE Voltage ................ – 0.3V to VCC + 0.3V (7V Max)
Sense Amplifier Input Common Mode .......–0.3V to 36V
Operating Ambient Temperature Range
Commercial ............................................ 0°C to 70°C
Industrial ............................................ – 40°C to 85°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
Required Field 
