LT1239

Input 1 Voltage ...................................................... ±30V
Input 2 Voltage ............................................. 30V, 0.6V
Output 1 Voltage ........................................... 30V, 0.6V
Output 2 Voltage ............................................. 6V, 0.6V
Adjust Pin Current .................................................. 10mA
SHDN1, SHDN2 (Note 2)
Input Voltage .................................................. 6V, 0.6V
Input Current ........................................................ 5mA
IMON1 Voltage
(Note 3) .......................... (VIN1  30V) < IMON1 < VIN1
IMON2 Voltage
(Note 4) .......................... (VIN2  30V) < IMON2 < VIN2
E/A Output Voltage (Note 5) .... 0.6V < VE/A(OUT) < VIN2
E/A Input Voltage (Note 5) ..........  0.6V < VE/A(IN) < VIN2
5V Input Voltage ............................................. 6V, 0.6V
Operating Temperature Range ......................... 0 to 70°C
Junction Temperature Range ............................. (Note 6)
Storage Temperature Range .................  65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C


Description

The LT®1239 is a micropower backup battery management system for portable computers and instrumentation. LT1239 contains two regulators for regulating the battery voltage and memory voltage and a comparator for switching between main power and backup power. The first regulator provides a constant voltage charge for the backup batteries and is adjustable from 3.75V up to 20V. An equalization amplifier combined with the first regulator provides precision charge equalization for a 2-cell lithium-ion system. 

A second regulator with 4.85V output provides a regulated backup battery voltage to the memory when main power is lost. The second regulator also isolates the backup battery from the main 5V supply during normal operation when the memory is being powered by the 5V supply. A comparator is included which provides automatic switchover from main 5V power to backup power ensuring uninterrupted power for memory and power monitor-If you want to know more about the LT1239, please pay more attention to our website.