Electronic Components Datasheet Search |
|
LTC4008EGN-1 Datasheet(PDF) 8 Page - Linear Technology |
|
LTC4008EGN-1 Datasheet(HTML) 8 Page - Linear Technology |
8 / 24 page 8 LTC4008 4008fa TEST CIRCUIT – + – + – + EA LT1055 LTC4008 VREF BAT 7 13 12 CSP 11 ITH 0.6V 4008 TC 9 BATMON 90.325k 9.675k VFB OVERVIEW The LTC4008 is a synchronous current mode PWM step down (buck) switcher battery charger controller. The charge current is programmed by the combination of a program resistor (RPROG) from the PROG pin to ground and a sense resistor (RSENSE) between the CSP and BAT pins. The final float voltage is programmed with an exter- nal resistor divider and the internal 1.19V reference volt- age. Charging begins when the potential at the DCIN pin rises above the voltage at BAT (and the UVLO voltage) and the ACP/SHDN pin is high. An external thermistor network is sampled at regular intervals. If the thermistor value exceeds design limits, charging is suspended and the FAULT pin is set low. If the thermistor value returns to an acceptable value, charging resumes and the FAULT pin is set high. An external resistor on the RT pin sets the sampling interval for the thermistor. OPERATIO As the battery approaches the final float voltage, the charge current will begin to decrease. When the current drops to 10% of the full-scale charge current, an internal C/10 comparator will indicate this condition by latching the FLAG pin low. If this condition is caused by an input current limit condition, described below, then the FLAG indicator will be inhibited. When the input voltage is not present, the charger goes into a sleep mode, dropping battery current drain to 15 µA. This greatly reduces the current drain on the battery and increases the standby time. The charger can be inhibited at any time by forcing the ACP/SHDN pin to a low voltage. Forcing ACP/SHDN low, or removing the voltage from DCIN, will also clear the FLAG pin if it is low. Table 1. Truth Table For Indicator States MODE DCIN ACP/SHDN FLAG** FAULT** ICL Shutdown by low adapter voltage (Disabled on LTC4008-1) <BAT LOW HIGH HIGH LOW Normal charging >BAT HIGH HIGH HIGH* HIGH* Input current limited charging >BAT HIGH HIGH* HIGH* LOW Charger shut down due to thermistor out of range >BAT HIGH X LOW HIGH Shut down by ACP/SHDN pin (USER) X Forced LOW HIGH HIGH LOW Shut down by undervoltage lockout >BAT + <UVL HIGH HIGH HIGH* LOW *Most probable condition, **Open-drain output, HIGH = Open with pull-up, X = Don’t care |
Similar Part No. - LTC4008EGN-1 |
|
Similar Description - LTC4008EGN-1 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |