LP78090 Datasheet, PDF (1/10 Pages) Lowpower Semiconductor inc – Programmable Charge Current Up to 1000mA

Preliminary Datasheet
Smart Charger With Power Path
LP78090
General Description
The LP78090 is a monolithic linear battery charger
whit smart power path switch for single-cell Li-ion
batteries in a wide range of tablet and other portable
devices. It integrates a linear regulated voltage for
power the system and charging the battery at the
same time. This device supports both USB and high
power DC adapter input. Its charger is a complete
constant-current constant voltage linear charger with
adjustable charge current up to 1000mA. No external
sense resistor is needed, and no blocking diode is
required due to the internal MOSFET architecture.
Thermal feedback regulates the charge current to limit
the die temperature during high power operation or
high ambient temperature. The charge voltage is fixed
at 4.2V, and the charge current can be ISET rammed
externally with a single resistor. The charger
automatically terminates the charge cycle when the
charge current drops to 1/10th the ISET rammed value
after the final float voltage is reached. When the input
supply (wall adapter or USB supply) is removed, the
LP78090 automatically enters a low current state,
dropping the battery drain current to less than 15µA.
When connecting a high power DC adapter, the smart
power path management allows LP78090 power the
system with VIN voltage or BAT voltage by switching
the voltage level on SC pin and charge the battery
simultaneously. This allows immediate system
operation even under moving away or deeply
discharged battery. When the input current limit is
reached, the voltage applied on the SYS pin would pull
down to the battery voltage making the charge current
decrease. If the current out of SYS pin is more than
charge current plus 1200mA, LP78090 with turn power
adapter and battery support the system load together.
The LP78090 provides an internal path from battery to
system in the event the input is removed.
Other features include charge current monitor, under
voltage lockout, automatic recharge and a status pin to
indicate charge termination and the presence of an
input voltage.
Order Information
LP78090 □ □ □
F: Pb-Free
Package Type
QV:TDFN-10
Features
 Programmable Charge Current Up to 1000mA
 Smart Power Path Management
 No MOSFET, Sense Resistor or Blocking Diode
Required
 Constant-Current/Constant-Voltage Operation
with Thermal Regulation to Maximize Charge
Rate Without Risk of Overheating
 Charges Single Cell Li-Ion Batteries Directly from
USB Port
 15µA Leakage Current in Shutdown
 Charging Operation and Charge Complete
Indicator
 Thermal Limiting Regulation on Chip
 Internal Soft Start Function
 Built-in Short-Circuit Protection
 Consumption Available in TDFN-10 Package
 RoHS Compliant and 100% Lead (Pb)-Free
Marking Information
Device
Marking Package Shipping
LP78090QVF
QV:TDFN10 3K/REEL
Applications
 MID/Pad
 Automobile Data Recorder or Event Data
Recorder
 Power Bank
 Smart Phone
 Bluetooth Applications
LP78090 – 00 Version 1.0 Feb.-2014 Email: [e-mail] www.lowpowersemi.com Page 1 of 10