|Alguien dijo ...|
|La menor parte de lo que ignoramos, es mayor de todo cuanto sabemos.|
Platón(427 AC - 347 AC)
|LTC4076/77: Standalone 950mA Li-Ion Battery Chargers Automatically
Select Between USB and AC Adapter Inputs|
MILPITAS, CA – Linear Technology Corporation
introduces the LTC4076 and LTC4077 standalone dual-input linear battery chargers. These devices charge single-cell
Li-Ion batteries from wall adapter or USB power sources. The LTC4076 and LTC4077 use a
constant-current/constant-voltage algorithm for charging, with charge current programmable up to 950mA from a wall
adapter supply, or programmable up to 650mA from a USB supply while automatically sensing the presence of voltage at
each input. The LTC4076 features programmable C/x charge current termination, while the LTC4077 offers fixed C/10
The LTC4076 features a choice of fixed C or C/5 USB charge current for low-power USB operation (via
the HPWR pin) and the LTC4077 offers programmable C or C/x low-power USB charge current (via the HPWR pin).
Applications include PDAs, MP3 players, digital cameras, lightweight portable medical and test equipment and large
color screen cell phones.
The LTC4076 and LTC4077 feature final float voltage accuracy of ±0.6%
and are equipped with a patented thermal regulation scheme that maximizes the charging rate without the risk of
overheating. The devices are extremely flexible with the following features programmable via a single resistor: wall
adapter supply charge current, USB supply charge current and charge termination currents. As standalone chargers,
they also feature trickle charge for battery pre-conditioning, undervoltage lockout, automatic recharge, a charge
status indicator and “power present” status outputs to indicate the presence of wall adapter or USB power.
The LTC4076 and LTC4077 are offered in a low profile (0.75mm) 10-lead 3mm x 3mm DFN package. The
total solution footprint is less than 25mm2 since no external MOSFET, sense resistors or blocking diodes are
required. To preserve battery energy, the LTC4076 and LTC4077 draw <6µA from the battery terminal in standby and
<2µA in shutdown mode.
The LTC4076 and LTC4077 are rated for operation from -40°C to 85°C.
1,000-piece pricing begins at $1.88 each.
Summary of Features: LTC4076 & LTC4077
Charges Single Cell Li-Ion Batteries from Wall Adapter & USB Inputs
* Automatic Input Power Detection &
* Standalone Charger in Low-Profile (0.75mm) 3mm x 3mm DFN Package
Programmable Charge Current up to 950mA from Wall Adapter Input via Resistor
* Programmable USB Charge
Current up to 650mA via Resistor
* Programmable C/x Charge Current Termination(LTC4076)
Fixed C or C/5 USB Charge Current for Low-Power USB Operation (LTC4076)
* Fixed C/10 Charge Current
* Programmable C or C/x USB Charge Current for Low-Power USB Operation
* Thermal Regulation Maximizes Charge Rate without Risk of Overheating
MOSFET, Sense Resistor or Blocking Diode Required
Jueves, 01 Septiembre, 2005 - 09:57