32V (40V max) Synchronous Monolithic 1-Cell Li-Ion/Polymer Battery Charger Delivers up to 4A Charge Current

News Release ⎜ www.linear.com
32V (40V max) Synchronous Monolithic 1-Cell Li-Ion/Polymer
Battery Charger Delivers up to 4A Charge Current
MILPITAS, CA – August 12, 2010 – Linear Technology Corporation introduces the
LT3651-4.2, a highly efficient, 4A monolithic synchronous buck battery charger for 1-cell
Li-Ion/Polymer batteries. The LT3651-4.2 accepts inputs up to 32V with a 40V absolute
maximum rating for added system margin. Charge current is programmable and dynamically
adjustable up to 4A; fully integrated synchronous power devices minimize power dissipation and
save board space. User-selectable timer or C/10 termination requires no external microcontroller
and simplifies the design. The LT3651-4.2 does not require external high-precision resistors to
set the float voltage, further saving cost and space. Applications include industrial handheld
instruments, 12V to 24V automotive and heavy equipment applications, desktop cradle chargers
and notebook or tablet computers.
The programmable switching frequency (200kHz to 1MHz) of the LT3651-4.2 enables
the designer to balance solution size, power loss, and filtering needs. Synchronous operation
enables charging efficiencies as high as 90%. Final float voltage accuracy is ±0.5%, charge
current accuracy is ±7.5% and C/10 detection accuracy is ±4%. Once charging is terminated, the
LT3651-4.2 automatically enters a low current standby mode which reduces the input supply
current to 80uA. In shutdown, the input bias current is reduced to 15uA. The LT3651-4.2
maximizes battery life during all non-charging periods by draining <1uA from the battery. For
safety and autonomous charge control, the device includes automatic restart and preconditioning,
a thermistor input for temperature-qualified charging, programmable input current limit, bad
battery detection and binary coded status output pins.
The LT3651-4.2 is available in a low-profile (0.75mm) 36-pin 5mm x 6mm QFN
package, and is offered in both E and I grade versions, guaranteed from –40°C to 125°C. Pricing
starts at $4.13 and $4.75 each, respectively, in 1,000-piece quantities. Two-cell 8.2V and 8.4V
options and a one-cell 4.1V version are planned for release within the next 2-3 months.
For more information, visit www.linear.com/3651.
32V (40V max) Synchronous Monolithic 1-Cell Li-Ion/Polymer
Battery Charger Delivers up to 4A Charge Current
page 2
Photo Caption: 32V, 4A Synchronous Monolithic 1-Cell Li Charger
Summary of Features: LT3651-4.2
Wide Input Voltage Range: 4.75V to 32V (40V Absolute Maximum Rated)
Programmable Charge Current up to 4A
1 Cell Li-Ion/Polymer Charge Capability, 4.2V Charge Voltage
Synchronous Rectification Increases Charging Efficiency
User-Selectable Termination: C/10 or Programmable Termination Timer
Programmable Switching Frequency (200kHz to 1MHz)
Programmable Input Current Limit
±0.5% Charge Voltage Accuracy
±7.5% Charge Current Accuracy
±4% C/10 Detection Accuracy
NTC Resistor Temperature Monitor
Automatic Recharge
Automatic Preconditioning
Binary Coded Open-Collector Charge Status Pins
Bad Battery Detection with Auto-Reset
Low-Profile (0.75mm) 5mm x 6mm QFN-36 Package
About Linear Technology
Linear Technology Corporation, a manufacturer of high performance linear integrated circuits,
was founded in 1981, became a public company in 1986 and joined the S&P 500 index of major
public companies in 2000. Linear Technology products include high performance amplifiers,
comparators, voltage references, monolithic filters, linear regulators, DC-DC converters, battery
chargers, data converters, communications interface circuits, RF signal conditioning circuits,
uModule™ products, and many other analog functions. Applications for Linear Technology’s
high performance circuits include telecommunications, cellular telephones, networking products
such as optical switches, notebook and desktop computers, computer peripherals,
video/multimedia, industrial instrumentation, security monitoring devices, high-end consumer
products such as digital cameras and MP3 players, complex medical devices, automotive
electronics, factory automation, process control, and military and space systems.
LT, LTC, LTM, uModule and
are registered trademarks of Linear Technology Corp. All other trademarks are the
property of their respective owners.
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Doug Dickinson, Media Relations Manager
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