DESCRIPTION
The KB3511 is a high efficiency monolithic synchronous buck regulator using a constant frequency, current mode architecture. The device is available in an adjustable version and fixed output voltages of 1.8V and 3.3V. Supply current during operation is only 25μA and drops to 1μA in shutdown. The 2.5V to 6.5V input voltage range makes the KB3511 ideally suited for single Li-Ion battery-powered applications. 100% duty cycle provides low dropout operation, extending battery life in portable systems.
Automatic Trickle Mode operation increases efficiency at light loads, further extending battery life. Switching frequency is internally set at 2.2MHz, allowing the use of small surface mount inductors and capacitors.
The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. The KB3511 is available in a low profile (0.8mm) DFN33-10 package.

FEATURES
*Up to 97% Efficiency
*25uA No Load Current Per Channel
*800mA Output Current
*2.5V to 6.5V Input Voltage Range
*2.2MHz Constant Frequency Operation
*No Schottky Diode Required
*Low Dropout Operation: 100% Duty Cycle
*0.6V Reference Allows Low Output Voltages
*Shutdown Mode Draws 1μA Supply Current
*Current Mode Operation for Excellent Line and Load Transient Response
*Overtemperature Protected
*DFN33-10 Package

APPLICATIONS
*Cellular Telephones
*Personal Information Appliances
*Wireless and DSL Modems
*Digital Still Cameras
*MP3 Players
*Portable Instruments

KB3511A, KB3511B  

KB3511 - High Efficiency, Low Noise, Fast Transient Dual 800mA, 2.2MHz Step-Down DC/DC Converter

DESCRIPTION
The KB3302 is a high-frequency current-mode step-up switching regulator with an integrated 2A power transistor. Its high switching frequency (programmable up to 2MHz) allows the use of tiny surface-mount external passive components. Programmable soft-start eliminates high inrush current during start-up. The internal switch is rated at 32V making the converter suitable for high voltage applications such as Boost, SEPIC and Flyback.
The operating frequency of the KB3302 can be set with an external resistor. The ability to set the operating frequency gives the KB3302 design flexibilities. A dedicated COMP pin allows optimization of the loop response. The KB3302 is available in thermally enhanced 8-Pin MSOP packages.

FEATURES
*Up to 95% Efficiency
*TDB uA No Load Current
*1000mA Output Current
*1.5V to 16V Input Voltage Range
*Programmable switching frequency up to 2MHz
*Output voltage up to 32V
*Constant switching frequency current-mode control
*1.23V Reference Allows Low Output Voltages
*Shutdown Mode Draws

KB3302DD, KB3302EMS  

KB3302 - 2Amp, 2MHz Step-up Switching regulator with Soft-Start

DESCRIPTION
The KB 4540 is a complete constant-current/constantvoltage linear charger for single cell lithium-ion batteries.
Its ThinSOT package and low external component count make the KB4540 ideally suited for portable applications.
Furthermore, the KB4540 is specifically designed to work within USB power specifications.
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 programmed externally with
a single resistor.
The KB4540 automatically terminates the charge cycle when the charge current drops to 1/10th
the programmed value after the final float voltage is reached.
When the input supply (wall adapter or USB supply) is removed, the KB4540 automatically enters a low current state, dropping the battery drain current to less than 2μA.
The KB4540 can be put into shutdown mode, reducing the supply current to 25μA.
Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage.

FEATURES
* Programmable Charge Current Up to 800mA
* No MOSFET, Sense Resistor or Blocking Diode Required
* Complete Linear Charger in SOT Package for Single Cell Lithium-Ion Batteries
* 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
* Preset 4.2V Charge Voltage with ±1% Accuracy
* Charge Current Monitor Output for Gas Gauging
* Automatic Recharge
* Charge Status Output Pin
* C/10 Charge Termination
* 25μA Supply Current in Shutdown
* 2.9V Trickle Charge Threshold (KB4540)
* Available Without Trickle Charge (KB4540X)
* Soft-Start Limits Inrush Current
* Available in SOT23-5 Package  

KB4540 - Li-Ion Battery Charger

DESCRIPTION
The KB4312 step-up converter drives white LEDs with a constant current to provide backlight in cell phones, PDAs, and other hand-held devices.
It features allowing series connection of the white LEDs so that the LED currents are identical for uniform brightness.
An enable input can be pulsed repeatedly to adjust LED’s brightness.
The fast 1.2MHz current-mode PWM control allows for smaller capacitor and inductor.
Fault condition protection uses cycle-by-cycle current limiting to sense maximum inductor current, thermal protection and over-voltage protection.
Also included soft-start eliminates inrush current during start-up.
The 0.24V low reference voltage minimized the power loss across the current-setting resistor.

FEATURES
* Operating Voltage:2.5V~6.5V
* High Operating Frequency: 1.2MHz
* High Efficiency: Up to 92%
* High Output Voltage: Up to 28V(max)
* Shutdown Current <1uA
* 18V Output Over-voltage protection (ADJ)
* Digital Dimming Control.
* Built-in Cycle-by Cycle Current-limiting.
* Built-in Soft-Start Function.
* 0.24V Low Reference Voltage(+/-5%)
* Tiny SOT23 Package

APPLICATIONS
* LED Module
* LED Backlight for LCD Display (1" ~6.5" )
* Constant Current Source

 

KB4312 - Tiny Package, High Performance, Constant Current Switching Regulator for White LED

DESCRIPTION
 The KB1365, step-down constant-current high-brightness LED (HB LED) drivers provide a cost-effective solution for automotive interior/exterior lighting, architectural and ambient lighting, LED bulbs such as MR16 and other LED illumination applications.
The KB1365 operate from a 5.5v to 40V input voltage range and feature a 5V/10mA on-board regulator.
A high-side current-sense resistor adjusts the output current and a dedicated PWM input (DIM) enables a wide range of pulsed dimming.
The KB1365 i well suited for applications requiring a wide input voltage range.
The high-side current-sensing and an integrated current-setting circuitry minimize the number of external components while delivteretic coltrol algorithm ensures excellent input-supply rejection and fast response during load transients and PWM dimming.
The KB1365 featurds a 20% inductor current ripple.
These devices operate up to 2MHz switching frequency, thus allowing for small component size.

FEATURES
* 5.5V to 40V Input Voltage Range
* High-Side Current Sense
* 20kHz Maximum Dimming Frequency
* Hysteretic Contorl: No Compensation
* 200m V Low Reference Voltage(5%)
* Dedicated Dimming Control Input
* Up to 2MHz Switching Frequency
* Adjustable Constant LED Current
* Up to 5 A Constant Current Output
* 5V, 10mA On-Board Regulator
* -40˚C to +125˚C Operating Temperature Range
* SOT23-6 package

APPLICATIONS
* MR16 and Other LED bulbs
* Power Led driver
* Constant Current Source

KB1365GRE

 

KB1365 - 2MHz High-Brightness LED Drivers with High-Side Current Sense and 5000:1 Dimming