特性 Features

? Drive up to 1.5A flash current

? Programmable threshold low-voltage input

protection

? High efficiency converter (up to 90)

? Input voltage range: 2.7V to 5.5V

? 2MHz step-up converter

? Very small inductor: 1.0μH to 2.2μH

? Very small load capacitor: 4.7μF to 10μF

? ExpressWireTM digital control enables and

programs flash and movie current in 16 steps

? External resistor sets maximum flash current

? Integrated thermal regulation control

? 2mA LED shorting test current and 1.7V

forward voltage threshold

? LED open/short protection

? Over-voltage protection

? Cycle-by-cycle inductor current limit

? Programmable flash timeout protection

? 0.1μA shutdown current

? Pb-free Package: UDFN22-10L

? -40°C to +85°C Temperature Range

Applications

? Mobile Phones

? Smart Phones and PDAs

? Digital Still Cameras

Brief Description

KTD2694 is the ideal power solution for high-power flash

LEDs used with cell phone camera modules or digital still

cameras. It is a highly integrated step up DC-DC converter

with very high switching frequency, fixed at 2MHz,

providing a very small total solution for portable photo

flash. KTD2694 uses ExpressWire single-wire

programming for maximum flexibility. The maximum flashmode

LED current is set by an external resistor, and the

flash-mode and movie-mode currents can be programmed

in 16 steps by the ExpressWire interface at CTRL pin. An

AUX pin allows highest priority ON/OFF flash mode

control. KTD2694 internally monitors the input voltage,

disabling LED current when the supply drops below the

programmed threshold voltage.

The LED output sink can drive up to 1.5A continuous LED

current. Thermal regulation is integrated in flash mode to

limit the IC’s temperature and continuously provide the

maximum allowed output current.

Various protection features are built into KTD2694,

including cycle-by-cycle input current limit protection,

output over-voltage protection, LED fault (open or short)

protection, flash timeout protection and thermal shutdown

protection. The leakage current in shutdown mode is

0.1μA.

KTD2694 is available in a RoHS and Green compliant

10-lead 2mm x 2mm x 0.52mm UDFN package.