SKY81292-11-001数据手册Skyworks中文资料规格书

描述 Description

Please note: SKY81292-11-001 is being discontinued and is not recommended for new designs. Please note: this product is being discontinued and is not recommended for new designs.The SKY81292 is a high-efficiency, 1.8 A high-current boostconverter with a programmable constant current. The device isintended for LED photo flash applications in all single-cell Li-ionpowered portable products.The SKY81292 maintains the flash LED output current using a DCDCstep-up converter with a bypass function to maximizeefficiency when under all load conditions. For single flash LEDapplications, the flash current can be programmed up to 1.8 A.For dual flash LED applications, the flash current can beprogrammed up to 900 mA. This provides a direct flash LEDcathode connection to the ground plane that helps heatdissipation.The high frequency 2 MHz DC-DC boost switching frequencyallows the use of a small external inductor and output capacitor,which makes the SKY81292 ideally suited for small batterypoweredapplications. A start-up control circuit automaticallysenses the flash LED forward voltage at any programmed outputcurrent setting and determines the most efficient operation mode.An industry standard I2C digital interface is used to program theSKY81292 LED flash and movie modes. Device operations arefully configurable; movie and flash current level, current limits,and fault reporting. Also included is a separate flash enable inputto initiate the flash operation and a flash inhibit input to reduce theflash current to movie-mode levels during high battery demandconditions. An additional low-level programmable current sourceoutput is provided to drive an LED indicator lamp.The integrated thermal management system protects the device inthe event of an output short-circuit condition. An NTC thermistorfunction protects the external flash LEDs from thermal damage.Fault status may be read using the I2C interface after the system isalerted by an open drain fault flag. Built-in soft-start circuitryprevents excessive in-rush current during start-up. The shutdownfeature reduces quiescent current to less than 1.0 μA.The SKY81292 is provided in a small, 16-bump, 2 mm x 2 mmWafer Level Chip Scale Package (WLCSP).

特性 Features

• Input voltage range: 2.5 V to 5.5 V
• Supports single and dual flash LEDs
• Up to 1.8 A regulated output current
• Up to 90% efficiency
• Switching frequency: 2 MHz
• True load disconnect
• Soft-start and input current limit
• Separate flash enable
• Industry standard I2C programming:
• Flash and Movie mode current
• Battery current limit
• Input voltage monitor with programmable thresholds
• Programmable safety timer
• Fault readback