SSL3250A_0912 Datasheet, PDF (1/26 Pages) NXP Semiconductors – Photo flash dual LED driver

SSL3250A
Photo flash dual LED driver
Rev. 05 — 16 December 2009
Product data sheet
1. General description
The SSL3250A is a photo flash LED driver designed for battery operated mobile devices
such as mobile phones and PDAs. The boost converter delivers high performance and
drives a single or dual, high brightness LED at up to 500 mA with over 85 % efficiency.
The driver can be programmed to operate in Flash, Torch or Indicator / Video-on mode.
The small silicon size and the high internal switching frequency of 1.2 MHz minimize the
SSL3250A footprint making it very suitable for mobile phones where space is limited, and
only requiring four external components. Driving a high power flash LED within its safe
operating limits was a concern when the SSL3250A was designed, so a time-out function
can be programmed via the I²C interface, which will prevent overstressing the LED. Due
to the specific requirements of a mobile phone, the flash current can be rapidly lowered
during RF transmit by using optional external setting resistors.
2. Features
„ High power single, or dual, LED output driving up to 500 mA flash current
„ Separate indicator LED output of 2.5 mA to 20 mA
„ Output voltage of up to 9.5 V
„ Wide input voltage range of 2.7 V to 5.5 V
„ High efficiency, over 85 % at optimum output current
„ Switching frequency of 1.2 MHz
„ Flash, Torch, and Indicator mode supported
„ Internally timed flash operation up to 820 ms
„ I²C-bus, programmable up to 400 kHz
„ Strobe signal to avoid I²C latency for flash
„ Discrete enable signals for stand-alone operation
„ Optional resistor configurable output currents
„ Fast response to accommodate external TxMasking functionality
„ Soft start in Torch and Flash modes to avoid battery overloading
„ Integrated protection circuits for enhanced system reliability
‹ Internal time-out function
‹ OverTemperature Protection (OTP)
‹ UnderVoltage LockOut (UVLO)
‹ OverVoltage Protection (OVP)
‹ Output current protection
‹ Interrupt signaling to system controller
„ Low device shut-down current, less than 1 μA
„ SOT758-3, thermally enhanced 16 terminal HVQFN package