PAM2804 1A STEP-DOWN CONSTANT CURRENT, HIGH EFFICIENCY LED DRIVER Description Pin Assignments The PAM2804 is a step-down constant current LED driver. When the Top View input voltage is down to lower than LED forward voltage, then TSOT25 PAM2804 goes into LDO mode. The PAM2804 supports a range of input voltages from 2.5V to 6.0V, allowing the use of a single Li+/Li-polymer cell, 3AA or 4AA cell, USB, and other standard power sources. The FB voltage is only 0.1V to achieve high efficiency. PAM2804 employs internal power switch and synchronous rectifier to minimize external part count and realize high efficiency. Applications During shutdown, the input is disconnected from the output and the 3AA or 4AA Batteries Powered Flashlight shutdown current is less than 1A. Other key features include 1 Cell Li-Ion Battery Powered Flashlight undervoltage lockout to prevent deep battery discharge of the Li+ battery. Features Efficiency up to 93% 180A(typ) Quiescent Current Output Current: Up to 1A Internal Synchronous Rectifier 1.5MHz Switching Frequency Soft-Start Undervoltage Lockout Short LED Protection Open LED Protection Thermal Shutdown 5-Pin Small TSOT25 Packages Pb-Free Package Typical Applications Circuit I = 0.1/R LED S 1 of 10 PAM2804 September 2015 Diodes Incorporated www.diodes.com Document number: DS36403 Rev. 3 - 2 PAM2804 Pin Description Pin Pin Function Number Name Enable control input. Force this pin voltage above 1.5V, enables the chip, EN 1 and below 0.3V shuts down the device. 2 GND Ground 3 SW The drains of the internal main and synchronous power MOSFET. 4 VIN Chip main power supply pin. 5 FB Feedback voltage to internal error amplifier, the threshold voltage is 0.1V. Block Diagram Absolute Maximum Ratings ( T = +25C, unless otherwise specified.) A These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect device reliability. All voltages are with respect to ground. Parameter Rating Unit Input Pin Voltage -0.3 to +6.5 EN, FB Pin Voltage -0.3 to V IN V SW Pin Voltage -0.3 to (V +0.3) IN Junction Temperature Range 150 Storage Temperature Range -65 to +150 C Soldering Temperature +300, 5sec 2 of 10 PAM2804 September 2015 Diodes Incorporated www.diodes.com Document number: DS36403 Rev. 3 - 2