MP3205 MPS | Alldatasheet

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Technical content

1.3MHz Fixed Frequency

5 White LED Driver

MP3205 Rev. 1.3 www.MonolithicPower.com 1 7/13/2005 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. The Future of Analog IC Technology TM TM

DESCRIPTION

The MP3205 is a step-up converter designed for driving up to 5 series white LEDs from a single cell Lithium Ion battery. The MP3205 uses current mode, fixed frequency architecture to regulate the LED current, which is measured through an external current sense resistor. Its low 104mV feedback voltage reduces power loss and improves efficiency. The MP3205 includes under-voltage lockout, current limiting and thermal overload protection preventing damage in the event of an output overload. The MP3205 is available in a small 5-pin TSOT23 package. EVALUATION BOARD REFERENCE Board Number Dimensions EV3205DJ-00A 1.9”X x 1.8”Y x 0.4”Z

FEATURES

  • On Board Power MOSFET
  • Drives up to 5 Series White LEDs
  • Up to 87% Efficiency
  • Over 1MHz Fixed Switching Frequency
  • Low 104mV Feedback Voltage
  • Soft-Start/PWM Dimming
  • UVLO, Thermal Shutdown
  • Internal Current Limit
  • Available in a TSOT23-5 Package

APPLICATIONS

  • Cell Phones
  • Handheld Computers and PDAs
  • Digital Still Cameras
  • Small LCD Displays Application “MPS” and “The Future of Analog IC Technology” are Trademarks of Monolithic Power Systems, Inc. TYPICAL APPLICATION MP3205 VIN 5V LED1 LED2 LED3 LED4 LED5EN MP3205-TAC-S01 CMDSH-3 FB 3 SWIN EN GND EFFICIENCY (%) 5 1 01 52 0 LED CURRENT (mA) MP3205-EC01 Efficiency vs LED Current

3 LEDs

4 LEDs

VIN=3.6V

5 LEDs

MP3205 – 1.3 MHz FIXED FREQUENCY 5 WHITE LED DRIVER MP3205 Rev. 1.3 www.MonolithicPower.com 2 7/13/2005 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. TM PACKAGE REFERENCE Part Number* Package Temperature MP3205DJ TSOT23-5 –40°C to +85°C * For Tape & Reel, add suffix –Z (eg. MP3205DJ–Z) For Lead Free, add suffix –LF (eg. MP3205DJ –LF–Z) ABSOLUTE MAXIMUM RATINGS (1) Recommended Operating Conditions (2) Thermal Resistance (3) θJA θJC Notes: 1) Exceeding these ratings may damage the device. 2) The device is not guaranteed to function outside of its operating conditions. 3) Measured on approximately 1” square of 1 oz copper.

ELECTRICAL CHARACTERISTICS

VIN = VEN = 5V, TA = +25°C, unless otherwise noted. Parameter Symbol Condition Min Typ Max Units Using Parameter Set Heading Operating Input Voltage V IN 2.5 6 V Supply Current (Shutdown) V EN = 0V 0.1 1 µA Supply Current (Quiescent) V FB = 0.15V 690 750 µA Switching Frequency f SW 1.0 1.3 1.5 MHz Maximum Duty Cycle V FB = 0V 85 92 % Undervoltage Lockout IN Under Voltage Lockout UVLO V IN Rising 2.25 2.45 V Under Voltage Lockout Hysteresis 92 mV Enable EN Threshold V EN Rising 1.0 1.35 1.6 V EN Threshold V EN Rising, VIN = 2.5V 0.8 V EN Hysteresis 90 mV EN Input Bias Current V EN = 0V, 5V 1 µA Feedback FB Voltage 94 104 114 mV FB Input Bias Current V FB = 0.1V –600 –300 nA Output Switch SW On-Resistance (4) R ON 0.5 Ω SW Current Limit Duty Cycle = 60% 350 mA Thermal Shutdown (4) 160 °C Note: 4) Guaranteed by design. SW GND FB IN EN MP3205-PD01_TSOT23 TOP VIEW

MP3205 – 1.3 MHz FIXED FREQUENCY 5 WHITE LED DRIVER MP3205 Rev. 1.3 www.MonolithicPower.com 3 7/13/2005 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. TM PIN FUNCTIONS Pin # Name Description 1 SW Power Switch Output. SW is the drain of the internal MOSFET switch. Connect the power inductor and output rectifier to SW. SW can swing between GND and 25V. 2 GND Ground. 3 FB Feedback Input. The MP3205 regulates the voltage across the current sense resistor between FB and GND. Connect a current sense resistor from the bottom of the LED string to GND. Connect the bottom of the LED string to FB. The regulation voltage is 104mV. 4 EN Regulator On/Off Control Input. A high input at EN turns on the converter, and a low input turns it off. When not used, connect EN to the input source for automatic startup. The EN pin cannot be left floating. 5 IN Input Supply Pin. Must be locally bypassed. OPERATION The MP3205 uses a constant frequency, peak current mode boost regulator architecture to regulate the series string of white LEDs. The operation of the MP3205 can be understood by referring to the block diagram of Figure 1. At the start of each oscillator cycle the FET is turned on through the control circuitry. To prevent sub- harmonic oscillations at duty cycles greater than 50 percent, a stabilizing ramp is added to the output of the current sense amplifier and the result is fed into the positive input of the PWM comparator. When this voltage equals the output voltage of the error amplifier the power FET is turned off. The voltage at the output of the error amplifier is an amplified version of the difference between the 104mV reference voltage and the feedback voltage. In this way the peak current level keeps the output in regulation. If the feedback voltage starts to drop, the output of the error amplifier increases. This results in more current to flow through the power FET, thus increasing the power delivered to the output. PWM COMPARATOR AMPLIFIER CONTROL LOGIC CURRENT SENSE AMPLIFIER SWM1 GND FB 1.3MHz OSC 104mV MP3205-F03-BD01 Figure 1—Functional Block Diagram

MP3205 – 1.3 MHz FIXED FREQUENCY 5 WHITE LED DRIVER NOTICE: The information in this document is subject to change wi thout notice. Please contact MPS for current specifications. Users should warrant and guarantee that th ird party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not assume any legal responsibility for any said applications. MP3205 Rev. 1.3 www.MonolithicPower.com 6 7/13/2005 MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2005 MPS. All Rights Reserved. TM OFF ON MP3205 VIN 2.5V to 6V LED1 LED2 LED3 MP3205_F09 CMDSH-3 IN EN GND FB 3 SW Figure 9—LED Driver with Overload Protection

PACKAGE INFORMATION

0.25 BSC . ±0.10 0.400 (2 p lcs) 10°TYP.

2.90 BSC

(5 P LCS ) 0.300( Min) LC TYP. 0.950 LC TYP. 0.950

2.80 BSC

1.60 BSC

0.500( Max) SEATING PLANE 0.87±0.03 0.00-0.10 1.00 Max. 0.127 TYP. (2 plcs) 10° TYP. Dimensions are in millimeters Note: 1.Dimensions and tolerances are as per ANSI Y14.5M, 1994. 2. Die is facing up for mold. Die is facing dow n for trim/form, ie. Reverse trim/form 3. Dimensions are exclusive of mold flash and gate burr. 4.The footlength measuring is based on the gauge plane method. 5. A ll s pec if ic ation c omply to Jedec Spec MO193 Is s ue C.