RT9300A RICHTEK | Alldatasheet

Document overview

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Technical content

Features

zzzzz Low 60/45mV Dropout at 20/15mA zzzzz 3% LED Current Matching zzzzz Simple LED Brightness Control zzzzz 2.5V to 5.5V Supply Voltage Range zzzzz Thermal Shutdown Protection zzzzz RoHS Compliant and 100% Lead (Pb)-Free

Applications

z Next-Generation Wireless Handsets z PDAs, Palmtops, and Handy Terminals z Digital Cameras, Camcorders z Battery-Powered Equipment Tiny Package, Low Dropout Current Source

Ordering Information

The RT9300A/B low-dropout bias supply for white LEDs is a high-performance alternative to the simple ballast resistors used in conventional white LED designs. The RT9300A/B uses a internal resistor to set the bias current for four LEDs, which are matched to 3%. The RT9300A/B's advantages over ballast resistors include much lower bias variation with supply voltage variation, significantly lower dropout voltage, and in some applications, significantly improved efficiency. The RT9300A/B requires a 60/45mV dropout at a 20/15mA load on each output to match the LED brightness. (TOP VIEW) SOT-23-6 Typical Application Circuit LED4GNDEN LED3LED2LED1 Note : There is no pin1 indicator on top mark for SOT-23-6 type, and pin 1 will be lower left pin when reading top mark from left to right. Pin Configurations Figure 1. Application circuit for backlight. ments of IPC/JEDEC J-STD-020. \`Suitable for use in SnPb or Pb-free soldering processes. \`100%matte tin (Sn) plating.

1 EN Chip Enable (Active High).

2 GND Ground

3 LED4

LED4 is High Impedance when EN is Low.

4 LED3

LED3 is High Impedance when EN is Low.

5 LED2

LED2 is High Impedance when EN is Low.

6 LED1

LED1 is High Impedance when EN is Low. Figure 2. Application circuit for keypad.

DS9300A/B-02 March 2007 www.richtek.com Absolute Maximum Ratings (Note 1) z Power Dissipation, PD @ TA = 25°C z Package Thermal Resistance (Note 3) z ESD Susceptibility (Note 2)

Electrical Characteristics

Parameter Symbol Test Condition Min Typ Max Units System Supply Input Operation Voltage Range V EN 2.5 -- 5.5 V Under Voltage Lock Out V(UVLO) -- 2.1 -- V UVLO Hysteresis -- 100 -- mV RT9300A -- 20 -- LED Maximum Sink Current RT9300B -- 15 -- mA Quiescent Current I EN I OUT = 0, -- -- 600 uA ILED = 20mA -- 60 -- LED Dropout Voltage ILED = 15mA -- 45 -- mV LED Current Deviation Matching -- -- 3 % Digital Input High Level V IH V EN > VIH for enable 2.5 -- -- V Digital Input Low Level V IL V EN < VIL for disable -- -- 0.7 V OTP -- 170 -- C OTP Hysteresis -- 10 -- C Shut Down Current I EN V EN = 0.4V -- -- 1 uA RT9300A 18 20 22 Initial Current RT9300B 13.5 15 16.5 mA (VIN = 3.7V, TA = 25°C, Unless Otherwise specification)

DS9300A/B-02 March 2007www.richtek.com Note 1. Stresses listed as the above “Absolute Maximum Ratings” may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. Note 3. θ JA is measured in the natural convection at T A = 25 °C on a low effective thermal conductivity test board (Single Layer, 1S) of JE DEC 51-3 therm\\al measurement standard. Note 4. Floating connection or pull low to disable this function.

DS9300A/B-02 March 2007 www.richtek.com LED Current vs. Input Voltage 22 . 533 . 544 . 55 Input Voltage (V) LED Current (mA) Typical Operating Characteristics Output Current vs. VEN VEN (V) Output Current (mA) IEN Current vs. VEN Supply Voltage 100 150 200 250 300 350 400 1.5 2 2.5 3 3.5 4 4.5 VEN Supply Voltage (V) IEN Current (uA) Dimming Operation Time (50 μs/Div) (2V/Div) (10mA/Div) VEN = 0V to 3V EN Pin Shutdown Response Time (50 μs/Div) EN Pin Voltage LED Current (2V/Div) (10mA/Div) (°C) LED 1 LED 2 LED 3 LED 4 VIN = 3.5V LED Current EN Pin Voltage LED Current vs. Temperature 15.1 15.2 15.3 15.4 15.5 - 4 0 - 3 0 - 2 0 - 1 00 1 02 03 04 05 06 07 08 09 0 Temperature LED Current (mA)

DS9300A/B-02 March 2007www.richtek.com VIN = 3.2V to 3.7V VIN Transient Response Time (100 μs/Div) Input Voltage (1V/Div) (25mA/Div) LED Current

DS9300A/B-02 March 2007 www.richtek.com Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Richtek Technology Corporation Taipei Office (Marketing) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com Outline Dimension A e b B D C H L SOT-23-6 Surface Mount Package Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 0.889 1.295 0.031 0.051 A1 0.000 0.152 0.000 0.006 B 1.397 1.803 0.055 0.071 b 0.250 0.560 0.010 0.022 C 2.591 2.997 0.102 0.118 D 2.692 3.099 0.106 0.122 e 0.838 1.041 0.033 0.041 H 0.080 0.254 0.003 0.010 L 0.300 0.610 0.012 0.024