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YB1303
Low Dropout LED Driver
Description
The YB1303 provides a simple solution for driving three channels of any color LEDs with current matching ability. The ultra low dropout LED driver features higher peak efficiency and very low shutdown current. The LED current can be adjusted by an external resistor or the control voltage. The YB1303 can work independently or combine with any boost converters which need to have current matching function for LED drivers. The YB1303 is available in 6-pin tiny SC70-6 package.
Features
LED Drivers for Parallel Connected
LEDs Only One External Resistor is Needed PWM and Analog Brightness Control No EMI and Switching Noise Power Saving Shutdown Mode (<0.1μA) Small Footprint SC70-6 Package
Applications
LCD Display Modules Keyboard Backlight PDA, DSC, MP3 players LED Displays Handheld Computers Cell Phones
Typical Application Circuit
Figure 1: Typical Application Circuit
YB1303 Rev.1.0
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YB1303
Low Dropout LED Driver
Pin Configuration
CTR LED2 LED1
1 2 3
SC70-6
6 5 4
EN LED3 GND
Figure 2: Pin Configuration
Pin Assignment &Description
Table 1
Pin 1 2 3 4 5 6
Name CTR LED2 LED1 GND LED3 EN
Description Connect this pin with a resistor to set the LED current. Connect this pin to LED cathode. Connect this pin to LED cathode. Ground pin. Connect this pin to LED cathode. Connect this pin to logic high to enable this chip, logic low to disable this chip.
Ordering Information
Table 2
Order Number YB1303SC76A
Package Type SC70-6
Supplied As 3000 Units Tape & Reel
Package Marking Please contact sales representative
YB1303 Rev.1.0
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YB1303
Low Dropout LED Driver
Absolute Maximum Ratings
LED1, LED2, LED3 to GND ........ -0.3V to 6V EN to GND.................................. -0.3V to 6V CTR to GND ............................... -0.3V to 3V Power Dissipation by SC70-6 TA=85℃ ........133mW Junction Temperature Range...............150℃ Storage Temperature Range .....-55℃ to 150℃ Lead Temperature................................250℃ ESD HBM .......................................... 1.5KV ESD CDM ...........................................750V
Recommended Operating Conditions
LED Cathode Voltage ................. 0.3V to1V Operating Temperature.........-40℃ to 85℃
Electrical Characteristics
Table 3 (VIN=3.3 to 5.5V, VEN=3V, TA=25°C, unless otherwise noted. VF is LED forward voltage.) Description LED Cathode Voltage Output Current Multiplication Factor Shutdown Current LED Current LED to LED Current Matching Efficiency SHDN Logic Low Level SHDN Logic High Level η VIL VIH VIN =3.3V, (VIN – VCATHODE) / VIN ILED < 1μA ISET = 100μA 3 ISD ILED Symbol VCATHODE ISET = 100μA, VLED = 300mV VEN = 0V ISET = 100μA -3 90 0.5 Test Conditions MIN 0.3 140 TYP 0.5 200 0.1 20 +3 MAX 1 260 1 μA mA % % V V Units V
YB1303 Rev.1.0
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YB1303
Low Dropout LED Driver
Typical Performance Characteristics
VIN=3.3 to 5.5V, VEN=3V, TA=25°C, unless otherwise noted. VF is LED forward voltage.
Iset vs. Control Voltage
(RSET=17.4k, Vcathode=0.3V) 160 140 120
22 20 18
LED Current vs. LED Cathode Voltage
(Vcontrol=3V, VEN=3V)
Rset=17.4k Iset=100uA
LED Current (mA)
16 14 12 10 8 6 4 2 0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.20
100 Iset (uA) 80 60 40 20 0 0.0 0.5 1.0 1.5 2.0 Vcontrol (V) 2.5 3.0 3.5 4.0
Cathode Voltage (V)
LED Current vs. Enable Voltage
(Vcontrol=3V, Vcathode=0.3V, Rset=17.4k) 22 20 18 16 LED Current (mA)
LED Current (mA) 45 40 35 30 25 20 15 10 5 0
LED Current vs. Rset
(VEN=3V, Vcontrol=3V)
14 12 10 8 6 4 2 0 0 1 2 3 VEN Voltage (V) 4 5 6
Vcathode=0.3 Vcathode=0.5 Vcathode=1
0
10
20
30
40 Rset (kOhms)
50
60
70
80
Control Voltage Transient Response
Enable Voltage Transient Response
YB1303 Rev.1.0
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YB1303
Low Dropout LED Driver
Application Information
Analog Dimming Control Table
Table 4 VEN=3V, VCONTROL=3V
voltage. The lower the VLED voltage, the higher the system efficiency. The system efficiency can be calculated as follows: Efficiency = (VIN-VCATHODE) / VIN Thermal Considerations At any given ambient temperature, the maximum package power dissipation can be determined by the following equation: PD(MAX) = [TJ(MAX)-TA] / θJA Constraints for the YB1303 are maximum junction temperature TJ(MAX)=125 ℃ , and package thermal resistance, θJA=300℃/W. The maximum total LED current for YB1303 depends on package power dissipation and the LED cathode voltage at TJ(MAX). At 85℃, PD(MAX)=133mW. At TA = 25℃, PD(MAX)=333mW. The maximum current is calculated by the following equation: ILED < (PD(MAX) / VLED(MAX)) For example, if ILED = 60mA, and TA = 85℃, VLED(MAX) = 2.2V. If the ambient temperature were to increase, the internal die temperature would increase, and the device would be damaged.
ILED (mA) 5 10 15 20 25
RSET (kΩ) 75 34 24 17.4 13
Table 5 VEN=3V, RSET=17.4k
ILED (mA) 5 10 15 20 25
VCONTROL (V) 1.5 2.1 2.5 3 3.6
Setting the LED Current The LED .