View KAB3405T_4685304.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

SEMICONDUCTOR
TECHNICAL DATA
Step Up Type DC/DC Converter for White LED
KAB3405T is a high efficient Step-Up Type DC/DC Converter specially designed for constant current drive of White LED. This IC can drive 2-10 white LEDs connected series using a Li-ion Battery. This IC contains N-ch MOS-FET Transistor for Coil-Switching, and LED Current (IF) is set with an external resistor.
G A F
KAB3405T
BICD LINEAR INTEGRATED CIRCUIT
E K B K
1
6
2
5
DIM A B C D E
F G H I J K L
D
Features
Variable LED Current IF is set with a external resistor : 20 mA (Typ.) @ RSENS = 15
C
3
4
MILLIMETERS _ 2.9 + 0.2 1.6+0.2/-0.1 _ 0.70 + 0.05 _ 0.4 + 0.1 2.8+0.2/-0.3 _ 1.9 + 0.2
0.95 _ 0.16 + 0.05 0.00-0.10 0.25+0.25/-0.15 0.60 0.55
Built in output over voltage protect circuit. Switching Frequency : 1.0 MHz (Typ.)
J
Applications
Back light white LEDs in LCD of PDA, Cellular Phone Handy Terminal Equipment.
Basic Application Circuit
2007. 4. 2
Revision No : 0
I
Output Over Voltage Shutdown
L
High Efficiency
G
H J
TS6
1/7
KAB3405T
Block Diagram
Pin Function
Pin No. 1 2 3 4 5 6 Symbol SHDN OVD VIN SW GND FB Function Description Voltage-Input Terminal for IC-Enable / Disable LED-IF. IF adjustment with PWM input signal is also available. Over Voltage Detection Terminal. IC Switching Operation is disabled with detection over voltage. If the voltage returns to detection level or less, Operation is enabled again. Supply Voltage Input Terminal. ( 2.8V to 5.5V) Switch Terminal for DC/DC Converter. Nch MOSFET Built-In. Ground Terminal. LED IF Setting Resister Connecting Terminal.
2007. 4. 2
Revision No : 0
2/7
KAB3405T
AUTE MAXIMUM RATINGS (Ta = 25 C if without notice)
Characteristics Power Supply Voltage Input Voltage Switching Terminal Voltage Switching Terminal Current Power Dissipation Symbol VIN VIN(SHDN) VO (SW) IO (SW) PD 0.47(on PCB)Caution 2 300(Device) Thermal Resistance Operation Temperature Range Storage Temperature Range Maximum Junction Temperature Rth(j-a) 260(on PCB) Topr Tstg Tj -40 to +85 -55 to +150 150 /W Ratings -0.3 to +6.0 -0.3 to +VIN + 0.3 -0.3 to 40 1500 0.41 (Device) W Unit V V V mA
Caution 2: Power Dissipation must be calculated with subtraction of 3.8 mW/ C from Maximum Rating with every 1 if Topr is upper 25 C. (on PCB)
ELECTRICAL CHARACTERISTICS (Ta = 25
Characteristics Input Voltage Range Operating Consumption Current Quiescent Consumption Current SHDNTerminal 'H' Level Input Voltage Symbol VIN IN(ON) IN(Off) VSHDNH
, VIN=2.8V to 5.5V if without notice)
Test Condition Min 2.8 1.3 0 0.77 285 285 -5 36 Typ 0.6 0.5 0 1.0 0.5 300 300 0.02 38 0.5 Max 5.5 0.9 1.0 VIN 0.4 1.0 1.43 1 315 315 5 39.5 1 V mV mV % MHz V V Unit V mA
VIN=3.6V, RSENS=15 VIN=3.6V,VSHDN=0V
SHDN Terminal 'L' Level Input Voltage VSHDNL SHDN Terminal Current Integrated MOS-Tr Switching requency Switching Terminal Leak Current FB Terminal Feedback Voltage (VFB) FB Terminal Line Regulation FB Terminal Current OVD terminal Voltage OVD Terminal Leakage Current ISHDN fOSC IOZ(SW) VFB VFB IFB VOVD IOVD VOVD=30V
VIN=3.6V,VSHDN=3.6V or 0V VIN=3.6V,VSHDN=3.6V VIN=3.6V, RSENS=15 , Ta=25 C, L=22 H VIN=3.6V, RSENS=15 , Ta=25 C, L=22 H VIN=3.6V center VIN=3.0 to 5.0V VIN=3.6V, VSHDN=3.6V, VFB=300mV -
2007. 4. 2
Revision No : 0
3/7
KAB3405T
Protection in LED opened condition The operation with OVD terminal is available for the protection in case LED Circuit opened. When the voltage of OVD terminal is over 38V (typ.), Nch MOS switching operation is disabled in the IC. When the voltage of OVD terminal drops below 38V (typ.), Nch MOS switching operation becomes available again. If load of LED is detached, Nch MOS switching operation is disabled with detection of boost circuit voltage and the IC is protected from unexpected over voltage. Setting of external Capacitor In case not using PWM signal to SHDN terminal for brightness control, recommended values are CIN = Over 2.2 ( F), COUT = Over 1.0 ( F) In case with PWM signal to SHDN terminal for brightness control, recommended values are CIN = Over 4.7 ( F), COUT=Under 1.0 ( F) The recommended values of the capacitors depend on the control of brightness. For details, please see the item Control of brightness from the next page.) These recommended values reduce fluctuation of input current to up accuracy of brightness. The capacitor value must be considered for gain enough accuracy of brightness with reduction of noise from Input current changing.
Setting of External Inductor Size Please select the inductor size with referring this table corresponding to each number of LEDs. Recommendation for the case that LED current IF = 20 mA LEDs 2-5 Over 6 Setting of IF Resistance connects between RSENS pin and GND. The average current is set by this RSENS value and average current are obtained by the following equation. IF[mA] = 300[mV] RSENS[ ] 5%. Indictor Size 10 H 22 H Note LED current IF = 20 mA
Current Value error is within
2007. 4. 2
Revision No : 0
4/7
KAB3405T
Current Dimming Control Recommended Brightness Control Circuits are 4 types. 1) Input PWM signal to SHDN terminal IF can be adjusted with PWM signal by inputting it to SHDN terminal.
[Notice] <> The recommended PWM signal frequency is from 100 Hz to 10 kHz. There is a possibility to arise the audible frequency in mounting to the board because it is within the auditory area. <> To reduce the fluctuation of input current and increase the accuracy of brightness, the values that CIN = 4.7 ( F) or more , COUT = 1.0 ( F) or less are recommended. When the PWM signal is off, the time to drain COUT of charge depends on the constant number. And so, the actual value is little different from the theoretical value. <> Set the amplitude of PWM signal within the range of SHDN terminal specification. <> In case dimming by inputting the PWM signal to the SHDN terminal, this IC turns on and off repeatedly. And the rush current, which provides the charge to COUT, arises in turning on. Take care in selecting the condenser. <> IF [mA] = 300 [mV] ON Duty [%] RSENS[ ]
<>
2007. 4. 2
Revision No : 0
5/7
KAB3405T
2) Input analog voltage to FB terminal IF can be adjusted with Analog voltage input to FB terminal. This method is without repeating IC ON/OFF, and no consider holding rash current. [Notice] LED current value goes ever 100% of current set with RSENS, if the input voltage is between 0 V to 300 mV(typ)
<>
3) Input PWM signal with filtering to FB terminal IF can be adjusted with filtering PWM signal using RC filter indicated in recommended circuit, because the PWM signal can be regard as analog voltage after filtering. This method is without repeating IC ON/OFF, and no need to consider holding rash current. [Notice] LED current value goes over 100% of the current set with RSENS, if the input voltage after filtering is between 0 V to 300 mV (typ).
<>
2007. 4. 2
Revision No : 0
6/7
KAB3405T
4) Input Logic signal IF can be adjusted with Logic signal input as indicated in recommended circuit. The resistor connected the ON-state Nch MOS Drain and RSENS determines IF. Average of setting current Io (mA) is next, approximately. IF=(300 [mV]/Sum of resistor value [ ]) IF [mA] = 300[mV] Sum of resistor v alue [ ]
<>
M1 OFF ON OFF ON
M2 OFF OFF ON ON 300[mV] 300[mV] 300[mV]
LED Current 300[mV] RSENS[ ] RSENS[ ] R1[ ] RSENS[ ]+ R1[ ] RSENS[ ] R2[ ] RSENS[ ]+ R2[ ] ] R2[ ]
RSENS[
RSENS[ ] R1[ ] R2[ ] ] R1[ ] + RSENS[ ] R2[ ] + R1[
2007. 4. 2
Revision No : 0
7/7

▲Up To Search▲

Price & Availability of KAB3405T

	To Download KAB3405T Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .