tb62731fu TOSHIBA Semiconductor CORPORATION, tb62731fu Datasheet
tb62731fu
Available stocks
Related parts for tb62731fu
tb62731fu Summary of contents
Page 1
... TOSHIBA BiCD Digital Integrated Circuit Silicon Monolithic Step-up DC-DC Converter for White LED Driver The TB62731FU is an LED driver which uses a high power efficiency step-up DC-DC converter. The converter turns on/off from white LEDs in series. The IC incorporates an N-channel MOSFET transistor which switches a coil. Also, a function which reduces LED current depending on increase in temperature ...
Page 2
... When Low, Standby Mode and pin A turned off. Input pin for power supply for operating the IC Operating voltage range: 3.0~5.5 V DC-DC converter switch pin The switch is an N-channel MOSFET transistor. Note: Connect both GND pins to ground Buffer (sub) GND Function 2 TB62731FU K 2006-06-14 ...
Page 3
... Test condition circuit ⎯ ⎯ ⎯ ⎯ ⎯ ⎯ ⎯ ⎯ tpw SHDN ⎯ OUT 3 TB62731FU = 25°C) Unit °C/W °C °C °C = −40~85°C) T opr Min Typ. Max Unit ⎯ 3.0 4.3 V − V ⎯ CC ...
Page 4
... V (A) o ⎯ ⎯ I (A) o ⎯ ⎯ 3.2~4 ⎯ R_sens = 1.8 Ω 25°C T opr Equivalent to R_sens = 1.8 Ω, ⎯ Tdel L = 4.7 µ TB62731FU = 3.0~5 Min Typ. Max Unit ⎯ 3.0 5.5 V ⎯ 0.6 0.9 mA ⎯ µA 0.5 1.0 ⎯ µA 4.2 7 ⎯ Ω 2.0 2.5 275 350 425 kHz ⎯ ...
Page 5
... STB IN REF Figure 1 Application Circuit The basic TB62731FU circuit uses a step-up DC-DC converter and burst control of current pulse. Basic Operation The internal MOS transistor (NMOS) is turned Inductance current IL increases from 0. When IL = ILpeak = 240 mA (typ.) or when 5/6 (83.3 kHz) is reached, the transistor is turned off. ...
Page 6
... Make sure the following condition for LED load between pins A and K is satisfied < LED Vf total IN CC Note that, regardless of control by the IC, LEDs are always on. Pulse stop time width: 7.5 µs (min)~15 µs (max) OSC Repetition of waveforms at left I A (peak) = 240 mA (typ.) is larger than the output power to the LED load. The IN 6 TB62731FU 2006-06-14 ...
Page 7
... too large, it may not be possible for the current characteristic to be the specified value. Note that K > 1. min) × 2 × (1/Ip min × Ip min formula 2 OSC (mA), LED forward voltage: Vf LED (V), o × (1/η) × (1 formula (mA), and η > (%), then I o > = 3.12 V the input power TB62731FU = 0.12 (mA result 2006-06-14 ...
Page 8
... Thus, 48.1 ( µ selected when the input voltage is low, 3.0 V. Note that the calculation does not consider fluctuations in inductance. Toshiba recommend selection of an inductance of 1.2 times the calculated value. The recommended inductance under the above conditions µ 48.1 ( µ H) × 1.2 > = 57.7 ( µ H (mA 1.1 o 43.8 ( µ TB62731FU = 3 4 2006-06-14 ...
Page 9
... Relation between set current IO and setting resistance R_sens 9.1 8.2 6.8 5.6 4 (mA). o and output voltage V exceeds (typical value 25° (mA) 3.3 2.7 2.2 2 1.8 1.5 1.2 1 Resistance for setting current R_sens (Ω) Figure 4 9 TB62731FU . The mean output current 320 (mW), mean current can be obtained. o 2006-06-14 ...
Page 10
... Output Derating Function Toshiba recommend derating LED current depending on the increase in ambient temperature. TB62731FU is intended to safely and efficiently drive white LEDs used as backlight sources for color LCDs. The IC incorporates a function which derates current based on the set temperature (the ambient temperature when the IC is mounted), Ta ...
Page 11
... Recommended LED current range (converted Figure 5 Derating Function of Set Current ( ° calculated as follows: ( ° calculated as follows 260 ( ° C/W) is the maximum value, θ Temperatures T (°C) and T (° TB62731FU = 210~260 ( ° C/W) is used 100 2006-06-14 ...
Page 12
... V (V) CC Current consumption at shutdown I (SHDN) CC 0.5 0.4 0.3 0.2 0 3 (V) CC Output switching frequency 400 380 360 340 320 300 3 3 TB62731FU 2 5.5 4 TB62731FU TB62731FU 1 2 5.5 12 TB62731FU OSC 5 2006-06-14 ...
Page 13
... sens 60 1.8 Ω 3.2 3.4 Input voltage – power efficiency/mean current 100 sens 60 1.8 Ω 3.2 3.4 13 TB62731FU η 3.6 3.8 4 4.2 Input voltage V ( η 3.6 3.8 4 4.2 Input voltage V ( η ...
Page 14
... R_sens 60 1.8 Ω 3.2 3.4 Input voltage – power efficiency/mean current 100 R_sens 60 1.8 Ω 3.2 3.4 14 TB62731FU η 3.6 3.8 4 4.2 Input voltage V ( η 3.6 3.8 4 4.2 Input voltage V ( η ...
Page 15
... Input voltage – power efficiency/mean current 100 8 R_sens 60 5.1 Ω 3.2 3.4 3.6 Input voltage V Input voltage – power efficiency/mean current 100 8 R_sens 60 2.4 Ω 3.2 3.4 3.6 Input voltage V 15 TB62731FU η 3.8 4 4.2 ( η 3.8 4 4.2 (V) IN 2006-06-14 ...
Page 16
... Package Dimensions Weight: 0.016 g (typ.) 16 TB62731FU 2006-06-14 ...
Page 17
... Toshiba does not grant any license to any industrial property rights by providing these examples of application circuits. 5. Test Circuits Components in the test circuits are used only to obtain and confirm the device characteristics. These components and circuits are not guaranteed to prevent malfunction or failure from occurring in the application equipment. 17 TB62731FU 2006-06-14 ...
Page 18
... If the current sink capability of the power supply is small, the device’s motor power supply and output pins might be exposed to conditions beyond maximum ratings. To avoid this problem, take the effect of back-EMF into consideration in system design. 18 TB62731FU 2006-06-14 ...
Page 19
... TOSHIBA for any infringements of patents or other rights of the third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of TOSHIBA or others. 021023_C • The products described in this document are subject to the foreign exchange and foreign trade laws. 021023_D 021023_B 060106_Q 19 TB62731FU 060116EBA 021023_E 2006-06-14 ...