TB62757FUG
2010-06-306
1
TOSHIBA BiCD Digital Integrated Circuit Silicon Monolithic
TB62757FUG
Step Up Type DC-DC Converter for White LED
The TB62757FUG is a high efficient Step-Up Type DC-DC
Converter specially designed for constant current driving of
White LED.
This IC can drive 2 to 6 white LEDs connected series using a
Li-ion battery.
This IC contains N-ch MOSFET Transistor for Coil-Switching,
and LED Current (IF) is set with an external resistor.
This IC is especially for driving back light white LEDs in LCD
of PDA, Cellular Phone, or Handy Terminal Equipment.
Features
• Can drive 2 to 6 white LEDs connected series
• Variable LED current IF is set with a external resistor: 20 mA (typ.) @RSENS = 16 Ω
• Output power: Available for 400 mW LED loading
• High efficiency: 87% @Maximum
• Output over voltage shutdown function:
Switching operation is shut downed when OVD terminal voltage is over 22 V (typ.).
• IC package: SOT23-6（SSOP6-P-0.95B）
• Switching frequency: 1.1 MHz (typ.)
Weight: 0.016 g (typ.)
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Block Diagram
Pin Assignment (top view)
Note 1: This IC could be destroyed in some case if amounted in 180° inverse direction.
Please be careful about IC direction in mounting.
Pin Function
Pin No. Symbol Function Description
1 SHDN
Voltage-input terminal for IC-enable.
SHDN = H → Operation Mode, SHDN = L → Shutdown Mode (IC shutdown)
Please do not open this terminal.
2 OVD
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.
3 VIN Supply voltage input terminal. (2.8 V to 5.5 V)
4 SW Switch terminal for DC-DC converter. N-ch MOSFET built-in.
5 GND Ground terminal.
6 FB LED IF setting resister connecting terminal.
3
5
24
Monostable
multivibrator
for
reference
Circuit
on/off 6
1
SW OVD
FB
GND
SHDN
VIN
Monostable
multivibrator
for
off time control
Error
AMP.
CTL
AMP.
Over voltage
detection
1
2
3
6
5
4
SHDN
OVD
VIN
FB
GND
SW
S
1
2
3
6
5
4
SHDN
OVD
VIN
FB
GND
SW
S
Week 1 to 26 Week 27 to 53
TB62757FUG
2010-06-306
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I/O Equivalent Pin Circuits
1. SHDN Terminal
2. OVD Terminal
3. VIN Terminal to GND Terminal
4. SW Terminal
5. FB Terminal
1
VIN
SHDN
6
VIN
FB
4
SW
3
VIN
5
GND
OVD 2
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Application Note
Protection in LED Opened Condition (OVD Function)
The operation with OVD terminal is available for the protection in case LED Circuit opened.
If load of LED is detached, N-ch MOS switching operation is disabled with detection of boost circuit voltage.
(* When the voltage value recovers below the detection voltage value, operation is restarted.)
3
5
2
4
Monostable
multivibrator
for
reference
Circuit
on/off 6
1
SW
OVD
FB
GND
SHDN
VIN
Monostable
multivibrator
for
off time control
Error
AMP.
CTL
AMP.
PWM
2.2 μF
VIN 4.7 to 10 μH
1 μF
16 Ω@20 mA
Over voltage
detection
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Setting of External Capacitor
In case not using PWM signal to SHDN terminal for brightness control, recommended values are
C1 = Over 2.2 (μF), C2 = Over 1.0 (μF)
In case with PWM signal to SHDN terminal for brightness control, recommended values are
C1 = Over 4.7 (μF), C2 = Under 0.1 (μF).
The recommended capacitor values depend on the Brightness Control Method.
<Please refer the next page or later>
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.
LEDs Indictor Size Note
2
3
4.7 μH
4 6.8 μH
5 8.1 μH
6 10 μH
LED current IF = 20 mA
LED Current IF Setting
The resistance between the FB pin and GND, RSENS (Ω) is the resistance for the setting the output current.
Depending on the resistance value, it is possible to set the average output current Io (mA).
The average output current Io (mA) can be approximated with the following equation:
IF = (325 [mV]/RSENS [Ω])
The current value error is ±5%.
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Brightness Control Method
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]
<<Minimum ON-time of PWM signal input>>
• Set the minimum ON-time or OFF-time 33 μs or more in inputting the PWM signal.
• Set the Duty ratio satisfying the condition above.
Ex) In case PWM Frequency is 1 kHz,
1 kHz is 1 ms (PWM Width = 100%) and it takes 10 μs per 1%.
To set the pulse width 33 μs or more, necessary ON-or-OFF-time is calculated below.
33 μs ÷ 10 μs = 3.3% (Under the condition that 10 μs equals 1%.)
Finally, the Duty Ratio can be set in range of 3.3% to 96.7%.
<<PWM signal frequency>>
• 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.
<<Constant number of external capacitor>>
• To reduce the fluctuation of input current and increase the accuracy of brightness, the values that
C1 = 4.7 (μF) or more, C2 = 0.1 (μF) or less are recommended.
• When the PWM signal is off, the time to drain C2 of charge depends on the constant number. And
so, the actual value is little different from the theoretical value.
<<PWM input signal>>
• Set the amplitude of PWM signal within the range of SHDN terminal specification.
<<Rush current in inputting>>
• 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 C2, arises in turning on. Take care in selecting
the condenser.
<<Current value in control with PWM: Ideal equation>>
][
[%]×][
=)( Ω
R
DutyONmV325
mA
ISENS
F
1 ms (1 kHz) = 100%
Set On-time
Set Off-time
33 μs or more = 3.3%
Available Duty Ratio
(3.3% to 96.7%)
33 μs or more = 3.3%
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<Reference Data>
Condition: VIN = 3.6 V, L = 6.8 μH, 4LEDs, RSENS = 16 mΩ@Io = 20 mA
(1) C1 = 4.7 μF, C2 = 0.1 μF
(2) C1 = 4.7 μF, C 2 = 0.47 μF
(3) C1 = 4.7 μF, C 2 = 1.0 μF
(4) C1 = 2.2 μF, C 2 = 1.0 μF
Wave Form
SHDN
VOUT
IIN
TB62737FUG
ON Duty width[%] V.S . Error with Ide al Value
0
5
10
15
20
25
0 20406080100
ON Duty width[%]
Error with Ideal Value[%]
500kHz
1kHz
2kHz
4kHz
8kHz
12kHz
TB62757FUG
Wave Form
SHDN
VOUT
IIN
TB62737FUG
ON Duty width[%] V.S . Error with Ide al Value
0
5
10
15
20
25
0 20406080100
ON Duty width[%]
Error with Ide al Value[% ]
500kHz
1kHz
2kHz
4kHz
8kHz
12kHz
TB62757FUG
Wave Form
SHDN
VOUT
IIN
TB62737FUG
ON Duty width[%] V.S . Error with Ide al Value
0
5
10
15
20
25
0 20406080100
ON Duty width[%]
Error with Ide al Value[% ]
500kHz
1kHz
2kHz
4kHz
8kHz
12kHz
TB62757FUG
TB62737FUG
ON Duty width[%] V.S . Error with Ide al Value
0
5
10
15
20
25
0 20406080100
ON Duty width[%]
Error with Ide al Value[% ]
500kHz
1kHz
2kHz
4kHz
8kHz
12kHz
TB62757FUG
Wave Form
SHDN
VOUT
IIN
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<<Recommended circuit>>
PWM signal
S-Di6.8 μH
VIN =
2.8 to 5.5 V
C1 = 4.7 μF
C2 = 0.1 μF
RSENS
= 16 Ω
VCC SW
OVD
FB
GND
SHDN
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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 need to consider holding rash current.
[Notice]
• LED current value goes over 100% of the current set with RSENS, if the input analog voltage is
between 0 V to 325 mV (typ.).
for ref.) Analog voltage = 0 to 2.2 V
About external parts value, please see recommended circuit.
Supply Voltage [V] Ratio with
Setting Current
No connect (OFF) 100%
0 116.0%
0.2 106.5%
0.4 95.4%
0.6 84.5%
0.8 73.6%
1 59.9%
1.2 48.4%
1.4 37.4%
1.6 26.6%
1.8 15.9%
2 5.8%
2.2 0.0%
<<Recommended circuit>>
TB62737FUG
Analog Voltage Input to FB Terminal
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
120.0%
140.0%
0 0.5 1 1.5 2 2.5
Input Voltage
Ratio with setting current(%)
TB62757FUG
16 kΩ
Analog voltage
S-Di6.8 μH
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
82 kΩ
RSENS
= 16 Ω
VCC SW
OVD
FB
GND
SHDN
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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 325 mV (typ.).
for ref.) Voltage during PWM Signal-ON = 2 V
About external parts value, please see recommended circuit.
Supply Voltage [V] Ratio with
Setting Current
No connect (OFF) 100%
0 116.1%
10% 105.3%
20% 95.1%
30% 84.8%
40% 74.6%
50% 64.0%
60% 53.8%
70% 43.7%
80% 34.0%
90% 24.2%
100% 13.3%
<<Recommended circuit>>
TB62737FUG
Input PWM signal filtered with R,C to the FB terminal
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
120.0%
140.0%
0% 20% 40% 60% 80% 100%
PWM Duty(%)
Setting current ratio(%)
TB62757FUG
16 kΩ
PWM signal
S-Di6.8 μH
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
82 kΩ
RSENS
= 16 Ω
VCC SW
OVD
FB
GND
SHDN
0.1 μF
10 kΩ
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4) Input logic signal
IF can be adjusted with Logic signal input as indicated in recommended circuit.
The Resistor connected the ON-State N-ch MOS Drain and RSENS determines IF.
Average of Setting Current Io (mA) is next, approximately.
IF = (325 [mV]/Sum of Resistor Value [Ω])
<<Recommended circuit>>
M1 M2 LED Current
OFF OFF ][
R
[mV]325
SENS Ω
ON OFF
OFF ON
ON ON
Logic signal
S-Di6.8 μH
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
RSENS
VCC SW
OVD
FB
GND
SHDN
R1 R2
M2M1
][1R][
RSENS
][1R][
RSENS
]mV[325 Ω×Ω
Ω+Ω
×
][2R][
RSENS
][2R][
RSENS
]mV[325 Ω×Ω
Ω+Ω
×
][2R][1R][
R
][2R][1R][2R][
R
][1R][
R
]mV[325
SENS
SENSSENS
Ω×Ω×Ω
Ω×Ω+Ω×Ω+Ω×Ω
×
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Absolute Maximum Ratings (Ta = 25°C if without notice)
Characteristics Symbol Rating Unit
Power supply voltage VIN −0.3 to +6.0 V
Input voltage VSHDN −0.3 to + VIN + 0.3 (Note 1) V
Switching terminal voltage Vo (SW) −0.3 to 24 V
0.41 (Device)
Power dissipation PD
0.47 (on PCB) (Note 2)
W
300 (Device)
Thermal resistance Rth (j-a)
260 (on PCB)
°C/W
Operation temperature range Topr −40 to +85 °C
Storage temperature range Tstg −55 to +150 °C
Maximum junction temperature Tj 150 °C
Note 1: However, do not exceed 6 V.
Note 2: Power dissipation must be calculated with subtraction of 3.8 mW/°C from Maximum Rating with every 1°C if
Topr is upper 25°C. (on PCB)
Recommended Operating Condition (Ta = −40°C to 85°C if without notice)
Characteristics Symbol Test Condition Min Typ. Max Unit
Power supply voltage VIN 2.8 ⎯ 5.5 V
SHDN terminal input pulse width tpw “H”, “L” duty width 33 ⎯ ⎯ μs
LED current (average value) IF1 VIN = 3.6 V, RSENS = 16 Ω
4 white LEDs, Ta = 25°C ⎯ 20 ⎯ mA
Electrical Characteristics (Ta = 25°C, VIN = 2.8 to 5.5 V, if without notice)
Characteristics Symbol Test Condition Min Typ. Max Unit
Input voltage range VIN 2.8 ⎯ 5.5 V
Operating consumption current IIN (On) VIN = 3.6 V, RSENS = 16 Ω ⎯ 0.9 1.5 mA
Quiescent consumption current IIN (Off) VIN = 3.6 V, VSHDN = 0 V ⎯ 0.5 1.0 μA
SHDN terminal “H” level input
voltage VHSHDN ⎯ 1.3 ⎯ V
IN V
SHDN terminal “L” level input
voltage VLSHDN ⎯ 0 ⎯ 0.4 V
SHDN terminal current ISHDN V
IN = 3.6 V, VSHDN = 3.6 V or 0 V −10 0 10 μA
Integrated MOS-Tr switching
frequency fOSC V
IN = 3.6 V, VSHDN = 3.6 V 0.77 1.1 1.43 MHz
Sw terminal protection voltage Vo (SW) ⎯ ⎯ 25 ⎯ V
Switching terminal current Ioz (SW) ⎯ ⎯ 400 ⎯ mA
Switching terminal leakage current Ioz (SW) ⎯ ⎯ 0.5 1 μA
FB terminal feedback voltage (VFB) VFB V
IN = 3.6 V, RSENS = 16 Ω, L = 6.8 μH 308 325 342 mV
FB terminal line regulation ΔVFB VIN = 3.6 V center
VIN = 3.0 to 5.0 V −5 ⎯ 5 %
OVD terminal voltage VOVD ⎯ 19 22 23.5 V
OVD terminal leakage current IOVDZ V
OVD = 16 V ⎯ 0.5 1 μA
TB62757FUG
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1. Application Circuit Example and Measurement Data (reference data)
* V
OUT voltage in driving 5 or 6 LEDs must be lower
than OVD detection level. (VOUT < 19 V)
Note: These application examples are provided for reference only. Thorough evaluation and testing should be
implemented when designing your application’s mass production design.
S-Di L1
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
RSENS
= 16 Ω
VIN SW
OVD
FB
GND
SHDN
WLEDs
2 to 6
•
Evaluation conditions (Ta = 25°C)
L1 : CXLD120 series (NEO MAX CO.,Ltd.)
(Size: 2.5 mm × 3.0 mm × 1.2 mm)
C1 : C2012JB1E225K (TDK Corp.)
C2 : C2012JB1E105K (TDK Corp.)
S-Di : CUS02 1 A/30 V (TOSHIBA Corp.)
WLEDs : NSCW215T (NICHIA Corp.)
Input Voltage - Efficiency/Output Current
4LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
<Measurement Data>
Efficiency in the range of VIN = 2.8 to 5.5 V
Efficiency (%) Average Efficiency (%)
2 LEDs 82.60 to 88.46 86.29
3 LEDs 82.69 to 87.78 85.95
4 LEDs 80.73 to 86.22 83.05
5 LEDs 80.73 to 87.28 83.45
6 LEDs 79.78 to 85.55 81.15
Output current in the range of VIN = 3.0 to 5.0 V (VIN = 3.6 V typ.)
Tolerance (%)
Output Current (mA)
VIN = 3.6 V Min Max
2 LEDs 21.13 −3.50 1.77
3 LEDs 20.60 −1.95 1.38
4 LEDs 20.87 −1.75 1.11
5 LEDs 20.06 −1.81 1.15
6 LEDs 19.90 −1.95 1.28
Input Voltage - Efficiency/Output Current
2LED Drive, L=4.7μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
3LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
5LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
6LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
TB62757FUG
2010-06-306
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2. Application Circuit Example and Measurement Data (reference data)
* V
OUT voltage in driving 5 or 6 LEDs must be lower
than OVD detection level. (VOUT < 19 V)
Note: These application examples are provided for reference only. Thorough evaluation and testing should be
implemented when designing your application’s mass production design.
S-Di L1
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
RSENS
= 16 Ω
VIN SW
OVD
FB
GND
SHDN
WLEDs
2 to 6
•
Evaluation conditions (Ta = 25°C)
L1 : 1001AS series (TOKO, INC)
(Size: 3.6 mm × 3.6 mm × 1.2 mm)
C1 : C2012JB1E225K (TDK Corp.)
C2 : C2012JB1E105K (TDK Corp.)
S-Di : CUS02 1 A/30 V (TOSHIBA Corp.)
WLEDs : NSCW215T (NICHIA Corp.)
Input Voltage - Efficiency/Output Current
2LED Drive, L=4.7μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOUT(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
5LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
3LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
6LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
4LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
<Measurement Data>
Efficiency in the range of VIN = 2.8 to 5.5 V
Efficiency (%) Average Efficiency (%)
2 LEDs 83.10 to 88.60 86.55
3 LEDs 81.32 to 86.47 84.54
4 LEDs 79.15 to 84.63 81.30
5 LEDs 79.72 to 86.39 82.87
6 LEDs 78.91 to 85.10 80.47
Output current in the range of VIN = 3.0 to 5.0 V (VIN = 3.6 V typ.)
Tolerance (%)
Output Current (mA)
VIN = 3.6 V Min Max
2 LEDs 21.17 −3.32 1.73
3 LEDs 20.85 −1.95 1.38
4 LEDs 20.56 −1.79 1.15
5 LEDs 20.10 −1.82 1.22
6 LEDs 19.95 −1.94 1.26
TB62757FUG
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3. Application Circuit Example and Measurement Data (reference data)
* V
OUT voltage in driving 5 or 6 LEDs must be lower
than OVD detection level. (VOUT < 19 V)
Note: These application examples are provided for reference only. Thorough evaluation and testing should be
implemented when designing your application’s mass production design.
S-Di L1
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
RSENS
= 16 Ω
VIN SW
OVD
FB
GND
SHDN
WLEDs
2 to 6
•
Evaluation conditions (Ta = 25°C)
L1 : LQH2M series
(Murata Manufacturing Co.,Ltd.)
(Size: 2.0 mm × 1.6 mm × 0.95 mm)
C1 : C2012JB1E225K (TDK Corp.)
C2 : C2012JB1E105K (TDK Corp.)
S-Di : CUS02 1 A/30 V (TOSHIBA Corp.)
WLEDs : NSCW215T (NICHIA Corp.)
Input Voltage - Efficiency/Output Current
2LED Drive, L=4.7μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
5LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
3LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOUT(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
6LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
4LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
<Measurement Data>
Efficiency in the range of VIN = 2.8 to 5.5 V
Efficiency (%) Average Efficiency (%)
2 LEDs 82.37 to 88.70 86.38
3 LEDs 80.19 to 86.55 84.12
4 LEDs 78.11 to 84.54 80.16
5 LEDs 74.79 to 84.94 79.94
6 LEDs 74.14 to 83.47 77.17
Output current in the range of VIN = 3.0 to 5.0 V (VIN = 3.6 V typ.)
Tolerance (%)
Output Current (mA)
VIN = 3.6 V Min Max
2 LEDs 21.19 −3.26 1.69
3 LEDs 20.90 −1.87 2.17
4 LEDs 20.63 −1.78 1.01
5 LEDs 20.09 −1.88 1.25
6 LEDs 19.93 −1.99 1.07
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4. Application Circuit Example and Measurement Data (reference data)
* V
OUT voltage in driving 5 or 6 LEDs must be lower
than OVD detection level. (VOUT < 19 V)
Note: These application examples are provided for reference only. Thorough evaluation and testing should be
implemented when designing your application’s mass production design.
S-Di L1
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
RSENS
= 16 Ω
VIN SW
OVD
FB
GND
SHDN
WLEDs
2 to 6
•
Evaluation conditions (Ta = 25°C)
L1 : VLF3010A series (TDK Corp.)
(Size: 3.0 mm × 3.0 mm × 1.0 mm)
C1 : C2012JB1E225K (TDK Corp.)
C2 : C2012JB1E105K (TDK Corp.)
S-Di : CUS02 1 A/30 V (TOSHIBA Corp.)
WLEDs : NSCW215T (NICHIA Corp.)
Input Voltage - Efficiency/Output Current
2LED Drive, L=4.7μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IO U T
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
5LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
3LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOUT(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
6LED Drive, L=10μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOUT
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
4LED Drive, L=6.8μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
IOU T(mA)
50
60
70
80
90
100
Efficiency(%)
IOU T
Efficiency
IF (mA)
IF
Efficiency
<Measurement Data>
Efficiency in the range of VIN = 2.8 to 5.5 V
Efficiency (%) Average Efficiency (%)
2 LEDs 79.85 to 86.97 84.02
3 LEDs 80.19 to 85.32 83.39
4 LEDs 78.77 to 83.60 80.69
5 LEDs 79.72 to 86.39 82.87
6 LEDs 78.91 to 85.10 80.49
Output current in the range of VIN = 3.0 to 5.0 V (VIN = 3.6 V typ.)
Tolerance (%)
Output Current (mA)
VIN = 3.6 V Min Max
2 LEDs 21.19 −3.08 1.67
3 LEDs 20.89 −1.86 1.33
4 LEDs 20.64 −1.68 1.11
5 LEDs 20.10 −1.82 1.22
6 LEDs 19.95 −1.94 1.26
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5. Application Circuit Example and Measurement Data (reference data)
Note: These application examples are provided for reference only. Thorough evaluation and testing should be
implemented when designing your application’s mass production design.
S-Di L1
VIN =
2.8 to 5.5 V
C1 = 2.2 μF
C2 = 1.0 μF
RSENS
= 16 Ω
VIN SW
OVD
FB
GND
SHDN
WLEDs
2 to 4
•
Evaluation conditions (Ta = 25°C)
L1 : 32R51 (KOA Corp.)
(Size: 3.2 mm × 2.5 mm × 0.6 mm)
C1 : C2012JB1E225K (TDK Corp.)
C2 : C2012JB1E105K (TDK Corp.)
S-Di : CUS02 1 A/30 V (TOSHIBA Corp.)
WLEDs : NSCW215T (NICHIA Corp.)
Input Voltage - Efficiency/Output Current
3LED Drive, L=5.1μH
10
15
20
25
30
35
2.83.13.43.7 4 4.34.64.95.25.5
VIN(V)
Output Current (mA)
50
60
70
80
90
100
Efficiency(%)
Iout
Efficiency
IF (mA)
IF
Efficiency
Input Voltage - Efficiency/Output Current
4LED Drive, L=5.1μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
Output Current (mA)
50
60
70
80
90
100
Efficiency(%)
Iout
Efficiency
IF (mA)
IF
Efficiency
<Measurement Data>
Efficiency in the range of VIN = 2.8 to 5.5 V
Efficiency (%) Average Efficiency (%)
2 LEDs 83.08 to 89.23 86.73
3 LEDs 79.02 to 86.30 83.52
4 LEDs 75.75 to 83.83 80.78
Output current in the range of VIN = 3.0 to 5.0 V (VIN = 3.6 V typ.)
Tolerance (%)
Output Current (mA)
VIN = 3.6 V Min Max
2 LEDs 21.06 −2.46 4.02
3 LEDs 20.57 −2.39 2.94
4 LEDs 20.22 −2.28 2.65
Input Voltage - Efficiency/Output Current
2LED Drive, L=5.1μH
10
15
20
25
30
35
2.8 3.1 3.4 3.7 4 4.3 4.6 4.9 5.2 5.5
VIN(V)
Output Current (mA)
50
60
70
80
90
100
Efficiency(%)
Iout
Efficiency
IF (mA)
IF
Efficiency
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Package Dimensions
Weight: 0.016 g (typ.)
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・Notes on Contents
1. Block Diagrams
Some of the functional blocks, circuits, or constants in the block diagram may be omitted or simplified for
explanatory purposes.
2. Equivalent Circuits
The equivalent circuit diagrams may be simplified or some parts of them may be omitted for explanatory
purposes.
3. Timing Charts
Timing charts may be simplified for explanatory purposes.
4. Application Circuits
The application circuits shown in this document are provided for reference purposes only. Thorough
evaluation is required, especially at the mass production design stage.
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.
IC Usage Considerations
Notes on handling of ICs
[1] The absolute maximum ratings of a semiconductor device are a set of ratings that must not be exceeded,
even for a moment. Do not exceed any of these ratings.
Exceeding the rating(s) may cause the device breakdown, damage or deterioration, and may result injury
by explosion or combustion.
[2] Use an appropriate power supply fuse to ensure that a large current does not continuously flow in case
of over current and/or IC failure. The IC will fully break down when used under conditions that exceed its
absolute maximum ratings, when the wiring is routed improperly or when an abnormal pulse noise
occurs from the wiring or load, causing a large current to continuously flow and the breakdown can lead
smoke or ignition. To minimize the effects of the flow of a large current in case of breakdown, appropriate
settings, such as fuse capacity, fusing time and insertion circuit location, are required.
[3] If your design includes an inductive load such as a motor coil, incorporate a protection circuit into the
design to prevent device malfunction or breakdown caused by the current resulting from the inrush
current at power ON or the negative current resulting from the back electromotive force at power OFF. IC
breakdown may cause injury, smoke or ignition.
Use a stable power supply with ICs with built-in protection functions. If the power supply is unstable, the
protection function may not operate, causing IC breakdown. IC breakdown may cause injury, smoke or
ignition.
[4] Do not insert devices in the wrong orientation or incorrectly.
Make sure that the positive and negative terminals of power supplies are connected properly.
Otherwise, the current or power consumption may exceed the absolute maximum rating, and exceeding
the rating(s) may cause the device breakdown, damage or deterioration, and may result injury by
explosion or combustion.
In addition, do not use any device that is applied the current with inserting in the wrong orientation or
incorrectly even just one time.
[5] Carefully select external components (such as inputs and negative feedback capacitors) and load
components (such as speakers), for example, power amp and regulator.
If there is a large amount of leakage current such as input or negative feedback condenser, the IC output
DC voltage will increase. If this output voltage is connected to a speaker with low input withstand voltage,
overcurrent or IC failure can cause smoke or ignition. (The over current can cause smoke or ignition from
the IC itself.) In particular, please pay attention when using a Bridge Tied Load (BTL) connection type IC
that inputs output DC voltage to a speaker directly.
TB62757FUG
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Points to remember on handling of ICs
(1) Heat Radiation Design
In using an IC with large current flow such as power amp, regulator or driver, please design the device so
that heat is appropriately radiated, not to exceed the specified junction temperature (TJ) at any time and
condition. These ICs generate heat even during normal use. An inadequate IC heat radiation design can
lead to decrease in IC life, deterioration of IC characteristics or IC breakdown. In addition, please design
the device taking into considerate the effect of IC heat radiation with peripheral components.
(2) Back-EMF
When a motor rotates in the reverse direction, stops or slows down abruptly, a current flow back to the
motor’s power supply due to the effect of back-EMF. 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.
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About solderability, following conditions were confirmed
Solderability
(1) Use of Sn-37Pb solder Bath
solder bath temperature: 230°C
dipping time: 5 seconds
the number of times: once
use of R-type flux
(2) Use of Sn-3.0Ag-0.5Cu solder Bath
solder bath temperature: 245°C
dipping time: 5 seconds
the number of times: once
use of R-type flux
TB62757FUG
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RESTRICTIONS ON PRODUCT USE
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in this document, and related hardware, software and systems (collectively “Product”) without notice.
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responsible for complying with safety standards and for providing adequate designs and safeguards for their hardware, software and
systems which minimize risk and avoid situations in which a malfunction or failure of Product could cause loss of human life, bodily
injury or damage to property, including data loss or corruption. Before customers use the Product, create designs including the
Product, or incorporate the Product into their own applications, customers must also refer to and comply with (a) the latest versions of
all relevant TOSHIBA information, including without limitation, this document, the specifications, the data sheets and application notes
for Product and the precautions and conditions set forth in the “TOSHIBA Semiconductor Reliability Handbook” and (b) the
instructions for the application with which the Product will be used with or for. Customers are solely responsible for all aspects of their
own product design or applications, including but not limited to (a) determining the appropriateness of the use of this Product in such
design or applications; (b) evaluating and determining the applicability of any information contained in this document, or in charts,
diagrams, programs, algorithms, sample application circuits, or any other referenced documents; and (c) validating all operating
parameters for such designs and applications. TOSHIBA ASSUMES NO LIABILITY FOR CUSTOMERS’ PRODUCT DESIGN OR
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• Product is intended for use in general electronics applications (e.g., computers, personal equipment, office equipment, measuring
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