TB62D901FNG
TOSHIBA BiCD Integrated Circuit Silicon Monolithic
TB62D901FNG
AC/DC Step-Down Conversion Type LED Lighting Driver
1. General
The TB62D901FNG is a constant current driver IC ideal for
use in the step-down AC/DC conversion type LED lighting
applications.
The TB62D901FNG features architecture with automatic Off
time adjustment control that can be used to achieve minimum
LED current variations by the effect of fluctuated input voltage
or change of LED forward voltage.
The device allows linear dimming or PWM dimming. It has
extensive detection functions that are thermal shutdown,
over-current detection, over-voltage detection, under-voltage
lockout, and current sensing input terminal (ISEN1) open
detection.
TB62D901FNG
SSOP16-P-225-0.65B
Weight: 0.07 g (typ.)
2. Application
LED lighting
3. Features
• Operating supply voltage
• Dimming function
• Switching frequency
• Operation mode
• Efficiency
• Detection function
• IC standby function
• Operating temperature
• Package
© 2014 TOSHIBA Corporation
: 12V to 30V
: Linear dimming (by adjustment of LED peak current)
PWM dimming
: Adjustable of up to 500kHz (MAX)
: Current continuous conduction mode
(Automatic OFF time control mode, Fixed off time mode)
Critical conduction mode
: 90% or more with recommended components
: Thermal shutdown (TSD)
: Over-current detection (OCP)
: Over-voltage detection (OVP)
: Under-voltage lockout (UVLO)
: ISEN terminal open detection (IOP)
: EN signal allows standby mode with 0.8mA (MAX) consumption
current
: Topr = −40 °C to 105 °C
: SSOP16-P-225-0.65B
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TB62D901FNG
4. Block Diagram
VCC
Vref
LDO
UVLO
TSD
VREG
COMP
PWMD
RC
OFF time
Control
VSEN
EN
LD
REF
COMP
R
Q
Gate
Driver
LOGIC
S
GATE
ISEN2
MS
PGND
OSC
ISEN2
PGND
ISEN
OPEN Protection
ISEN1
GND
2
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TB62D901FNG
5. Pin Assignment (top view)
VCC
1
16 PGND
VREG
2
15 GATE
MS
3
14 ISEN1
PWMD
4
13 ISEN2
LD
5
12 VSEN
RC
6
11 NC
EN
7
10 NC
GND
8
9
NC
6. Pin Description
Pin
No
1
2
Pin
Name
VCC
VREG
3
MS
I
4
PWMD
I
5
6
LD
RC
I
I
7
EN
I
8
9
10
11
GND
NC
NC
NC
P
-
12
VSEN
I
13
ISEN2
I
14
ISEN1
I
15
16
GATE
PGND
O
P
I/O
Function
P
O
Power supply input.
Output of the internal regulator.
Input to set switching operation mode.
GND short-circuit: Continuous mode
VREG terminal short-circuit: Critical mode
PWM signal input for the PWM dimming.
“H" level voltage input: LED lighting current on
"L" level voltage input: LED lighting current off
Analogue input voltage to set the peak value of the LED current.
Analog input to set the ripple range of the LED current.
IC enable signal input.
“H" level voltage input: Operation mode
"L" level voltage input: Standby mode.
In standby mode, circuits other than the regulator circuit, the standard voltage circuit,
and the UVLO circuit stop operation.
Ground.
No Connect. Connect to GND
No Connect. Connect to GND
No Connect. Connect to GND
Input for feedback voltage.
This input voltage of VSEN determines the OFF time of the control output GATE for
external power MOSFET of the step-down driver.
Detection terminal for LED current.
Connect to the GND side of the current sensing resistor between ISEN1 and GND.
Detection terminal for LED current.
The peak value of LED current is determined by the resistance connected between
ISEN1 terminal and GND.
Output for controlling the Gate of the Power MOSFET
Power ground for GATE diver.
*I/O symbol I: Input, O: Output, P: Power supply
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7. I/O Equivalent Circuits
Pin
No
Pin
Name
1
VCC
Equivalent circuit
Pin
No
Pin
Name
8
GND
Equivalent circuit
VCC
Regulator
VREG
VREG VCC
GND
2
VREG
13
PGND
PGND
GND
ISEN2
VREG
3
MS
16
GND
ISEN2
GND
VREG
5
LD
12
VSEN
VREG
GND
VREG
GND
6
RC
14
ISEN1
GND
GND
VCC
4
PWMD
15
GATE
VREG
PGND
PGND
GND
7
EN
4
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TB62D901FNG
8. Absolute Maximum Ratings (Ta = 25°C)
Characteristics
Symbol
Rating Note1
Unit
Supply voltage
VCC
−0.3 to 40
V
Input pin voltage (PWMD, LD, RC, EN,
and MS)
VIN
−0.3 to 6.0
V
VREG pin voltage
VREG
−0.3 to 6.0
V
Feedback pin voltage
(ISEN1 and VSEN)
VFB
−0.3 to 6.0
V
VGATE
−0.3 to VCC
V
Operating temperature
Topr
−40 to 105
°C
Storage temperature
Tstg
−55 to 150
°C
Thermal resistance
Rth(j-a)
87.3* Note 2
°C/ W
Power dissipation
PD
1.43* Note2,3
W
GATE pin voltage
Note1: Voltage is PGND/GND/ISEN2 referenced.
Note2: PCB condition is 76.2×114.3×1.6mm (JEDEC 4 layer substrate)
Note3: When ambient temperature is 25°C or more. Every time ambient temperature exceeded 1°C, please decrease 1/Rth(j-a).
9. Operating Condition (Unless otherwise noted, Ta = -40 to 105 °C)
Characteristics
Symbol
Test Conditions
Min
Typ.
Max
Unit
Operating supply voltage
VCC
12
―
30
V
Switching frequency
fSW
―
―
500
kHz
VLD1
When LED peak current adjustment
function is used
0.2
―
3.8
VLD2
When LED peak
function is not used
current
adjustment
4.5
―
VREG
VRC1
When LED peak
function is used
current
adjustment
1
―
4.0
VRC2
When LED peak
function is not used
current
adjustment
0
―
0.5
When using it in automatic OFF time
control mode
0.5
―
3
When using it in Fixed OFF time mode
4.5
―
VREG
V
LD pin input voltage
RC pin input voltage
VVSEN1
VSEN pin input voltage
VVSEN2
V
V
GATE pin output voltage which is the same level as VCC. Please set up VCC in consideration of the Absolute Maximum Ratings of
the external power MOSFET
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10. Electrical Characteristics (Unless otherwise noted, Ta = 25 °C, VCC=12V)
Characteristics
Symbol
Test Conditions
Min
Typ.
Max
Unit
＜Consumption current＞
Operating consumption current
ICC(ON)
EN=H, PWMD=H, MS=L
VVSEN= VREG, VLD=VREG, VRC=0V
VISEN1=0V
―
2.0
2.5
Standby consumption current
ICC(OFF)
EN=L
―
0.5
0.8
VREG
IREG
IREG=0mA
4.9
―
5
―
5.1
2
V
mA
VUVLO(UP)
VUVLO(DOWN)
VCC rising
VCC falling
10.5
8.0
11
8.5
11.5
9.0
V
V
―
―
―
―
5
2.5
15
15
10
5
30
30
Ω
Ω
ns
ns
3.87
4
4.13
μs
32
1.4
VLD
+0.1
VLD
-0.0
130
10
35
1.6
VLD
+0.4
VLD
+0.2
140
20
38
1.8
VLD
+0.7
VLD
+0.4
150
30
V
°C
°C
VINH
1.5
―
VREG
V
VINL
0
―
0.4
V
―
―
1
μA
-1
―
―
μA
240
300
360
kΩ
mA
＜Regulator part＞
VREG output voltage
VREG maximum output current
＜UVLO part＞
UVLO release voltage
UVLO operation voltage
＜GATE Driver part＞
GATE pin source resistance
GATE pin sink resistance
GATE pin rising time
GATE pin falling time
MOSFET OFF time
RGATEH
RGATEL
trGATE
tfGATE
tOFF
IGATE=-100mA
IGATE=100mA
CL=1nF
CL=1nF
EN=H, PWMD=H, MS=L
VVSEN= VREG, VLD=VREG , VRC=0V
＜Detection circuit part＞
OVP operation voltage
OCP operation voltage
TSD operation temperature
TSD hysteresis temperature
VOVP
VOCP1
VCC pin
ISEN pin, VLD=VREG
VOCP2
ISEN pin, VLD=0.2V
VOCP3
ISEN pin, VLD=3.8V
TTSD
TTSD(HYS)
Temperature rising
Temperature falling
V
＜Input pin part＞
Input pin high level
input voltage
(PWMD, EN, and MS)
Input pin Low level
input voltage
(PWMD, EN, and MS)
IINH
Input pin input current
IINL
MS pin pull down resistance
Measurement pin is PWMD, EN, LD, and RC.
VIN=VREG, VISEN1=0V
Measurement pin is PWMD, EN, MS, LD, and
RC.
VIN=0V, VISEN1=0V
RUP
＜Detection pin part＞
ISEN pin peak voltage
Detection blanking time
VPEAK1
VLD=VREG
VPEAK2
VLD=0.2V to 3.8V
tBLK
0.95
1.0
1.05
VLD/1.5
VLD/1.5
VLD/1.5
-0.1
+0.1
250
6
400
550
V
ns
2014-10-01
TB62D901FNG
11. Description of Operation
11.1 Standard connection diagram
FUSE
TB62D901FNG
VREG
EN
VSEN
VCC
PWMD
PWM input
LD
RC
MS
GATE
GND PGND
ISEN1
ISEN2
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11.2 Operation modes
There are three operation modes, and the modes are set by pins MS and VSEN. Each mode has the different
control method resulting in the different GATE output to the external power MOSFET.
Table 1 Operation Mode Comparison
Output of GATE to Control the Power MOS (M1)
OFF time
On time
It is determined by
It is fixed at 4μs (TYP.).
voltage detection in
(when VRC=0V)
ISEN1 pin
It is determined by
It is determined by voltage
voltage detection in
detection in VSEN pin
ISEN1 pin
It is determined by detecting It is determined by
0 mA of LED current in
voltage detection in
VSEN pin
ISEN1 pin
Pin Settings
Operation mode
MS l
VSEN
VREG
1
Fixed OFF time mode
GND
2
Automatic OFF time
control mode
GND
3
Critical mode
VREG
Connected to the
secondary side of the
transformer
Connected to the
secondary side of the
transformer
11.2.1 Fixed Off time mode
LED current ILED in path A is detected as the voltage on the current-sense resistor RSET on the ISEN1 input.
When I LED rises to the set peak current I LEDP , M1 is turned off. And M1 is turned on again after turned off a
period of time, for example, 4 μs (Typ.) when VRC is 0 V. The peak current can be set with the input voltage to LD
pin. (Please refer to 12.2, Figure for details). The off period can be set by an applied voltage to the RC pin. (Please
refer to 12.3, Figure for details).
VIN of the LEDs is referred to the unregulated diode bridge rectified DC voltage that can fluctuate considerably.
The influence of the input voltage (VIN) change on the LED current can be reduced to the minimum by this control
system. This mode can be implemented with fewer components.
ILED route A
ILED route B
VIN
4us
(TYP)
4us
(TYP)
4us
(TYP)
4us
(TYP)
4us
(TYP)
4us
(TYP)
4us
(TYP)
4us
(TYP)
4us
(TYP)
M1 is ON
VGATE
M1 is OFF
L
Peak current
ILEDP
VSEN
VREG
MS
GATE
VGATE
M1
ISEN1
ISEN2
RSET
ILED
Route where
ILED flows
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
Figure 1. Fixed Off-Time Control
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11.2.2 Automatic OFF Time Control Mode
ILED route A
ILED route B
VIN
TOFF
TOFF
TOFF
TOFF
TOFF
TOFF
TOFF
TOFF
TOFF
M1 is ON
VGATE
M1 is OFF
Peak current
set at pin LD
and sensed at
pin ISEN1
VSEN
MS
ILED
GATE
ISEN1
ISEN2
VGATE
M1
Pathes where
ILED flows
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
RSET
Figure 2 Automatic Off-Time Control
When LED current ILED in path A, which is detected at the ISEN1 pin, rises to the set peak current, M1 is turned off.
And M1 is turned on again after the OFF period of M1 (tOFF) (refer to Figure 2).
The peak current is set by an applied voltage to the LD pin. (Please refer to 12.2 for details).
tOFF is determined by the voltage on inputs VSEN and RC.(Please refer to 12.3, Figure 3 and 8 for details.). In the
example of Figure 2, the voltage at VSEN pin is generated by the secondary side of the transformer and the input
voltage of RC pin.
Secondary side voltage is stabilized by total Vf of LED.
It is recommended that the voltage generated on the secondary side is divided by resistors and to keep the voltage
applied to VSEN pin at around 1V. The Off time of M1 is adjusted automatically when Vf of the LED and the free
wheeling diode are changed due to the temperature characteristics and the change of the voltage applied to VSEN pin
(compared to 1 V) is detected.
Figure 3. OFF time vs. VSEN when VRC
