TS1916
1.7A Boost WLED Driver
SOT-26
Pin Definition:
1. Switch
2. Ground
3. Feedback
4. Enable
5. OVP
6. V
CC
General Description
The TS1916 is a step-up (Boost) converter designed for driving up to 10 series white LEDs for backlighting
application. The TS1916 uses current mode, 1MHz fixed frequency architecture to regulate the LED current,
which is set through an external current sense resistor. It’s low feedback voltage reduces power loss and
improves efficiency. The OVP pin monitors the output voltage and turns off the converter if an over-voltage
condition is present due to an open circuit condition. The TS1916 includes under-voltage lockout, current limiting
and thermal shutdown protection preventing damage in the event of an output overload.
Features
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●
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●
●
●
●
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2.5V to 5.5V operating input voltage range
Drives up to 10 series white LEDs
1MHz fixed switching frequency
Wide range for PWM dimming (200Hz to 200kHz)
Internal 1.7A switching current limit
Over voltage protection (OVP)
Internal soft-start function
Current limit and thermal shutdown protection
Under voltage lockout
Application
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Digital Still Cameras
Portable Electronics
PDAs and Palm-Top Computers
Local Boost Regulator
Ordering Information
Part No.
Package
Packing
TS1916CX6 RFG
SOT-26
3kpcs / 7” Reel
Note:
“G” denotes for Halogen- and Antimony-free as those which
contain <900ppm bromine, <900ppm chlorine (<1500ppm
total Br + Cl) and <1000ppm antimony compounds
Absolute Maximum Ratings
Parameter
V
CC
Pin Voltage
SW Pin Voltage
OVP Pin Voltage
EN, FB Pin Voltage
Power Dissipation
Storage Temperature Range
Operating Junction Temperature Range
Thermal Resistance from junction to case
P
D
T
STG
T
OP
R
θJC
Symbol
V
CC
V
SW
V
OVP
Limit
-0.3 to 6
-0.3 to 45
-0.3 to 45
-0.3 to 6
( T
J
-T
A
) / R
θJA
-65 to +150
-40 to +125
15
40
Unit
V
V
V
V
mW
°C
°C
°C/W
°C/W
R
θJA
Thermal Resistance from junction to ambient
Note:
R
θJA
is measured with the PCB copper area of approximately 1 in
2
(Multi-layer).
1/10
Version: A14
TS1916
1.7A Boost WLED Driver
Electrical Specifications
(T
A
=25
o
C, V
IN
=5V, I
OUT
=20mA unless otherwise noted)
Characteristics
Input Voltage Range
Step-Up Voltage Range
OVP Sense Voltage
Under Voltage Lockout
UVLO Hysteresis
Feedback Voltage
EN Threshold
EN Hysteresis
Operating Quiescent Current
Shutdown Current
N-Channel MOSFET Current Limit
MOSFET On-Resistance
(Note)
Maximum Duty Cycle
Line Regulation
Switching Frequency
Dimming Clock Rate
FB Input Leakage Current
SW Leakage Current
EN Input Leakage Current
Shutdown Delay
Thermal Shutdown
Thermal Shutdown Hysteresis
Note:
Guaranteed by design
f
OSC
f
DIM
I
FB-LKG
I
SWL
I
EN-LKG1
I
EN-LKG2
t
SHDN
T
SD
T
SH
V
FB
= 0.5V
V
LX
= 30V, V
FB
=0.5V
V
EN
= V
CC
V
EN
= GND
(Note)
Symbol
V
CC
V
OUT
V
OVP
U
VLO
Rising
Conditions
Min
2.5
3
--
--
--
Typ
--
--
38
2.2
100
200
--
--
200
300
1
1.7
0.6
88
1
1
--
0.01
--
1.5
--
10
160
30
Max
5.5
40
--
2.4
--
210
--
0.4
--
500
10
--
1.0
--
--
1.25
200
100
1
3
1
--
--
--
Units
V
V
V
V
mV
mV
V
V
mV
μA
μA
A
Ω
%
%
MHz
kHz
nA
µA
μA
μA
ms
°C
V
FB
V
IH
V
IL
190
2.0
--
--
Logic-High Voltage
Logic-Low Voltage
I
CCQ
I
SD
I
LIM
R
DS(on)
D
MAX
I
OUT
= 0mA, V
FB
=0.5V
V
EN
=0V, t
EN
> 20ms
Duty=50%
--
--
--
--
--
V
CC
= 3V to 5V
--
0.75
0.2
--
--
--
--
--
--
--
2/10
Version: A14
TS1916
1.7A Boost WLED Driver
Block Diagram
VCC
EN
UVLO
Reference
1.238V
Soft Start
Enable
Logic
10ms
OVP
Shutdown
OV
300mV
FB
Error Amplifier
Summing
Comparator
Thermal
Shutdown
SW
Control and
Driver Logic
N-MOS
Oscillator
1MHz
GND
Slope
Compensation
Current
Sense
Pin Description
Pin Number
1
2
3
4
5
6
Pin Name
SW
GND
FB
EN
OVP
V
CC
Description
Switch Output Pin
Ground Pin
Feedback Pin; Put a Resistor to GND to Setting the Current
Enable with Dimming Pin; Internal Pull-Low; Logic High Active
OVP Sense Pin
Power Input Pin
3/10
Version: A14
TS1916
1.7A Boost WLED Driver
Application Circuit
For 10 series LED Application with Dimming
I
LED
=V
FB
/R3, V
FB
=200mV
4/10
Version: A14
TS1916
1.7A Boost WLED Driver
Application Information
Setting the ILED Current
Application circuit item shows the basic application circuit with TS1916 adjustable output version. The external
resistor sets the LED output current according to the following equation:
I
LED =
( V
FB
/ R3 )
Part No.
TS1916
I
LED
20mA
350mA
R3
10Ω
0.571Ω
4mW
70mW
Over Voltage Protection
The Over Voltage Protection is detected by a junction breakdown detecting circuit. Once V
OUT
goes over the
detecting voltage, SW pin stops switching and the power N-MOSFET will be turned off. Then, the V
OUT
will be
clamped to be near V
OVP
.
Under Voltage Lockout (UVLO)
To avoid mis-operation of the device at low input voltages an under voltage lockout is included that disables the
device, if the input voltage falls below (2.25V-100mV).
Input Capacitor Selection
The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input
capacitor impedance at the switching frequency shall be less than input source impedance to prevent high
frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must
be used. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and
small temperature coefficients. A 4.7µF ceramic capacitor for most applications is sufficient. For a lower output
power requirement application, this value can be decreased.
Output Capacitor Selection
The output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability. The
output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R
dielectrics are recommended due to their low ESR and high ripple current. A 1µF ceramic capacitors works for most
of the applications. Higher capacitor values can be used to improve the load transient response.
5/10
Version: A14
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