Datasheet

UNISONIC TECHNOLOGIES CO., LTD
UPSL102
Preliminary
LINEAR INTEGRATED CIRCUIT
HIGH PRECISION CC
PRIMARY-SIDE LED
CONTROLLER
3

2
1
DESCRIPTION
5
The UTC UPSL102 is a high performance offline PSR controller
for LED lighting, which can achieve accurate LED current and low
system cost for an isolated lighting application in a single stage
converter. Consequently, opto-coupler and TL431 could be
eliminated. Constant Current (CC) control is intergrated as shown
in the figure below.
In CC control, the current can be adjusted externally by the
sense resistor RS at CS pin. The chip consumes low start up
current and very low operation current (typical 350μA), it can
achieve high efficiency and low standby power consumption.
The UTC UPSL102 offers comprehensive protection coverage
with auto-recovery features including open loop protection, short
circuit protection, cycle-by-cycle current limiting, VDD over voltage
protection, built-in leading edge blanking, VDD under voltage
lockout (UVLO), etc.

SOT-25
FEATURES
* Primary-side sensing and regulation without TL431 and
opto-coupler
* High precision constant current regulation at universal AC input
* Low system cost and high efficiency
* Built-in primary winding inductance compensation
* Programmable CC regulation
* Drivability for BJT switch

4
* Short circuit protection
* Ultra low start-up current (Typ. 1μA)
* Open loop protection
* Built-in leading edge blanking (LEB)
* Cycle-by-cycle current limiting
* VDD under voltage lockout with hysteresis
* VDD over voltage protection
ORDERING INFORMATION
Ordering Number
UPSL102G-AF5-R
UPSL102G-AF5-R
Package
SOT-25
(1)Packing Type
(1) R: Tape Reel
(2)Package Type
(2) AF5: SOT-25
(3)Green Package
(3) G: Halogen Free and Lead Free
www.unisonic.com.tw
Copyright © 2014 Unisonic Technologies Co., Ltd
Packing
Tape Reel
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UPSL102

Preliminary
LINEAR INTEGRATED CIRCUIT
MARKING
5
4
L102G
1

2
3
PIN CONFIGURATION
VDD
INV
4
5

2
3
GND
CS
BASE
PIN DESCRIPTION
PIN NO.
1
2
3
4
5

1
PIN NAME
GND
CS
BASE
INV
VDD
DESCRIPTION
Ground
Current sense input.
Base driver with current limit for power BJT.
The voltage feedback from auxiliary winding.
Power supply.
BLOCK DIAGRAM
VDD
5
Internal
Supply
OVP
UVLO
OSC
5V
POR
INV 4
CC
Controller
GND 1
Base
Drive
Logic
Control
OTP
OCP
3 BASE
2 CS
LEB
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UPSL102

Preliminary
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
RATINGS
UNIT
VDD Voltage
-0.3~30
V
BASE Voltage
-0.3~7
V
CS Input Voltage
-0.3~7
V
INV Input Voltage
-0.3~7
V
Junction Temperature
TJ
-40~150
°C
Storage Temperature
TSTG
-55~150
°C
Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged.
Absolute maximum ratings are stress ratings only and functional device operation is not implied.

CAL CHARACTERISTICS (VDD=15V, TA=25°C, if not otherwise noted.)
PARAMETER
Supply Voltage (VDD) Section
Start up Current
Static Current
VDD Under Voltage Lockout Enter
VDD Under Voltage Lockout Exit
VDD Over Voltage Protection
Current Sense Input Section
Lead Time
Over Current Threshold
OCP Propagation Delay
INV Input Section
Maximum Pause
BASE Drive Section
Base Sourcing Maximum Current
Base Sourcing Current After Pre-off
Base Drive Low Side On Resistor
SYMBOL
ISTART-UP
ISTATIC
UVLO(ON)
UVLO(OFF)
VDD_OVP
TEST CONDITIONS
MAX
UNIT
5.0
11.5
23
0.1
350
6.0
12.5
26
3
500
7.6
13.5
29
μA
μA
V
V
V
1.21
0.5
1.23
1.25
μS
V
From OCP Comparator to
Base Drive
100
nS
TPAUSE_MAX
710
765
810
μS
IS_MAX
40
1.9
50
2.4
1.8
60
2.9
mA
mA
Ω
IS_PREOFF
RDSON_l
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
TYP
VDD=11V
VDD=15V
TLEB
Vth_OCP
Td_OC
MIN
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UPSL102

Preliminary
LINEAR INTEGRATED CIRCUIT
OPERATION DESCRIPTION
The UTC UPSL102 is a cost effective PSR controller optimized for off-line LED lighting applications which can
achieve accurate LED current. It operates in primary side sensing and regulation, eliminating the need of
opto-coupler and TL431, which makes the solution simple, small and low cost. Proprietary built-in CC control
meeting accurate LED current.
Startup Current and Start up Control
Startup current of UTC UPSL102 is designed to be very low so that VDD can be charged up quickly. A large value
startup resistor can therefore be used to minimize the power loss in application.
Operating Current
The operating current of UTC UPSL102 is designed to be very low so that VDD could be charged up above UVLO
threshold and starts up quickly. Good efficiency and very low standby power is achieved with the low operating
current.
Adjustable CC point
In UTC UPSL102, the CC point can be externally adjusted by external current sense resistor RS at CS pin as
illustrated in typical application diagram. The larger RS is, the smaller CC point is, and vice versa.
Principle of CC Operation
To support the UTC UPSL102 proprietary CC control, system needs to be designed in DCM mode for flyback
system. For flyback operating in DCM, the output current Iout is given by
1
Iout = LPFSWIP2 η / Vout
(1)
2
Where LP indicates the inductance of primary winding and IP is the peak current of primary winding.
Refer to the equation 1, the change of the primary winding inductance results in the change of the constant output
current. To compensate the change from variations of primary winding inductance, the switching frequency is locked
by an internal loop such that the switching frequency is
1
FSW =
(2)
2TDemag
Since TDemag is inversely proportional to the inductance, as a result, the product LP and fSW is constant, thus output
current will not change as primary winding inductance changes. Up to ±10% variation of the primary winding
inductance can be compensated.
The output LED current is
1 V
Iout = N thoc
(3)
4
RS
Where N is the ratio of transformer between primary side winding and secondary winding.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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UPSL102

Preliminary
LINEAR INTEGRATED CIRCUIT
OPERATION DESCRIPTION(Cont.)
CS and LEB
Cycle-by-Cycle current limiting is offered in UTC UPSL102. The switch current is detected by a sense resistor into
the CS pin. An internal leading edge blanking circuit chops off the sensed voltage spike at initial power BJT on state
so that the external RC filtering on sense input is no longer needed.
Protection Control
Good power supply system reliability is achieved with its rich protection features including Cycle-by-Cycle current
limiting (OCP), VDD over voltage protection, feedback loop open protection, short circuit protection and Under
Voltage Lockout on VDD (UVLO).
Because of the coupling between secondary winding and auxiliary winding, the voltage at VDD pin will rise up if the
output of secondary side is open-circuited, when VDD pin voltage is larger than 27V, the UTC UPSL102 will stop
sending pulses to BASE pin and enter auto restart mode.
If the output of secondary side is short-circuited, the VDD voltage will drop down and the system enters under
voltage lockout protection.
Base Drive
The drive is a push pull stage with supply voltage VDD. It provides the driving current for the external power bipolar
transistor. The output signal is current limit to Is_max (typical 30mA).
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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UPSL102

Preliminary
LINEAR INTEGRATED CIRCUIT
TYPICAL APPLICATION CIRCUIT
VLED
NP
~
AC
+
NS
UTC
UPSL102
GND
+ CO
+
NAUX
VDD
CS
BASE
INV
RS
UTC assumes no responsibility for equipment failures that result from using products at values that
exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or
other parameters) listed in products specifications of any and all UTC products described or contained
herein. UTC products are not designed for use in life support appliances, devices or systems where
malfunction of these products can be reasonably expected to result in personal injury. Reproduction in
whole or in part is prohibited without the prior written consent of the copyright owner. The information
presented in this document does not form part of any quotation or contract, is believed to be accurate
and reliable and may be changed without notice.
UNISONIC TECHNOLOGIES CO., LTD
www.unisonic.com.tw
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