UPSRB03 [UTC]
HIGH PRECISION CC/CV PRIMARY SIDE SWITCHING REGULATOR;
| 型号： | UPSRB03 |
| 厂家： | 
Unisonic Technologies |
| 描述： | HIGH PRECISION CC/CV PRIMARY SIDE SWITCHING REGULATOR 开关 |
| 文件： | 总7页 (文件大小：164K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
UNISONIC TECHNOLOGIES CO., LTD
UPSRB03
Preliminary
LINEAR INTEGRATED CIRCUIT
HIGH PRECISION CC/CV
PRIMARY SIDE SWITCHING
REGULATOR
DESCRIPTION
The UTC UPSRB03 is a primary control unit for switch mode
charger and adapter applications. The controlled variable is
transferred by an auxiliary winding from the secondary to the
primary side. The device uses multi-mode operations to achieve
high performance and high efficiency. Device operations in PFM
in CC mode at large load condition and it operates in PWM with
frequency reduction at light/medium load which can cancel audio
noise.
The UTC UPSRB03 operates in primary-side sensing and
regulation. Opto-coupler and TL431 could be eliminated. It also
eliminates the need of loop compensation circuitry while
maintaining stability.
The UTC UPSRB03 achieves high precision CV/CC regulation
and high power efficiency. It offers comprehensive protection
coverage with auto-recovery features including Cycle-by-cycle
current limiting, output over voltage protection, VDD over voltage
protection, feedback loop open protection, short circuit protection,
leading edge blanking, VDD under voltage lockout, etc.
FEATURES
* Multi-Mode control for cancel audio noise
* ±5% constant voltage regulation at universal AC input
* Primary side control without TL431 and opto-coupler
* Built-in leading edge blanking
* Driver soft start
* Built-in primary winding inductance
* High precision constant current regulation at universal AC input compensation
* Programmable CV and CC regulation
* Eliminates control loop compensation circuitry
* Flyback topology in DCM operation
* Driver BJT switch
* Open circuit protection
* Output over voltage protection
* VDD over voltage protection
* Short circuit protection
* Built-in Line CC compensation
ORDERING INFORMATION
Ordering Number
Package
Packing
UPSRB03G-AF5-R
SOT25
Tape Reel
UPSRB03G-AF5-R
(1)Packing Type
(1) R: Tape Reel
(2) AF5: SOT-25
(2)Package Type
(3)Green Package
(3) G: Halogen Free and Lead Freee
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Copyright © 2016 Unisonic Technologies Co., Ltd
QW-R129-020.a
UPSRB03
Preliminary
LINEAR INTEGRATED CIRCUIT
MARKING
PIN CONFIGURATION
FB
4
VDD
5
1
2
3
GND CS BASE
PIN DESCRIPTION
PIN NO.
PIN NAME
GND
CS
DESCRIPTION
1
2
3
4
5
Ground
Current sense input.
BASE
FB
Base drive for power BJT.
The voltage feedback from the auxiliary winding
Power supply
VDD
BLOCK DIAGRAM
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QW-R129-020.a
UPSRB03
Preliminary
LINEAR INTEGRATED CIRCUIT
ABSOLUTE MAXIMUM RATING
PARAMETER
SYMBOL
VDD
RATINGS
-0.3~30
-0.3~7
UNIT
V
VDD Voltage
BASE Voltage
CS Input Voltage
FB Input Voltage
VBASE
VCS
V
-0.3~7
V
VFB
-0.3~7
V
Junction Temperature
TJ
-40 ~ +150
-55 ~ +150
260
°C
°C
°C
Storage Temperature
TSTG
TOPR
Lead Temperature (Soldering, 10 secs)
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.
ELECTRICAL CHARACTERISTICS (TA=25°C, VDD=20V, if not otherwise noted)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX UNIT
Supply Voltage (VDD) Section
Start up Current
IST
VDD= VTH (ON)-1V
VDD=20V
3
0.8
6.5
18
20
1.5
7.5
19.5
30
μA
mA
V
Static Current
IOP
Turn-off Threshold Voltage
Turn-on Threshold Voltage
VDD Over Voltage Protection
VDD Clamp Voltage
VTH(OFF)
VTH (ON)
VDD_OVP
VDD_Clamp
5.5
16.5
25
V
27.5
30
V
28
32
V
Current Sense Input Section
LEB Time
TLEB
VCS
0.5
μS
Over Current Threshold
490
500
510
mV
From OCP Comparator to
Base Drive
OCP Propagation Delay
TD_OC
100
nS
FB Input Section
Reference Voltage for Feedback
Threshold
VFB
1.98
2.00
2.02
V
Demagnetization comparator threshold
Minimum Pause
VFB DEM
TPAUSE_MIN
TPAUSE_MAX
VFB short
25
2.0
5
mV
μS
mS
V
Maximum Pause
Output Short Circuit Threshold
Output Short Circuit Debounce Time
Ratio between switching period in CC
mode and demagnetization time
Max Cable compensation current
BASE Drive Section
0.6
13
TFB short
mS
T
CC/TDEM
Icable
2
60
μA
Base Sourcing Maximum Current
Base Sourcing Current After Pre-off
Base Drive Low Side On Resistor
IOUT(SOURCE)
IOUT(PRE)
20
30
1
40
mA
mA
Ω
0.5
1.5
RDSON_L
1
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QW-R129-020.a
UPSRB03
Preliminary
LINEAR INTEGRATED CIRCUIT
OPERATION DESCRIPTION
The UTC UPSRB03 is a primary control unit for switch mode charger and adapter applications. It operates in
primary-side sensing and regulation. Opto-coupler and TL431 could be eliminated. Proprietary built-in CV and CC
control can achieve high precision CV/CC performance. It uses Pulse Frequency Modulation (PFM) method to build
discontinuous conduction mode (DCM) flyback power supplies.
Startup control
The VDD pin of UTC UPSRB03 is connected to the line input through a resistor. A large value startup resistor can
be used to minimize the power loss in application because the start current of UTC UPSRB03 is very low. When the
VDD voltage reaches VTH (ON), the internal startup circuit is disabled and the IC turns on.
Operating Current
The Operating current of UTC UPSRB03 is as low as 800μA. Good efficiency and very low standby power can be
achieved.
Constant Voltage Operation
The output voltage is defined by the transmission ratio between the secondary and auxiliary winding. The UTC
UPSRB03 captures the auxiliary winding feedback voltage at FB pin and operates in constant-voltage (CV) mode to
regulate the output voltage. The auxiliary voltage reflects the output voltage is given by:
NA
VAUX
=
×ꢁVO + ∆Vꢀ
(1)
NS
Where △V indicates the drop voltage of the output diode.
Figure2. Auxiliary voltage waveform
Via a resistor divider connected between the auxiliary winding and FB, the VAUX is sampled at the Tsampling end
and it is hold until the next sampling. The sampled voltage is compared with 2V reference voltage and the error is
amplified. The error amplifier output reflects the load condition and controls the Toff time to regulate the output
voltage, thus constant output voltage can be achieved.
Constant Current Operation
When the sampled voltage is below 2V reference voltage and the error amplifier output reaches its maximum, thus
UTC UPSRB03 operates in constant-current (CC) mode. The CC point and maximum output power can be
externally adjusted by external current sense resistor Rcs. The larger Rcs, the smaller CC point is, and the smaller
output power becomes.
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QW-R129-020.a
UPSRB03
Preliminary
LINEAR INTEGRATED CIRCUIT
OPERATION DESCRIPTION (Cont.)
Figure3. Adjustable output power by changing RCS
Figure4. Secondary current waveform
In CC operation, the CC loop control function of UTC UPSRB03 will keep a fixed proportion between secondary
inductance de-magnetization time (Tdemag) and switching cycle time (Tsw). The fixed proportion is
Tdemag
1
2
=
(2)
(3)
TSW
Thus the output current is given by:
Tdemag
1
2
NP
NS
1
4
NP
NS
Iout
=
×
×IPK
×
=
×
×IPK
TSW
Current Sensing and Leading Edge Blanking
Cycle-by-cycle current limiting is offered in UTC UPSRB03. The switch current is detected by a sense resistor into
the CS pin. When the power switch is turned on, a turn-on spike will occur on this resistor. A 500ns leading-edge
blanking is built in to avoid false-termination of the switching pulse so that the external RC filtering is no longer
needed.
Programmable Cable Drop Compensation
UTC UPSRB03 has a built-in cable voltage drop compensation to achieve good load regulation. An offset voltage
is generated at FB pin by an internal current flowing into the resistor divider. The current is inversely proportional to
the output load current. The voltage drop across the cable is compensated by this offset voltage at FB pin. It can
also be programmed by adjusting the resistance of the divider to compensate the drop for various cable lines used.
Built-in Load and Line CC Compensation
In conventional PSR system, the output CC point can vary with output and line voltage. UTC UPSRB03 has
built-in blocks to compensate the variation. The device can adjust CC point based on sensed output voltage and
PFM duty. In this way, CC accuracy can be improved.
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QW-R129-020.a
UPSRB03
Preliminary
LINEAR INTEGRATED CIRCUIT
OPERATION DESCRIPTION (Cont.)
Drive BJT
The driver is a push pull stage with the supply voltage VDD. It provides the driving current for the external power
bipolar transistor. The output signal is current-limited to IOUT(SOURCE)
.
Protection Control
Good power supply system reliability is achieved with its comprehensive protection features including output
over-voltage protection, VDD over voltage protection, feedback loop open protection, Cycle-by-cycle current limiting,
short circuit protection, leading edge blanking and UVLO, etc.
VDD is supplied by transformer auxiliary winding output. The output of UTC UPSRB03 is shutdown when VDD drops
below VTH(OFF) and the power converter enters power on start-up sequence thereafter.
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QW-R129-020.a
UPSRB03
Preliminary
LINEAR INTEGRATED CIRCUIT
TYPICAL APPLICATION CIRCUIT
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.
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