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UCC28700, UCC28701, UCC28702, UCC28703
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
UCC2870x Constant-Voltage, Constant-Current Controller With Primary-Side Regulation
1 Features
3 Description
•
•
The UCC28700 family of flyback power supply
controllers provides Constant-Voltage (CV) and
Constant-Current (CC) output regulation without the
use of an optical coupler. The devices process
information from the primary power switch and an
auxiliary flyback winding for precise control of output
voltage and current. Low start-up current, dynamically
controlled operating states and a tailored modulation
profile support very low standby power without
sacrificing start-up time or output transient response.
1
•
•
•
•
•
•
•
•
•
•
< 30-mW No-Load Power for 5-Star Rating
Primary-Side Regulation (PSR) Eliminates OptoCoupler
±5% Voltage and Current Regulation
130-kHz Maximum Switching Frequency Enables
High-Power Density Charger Designs
Quasi-Resonant Valley-Switching Operation for
Highest Overall Efficiency
Patent-Pending Frequency-Jitter Scheme to Ease
EMI Compliance
Wide VDD Range Allows Small Bias Capacitor
Clamped Gate-Drive Output for MOSFET
Protection Functions: Overvoltage, Low-Line, and
Overcurrent
Programmable Cable Compensation (UCC28700
Only)
NTC Resistor Interface (UCC28701, UCC28702
and UCC28703 Only) With Fixed Cable
Compensation Options
SOT-23 Package
Control algorithms in the UCC28700 family allow
operating efficiencies to meet or exceed applicable
standards. The output drive interfaces to a MOSFET
power switch. Discontinuous Conduction Mode
(DCM) with valley switching reduces switching losses.
Modulation of switching frequency and primary
current peak amplitude (FM and AM) keeps the
conversion efficiency high across the entire load and
line ranges.
The controllers have a maximum switching frequency
of 130 kHz and always maintain control of the peakprimary current in the transformer. Protection features
help keep primary and secondary component
stresses in check. The UCC28700 allows the level of
cable compensation to be programmed. The
UCC28701, UCC28702, and UCC28703 devices
allow remote temperature sensing using a Negative
Temperature Coefficient (NTC) resistor while
providing fixed cable-compensation levels.
2 Applications
•
•
USB-Compliant Adapters and Chargers for
Consumer Electronics (Cell Phones, Tablets and
Cameras)
AC and DC Power Supplies
Device Information(1)
PART NUMBER
PACKAGE
BODY SIZE (NOM)
UCC28700
UCC28701
SOT-23 (6)
UCC28702
2.90 mm × 1.60 mm
UCC28703
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Typical Application Schematic
+ VF -
VBLK
CB2
+
CB1
NP
NS
COUT
RPL VOUT
–
VAC
RSTR
UCC28700
SOT23-6
+ VFA -
VAUX
VDD
CDD
NA
RS1
DRV
VS
RLC
CS
RS2
CBC
RCS
RCBC
GND
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
UCC28700, UCC28701, UCC28702, UCC28703
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
www.ti.com
Table of Contents
1
2
3
4
5
6
7
8
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Device Comparison Table.....................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
3
4
7.1
7.2
7.3
7.4
7.5
7.6
7.7
4
4
4
5
5
6
7
Absolute Maximum Ratings .....................................
ESD Ratings ............................................................
Recommended Operating Conditions.......................
Thermal Information ..................................................
Electrical Characteristics...........................................
Switching Characteristics ..........................................
Typical Characteristics ..............................................
Detailed Description .............................................. 9
8.1 Overview ................................................................... 9
8.2 Functional Block Diagram ......................................... 9
8.3 Feature Description................................................. 10
8.4 Device Functional Modes........................................ 12
9
Applications and Implementation ...................... 17
9.1 Application Information............................................ 17
9.2 Typical Application .................................................. 17
10 Power Supply Recommendations ..................... 24
11 Layout................................................................... 24
11.1 Layout Guidelines ................................................. 24
11.2 Layout Example .................................................... 25
12 Device and Documentation Support ................. 25
12.1
12.2
12.3
12.4
12.5
Device Support......................................................
Documentation Support ........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
25
27
28
28
28
13 Mechanical, Packaging, and Orderable
Information ........................................................... 28
4 Revision History
Changes from Original (July 2012) to Revision A
•
2
Page
Added Handling Rating table, Feature Description section, Device Functional Modes, Application and
Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation
Support section, and Mechanical, Packaging, and Orderable Information section ............................................................... 1
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Copyright © 2012–2014, Texas Instruments Incorporated
Product Folder Links: UCC28700 UCC28701 UCC28702 UCC28703
UCC28700, UCC28701, UCC28702, UCC28703
www.ti.com
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
5 Device Comparison Table (1) (2)
PART NUMBER
(1)
(2)
VERSION
UCC28700
Programmable cable compensation
UCC28701
NTC, 0 mV (at 5-V output) cable compensation option
UCC28702
NTC, 150 mV (at 5-V output) cable compensation option
UCC28703
NTC, 300 mV (at 5-V output) cable compensation option
See Addendum for specific device ordering information.
For other fixed cable compensation options, please consult the factory.
6 Pin Configuration and Functions
UCC28700/1/2/3
SOT-6 (DBV)
CBC (00)
1
NTC (1/2/3)
6
VS
VDD 2
5
GND
DRV 3
4
CS
(TOP VIEW)
Pin Functions
PIN
NAME
CBC
UCC28700
UCC28701/2/3
NO.
NO.
1
—
I/O
DESCRIPTION
I
Cable Compensation (CBC) is a programming pin for compensation of
cable voltage drop. Cable compensation is programmed with a resistor to
GND.
CS
4
4
I
Current Sense (CS) input connects to a ground-referenced current-sense
resistor in series with the power switch. The resulting voltage is used to
monitor and control the peak primary current. A series resistor can be
added to this pin to compensate the peak switch current levels as the ACmains input varies.
DRV
3
3
O
Drive (DRV) is an output used to drive the gate of an external high voltage
MOSFET switching transistor.
GND
5
5
—
The Ground (GND) pin is both the reference pin for the controller and the
low-side return for the drive output. Special care should be taken to return
all AC decoupling capacitors as close as possible to this pin and avoid any
common trace length with analog signal return paths.
NTC
—
1
I
NTC is an interface to an external NTC (negative temperature coefficient)
resistor for remote temperature sensing. Pulling this pin low shuts down
PWM action.
VDD
2
2
—
VDD is the bias supply input pin to the controller. A carefully-placed bypass
capacitor to GND is required on this pin.
I
Voltage Sense (VS) is an input used to provide voltage and timing feedback
to the controller. This pin is connected to a voltage divider between an
auxiliary winding and GND. The value of the upper resistor of this divider is
used to program the AC-mains run and stop thresholds and line
compensation at the CS pin.
VS
6
6
Copyright © 2012–2014, Texas Instruments Incorporated
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3
UCC28700, UCC28701, UCC28702, UCC28703
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
www.ti.com
7 Specifications
Absolute Maximum Ratings (1)
7.1
over operating free-air temperature range (unless otherwise noted)
MIN
MAX
UNIT
38
V
Bias supply voltage
VVDD
Continuous gate current sink
IDRV
50
Continuous gate current source
IDRV
Selflimiting
Peak VS pin current
IVS
Gate-drive voltage at DRV
−1.2
VDRV
−0.5
Selflimiting
VS
−0.75
7
Voltage range
CS, CBC (UCC28700),
NTC (UCC28701/2/3)
−0.5
5
Operating junction temperature range
TJ
−55
150
Lead temperature 0.6 mm from case for 10 seconds
V
°C
260
Storage temperature, Tstg
(1)
mA
–65
150
°C
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating
Conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. All voltages
are with respect to GND. Currents are positive into, negative out of the specified terminal. These ratings apply over the operating
ambient temperature ranges unless otherwise noted.
7.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±2000
Charged-device model (CDM), per JEDEC specification JESD22C101 (2)
±500
UNIT
V
JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
7.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
MIN
MAX
9
35
0.047
1
UNIT
VDD
Bias supply operating voltage
CVDD
VDD bypass capacitor
RCBC
Cable-compensation resistance
10
kΩ
IVS
VS pin current
−1
mA
TJ
Operating junction temperature
4
Submit Documentation Feedback
−20
125
V
µF
°C
Copyright © 2012–2014, Texas Instruments Incorporated
Product Folder Links: UCC28700 UCC28701 UCC28702 UCC28703
UCC28700, UCC28701, UCC28702, UCC28703
www.ti.com
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
7.4 Thermal Information
UCC2870x
THERMAL METRIC (1)
DBV
UNIT
6 PINS
Junction-to-ambient thermal resistance (2)
θJA
180
(3)
θJCtop
Junction-to-case (top) thermal resistance
θJB
Junction-to-board thermal resistance (4)
44.4
ψJT
Junction-to-top characterization parameter (5)
5.1
ψJB
Junction-to-board characterization parameter (6)
43.8
(1)
(2)
(3)
(4)
(5)
(6)
71.2
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, high-K board, as
specified in JESD51-7, in an environment described in JESD51-2a.
The junction-to-case (top) thermal resistance is obtained by simulating a cold plate test on the package top. No specific JEDECstandard test exists, but a close description can be found in the ANSI SEMI standard G30-88.
The junction-to-board thermal resistance is obtained by simulating in an environment with a ring cold plate fixture to control the PCB
temperature, as described in JESD51-8.
The junction-to-top characterization parameter, ψJT, estimates the junction temperature of a device in a real system and is extracted
from the simulation data for obtaining RθJA, using a procedure described in JESD51-2a (sections 6 and 7).
The junction-to-board characterization parameter, ψJB, estimates the junction temperature of a device in a real system and is extracted
from the simulation data for obtaining RθJA, using a procedure described in JESD51-2a (sections 6 and 7).
7.5 Electrical Characteristics
over operating free-air temperature range, VDD = 25 V, RCBC = RNTC = open, –20°C ≤ TA ≤ 125°C, TJ = TA
(unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
mA
BIAS SUPPLY INPUT
IRUN
Supply current, run
IDRV = 0, run state
2.1
2.65
IWAIT
Supply current, wait
IDRV = 0, wait state
85
110
ISTART
Supply current, start
IDRV = 0, VVDD = 18 V, start state
1
1.5
IFAULT
Supply current, fault
IDRV = 0, fault state
2.1
2.8
µA
mA
UNDER-VOLTAGE LOCKOUT
VVDD(on)
VDD turn-on threshold
VVDD low to high
19
21
23
VVDD(off)
VDD turn-off threshold
VVDD high to low
7.7
8.1
8.45
VVSR
Regulating level
Measured at no-load condition, TJ = 25°C
4.01
4.05
4.09
V
VVSNC
Negative clamp level
IVS = -300 µA, volts below ground
190
250
325
mV
IVSB
Input bias current
VVS = 4 V
–0.25
0
0.25
µA
V
VS INPUT
CS INPUT
VCST(max) Max CS threshold voltage
VVS = 3.7 V (1)
715
750
775
VCST(min)
Min CS threshold voltage
VVS = 4.35 V (1)
230
250
270
KAM
AM control ratio
VCST(max) / VCST(min)
2.75
3.0
3.15
V/V
VCCR
constant-current regulating
level
CC regulation constant
310
319
329
mV
KLC
Line compensating current
ratio
IVSLS = -300 µA, IVSLS / current out of CS pin
23
25
28
A/A
TCSLEB
Leading-edge blanking time
DRV output duration, VCS = 1 V
195
235
275
ns
IDRS
DRV source current
VDRV = 8 V, VVDD = 9 V
20
25
RDRVLS
DRV low-side drive resistance IDRV = 10 mA
VDRCL
DRV clamp voltage
RDRVSS
DRV pull-down in start state
mV
DRV
(1)
VVDD = 35 V
150
mA
Ω
6
12
14
16
V
200
230
kΩ
These devices automatically vary the control frequency and current sense thresholds to improve EMI performance, these threshold
voltages and frequency limits represent average levels.
Copyright © 2012–2014, Texas Instruments Incorporated
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Product Folder Links: UCC28700 UCC28701 UCC28702 UCC28703
5
UCC28700, UCC28701, UCC28702, UCC28703
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
www.ti.com
Electrical Characteristics (continued)
over operating free-air temperature range, VDD = 25 V, RCBC = RNTC = open, –20°C ≤ TA ≤ 125°C, TJ = TA
(unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNITS
PROTECTION
VOVP
Over-voltage threshold
At VS input, TJ = 25°C
4.52
4.6
4.68
VOCP
Over-current threshold
At CS input
1.4
1.5
1.6
IVSL(run)
VS line-sense run current
Current out of VS pin – increasing
190
220
260
IVSL(stop)
VS line-sense stop current
Current out of VS pin – decreasing
70
80
95
KVSL
VS line-sense ratio
IVSL(run) / IVSL(stop)
2.5
2.8
3.05
TJ(stop)
Thermal shut-down
temperature
Internal junction temperature
165
V
µA
A/A
°C
CABLE COMPENSATION (UCC28700 ONLY)
VCBC(max)
Cable compensation
maximum voltage
Voltage at CBC at full load
2.8
3.0
3.4
VCVS(min)
Compensation at VS
VCBC = open, change in VS regulating level at full
load
–45
–15
25
VCVS(max)
Maximum compensation at
VS
VCBC = 0 V, change in VS regulating level at full
load
275
320
365
–45
–15
25
V
mV
CABLE COMPENSATION (UCC28701, UCC28702, AND UCC28703 ONLY)
VCVS
Compensation at VS
(UCC28701)
Change in VS regulating level at full load
VCVS
Compensation at VS
(UCC28702)
Change in VS regulating level at full load
100
VCVS
Compensation at VS
(UCC28703)
Change in VS regulating level at full load
200
mV
NTC INPUT (UCC28701, UCC28702, AND UCC28703 ONLY)
VNTCTH
NTC shut-down threshold
Fault UVLO cycle when below this threshold
0.95
V
INTC
NTC pull-up current
Current out of pin
105
µA
7.6 Switching Characteristics
over operating free-air temperature range (unless otherwise noted)
MIN
TYP
MAX
UNIT
fSW(max)
Maximum switching frequency
PARAMETER
VVS = 3.7 V (1)
120
130
140
kHz
fSW(min)
Minimum switching frequency
VVS = 4.35 V (1)
875
1000
1100
Hz
TZTO
Zero-crossing timeout delay
1.8
2.1
2.45
µs
(1)
6
TEST CONDITIONS
These devices automatically vary the control frequency and current sense thresholds to improve EMI performance, these threshold
voltages and frequency limits represent average levels.
Submit Documentation Feedback
Copyright © 2012–2014, Texas Instruments Incorporated
Product Folder Links: UCC28700 UCC28701 UCC28702 UCC28703
UCC28700, UCC28701, UCC28702, UCC28703
www.ti.com
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
7.7 Typical Characteristics
At VDD = 25 V, unless otherwise noted.
10
10
Run State
IRUN, VDD = 25 V
1
IVDD − Bias Supply Current (mA)
IVDD − Bias Supply Current (mA)
1
Wait State
0.1
0.01
VDD Turn−Off
0.001
VDD Turn−On
IWAIT, VDD = 25 V
0.1
0.01
0.001
0.0001
ISTART, VDD = 18 V
Start State
0.00001
0
5
10
15
20
25
VDD − Bias Supply Voltage (V)
30
35
0.0001
−25
0
25
50
75
TJ − Temperature (°C)
100
G001
G002
Figure 1. Bias Supply Current vs. Bias Supply Voltage
Figure 2. Bias Supply Current vs. Temperature
300
4.10
250
VS Line Sense Current (µA)
VVSR − VS Regulation Voltage (V)
4.08
4.06
4.04
4.02
4.00
IVSLRUN
200
150
100
IVSLSTOP
50
3.98
3.96
−25
0
25
50
75
TJ − Temperature (°C)
100
0
−20
125
5
30
55
80
TJ − Temperature (°C)
105
G003
Figure 4. Line-Sense Current vs. Temperature
330
VCCR − Constant Current Regulating Level (mV)
270
VCSTMIN − Minimum CS Threshold Voltage (mV)
125
G004
Figure 3. VS Regulation Voltage vs. Temperature
265
260
255
250
245
240
235
230
−25
125
0
25
50
75
TJ − Temperature (°C)
100
125
325
320
315
310
−25
0
25
50
75
TJ − Temperature (°C)
G005
Figure 5. Minimum CS Threshold Voltage vs. Temperature
Copyright © 2012–2014, Texas Instruments Incorporated
100
125
G006
Figure 6. Constant-Current Regulating Level vs.
Temperature
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UCC28700, UCC28701, UCC28702, UCC28703
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
www.ti.com
Typical Characteristics (continued)
At VDD = 25 V, unless otherwise noted.
FSWMIN − Minimum Switching Frequency (Hz)
1100
1075
1050
1025
1000
975
950
925
900
875
−25
0
25
50
75
TJ − Temperature (°C)
100
125
G007
VDRV = 8 V, VVDD = 9 V
Figure 7. Minimum Switching Frequency vs. Temperature
Figure 8. DRV Source Current vs. Temperature
120
115
0.98
INTC −NTC Pull−up Current (µA)
VNTCTH − NTC Shutdown Threshold Voltage (V)
1.00
0.96
0.94
0.92
0.90
−25
110
105
100
95
0
25
50
75
TJ − Temperature (°C)
100
90
−25
125
0
25
50
75
TJ − Temperature (°C)
G009
100
125
G010
Figure 9. NTC Shutdown Threshold Voltage vs. Temperature
Figure 10. NTC Pullup Current vs. Temperature
4.68
VOVP − VS Over−Voltage Threshold (V)
4.66
4.64
4.62
4.60
4.58
4.56
4.54
4.52
−25
0
25
50
75
TJ − Temperature (°C)
100
125
G011
Figure 11. Overvoltage Threshold vs. Temperature
8
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Copyright © 2012–2014, Texas Instruments Incorporated
Product Folder Links: UCC28700 UCC28701 UCC28702 UCC28703
UCC28700, UCC28701, UCC28702, UCC28703
www.ti.com
SLUSB41A – JULY 2012 – REVISED DECEMBER 2014
8 Detailed Description
8.1 Overview
The UCC28700 is a flyback power supply controller which provides accurate voltage and constant current
regulation with primary-side feedback, eliminating the need for opto-coupler feedback circuits. The controller
operates in discontinuous conduction mode with valley-switching to minimize switching losses. The modulation
scheme is a combination of frequency and primary peak current modulation to provide high conversion efficiency
across the load range. The control law provides a wide-dynamic operating range of output power to achieve the