UCC28C4x-EP
BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS
www.ti.com
FEATURES
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(1)
Controlled Baseline
– One Assembly/Test Site, One Fabrication
Site
– Extended Temperature Performance of
–55°C to 125°C
Enhanced Diminishing Manufacturing Sources
(DMS) Support
Enhanced Product-Change Notification
Qualification Pedigree (1)
Enhanced Replacements for UC2842A Family
With Pin-to-Pin Compatibility
1 MHz Operation
50 µA Standby Current, 100 µA Maximum
Component qualification in accordance with JEDEC and
industry standards to ensure reliable operation over an
extended temperature range. This includes, but is not limited
to, Highly Accelerated Stress Test (HAST) or biased 85/85,
temperature cycle, autoclave or unbiased HAST,
electromigration, bond intermetallic life, and mold compound
life. Such qualification testing should not be viewed as
justifying use of this component beyond specified
performance and environmental limits.
SGLS352B – DECEMBER 2006 – REVISED MAY 2007
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Low Operating Current of 2.3 mA at 52 kHz
Fast 35 ns Cycle-by-Cycle Overcurrent
Limiting
±1 A Peak Output Current
Rail-to-Rail Output Swings With 25 ns Rise
and 20 ns Fall Times
±1% Initial Trimmed 2.5 V Error Amplifier
Reference
Trimmed Oscillator Discharge Current
New Undervoltage Lockout Versions
MSOP-8 Package Minimizes Board Space
APPLICATIONS
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Switch Mode Power Supplies
DC-to-DC Converters
Board Mount Power Modules
DESCRIPTION
The UCC28C4x family are high performance current mode PWM controllers. They are enhanced BiCMOS
versions with pin-for-pin compatibility to the industry standard UC284xA family and UC284x family of PWM
controllers. In addition, lower startup voltage versions of 7 V are offered as UCC28C40 and UCC28C41.
Providing necessary features to control fixed frequency, peak current mode power supplies, this family offers
several performance advantages. These devices offer high frequency operation up to 1 MHz with low start up
and operating currents, thus minimizing start up loss and low operating power consumption for improved
efficiency. The devices also feature a fast current sense to output delay time of 35 ns, and a ±1 A peak output
current capability with improved rise and fall times for driving large external MOSFETs directly.
The UCC28C4x family is offered in 8-pin package SOIC (D).
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2006–2007, Texas Instruments Incorporated
UCC28C4x-EP
BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS
www.ti.com
SGLS352B – DECEMBER 2006 – REVISED MAY 2007
AVAILABLE OPTIONS
TA
MAXIMUM
DUTY CYCLE
100%
–55°C to 125°C
50%
(1)
(2)
UVLO
ON/OFF
SOIC-8
SMALL OUTLINE
(D) (1)
14.5 V/9 V
UCC28C42MDREP (2)
8.4 V/7.6 V
UCC28C43MDREP
7 V/6.6 V
UCC28C40MDREP (2)
14.5 V/9 V
UCC28C44MDREP (2)
8.4 V/7.6 V
UCC28C45MDREP
7 V/6.6 V
UCC28C41MDREP (2)
D (SOIC-8) packages are available taped and reeled. Add R suffix to device type (e.g., UCC28C42DREP) to order quantities of 2500
devices per reel. Tube quantities are 75 for D packages (SOIC-8).
Product Preview
FUNCTIONAL BLOCK DIAGRAM
Note: Toggle flip-flop used only in UCC28C41, UCC28C44, and UCC28C45.
2
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UCC28C4x-EP
BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS
www.ti.com
SGLS352B – DECEMBER 2006 – REVISED MAY 2007
Absolute Maximum Ratings
(1) (2)
over operating free-air temperature range (unless otherwise noted)
MIN
Supply voltage
MAX
20
V
Max ICC
30
mA
Output current, IOUT peak
±1
A
5
µJ
Output energy, capacitive load
Voltage rating
UNIT
VDD
COMP, CS, FB
–0.3
6.3
OUT
–0.3
20
RT/CT
–0.3
6.3
VREF
V
7
10
mA
TJ
Error amplifier output sink current
Operating junction temperature range (3)
–55
150
°C
Tstg
Storage temperature range
–65
150
°C
300
°C
Lead temperature (soldering, 10 s)
(1)
(2)
(3)
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 ground. Currents are positive into and negative out of the specified terminals.
Long-term high temperature storage and/or extended use at maximum recommended operating conditions may result in a reduction of
overall device life. See http://www.ti.com/ep_quality for additional information about enhanced plastic packaging.
Dissipation Ratings
PACKAGE
D
θja
TA < 25°C
DERATING FACTOR
TA = 70°C
TA = 85°C
TA = 125°C
(°C/W)
POWER RATING
ABOVE TA = 25°C
POWER RATING
POWER RATING
POWER RATING
176
710 mW
5.68 mW/°C
454 mW
369 mW
142 mW
Recommended Operating Conditions
MIN
MAX
UNIT
VDD
Input voltage
18
V
VOUT
Output voltage range
18
V
IOUT
(1)
Average output current
200
mA
IOUT(ref) (1)
Reference output current
–20
mA
TJ (1)
Operating junction temperature
150
°C
(1)
–55
It is not recommended that the device operate under conditions beyond those specified in this table for extended periods of time.
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UCC28C4x-EP
BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS
www.ti.com
SGLS352B – DECEMBER 2006 – REVISED MAY 2007
Electrical Characteristics
VDD = 15 V (1), RT = 10 kΩ, CT = 3.3 nF, CVDD = 0.1 µF and no load on the outputs, TA = TJ = –55°C to 125°C for the
UCC28C4x
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
5
5.1
V
0.2
20
mV
Reference
Output voltage, initial accuracy
TA = 25°C , IOUT = 1 mA
Line regulation
VDD = 12 V to 18 V
Load regulation
1 mA to 20 mA
Temperature stability
(2)
Total output variation
(2)
4.9
3
25
mV
0.2
0.4
mV/°C
5.18
V
4.82
Output noise voltage
10 Hz to 10 kHz, TA = 25°C
Long term stability
1000 hours, TA = 125°C (2)
µV
50
5
25
mV
–30
–45
–55
mA
TA = 25°C (3)
50.5
53
55
kHz
TA = Full Range (3)
50.5
57
KHz
Output short circuit
Oscillator
Initial accuracy
Voltage stability
VDD = 12 V to 18 V
(2)
Temperature stability
TMIN to TMAX
Amplitude
RT/CT pin peak to peak
Discharge current
0.2
2.85
%
1
2.5
%
1.9
V
TA = 25°C, RT/CT = 2 V (4)
7.7
8.4
9
mA
RT/CT = 2 V (4)
7.2
8.4
9.5
mA
2.475
2.500
2.525
2.45
2.50
2.55
V
–0.1
–2
µA
Error Amplifier
Feedback input voltage, initial accuracy
VCOMP = 2.5 V, TA = 25°C
Feedback input voltage, total variation
VCOMP = 2.5 V
Input bias current
AVOL
Open-loop voltage gain
VOUT = 2 V to 4 V
65
90
dB
1.5
MHz
2
14
mA
–0.5
–1
mA
5
6.8
Unity gain bandwidth
PSRR
Power-supply rejection ratio
VDD = 12 V to 18 V
Output sink current
VFB = 2.7 V, VCOMP = 1.1 V
Output source current
VFB = 2.3 V, VCOMP = 5 V
VOH
High-level output voltage
VFB = 2.3 V, RLOAD = 15 k to GND
VOL
Low-level output voltage
VFB = 2.7 V, RLOAD = 15 k to VREF
V
60
dB
V
0.1
1.1
V
3
3.15
V/V
3.15
V/V
Current Sense
Gain
PSRR
TA = 25°C
(5) (6)
TA = Full Range
2.85
(5) (6)
Maximum input signal
VFB < 2.4 V
Power-supply rejection ratio
VDD = 12 V to 18 V (2) (5)
2.825
Input bias current
CS to output delay
0.9
1
1.1
70
V
dB
–0.1
–2
µA
35
70
ns
COMP to CS offset
VCS = 0 V
1.15
V
VOUT low (RDS(on) pull-down)
ISINK = 200 mA
5.5
15
Ω
VOUT high (RDS(on) pull-up)
ISOURCE = 200 mA
10
25
Ω
Output
(1)
(2)
(3)
(4)
(5)
(6)
4
Adjust VDD above the start threshold before setting at 15 V.
Not production tested.
Output frequencies of the UCC28C41, UCC28C44, and UCC28C45 are one-half the oscillator frequency.
Oscillator discharge current is measured with RT = 10 kΩ to VREF.
Parameter measured at trip point of latch with VFB = 0 V.
DV
COM , 0 V v V
ACS +
CS v 900 mV
DVCS
Gain is defined as
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UCC28C4x-EP
BiCMOS LOW-POWER CURRENT-MODE PWM CONTROLLERS
www.ti.com
SGLS352B – DECEMBER 2006 – REVISED MAY 2007
Electrical Characteristics (continued)
VDD = 15 V, RT = 10 kΩ, CT = 3.3 nF, CVDD = 0.1 µF and no load on the outputs, TA = TJ = –55°C to 125°C for the UCC28C4x
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Rise tIme
TA = 25°C, CLOAD = 1 nF
25
50
ns
Fall time
TA = 25°C, CLOAD = 1 nF
20
40
ns
15.5
Undervoltage Lockout (UVLO)
Start threshold
Minimum operating voltage
UCC28C42-EP, UCC28C44-EP
13.5
14.5
UCC28C43-EP, UCC28C45-EP
7.8
8.4
9
UCC28C40-EP, UCC28C41-EP
6.5
7
7.5
UCC28C42-EP, UCC28C44-EP
8
9
10
UCC28C43-EP, UCC28C45-EP
7
7.6
8.2
UCC28C40-EP, UCC28C41-EP
6.1
6.6
7.1
UCC28C42-EP, UCC28C43-EP,
UCC28C40-EP, UCC28C44-EP,
UCC28C45-EP, UCC28C41-EP
94
96
47
48
V
V
PWM
Maximum duty cycle
Minimum duty cycle
%
0%
Current Supply
ISTART-UP Start-up current
VDD = UVLO start threshold (–0.5 V)
50
100
µA
IDD
VFB = VCS = 0 V
2.3
3
mA
Operating supply current
PDIP (P) or SOIC (D) PACKAGE
(TOP VIEW)
COMP
FB
CS
RT/CT
1
8
2
7
3
6
4
5
VREF
VDD
OUT
GND
Pin Assignments
COMP: This pin provides the output of the error amplifier for compensation. In addition, the COMP pin is
frequently used as a control port by utilizing a secondary-side error amplifier to send an error signal across the
secondary-primary isolation boundary through an opto-isolator.
CS: The current-sense pin is the noninverting input to the PWM comparator. This is compared to a signal
proportional to the error amplifier output voltage. A voltage ramp can be applied to this pin to run the device with
a voltage mode control configuration.
FB: This pin is the inverting input to the error amplifier. The noninverting input to the error amplifier is internally
trimmed to 2.5 V ± 1%.
GND: Ground return pin for the output driver stage and the logic-level controller section.
OUT: The output of the on-chip drive stage. OUT is intended to directly drive a MOSFET. The OUT pin in the
UCC28C40, UCC28C42, and UCC28C43 is the same frequency as the oscillator, and can operate near 100%
duty cycle. In the UCC28C41, UCC28C44, and the UCC28C45, the frequency of OUT is one-half that of the
oscillator due to an internal T flipflop. This limits the maximum duty cycle to