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UCC2808-1, UCC2808-2, UCC3808-1, UCC3808-2
SLUS168E – APR 1999 – REVISED AUGUST 2015
UCCx808-x Low Power Current Mode Push-Pull PWM
1 Features
3 Description
•
The UCCx808-x is a family of BiCMOS push-pull,
high-speed, low-power, pulse-width modulators. The
UCCx808 contains all of the control and drive circuitry
required for offline or DC-to-DC fixed frequency
current-mode switching power supplies with minimal
external parts count.
1
•
•
•
•
•
•
•
Dual Output Drive Stages in Push-Pull
Configuration
130-μA Typical Starting Current
1-mA Typical Run Current
Operation to 1-MHz
Internal Soft-Start
On-Chip Error Amplifier With 2-MHz Gain
Bandwidth Product
On-Chip VDD Clamping
Output Drive Stages Capable Of 500-mA Peak
Source Current, 1-A Peak Sink Current
The UCCx808-x dual output drive stages are
arranged in a push-pull configuration. Both outputs
switch at half the oscillator frequency using a toggle
flip-flop. The dead time between the two outputs is
typically 60 ns to 200 ns depending on the values of
the timing capacitor and resistors, thus limiting each
output stage duty cycle to less than 50%.
Device Information(1)
2 Applications
•
•
•
•
PART NUMBER
Server and Desktop Power Supplies
Telecom Power Supplies
DC-DC Converters
Switched-Mode Power Supplies
PACKAGE
UCC2808-1
UCC2808-2
UCC3808-1
UCC3808-2
BODY SIZE (NOM)
SOIC (8)
4.90 mm × 3.91 mm
PDIP (8)
9.81 mm × 6.35 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Simplified Schematic
ER28
8:2
32CTQ030
NP2
NS1
NP1
NS2
VO
5 V 50 W
+
EF25 7µH
680 µF
0.01 µF
+
–
LOOP B
VIN
36 V TO 72 V
4700 µF
0.47 µF
1000 pF
–
BYV
28–200
62 Ω
62 Ω
BYV
28–200
1000 pF
LOOP A
COMP
51 kΩ
1/4 W
19.1 kΩ
IRF640
IRF640
4700 pF 20 kΩ
12
10 Ω
2.2 Ω
470 pF
DF02SGICT
2.2 Ω
1 mH
3
0.1 µF
10 µF
200 Ω
0.1 µF
1 TL431
2
19.1 kΩ
2 kΩ
0.2 Ω
330 pF
20 kΩ
VDD
8
OUTA OUTB GND
7
6
PRIMARY
GROUND
5
UCC3808D-1
1
2
COMP FB
3
CS
4
240 Ω
RC
RC
4.99 kΩ
2.80 kΩ
CURRENT
86.6 kΩ SENSE
4.99 kΩ
2N2907
4
H11A1
U3
3
5
2
6
1
20 kΩ
330 pF
432 Ω
0.1 µF
0.01 µF
1 kV
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.
UCC2808-1, UCC2808-2, UCC3808-1, UCC3808-2
SLUS168E – APR 1999 – REVISED AUGUST 2015
www.ti.com
Table of Contents
1
2
3
4
5
6
7
Features ..................................................................
Applications ...........................................................
Description .............................................................
Revision History.....................................................
Pin Configuration and Functions .........................
Specifications.........................................................
1
1
1
2
3
4
6.1
6.2
6.3
6.4
6.5
4
4
4
4
6
Absolute Maximum Ratings ......................................
ESD Ratings..............................................................
Recommended Operating Conditions.......................
Electrical Characteristics...........................................
Typical Characteristics ..............................................
Detailed Description .............................................. 7
7.1
7.2
7.3
7.4
Overview ...................................................................
Functional Block Diagram .........................................
Feature Description...................................................
Device Functional Modes..........................................
7
7
8
9
8
Application and Implementation ........................ 10
8.1 Application Information............................................ 10
8.2 Typical Application ................................................. 10
9 Power Supply Recommendations...................... 11
10 Layout................................................................... 12
10.1 Layout Guidelines ................................................. 12
10.2 Layout Example .................................................... 12
11 Device and Documentation Support ................. 13
11.1
11.2
11.3
11.4
11.5
11.6
Related Links ........................................................
Documentation Support .......................................
Community Resources..........................................
Trademarks ...........................................................
Electrostatic Discharge Caution ............................
Glossary ................................................................
13
13
13
13
13
13
12 Mechanical, Packaging, and Orderable
Information ........................................................... 13
4 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from Revision D (August 2002) to Revision E
Page
•
Removed references to the TSSOP packaging .................................................................................................................... 1
•
Added ESD Ratings 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
2
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Copyright © 1999–2015, Texas Instruments Incorporated
Product Folder Links: UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2
UCC2808-1, UCC2808-2, UCC3808-1, UCC3808-2
www.ti.com
SLUS168E – APR 1999 – REVISED AUGUST 2015
5 Pin Configuration and Functions
D Package
8-Pin SOIC
Top View
COMP
FB
CS
RC
1
8
2
7
3
6
4
5
VDD
OUTA
OUTB
GND
P Package
8-Pin PDIP
Top View
OUTA
VDD
COMP
FB
1
2
3
4
8
7
6
5
OUTB
GND
RC
CS
Pin Functions
PIN
I/O
DESCRIPTION
NAME
NO.
COMP
1
I/O
CS
3
I
Input to the PWM, peak current, and overcurrent comparators.
FB
2
I
Inverting input to the error amplifier.
GND
5
—
Reference ground and power ground for all functions.
OUTA
7
O
Alternating high current output stage.
OUTB
6
O
Alternating high current output stage.
RC
4
I
Oscillator programming pin.
VDD
8
—
Output of the error amplifier and the input of the PWM comparator.
Power input connection for this device.
Copyright © 1999–2015, Texas Instruments Incorporated
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3
UCC2808-1, UCC2808-2, UCC3808-1, UCC3808-2
SLUS168E – APR 1999 – REVISED AUGUST 2015
www.ti.com
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted) (1)
MIN
Supply voltage (IDD ≤ 10 mA)
Supply current
OUTA/OUTB source current (peak) (2)
(2)
20
mA
A
A
Analog inputs (FB, CS) – 0.3 V to VDD+0.3 V
6
V
Power dissipation at TA = 25 ° C (N Package)
1
W
Power dissipation at T A = 25 ° C (D Package)
650
mW
400
mW
150
°C
300
°C
150
°C
Junction temperature
–55
Lead temperature (soldering, 10 sec.)
(1)
V
1.0
Power dissipation at T A = 25 ° C (PW Package)
Tstg
UNIT
15
–0.5
OUTA/OUTB sink current (peak) (2)
TJ
MAX
Storage temperature
–65
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended
Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Currents are positive into, negative out of the specified terminal. Consult Packaging Section of the Power Supply Control Data Book
(SLUD003) for thermal limitations and considerations of packages.
6.2 ESD Ratings
VALUE
V(ESD)
(1)
(2)
Electrostatic discharge
Human body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1)
±2500
Charged-device model (CDM), per JEDEC specification JESD22C101 (2)
±1500
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.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
VDD
Supply Voltage
TJ
Junction Temperature
MIN
MAX
UCCx808-1
13
14
UCCx808-2
5
14
UCC2808-x
–40
85
UCC3808-x
0
70
UNIT
V
°C
6.4 Electrical Characteristics
TA = 0°C to 70°C for the UCC3808-x, –40°C to 85°C for the UCC2808-x and –55°C to 125°C for the UCC1808-x, VDD = 10
V (1), 1-μF capacitor from VDD to GND, R = 22 kΩ , C = 330 pF, TA = TJ , (unless otherwise specified)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Oscillator frequency
175
Oscillator amplitude/VDD (2)
0.44
194
213
kHz
0.5
0.56
V/V
1.95
2
2.05
OSCILLATOR SECTION
ERROR AMPLIFIER SECTION
Input voltage
COMP = 2 V
(1)
(2)
4
V
–1
Open-loop voltage gain
60
80
dB
0.3
2.5
mA
COMP sink current
FB = 2.2 V, COMP = 1 V
1
μA
Input bias current
Does not include current in the external oscillator network.
Measured at RC. Signal amplitude tracks VDD.
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Product Folder Links: UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2
UCC2808-1, UCC2808-2, UCC3808-1, UCC3808-2
www.ti.com
SLUS168E – APR 1999 – REVISED AUGUST 2015
Electrical Characteristics (continued)
TA = 0°C to 70°C for the UCC3808-x, –40°C to 85°C for the UCC2808-x and –55°C to 125°C for the UCC1808-x, VDD = 10
V(1), 1-μF capacitor from VDD to GND, R = 22 kΩ , C = 330 pF, TA = TJ , (unless otherwise specified)
PARAMETER
TEST CONDITIONS
COMP source current
FB = 1.3 V, COMP = 3.5 V
MIN
TYP
–0.25
–0.5
48%
49%
MAX
UNIT
mA
PWM SECTION
Maximum duty cycle
Measured at OUTA or OUTB
Minimum duty cycle
COMP = 0 V
50%
0%
CURRENT SENSE SECTION
Gain (3)
(4)
Maximum input signal
COMP = 5 V
CS to output delay
COMP = 3.5 V, CS from 0 to 600
mV
CS source current
1.9
2.2
2.5
V/V
0.45
0.5
0.55
V
100
200
ns
0.7
0.75
0.8
V
0.35
0.8
1.2
V
1
V
–200
Over current threshold
COMP to CS offset
CS = 0 V
nA
OUTPUT SECTION
OUT low level
I = 100 mA
0.5
OUT high level
I = – 50 mA, VDD – OUT
0.5
1
V
Rise time
CL = 1 nF
25
60
ns
Fall time
CL = 1 nF
25
60
ns
UNDERVOLTAGE LOCKOUT SECTION
UCCx808-1
Start threshold
Minimum operating voltage after
start
Hysteresis
(1)
11.5
12.5
13.5
UCCx808-2
4.1
4.3
4.5
UCCx808-1
7.6
8.3
9
UCCx808-2
3.9
4.1
4.3
UCCx808-1
3.5
4.2
5.1
UCCx808-2
0.1
0.2
0.3
FB = 1.8 V, rise from 0.5 V to 4 V
3.5
20
ms
VDD < start threshold
130
260
µA
1
2
mA
14
15
V
V
V
V
SOFT-START SECTION
COMP rise time
OVERALL SECTION
Start-up current
Operating supply current
FB = 0 V, CS = 0 V
VDD zener shunt voltage
IDD = 10 mA
A=
(3)
(4)
(5)
(6)
(5) (1)
(6)
13
DVCOMP
,0 £ VCS £ 0.4V
DVCS
0 v VCS v 0.4 V
Gain is defined by:
Parameter measured at trip point of latch with FB at 0 V.
For UCCx808 – 1, set VDD above the start threshold before setting at 10 V
Start threshold and Zener shunt threshold track one another.
Copyright © 1999–2015, Texas Instruments Incorporated
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UCC2808-1, UCC2808-2, UCC3808-1, UCC3808-2
SLUS168E – APR 1999 – REVISED AUGUST 2015
www.ti.com
6.5 Typical Characteristics
14
1000
VDD = 10 V, T = 25°C
12
CT=100pF
10
IDD With 1 nF
Load
100
IDD – mA
Frequency – kHz
CT=330pF
CT=220pF
10
CT=1000pF
8
6
4
CT=820pF
IDD Without
Load
CT=560pF
2
0
0
0
50
100
150
200
250
0
200
400
600
800
1000
1200
Oscillator Frequency – kHz
RT – Timing Resistor – kΩ
Figure 2. IDD vs Oscillator Frequency
Figure 1. Frequency vs Timing Resistor
1.2
COMP – CS Offset – V
1.0
0.8
0.6
0.4
0.2
0
–55
–35
–15
5
25
45
65
85
105
125
Temperature – °C
Figure 3. CS Offset vs Temperature
6
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Product Folder Links: UCC2808-1 UCC2808-2 UCC3808-1 UCC3808-2
UCC2808-1, UCC2808-2, UCC3808-1, UCC3808-2
www.ti.com
SLUS168E – APR 1999 – REVISED AUGUST 2015
7 Detailed Description
7.1 Overview
The UCCx808-x device is a highly-integrated, low power current mode push-pull PWM controller. The controller
employs low starting current, and employs an internal control algorithm that offers accurate static output voltage
regulation against line and load. The UCCx808-x family offers a variety of package temperature range options,
and choice of undervoltage lockout levels. The family has UVLO thresholds and hysteresis options for offline and
battery-powered system.
Table 1. Undervoltage Lockout Levels
PART NUMBER
TURN ON THRESHOLD
TURN OFF THRESHOLD
UCCx808-1
12.5 V
8.3 V
UCCx808-2
4.3 V
4.1 V
Table 2. Undervoltage Lockout Options
PACKAGED DEVICES
TA = TJ
UVLO OPTION
SOIC (D)
PDIP (N)
12.5 V/8.3 V
UCC2808D-1
UCC2808N-1
4.3 V/4.1 V
UCC2808D-2
UCC2808N-2
12.5 V/8.3 V
UCC3808D-1
UCC3808N-1
4.3 V/4.1 V
UCC3808D-2
UCC3808N-2
–40°C to 85°C
0°C to 70°C
7.2 Functional Block Diagram
OVERCURRENT
COMPARATOR
FB
COMP
CS
2
1
3
22 k Ω
PEAK CURRENT
COMPARATOR
8
VDD
7
OUTA
6
OUTB
5
GND
14 V
0.75 V
0.5 V
2.0 V
2.2 V
VDD OK
OSCILLATOR
S
Q
PWM
LATCH
R
1.2R
VDD–1 V
Q
S
S
T
Q
Q
Q
R
R
PWM
COMPARATOR
VDD
0.5 V
R
SOFT START
VOLTAGE
REFERENCE
SLOPE = 1 V/ms
4
RC
Pinout shown is for SOIC and PDIP packages.
Figure 4. Functional Block Diagram
Copyright © 1999–2015, Texas Instruments Incorporated
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SLUS168E – APR 1999 – REVISED AUGUST 2015
www.ti.com
Functional Block Diagram (continued)
The oscillator generates a sawtooth waveform on RC. During the RC rise time, the output stages alternate on time,
but both stages are off during the RC fall time. The output stages switch at ½ the oscillator frequency, with
guaranteed duty cycle of