SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
!"#
FEATURES
DUp To 85% Efficiency
DThermal Protection
DDevice-to-Device Synchronization
DShort-Circuit Protection
DEN55022 Class B EMC Performance
DUL1950 Recognized Component
DJEDEC DIP-14 and SOP-14 Packages
APPLICATIONS
DPoint-of-Use Power Conversion
DGround Loop Elimination
DData Acquisition
DIndustrial Control and Instrumentation
DTest Equipment
DESCRIPTION
The DCP01B series is a family of 1W, unregulated,
isolated DC/DC converters. Requiring a minimum of
external components and including on-chip device
protection, the DCP01B series provides extra features
such as output disable and synchronization of switching
frequencies.
The use of a highly-integrated package design results in
highly reliable products with a power density of 40W/in3
(2.4W/cm3). This combination of features and small sizes
makes the DCP01B suitable for a wide range of
applications.
IBIAS
Power
Stage
VOUT
÷2
Reset
800kHz
Oscillator
Watch−dog/
start−up
PSU
Thermal
Shutdown
SYNCOUT
SYNCIN
VS
0V
Power Controller IC
0V
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Copyright 2000−2007, Texas Instruments Incorporated
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.
All trademarks are the property of their respective owners.
! $% & $ '(& ) !&
&$% '&$& ' * % $ + % ,-)
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SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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2
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate
precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to
damage because very small parametric changes could cause the device not to meet its published specifications.
ABSOLUTE MAXIMUM RATINGS
over o p e r a t i n g f ree-air temperature range unless otherwise noted(1)
DCP01B SERIES UNIT
5−V models 7 V
Input voltage 15−V models 18 V
Input voltage
24−V models 29 V
Storage temperature −60 to +125 °C
Lead temperature (soldering, 10s) +270 °C
(1) Stresses above these ratings may cause permanent damage.
Exposure to absolute maximum conditions for extended periods
may degrade device reliability. These are stress ratings only, and
functional operation of the device at these or any other conditions
beyond those specified is not implied.
SUPPLEMENTAL ORDERING INFORMATION
Basic Model Number: 1W Product
Voltage Input:
5V In
Voltage Output:
Dual Output:
Model Revision:
Package Code:
5V Out
P=DIP−14
P−U = SOP−14 (Gull−wing)
DCP01 05 05 (D) (B) ( )
ORDERING INFORMATION (1)
PRODUCT PACKAGE-LEAD PACKAGE
DESIGNATOR
SPECIFIED
TEMPERATURE
RANGE PACKAGE
MARKING ORDERING NUMBER(2) TRANSPORT
MEDIA
SINGLE VOLT AGE(3)
DCP010505
DIP-14 NVA −40°C to +100°C DCP010505BP DCP010505BP Rails
DCP010505
SOP-14(4) DUA −40°C to +100°C DCP010505BP−U DCP010505BP−U/700 Tape and Reel
DCP010512
DIP-14 NVA −40°C to +100°C DCP010512BP DCP010512BP Rails
DCP010512
SOP-14(4) DUA −40°C to +100°C DCP010512BP−U DCP010512BP−U/700 Tape and Reel
DCP010515
DIP-14 NVA −40°C to +100°C DCP010515BP DCP010515BP Rails
DCP010515
SOP-14(4) DUA −40°C to +100°C DCP010515BP−U DCP010515BP−U/700 Tape and Reel
DCP012405
DIP-14 NVA −40°C to +100°C DCP012405BP DCP012405BP Rails
DCP012405
SOP-14(4) DUA −40°C to +100°C DCP012405BP−U DCP012405BP−U/700 Tape and Reel
DUAL VOLTAGE(3)
DCP010505
DIP-14 NVA −40°C to +100°C DCP010505DBP DCP010505DBP Rails
DCP010505
SOP-14(4) DUA −40°C to +100°C DCP010505DBP−U DCP010505DBP−U/700 Tape and Reel
DCP010507
DIP-14 NVA −40°C to +100°C DCP010507DBP DCP010507DBP Rails
DCP010507
SOP-14(4) DUA −40°C to +100°C DCP010507DBP−U DCP010507DBP−U/700 Tape and Reel
DCP010512
DIP-14 NVA −40°C to +100°C DCP010512DBP DCP010512DBP Rails
DCP010512
SOP-14(4) DUA −40°C to +100°C DCP010512DBP−U DCP010512DBP−U/700 Tape and Reel
DCP010515
DIP-14 NVA −40°C to +100°C DCP010515DBP DCP010515DBP Rails
DCP010515
SOP-14(4) DUA −40°C to +100°C DCP010515DBP−U DCP010515DBP−U/700 Tape and Reel
DCP011512
DIP-14 NVA −40°C to +100°C DCP011512DBP DCP011512DBP Rails
DCP011512
SOP-14(4) DUA −40°C to +100°C DCP011512DBP−U DCP011512DBP−U/700 Tape and Reel
DCP011515
DIP-14 NVA −40°C to +100°C DCP011515DBP DCP011515DBP Rails
DCP011515
SOP-14(4) DUA −40°C to +100°C DCP011515DBP−U DCP011515DBP−U/700 Tape and Reel
DCP012415
DIP-14 NVA −40°C to +100°C DCP012415DBP DCP012415DBP Rails
DCP012415
SOP-14(4) DUA −40°C to +100°C DCP012415DBP−U DCP012415DBP−U/700 Tape and Reel
(1) All devices also available in tray quatities. For the most current package and ordering information, see the Package Option Addendum at the end of this data sheet,
or refer to our web site at www.ti.com.
(2) Models with a (/) are available only in Tape and Reel in the quantities indicated (for example, /700 indicates 700 devices per reel). Ordering 700 pieces of
DCP010505BP−U/700 will get a single 700-piece Tape and Reel.
(3) Single voltage versions have six active pins; dual voltage versions have seven active pins.
(4) SOP package is gull-wing surface-mount.
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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3
ELECTRICAL CHARACTERISTICS
At TA = +25°C, VS = nominal, CIN = 2.2µF, and COUT = 0.1µF, unless otherwise noted.
DCP01B SERIES
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
Output
Power 100% full load 0.97 W
Ripple O/P capacitor = 1µF, 50% load 20 mVPP
Voltage vs temperature
Room to cold 0.046 %/°C
Voltage vs temperature Room to hot 0.016 %/°C
Input
Voltage range on VS−10 +10 %
Isolation
Voltage
1s flash test 1 kVrms
Voltage 60s test, UL1950(1) 1 kVrms
Line Regulation
Output voltage
IO = constant(2)
VS (min) to VS (typ) 1 15 %
Output voltage IO = constant
(2)
VS (typ) to VS (max) 1 15 %
Switching/Synchronization
Oscillator frequency (fOSC)Switcing frequency = fOSC/2 800 kHz
Sync input low 0.4 V
Sync input current VSYNC = +2V 75 µA
Disable time 2µs
Capacitance loading on SYNCIN pin External 3 pF
Reliability
Demonstrated MSL 3−(U) versions, TA = +55°C 55 FITS
Thermal Shutdown
IC temperature at shutdown +150 °C
Shutdown current 3 mA
Temperature Range
Operating −40 +100 °C
(1) During UL1950 recognition tests only.
(2) IOUT ≥ 10% load current.
ELECTRICAL CHARACTERISTICS PER DEVICE
At TA = +25°C, VS = nominal, CIN = 2.2µF, and COUT = 0.1µF, unless otherwise noted.
INPUT VOLTAGE
(V) OUTPUT VOLTAGE
(V) LOAD REGULATION
(%)
NO LOAD
CURRENT
(mA) EFFICIENCY
(%)
BARRIER
CAPACITANCE
(pF)
VSVNOM AT VS (TYP) IQCISO
75% LOAD(3) 10% TO 100% LOAD(4) 0% LOAD 100% LOAD VISO = 750VRMS
PRODUCT MIN TYP MAX MIN TYP MAX TYP MAX TYP TYP TYP
DCP010505B 4.5 5 5.5 4.75 5 5.25 19 31 20 80 3.6
DCP010505DB 4.5 5 5.5 ±4.25 ±5±5.75 18 32 22 81 3.8
DCP010507DB 4.5 5 5.5 ±5.75 ±6.5 ±7.25 21 35 38 81 3.0
DCP010512B 4.5 5 5.5 11.4 12 12.6 21 38 29 85 5.1
DCP010512DB 4.5 5 5.5 ±11.4 ±12 ±12.6 19 37 40 82 4.0
DCP010515B 4.5 5 5.5 14.25 15 15.75 26 42 34 82 3.8
DCP010515DB 4.5 5 5.5 ±14.25 ±15 ±15.75 19 41 42 85 4.7
DCP011512DB 13.5 15 16.5 ±11.4 ±12 ±12.6 11 39 19 78 2.5
DCP011515DB 13.5 15 16.5 ±14.25 ±15 ±15.75 12 39 20 80 2.5
DCP012405B 21.6 24 26.4 4.75 5 5.25 13 23 14 77 2.5
DCP012415DB 21.6 24 26.4 ±14.25 ±15 ±15.75 10 35 17 76 3.8
(3) 100% load current = 1W/VNOM (typ).
(4) Load regulation = (VOUT at 10% load − VOUT at 100% load)/VOUT at 75% load.
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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4
PIN ASSIGNMENTS (Single Voltage Version)
NVA and DUA
PACKAGES
(TOP VIEW)
DCP01B
1
2
5
6
7
14
8
VS
0V
0V
+VOUT
NC
SYNCIN
SYNCOUT
Terminal Functions (Single Voltage)
TERMINAL
NAME NO. I/O DESCRIPTION
VS1 I Voltage input
0V 2 I Input side common
0V 5 O Output side common
+VOUT 6 O +Voltage out
NC 7Not connected
SYNCOUT 8 O Unrectified transformer output
SYNCIN 14 I Synchronization pin
NOTE:I = input and O = output.
PIN ASSIGNMENTS (Dual Voltage Version)
NVA and DUA
PACKAGES
(TOP VIEW)
DCP01DB
1
2
5
6
7
14
8
VS
0V
0V
+VOUT
−VOUT
SYNCIN
SYNCOUT
Terminal Functions (Dual Voltage)
TERMINAL
NAME NO. I/O DESCRIPTION
VS1 I Voltage input
0V 2 I Input side common
0V 5 O Output side common
+VOUT 6 O +Voltage out
−VOUT 7 O −Voltage out
SYNCOUT 8 O Unrectified transformer output
SYNCIN 14 I Synchronization pin
NOTE:I = input and O = output.
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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5
TYPICAL CHARACTERISTICS
At TA = 25°C, unless otherwise noted.
DCP010505B
OUTPUT RIPPLE vs LOAD (20MHz BW)
Load (%)
Ripple (mVPP)
50
45
40
35
30
25
20
15
10
5
020 30 50 7060 80 90 1004010
1µF Ceramic
4.7µFCeramic
10µF Ceramic
DCP010505B VOUT vs VS
VS(V)
VOUT (V)
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
4.7
4.6
4.5
4.4 4.6 4.7 4.9 5.15.0 5.2 5.45.3 5.54.84.5
DCP010505B VOUT vs LOAD
Load (%)
VOUT (V)
5.8
5.7
5.6
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
4.7 10010 20 30 40 50 60 70 80 90
DCP010505B EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
85
80
75
70
65
60
55 10010 20 30 40 50 60 70 80 90
DCP010505DB VOUT vs LOAD
Load (%)
VOUT (V)
5.8
5.7
5.6
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
4.7 10010 20 30 40 50 60 70 80 90
+VOUT
−VOUT
DCP010505DB EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
85
80
75
70
65
60
55 10010 20 30 40 50 60 70 80 90
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SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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6
TYPICAL CHARACTERISTICS (continued)
At TA = 25°C, unless otherwise noted.
DCP010507DB VOUT vs LOAD
Load (%)
VOUT (V)
7.6
7.4
7.2
7.0
6.8
6.6
6.4
6.2
6.0 10010 20 30 40 50 60 70 80 90
+VOUT
−VOUT
DCP010507DB EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
85
80
75
70
65
60
55
50 10010 20 30 40 50 60 70 80 90
DCP010512B VOUT vs LOAD
Load (%)
VOUT (V)
14.5
14.0
13.5
13.0
12.5
12.0
11.5
11.0 10010 20 30 40 50 60 70 80 90
DCP010512B EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
90
85
80
75
70
65
60
55
50 10010 20 30 40 50 60 70 80 90
DCP010512DB VOUT vs LOAD
Load (%)
VOUT (V)
14.5
14.0
13.5
13.0
12.5
12.0
11.5
11.0
10.5
10.0 20 30 50 7060 80 90 1004010
+VOUT
−VOUT
DCP010512DB EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
85
80
75
70
65
60
55
50 20 30 50 7060 80 90 1004010
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SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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7
TYPICAL CHARACTERISTICS (continued)
At TA = 25°C, unless otherwise noted.
DCP010515B VOUT vs LOAD
Load (%)
VOUT (V)
18.0
17.5
17.0
16.5
16.0
15.5
15.0
14.5
14.0 10010 20 30 40 50 60 70 80 90
DCP010515B EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
85
80
75
70
65
60
55
50 10010 20 30 40 50 60 70 80 90
DCP010515DB VOUT vs LOAD
Load (%)
VOUT (V)
18
17
16
15
14 20 30 50 7060 80 90 1004010
+VOUT
−VOUT
DCP010515DB EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
90
85
80
75
70
65
60
55
50 20 30 50 7060 80 90 1004010
DCP012405B VOUT vs LOAD
Load (%)
VOUT (V)
5.60
5.50
5.40
5.30
5.20
5.10
5.00
4.90
4.80 20 30 6050 70 80 1004010
DCP012405B EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
90
80
70
60
50
40
30
20
10
020 30 7060 80 90 10040 5010
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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8
TYPICAL CHARACTERISTICS (continued)
At TA = 25°C, unless otherwise noted.
DCP010505B
CONDUCTED EMISSIONS (125% Load)
Emission Level, Peak (dBµA)
Frequency (MHz)
10.15 10 30
60
50
40
30
20
10
0
−10
−20
DCP010505B
CONDUCTED EMISSIONS (8% Load)
Emission Level, Peak (dBµA)
Frequency (MHz)
10.15 10 30
60
50
40
30
20
10
0
−10
−20
DCP011512DBP VOUT vs LOAD
Load (%)
VOUT (V)
13.50
13.00
12.50
12.00
11.50
11.00
10.50 10010 20 30 40 50 60 70 80 90
+VOUT
−VOUT
DCP011512DBP
EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
80
75
70
65
60
55
50
45
40
35
30 20 30 50 7060 80 90 1004010
DCP011515DBP
EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
90
80
70
60
50
40
30 10010 20 30 40 50 60 70 80 90
DCP011515DBP VOUT vs LOAD
Load (%)
Efficiency (%)
17.00
16.50
16.00
15.50
15.00
14.50
14.00
13.50
13.00 10010 20 30 40 50 60 70 80 90
+VOUT
−VOUT
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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9
TYPICAL CHARACTERISTICS (continued)
At TA = 25°C, unless otherwise noted.
DCP012415DBP EFFICIENCY vs LOAD
Load (%)
Efficiency (%)
90
80
70
60
50
40
30
20 10010 20 30 40 50 60 70 80 90
DCP012415DBP VOUT vs LOAD
Load (%)
VOUT (V)
16.50
16.00
15.50
15.00
14.50
14.00
13.50 10010 20 30 40 50 60 70 80 90
+VOUT
−VOUT
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SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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10
FUNCTIONAL DESCRIPTION
OVERVIEW
The DCP01B offers up to 1W of unregulated output power
with a typical efficiency of up to 85%. This is achieved
through highly integrated packaging technology and the
implementation of a custom power stage and control IC.
The circuit design uses an advanced BiCMOS/DMOS
process. For additional information, refer to the application
notes located in the DCP01B product folder at www.ti.com.
POWER STAGE
This uses a push-pull, center-tapped topology switching at
400kHz (divide-by-2 from 800kHz oscillator).
OSCILLATOR AND WATCHDOG
The onboard 800kHz oscillator generates the switching
frequency via a divide-by-2 circuit. The oscillator can be
synchronized to other DCP01B circuits or an external
source, and is used to minimize system noise.
A watchdog circuit checks the operation of the oscillator
circuit. The oscillator can be stopped by pulling the SYNC
pin low. The output pins will be tri-stated. This will occur in
2µs.
THERMAL SHUTDOWN
The DCP01B is protected by a thermal shutdown circuit.
If the on-chip temperature exceeds 150°C, the device will
shut down. Once the temperature falls below 150°C,
normal operation will resume. If the thermal condition
continues, operation will randomly cycle on and off. This
will continue until the temperature is reduced.
SYNCHRONIZATION
In the event that more than one DC/DC converter is
needed onboard, beat frequencies and other electrical
interference can be generated. This is due to the small
variations in switching frequencies between the DC/DC
converters.
The DCP01B overcomes this by allowing devices to be
synchronized to one another. Up to eight devices can be
synchronized by connecting the SYNCIN pins together,
taking care to minimize the stray capacitance. Stray
capacitance (> 3pF) will have the effect of reducing the
switching frequency, or even stopping the oscillator circuit.
If synchronized devices are used, it should be noted that
at startup, all devices will draw maximum current
simultaneously. This can cause the input voltage to dip. If
it dips below the minimum input voltage (4.5V), the devices
may not start up. A 2.2µF capacitor should be connected
close to the input pins.
If more than eight devices are to be synchronized, it is
recommended that the SYNCIN pins are driven by an
external device. Details are contained in Application
Report SBAA035, External Synchronization of the
DCP01/02 Series of DC/DC Converters, available for
download at www.ti.com.
CONSTRUCTION
The DCP01B basic construction is the same as standard
ICs. There is no substrate within the molded package. The
DCP01B is constructed using an IC, rectifier diodes, and
a wound magnetic toroid on a leadframe. Since there is n o
solder within the package, the DCP01B does not require
any special PCB assembly processing. This results in an
isolated DC/DC converter with inherently high reliability.
ADDITIONAL FUNCTIONS
DISABLE/ENABLE
The DCP01B can be disabled or enabled by driving the
SYNCIN pin using an open drain CMOS gate. If the
SYNCIN pin is pulled low, the DCP01B will be disabled.
The disable time depends upon the external loading; the
internal disable function is implemented in 2µs. Removal
of the pull-down will cause the DCP01B to be enabled.
Capacitive loading on the SYNCIN pin should be
minimized in order to prevent a reduction in the oscillator
frequency.
DECOUPLING
Ripple Reduction
A high switching frequency of 400kHz allows simple
filtering. To reduce ripple, it is recommended that at least
a 1 µF capacitor is used on VOUT. Dual outputs should have
both the positive and negative buses decoupled to VOUT
ground (pin 5). The required 2.2µF low equivalent series
resistance (ESR) ceramic capacitor on the input of the 5V
to 15V versions, and the ≥ 0.47µF low-ESR ceramic
capacitor on the 24V versions help reduce ripple and
noise. See Application Bulletin SBVA012, DC-to-DC
Converter Noise Reduction, available for download at
www.ti.com.
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
www.ti.com
11
Connecting the DCP01B in Series
Multiple DCP01B isolated 1W DC/DC converters can be
connected in series to provide nonstandard voltage rails.
This is possible by using the floating outputs provided by
the DCP01B galvanic isolation.
Connect the positive VOUT from one DCP01B to the
negative VOUT (0V) of another , as shown in Figure 1. If the
SYNCIN pins are tied together, the self-synchronization
feature of the DCP01B will prevent beat frequencies on the
voltage rails. The SYNCIN feature of the DCP01B allows
easy connection in series, which reduces separate filtering
components.
The outputs on dual output DCP01B versions can also be
connected in series to provide two times the magnitude of
VOUT, as shown in Figure 2. For example, a dual 15V
DCP01B could be connected to provide a 30V rail.
Connecting the DCP01B in Parallel
If the output power from one DCP01B is not sufficient, it is
possible to parallel the outputs of multiple DCP01B
converters (see Figure 3). Again, the SYNCIN feature
allows easy synchronization to prevent power-rail beat
frequencies at no additional filtering cost.
DCP 01B
VOUT 1
VSUPPLY VS
0V
DCP 01B
VOUT 2
VOUT1 +V
OUT2
SYNCIN
CIN(1) COUT
COUT
CIN(1) SYNCIN
VS
0V
0V
0V
COM NOTE: (1) CIN requires a low−ESR ceramic capacitor: 5V to 15V version is 2.2µF;
24V version is minimum 0.47µF. COUT =1.0
µF.
Figure 1. Connecting the DCP01B in Series
DCP 01B
+VOUT
VSUPPLY +VOUT
−VOUT
−VOUT
0V
VS
0V
COM
COUT(1)
COUT(1)
CIN(1)
NOTE: (1) CIN requires a low−ESR ceramic capacitor: 5V to 15V version is 2.2µF;
24V version is minimum 0.47µF. COUT =1.0
µF.
Figure 2. Connecting Dual Outputs in Series
DCP 01B
0V
0V
VOUT
VSUPPLY VS
0V
DCP 01B
VOUT
2xPowerOut
SYNCIN
SYNCIN
VS
0V
COM
COUT(1)
COUT(1)
CIN(1)
CIN(1)
NOTE: (1) CIN requires a low−ESR ceramic capacitor: 5V to 15V version is 2.2µF;
24V version is minimum 0.47µF. COUT =1.0
µF.
Figure 3. Connecting Multiple DCP01Bs in Parallel
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
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12
APPLICATION INFORMATION
The DCP01B, DCV01, and DCP02 are three families of
miniature DC/DC converters providing an isolated
unregulated voltage output. All are fabricated using a
CMOS/DMOS process with the DCP01B replacing the
familiar DCP01 family that was fabricated from a bipolar
process. The DCP02 is essentially an extension of the
DCP01B family providing a higher power output with a
significantly improved load regulation, and the DCV01 is
tested to a higher isolation voltage.
TRANSFORMER DRIVE CIRCUIT
Transformer drive transistors have a characteristically low
value of transistor on resistance (RDS); thus, more power
is transferred to the transformer. The transformer drive
circuit is limited by the base current available to switch on
the power transistors driving the transformer and the
characteristic current gain (beta), resulting in a slower
turn-on time. Consequently, more power is dissipated
within the transistor. This results in a lower overall
efficiency, particularly at higher output load currents.
SELF-SYNCHRONIZATION
The input synchronizations facility (SYNCIN), allows for
easy synchronizing of multiple devices. If two to eight
devices (maximum) have their respective SYNCIN pins
connected together, then all devices will be synchronized.
Each device has its own onboard oscillator. This is
generated by charging a capacitor from a constant current
and producing a ramp. When this ramp passes a
threshold, an internal switch is activated that discharges
the capacitor to a second threshold before the cycle is
repeated.
When several devices are connected together, all the
internal capacitors are charged simultaneously.
When one device passes its threshold during the charge
cycle, it starts the discharge cycle. All the other devices
sense this falling voltage and, likewise, initiate a discharge
cycle so that all devices discharge together. A subsequent
charge cycle is only restarted when the last device has
finished its discharge cycle.
OPTIMIZING PERFORMANCE
Optimum performance can only be achieved if the device
is correctly supported. By the very nature of a switching
converter, it requires power to be instantly available when
it switches on. If the converter has DMOS switching
transistors, the fast edges will create a high current
demand on the input supply. This transient load placed on
the input is supplied by the external input decoupling
capacitor, thus maintaining the input voltage. Therefore,
the input supply does not see this transient (this is an
analogy to high-speed digital circuits). The positioning of
the capacitor is critical and must be placed as close as
possible to the input pins and connected via a
low-impedance path.
The optimum performance is primarily dependent on two
factors:
1. Connection of the input and output circuits for
minimal loss.
2. The ability of the decoupling capacitors to maintain
the input and output voltages at a constant level.
PCB Design
The copper losses (resistance and inductance) can be
minimized by the use of mutual ground and power planes
(tracks) where possible. If that is not possible, use wide
tracks to reduce the losses. If several devices are being
powered from a common power source, a star-connected
system for the track must be deployed; devices must not
be connected in series, as this will cascade the resistive
losses. The position of the decoupling capacitors is
important. They must be as close to the devices as
possible in order to reduce losses. See the PCB Layout
section for more details.
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
www.ti.com
13
Decoupling Ceramic Capacitors
All capacitors have losses due to their internal equivalent
series resistance (ESR), and to a lesser degree their
equivalent series inductance (ESL). Values for ESL are
not always easy to obtain. However, some manufacturers
provide graphs of Frequency versus Capacitor
Impedance. These will show the capacitors’ impedance
falling as frequency is increased (see Figure 4). As the
frequency is increased, the impedance will stop
decreasing and begin to rise. The point of minimum
impedance indicates the capacitors’ resonant frequency.
This frequency is where the components of capacitance
and inductance reactance are of equal magnitude. Beyond
this point, the capacitor is not effective as a capacitor.
0fOFrequency
XL
XC
Z
Where:
XCis the reactance due to the capacitance
XListhereactanceduetotheESL
fOthe resonant frequency
Z=√{(XC−XL)2+(ESR)
2}
Figure 4. Capacitor Impedance vs Frequency
At fO, XC = XL; however, there is a 180° phase difference
resulting in cancellation of the imaginary component. The
resulting effect is that the impedance at the resonant point
is the real part of the complex impedance; namely, the
value of the ESR. The resonant frequency must be well
above the 800kHz switching frequency of the DCP and
DCVs.
The effect of the ESR is to cause a voltage drop within the
capacitor. The value of this voltage drop is simply the
product of the ESR and the transient load current, as
shown in Equation (1):
VIN +VPK *(ESR ITR)
Where:
VIN is the voltage at the device input.
VPK is the maximum value of the voltage on the
capacitor during charge.
ITR is the transient load current.
The other factor that affects the performance is the value
of the capacitance. However, for the input and the full wave
outputs (single-output voltage devices), the ESR is the
dominant factor.
Input Capacitor and the effects of ESR
If the input decoupling capacitor is not ceramic with
< 20mΩ ESR, then at the instant the power transistors
switch on, the voltage at the input pins will fall momentarily.
Should the voltage fall below approximately 4V, the DCP
will detect an under-voltage condition and switch the DCP
drive circuits to the off state. This is carried out as a
precaution against a genuine low input voltage condition
that could slow down or even stop the internal circuits from
operating correctly. This would result in the drive
transistors being turned on too long, causing saturation of
the transformer and destruction of the device.
Following detection of a low input voltage condition, the
device switches off the internal drive circuits until the input
voltage returns to a safe value. Then the device tries to
restart. If the input capacitor is still unable to maintain the
input voltage, shutdown recurs. This process is repeated
until the capacitor is charged suf ficiently to start the device
correctly. Otherwise, the device will be caught up in a loop.
Normal startup should occur in approximately 1ms from
power being applied to the device. If a considerably longer
startup duration time is encountered, it is likely that either
(or both) the input supply or the capacitors are not
performing adequately.
For 5V to 15V input devices, a 2.2µF low-ESR ceramic
capacitor will ensure a good startup performance, and for
the remaining input voltage ranges, 0.47µF ceramic
capacitors are good. Tantalum capacitors are not
recommended, since most do not have low-ESR values
and will degrade performance. If tantalum capacitors must
be used, close attention must be paid to both the ESR and
voltage as derated by the vendor.
Output Ripple Calculation Example
DCP020505: Output voltage 5V, Output current 0.4A. At
full output power, the load resistor is 12.5Ω. Output
capacitor of 1µF, ESR of 0.1Ω. Capacitor discharge time
1% of 800kHz (ripple frequency):
tDIS = 0.0125µs
τ = C × RLOAD
τ = 1 × 10−6 × 12.5 = 12.5µs
VDIS = VO(1 − EXP(−tDIS/τ))
VDIS = 5mV
By contrast the voltage dropped due to the ESR:
VESR = ILOAD × ESR
VESR = 40mV
Ripple voltage = 45mV
Clearly, increasing the capacitance will have a much
smaller effect on the output ripple voltage than reducing
the value of the ESR for the filter capacitor.
(1)
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
www.ti.com
14
DUAL OUTPUT VOLTAGE DCP AND DCVs
The voltage output for the dual DCPs is half wave rectified;
therefore, the discharge time is 1.25µs. Repeating the
above calculations using the 100% load resistance of 25Ω
(0.2A per output), the results are shown below:
τ = 25µs
tDIS = 1.25µs.
VDIS = 244mV
VESR = 20mV
Ripple Voltage = 266mV
This time, it is the capacitor discharging that is contributing
to the largest component of ripple. Changing the output
filter to 10µF, and repeating the calculations:
Ripple Voltage = 45mV.
This value is composed of almost equal components.
The above calculations are given only as a guide.
Capacitor parameters usually have large tolerances and
can be susceptible to environmental conditions.
PCB LAYOUT
Figure 5 and Figure 6 illustrate a printed circuit board
(PCB) layout for the two conventional (DCP01/02,
DCV01), and two SO-28 surface-mount packages
(DCP02U). Figure 7 shows the schematic.
Input power and ground planes have been used, providing
a low-impedance path for the input power. For the output,
the common or 0V has been connected via a ground plane,
while the connections for the positive and negative voltage
outputs are conducted via wide traces in order to minimize
losses.
The location of the decoupling capacitors in close
proximity to their respective pins ensures low losses due
to the effects of stray inductance; thus, improving the ripple
performance. This is of particular importance to the input
decoupling capacitor as this supplies the transient current
associated with the fast switching waveforms o f the power
drive circuits.
The SYNCIN pin, when not being used, is best left as a
floating pad. A ground ring or annulus connected around
the pin will prevent noise being conducted onto the pin. If
the SYNCIN pin is to be connected to one or more SYNCIN
pins, then the linking trace should be narrow and must be
kept short in length. In addition, no other trace should be
in close proximity to this trace because that will increase
the stray capacitance on this pin, and that will effect the
performance of the oscillator.
Ripple and Noise
Careful consideration should be given to the layout of the
PCB, in order that the best results can be obtained.
The DCP01B is a switching power supply and as such can
place high peak current demands on the input supply. In
order to avoid the supply falling momentarily during the
fast switching pulses, ground and power planes should be
used to connect the power to the input of DCP01B. If this
is not possible, then the supplies must be connected in a
star formation with the traces made as wide as possible.
If the SYNCIN pin is being used, then the trace connection
between device SYNCIN pins should be short to avoid
stray capacitance. If the SYNCIN pin is not being used, it
is advisable to place a guard ring (connected to input
ground) around this pin to avoid any noise pick up.
The output should be taken from the device using ground
and power planes; this ensures minimum losses.
A good quality low-ESR ceramic capacitor placed as close
as practical across the input will reduce reflected ripple
and ensure a smooth startup.
A good quality low-ESR capacitor (ceramic preferred)
placed as close as practical across the rectifier output
terminal and output ground gives the best ripple and noise
performance. See SBVA012 for more information on noise
rejection.
THERMAL MANAGEMENT
Due to the high power density of this device, it is advisable
to provide ground planes on the input and output.
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
www.ti.com
15
Figure 5. Example of PCB Layout, Component-Side View
Figure 6. Example of PCB Layout, Non-component-Side View
!"#
SBVS012E − DECEMBER 2000 − REVISED DECEMBER 2007
www.ti.com
16
(1) Capacitors C2−1, C4−1, C7−1, and C9−1 are through-hole plated components connected in parallel with C2, C4, C7 and C9 (1206 SMD), respectively.
(2) For optimum low-noise performance, use low-ESR capacitors.
(3) Do not connect the SYNC pin jumper (JP1−JP4) if the SYNC function is not being used.
(4) Connections to the power input should be made with a minimum wire of 16/0.2 twisted pair, with the length kept short.
(5) VSx and 0Vx are input supply and ground respecively (x represents the channel).
(6) +Vx and −Vx are the positive and negative outputs, referenced to a common ground COMx.
(7) JPx are the links used for self-synchronization; if this facility is not being used, the links should be unconnected.
(8) R1−R8 are the power output loads; do not fit these if an external load is connected.
(9) CON1 and CON2 are DIL-14; CON3 and CON4 are SO-28 packages.
(10)NC = not connected.
1
2
3
13
12
14
DCP02xU
28
27
26
C16
R7C17 C18
R8C20 C19
VS4
0S4
+V4
COM4
−V4
NC
NC
1
2
3
13
12
14
C11
R5C13 C12
R6C14 C15
VS3
0S3
+V3
COM3
−V3
28
27
26
C1
R1C3C2−1 C2
R2C5C4−1 C4
VS1
0V1
+V1
COM1
−V1
C6
R3C8C7−1 C7
R4C10 C9−1C9
VS2
0V2
+V2
COM2
−V2
1
2
6
5
7
1
2
6
5
7
14
14
DCP02xP
SYNC
DCP02xP
SYNC
DCP02xU
SYNC
SYNC
JP1
JP2
JP1
JP2
CON1
CON2
CON3
CON4
Figure 7. Example of PCB Layout, Schematic Diagram
PACKAGING INFORMATION
Orderable Device Status (1) Package
Type Package
Drawing Pins Package
Qty Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
DCP010505BP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010505BP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010505BP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010505BP-U/7E4 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010505BP-UE4 ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010505DBP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010505DBP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010505DBP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010505DBP-U/7E4 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010505DBP-UE4 ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010507DBP-U/7E4 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010507DBP-UE4 ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010507DBPE4 ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010512BP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010512BP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010512BP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010512DBP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010512DBP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010512DBP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010512DBPE4 ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010515BP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010515BP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010515BP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP010515DBP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP010515DBP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2009
Addendum-Page 1
Orderable Device Status (1) Package
Type Package
Drawing Pins Package
Qty Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
DCP010515DBP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP011512DBP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP011512DBP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP011512DBP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP011515DBP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP011515DBP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP011515DBP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP012405BP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP012405BP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP012415DBP ACTIVE PDIP NVA 7 25 Pb-Free
(RoHS) CU NIPDAU N / A for Pkg Type
DCP012415DBP-U ACTIVE SOP DUA 7 25 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
DCP012415DBP-U/700 ACTIVE SOP DUA 7 700 Pb-Free
(RoHS) CU NIPDAU Level-3-260C-168 HR
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and
package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS
compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is
provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the
accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take
reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on
incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited
information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2009
Addendum-Page 2
to Customer on an annual basis.
PACKAGE OPTION ADDENDUM
www.ti.com 16-Apr-2009
Addendum-Page 3
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