TI DCP022405U/1K Miniature, 2w, isolated unregulated dc/dc converter Datasheet

 DCP02 Series
DC
P0
2
DC
P0
2
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
Miniature, 2W, Isolated
UNREGULATED DC/DC CONVERTERS
FEATURES
DESCRIPTION
1
•
•
•
•
•
•
•
2
Up To 89% Efficiency
Thermal Protection
Device-to-Device Synchronization
SO-28 Power Density of 106W/in3 (6.5W/cm3 )
EN55022 Class B EMC Performance
UL1950 Recognized Component
JEDEC 14-Pin and SO-28 Packages
APPLICATIONS
•
•
•
•
•
Point-of-Use Power Conversion
Ground Loop Elimination
Data Acquisition
Industrial Control and Instrumentation
Test Equipment
800kHz
Oscillator
SYNC/DISABLE
The DCP02 series is a family of 2W, isolated,
unregulated DC/DC converters. Requiring a minimum
of external components and including on-chip device
protection, the DCP02 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 power densities of
79W/in3 (4.8W/cm3) for DIP-14, and 106W/in3
(6.5W/cm3) for SO-28. This combination of features
and small size makes the DCP02 suitable for a wide
range of applications.
Divide-by-2
Reset
VOUT
Power
Stage
0V
Watchdog/
Startup
PSU
Thermal
Shutdown
IBIAS
VS
Power Controller IC
0V
1
2
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.
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 © 2000–2007, Texas Instruments Incorporated
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
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.
ORDERING INFORMATION
For the most current package and ordering information, see the Package Option Addendum at the end of this
data sheet, or see the TI website at www.ti.com.
Supplemental Ordering Information
DCP02
05
05
(D) ( )
Basic Model Number: 2W Product
Voltage Input:
5V In
Voltage Output:
5V Out
Dual Output:
Package Code:
P = DIP-14
U = SO-28
ABSOLUTE MAXIMUM RATINGS
Over operating free-air temperature range (unless otherwise noted)
(1)
PARAMETER
Input Voltage
DCP02 Series
UNIT
5V input models
7
V
12V input models
15
V
15V input models
18
V
24V input models
29
V
–60 to +125
°C
Storage temperature range
(1)
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.
ELECTRICAL CHARACTERISTICS
At TA = +25°C, unless otherwise noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
OUTPUT
Power
100% full load
Ripple
Output capacitor = 1µF, 50% load
Voltage vs. Temperature
2
W
20
mVPP
Room to cold
0.046
%/°C
Room to hot
0.016
%/°C
INPUT
Voltage range on VS
–10
10
%
ISOLATION
Voltage
1s Flash test
1
kVrms
60s test, UL1950 (1)
1
kVrms
LINE REGULATION
Output Voltage
(1)
(2)
2
IO = constant (2)
VS (min) to VS (typ)
1
15
%
VS (typ) to VS (max)
1
15
%
During UL1950 recognition tests only.
IOUT ≥ 10% load current
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
ELECTRICAL CHARACTERISTICS (continued)
At TA = +25°C, unless otherwise noted.
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
SWITCHING/SYNCHRONIZATION
Oscillator frequency (fOSC)
Switching frequency = fOSC/2
800
Sync input low
0
Sync input current
kHz
0.4
VSYNC = +2V
V
µA
75
Disable time
µs
2
Capacitance loading on SYNC pin
3 (3)
External
pF
RELIABILITY
Demonstrated
TA = +55°C
75
FITS
THERMAL SHUTDOWN
IC temperature at shutdown
+150
°C
3
mA
Shutdown current
TEMPERATURE RANGE
Operating
(3)
–40
°C
+85
For more information, refer to application report SBAA035, available for download at www.ti.com.
ELECTRICAL CHARACTERISTICS PER DEVICE
At TA = +25°C, VS = nominal, CIN = 2.2µF, COUT = 1.0 µF, unless otherwise noted.
INPUT
VOLTAGE
(V)
OUTPUT
VOLTAGE
(V)
VS
VNOM AT VS (TYP)
LOAD
REGULATION
(%)
NO LOAD
CURRENT
(mA)
EFFICIENCY
(%)
IQ
10% TO 100%
LOAD (2)
75% LOAD (1)
BARRIER
CAPACITANCE
(pF)
CISO
0% LOAD
100% LOAD
VISO = 750Vrms
TYP
TYP
TYP
30
18
74
26
14
20
18
80
22
7.35
14
25
20
81
30
9
9.45
12
20
23
82
31
±14.25
±15
±15.75
11
20
27
85
24
13.2
4.75
5
5.25
7
15
14
83
33
12
13.2
11.4
12
12.6
7
20
15
87
47
10.8
12
13.2
±11.4
±12
±12.6
6
20
16
88
35
DCP021215DP
10.8
12
13.2
±14.25
±15
±15.75
6
20
21
87
33
DCP021505U
13.5
15
16.5
4.75
5
5.25
10
15
11
81
34
DCP021515P, U
13.5
15
16.5
14.25
15
15.75
6
20
15
88
42
DCP022405P
21.6
24
26.4
4.85
5
5.35
6
10
13
81
33
DCP022405U
21.6
24
26.4
4.75
5
5.25
10
15
13
81
33
DCP022405DP, U
21.6
24
26.4
±4.75
±5
+5.25
6
15
12
80
22
DCP022412DP
21.6
24
26.4
±11.4
±12
±12.6
4
16
19
83
29
DCP022415DP, U
21.6
24
26.4
±14.25
±15
±15.75
6
25
16
79
44
DCP022418DP
21.6
24
26.4
±17.1
±18
±18.9
9
25
20
84
32
PRODUCT
MIN
TYP
MAX
MIN
TYP
MAX
TYP
MAX
DCP020503P, U
4.5
5
5.5
3.13
3.3
3.46
19
DCP020505P, U
4.5
5
5.5
4.75
5
5.25
DCP020507P, U
4.5
5
5.5
6.65
7
DCP020509P, U
4.5
5
5.5
8.55
DCP020515DP, U
4.5
5
5.5
DCP021205P, U
10.8
12
DCP021212P, U
10.8
DCP021212DP, U
(1)
(2)
100% load current = 2W/VNOM (typ)
Load regulation = (VOUT at 10% load - VOUT at 100%)/VOUT at 75% load
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
3
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
DEVICE INFORMATION
NVA PACKAGE
DIP-14 (Single-DIP)
(Top View)
VS
1
0V
2
NVA PACKAGE
DIP-14 (Dual-DIP)
(Top View)
14 SYNC
VS
1
0V
2
14 SYNC
DCP02
DCP02
0V
5
0V
5
+VOUT
6
+VOUT
6
NC
7
-VOUT
7
8
NC
Table 1. Pin Description (Single-DIP)
NC
Table 3. TERMINAL FUNCTIONS (Dual-DIP)
TERMINAL
NAME
8
TERMINAL
NO.
DESCRIPTION
NAME
NO.
DESCRIPTION
VS
1
Voltage input
VS
1
Voltage input
0V
2
Input side common
0V
2
Input side common
0V
5
Output side common
0V
5
Output side common
+VOUT
6
+Voltage out
+VOUT
6
+Voltage out
NC
7, 8
Not connected
–VOUT
7
–Voltage out
SYNC
14
Synchronization pin
NC
8
Not connected
SYNC
14
Synchronization pin
DVB PACKAGE
SO-28 (Single-SO)
(Top View)
DVB PACKAGE
SO-28 (Dual-SO)
(Top View)
VS
1
28 SYNC
0V
2
27 NC
VS
1
28 SYNC
0V
3
26 NC
0V
2
27 NC
0V
3
26 NC
DCP02
DCP02
0V 12
17 NC
+VOUT 13
16 NC
NC 14
15 NC
0V 12
17 NC
+VOUT 13
16 NC
14
15 NC
-VOUT
Table 2. TERMINAL FUNCTIONS (Single-SO)
Table 4. TERMINAL FUNCTIONS (Dual-SO)
TERMINAL
NAME
NO.
DESCRIPTION
TERMINAL
VS
1
Voltage input
NAME
0V
2
Input side common
VS
1
Voltage input
0V
3
Input side common
0V
2
Input side common
0V
12
Output side common
0V
3
Input side common
+VOUT
13
+Voltage out
0V
12
Output side common
Not connected
+VOUT
13
+Voltage out
–VOUT
14
–Voltage out
NC
SYNC
14, 15, 16,
17, 26, 27
28
Synchronization pin
NC
SYNC
4
Submit Documentation Feedback
NO.
15, 16, 17,
26, 27
28
DESCRIPTION
Not connected
Synchronization pin
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
TYPICAL CHARACTERISTICS
At TA = +25°C, unless otherwise noted.
DCP020505P
VOUT vs TEMPERATURE (75% Load)
60
5.04
50
5.02
40
5.00
30
VOUT (V)
Emission Level, Peak (dBmA)
DCP020505P
CONDUCTED EMISSIONS (500mA Load)
20
4.96
10
4.94
0
4.92
-10
4.90
-20
0.15
1
5.4
10
-40
30
0
20
40
60
80
100
Temperature (°C)
Figure 1.
Figure 2.
DCP021205P
VOUT vs LOAD
DCP021205P
POWER OUT vs TEMPERATURE (400mA Load)
2.5
5.3
2.0
5.2
1.5
5.1
5.0
1.0
0.5
4.9
0
0
20
40
60
80
100
-50
Load (%)
-25
0
25
50
Temperature (°C)
75
Figure 3.
Figure 4.
DCP0212
EFFICIENCY vs LOAD
DCP020505P
OUTPUT AC RIPPLE (20MHz Band)
100
450
100
DCP1212DP
400
80
350
DCP1205P
0.1mF
Ripple (mVPP)
Efficiency (%)
-20
Frequency (MHz)
POUT (W)
VOUT (V)
4.98
60
40
300
250
200
150
100
20
1m F
50
0
0
0
25
50
75
100
0
Load (%)
200
400
Load Current (mA)
Figure 5.
Figure 6.
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
5
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
FUNCTIONAL DESCRIPTION
OVERVIEW
This interference occurs because of the small
variations in switching frequencies between the
DC/DC converters.
The DCP02 offers up to 2W of unregulated output
power from a 5V, 12V, 15V, or 24V input source with
a typical efficiency of up to 89%. This efficiency 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.
The DCP02 overcomes this interference by allowing
devices to be synchronized to one another. Up to
eight devices can be synchronized by connecting the
SYNC pins together, taking care to minimize the
capacitance of tracking. Stray capacitance (> 10pF)
has the effect of reducing the switching frequency, or
even stopping the oscillator circuit. It is also
recommended that power and ground lines be
star-connected.
POWER STAGE
The DCP02 uses a push-pull, center-tapped topology
switching at 400kHz (divide-by-2 from an 800kHz
oscillator).
It should be noted that if synchronized devices are
used at start up, all devices will draw maximum
current simultaneously. This configuration 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.
OSCILLATOR AND WATCHDOG
The onboard 800kHz oscillator generates the
switching frequency via a divide-by-2 circuit. The
oscillator can be synchronized to other DCP02
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, which occurs in 2µs.
If more than eight devices are to be synchronized, it
is recommended that the SYNC pins be 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 from www.ti.com.
THERMAL SHUTDOWN
CONSTRUCTION
The DCP02 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 resumes.
The basic construction of the DCP02 is the same as
standard ICs; there is no substrate within the molded
package. The DCP02 is constructed using an IC,
rectifier diodes, and a wound magnetic toroid on a
leadframe. Since there is no solder within the
package, the DCP02 does not require any special
printed circuit board (PCB) assembly processing. This
architecture results in an isolated DC/DC converter
with inherently high reliability.
SYNCHRONIZATION
In the event that more than one DC/DC converter is
needed onboard, beat frequencies and other
electrical interference can be generated.
VSUPPLY
VOUT 1
VS
CIN
(1)
SYNC
DCP
COUT
1.0mF
02
0V
0V
VS
VOUT 2
VOUT 1 + VOUT 2
CIN(1)
SYNC
0V
COM
DCP
COUT
1.0mF
02
0V
NOTE: (1) CIN requires a low-ESR ceramic capacitor: 5V to 15V version is 2.2mF;
24V version is minimum 0.47mF.
Figure 7. Connecting the DCP02 in Series
6
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
ADDITIONAL FUNCTIONS
DISABLE/ENABLE
The DCP02 can be disabled or enabled by driving the
SYNC pin using an open drain CMOS gate. If the
SYNC pin is pulled low, the DCP02 will be disabled.
The disable time depends upon the external loading;
the internal disable function is implemented in 2µs.
Removal of the pull down causes the DCP02 to be
enabled.
Capacitive loading on the SYNC pin should be
minimized in order to prevent a reduction in the
oscillator frequency.
Connect the positive VOUT from one DCP02 to the
negative VOUT (0V) of another (see Figure 7). If the
SYNC pins are tied together, the self-synchronization
feature of the DCP02 prevents beat frequencies on
the voltage rails. The SYNC feature of the DCP02
allows easy series connection without external
filtering, thus minimizing cost.
The outputs on the dual-output DCP02 versions can
also be connected in series to provide two times the
magnitude of VOUT, as shown in Figure 8. For
example, a dual 15V DCP022415D could be
connected to provide a 30V rail.
DECOUPLING
Connecting the DCP02 in Parallel
Ripple Reduction
The high switching frequency of 400kHz allows
simple filtering. To reduce ripple, it is recommended
that a 1µF capacitor be used on VOUT. Dual outputs
should both be decoupled to pin 5. A 2.2µF capacitor
on the input is also recommended.
If the output power from one DCP02 is not sufficient,
it is possible to parallel the outputs of multiple
DCP02s, as shown in Figure 9. Again, the SYNC
feature allows easy synchronization to prevent
power-rail beat frequencies at no additional filtering
cost.
Connecting the DCP02 in Series
Multiple DCP02 isolated 2W DC/DC converters can
be connected in series to provide nonstandard
voltage rails. This configuration is possible by using
the floating outputs provided by the galvanic isolation
of the DCP02.
VSUPPLY
VS
CIN(1)
+VOUT
DCP
02
0V
COM
-VOUT
+VOUT
COUT
1.0mF
COUT
1.0mF
0V
-VOUT
NOTE: (1) CIN requires a low-ESR ceramic capacitor: 5V to 15V version is 2.2mF;
24V version is minimum 0.47mF.
Figure 8. Connecting Dual Outputs in Series
VSUPPLY
VOUT
VS
CIN
(1)
SYNC
DCP
COUT
1.0mF
02
0V
0V
VS
VOUT
2 x Power Out
CIN(1)
SYNC
0V
COM
DCP
COUT
1.0mF
02
0V
NOTE: (1) CIN requires a low-ESR ceramic capacitor: 5V to 15V version is 2.2mF;
24V version is minimum 0.47mF.
Figure 9. Connecting Multiple DCP02s in Parallel
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
7
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
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. 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, resulting 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
oscillator 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.
OPTIMIZING PERFORMANCE
Optimum performance can only be achieved if the
device is correctly supported. The very nature of a
switching converter 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 primarily depends 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.
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.
8
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
Decoupling Ceramic Capacitors
Input Capacitor and the Effects of ESR
All capacitors have losses because of internal
equivalent series resistance (ESR), and to a lesser
degree, equivalent series inductance (ESL). Values
for ESL are not always easy to obtain. However,
some manufacturers provide graphs of frequency
versus capacitor impedance. These graphs typically
show the capacitor impedance falling as frequency is
increased (as shown in Figure 10). As the frequency
increases, the impedance stops decreasing and
begins to rise. The point of minimum impedance
indicates the resonant frequency of the capacitor.
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.
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 falls
momentarily. Should the voltage fall below
approximately 4V, the DCP detects an under-voltage
condition and switches the DCP drive circuits to the
off state. This detection 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. A slow-down or stoppage
would result in the drive transistors being turned on
too long, causing saturation of the transformer and
destruction of the device.
Z
XC
XL
0
fO
Frequency
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.
Z = Ö(XC - XL)2 + (ESR)2
Where:
XC is the reactance due to the capacitance.
XL is the reactance due to the ESL.
fO is the resonant frequency.
Figure 10. 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:
VIN = VPK – (ESR × ITR)
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 sufficiently to start the device correctly.
Otherwise, the device will be caught up in a loop.
(1)
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),
ESR is the dominant factor.
For 5V to 15V input devices, a 2.2µF low-ESR
ceramic capacitor ensures a good startup
performance. For the remaining input voltage ranges,
0.47µF ceramic capacitors are recommended.
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 because of ESR:
VESR = ILOAD × ESR
VESR = 40mV
Ripple voltage = 45mV
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
9
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
Clearly, increasing the capacitance has a much
smaller effect on the output ripple voltage than does
reducing the value of the ESR for the filter capacitor.
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:
τ = 25µs
tDIS = 1.25µs
VDIS = 244mV
VESR = 20mV
Ripple Voltage = 266mV
This time, it is the capacitor discharging that
contributes to the largest component of ripple.
Changing the output filter to 10µF, and repeating the
calculations, the result is:
Ripple Voltage = 45mV.
This value is composed of almost equal components.
The previous calculations are given only as a guide.
Capacitor parameters usually have large tolerances
and can be susceptible to environmental conditions.
PCB LAYOUT
Figure 11 and Figure 12 illustrate a printed circuit
board (PCB) layout for the two conventional
(DCP01/02, DCV01), and two SO-28 surface-mount
packages (DCP02U). Figure 13 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 location is of particular
importance to the input decoupling capacitor,
because this capacitor supplies the transient current
associated with the fast switching waveforms of the
power drive circuits.
10
The SYNCIN pin, when not being used, is best left as
a floating pad. A ground ring or annulus connected
around the pin prevents 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. In turn, the stray capacitance affects the
performance of the oscillator.
Ripple and Noise
Careful consideration should be given to the layout of
the PCB in order to obtain the best results.
The DCP02 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 DCP02. If this connection 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, thereby ensuring minimum
losses.
A good quality, low-ESR ceramic capacitor placed as
close as practical across the input reduces reflected
ripple and ensures 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 Application
Bulletin SBVA012, DC-to-DC Converter Noise
Reduction, 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.
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
Figure 11. Example of PCB Layout, Component-Side View
Figure 12. Example of PCB Layout, Non-Component-Side View
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
11
DCP02 Series
www.ti.com
SBVS011I – MARCH 2000 – REVISED NOVEMBER 2007
CON3
CON1
1
VS1
C1
2
0V1
SYNC
14
VS3
JP1
6
+V1
R1
C3
C2-1
C2
R2
C5
C4-1
C11
0S3
2
3
+V3
13
DCP02xP
C13
R5
5
COM1
1
JP1
26
NC
12
R6
7
-V1
28
27
DCP02xU
C12
COM3
C4
SYNC
C14
C15
14
-V3
CON4
CON2
1
VS2
C6
SYNC 14
2
0V2
6
+V2
R3
C8
C7-1
5
COM2
R4
C10
C9-1
JP2
C16
0S4
2
3
+V4
13
DCP02xP
C7
1
VS4
R7
26 NC
12
R8
-V2
JP2
DCP02xU
C18
COM4
C9
7
C17
SYNC 28
27
C20
C19
14
-V4
(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 respectively (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.
Figure 13. Example of PCB Layout, Schematic Diagram
12
Submit Documentation Feedback
Copyright © 2000–2007, Texas Instruments Incorporated
Product Folder Link(s): DCP02 Series
PACKAGE OPTION ADDENDUM
www.ti.com
28-Nov-2007
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
DCP020503P
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP020503U
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020505P
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP020505U
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020505U/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020505U/1KE4
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020505UE4
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020507P
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP020507U
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020507U/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020509P
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP020509U
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020515DP
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP020515DU
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP020515DU/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP021205P
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
CU SNPB
N / A for Pkg Type
DCP021205PE4
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
CU SNPB
N / A for Pkg Type
DCP021205U
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
CU SNPB
Level-3-260C-168 HR
DCP021205U/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
CU SNPB
Level-3-260C-168 HR
DCP021212DP
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP021212DU
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP021212DU/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP021212P
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
CU NIPDAU
N / A for Pkg Type
DCP021212U
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP021212U/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
Addendum-Page 1
Lead/Ball Finish
MSL Peak Temp (3)
PACKAGE OPTION ADDENDUM
www.ti.com
28-Nov-2007
Status (1)
Package
Type
Package
Drawing
DCP021215DP
ACTIVE
PDIP
NVA
7
DCP021505U
PREVIEW
SOP
DVP
12
DCP021515P
ACTIVE
PDIP
NVA
7
DCP021515PE4
ACTIVE
PDIP
NVA
DCP021515U
ACTIVE
SOP
DCP021515U/1K
ACTIVE
DCP022405DP
Orderable Device
Pins Package Eco Plan (2)
Qty
25
Lead/Ball Finish
MSL Peak Temp (3)
TBD
Call TI
Call TI
TBD
Call TI
Call TI
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP022405DU
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP022405P
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
DCP022405U
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP022405U/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP022412DP
ACTIVE
PDIP
NVA
7
25
TBD
Call TI
DCP022415DP
ACTIVE
PDIP
NVA
7
25
Pb-Free
(RoHS)
Cu NiPdAu
N / A for Pkg Type
DCP022415DU
ACTIVE
SOP
DVB
12
28
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP022415DU/1K
ACTIVE
SOP
DVB
12
1000
Pb-Free
(RoHS)
Cu NiPdAu
Level-3-260C-168 HR
DCP022418DP
ACTIVE
PDIP
NVA
7
25
TBD
Call TI
CU NIPDAULATEN / A for Pkg Type
Call TI
Call TI
(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
Addendum-Page 2
PACKAGE OPTION ADDENDUM
www.ti.com
28-Nov-2007
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
to Customer on an annual basis.
Addendum-Page 3
PACKAGE MATERIALS INFORMATION
www.ti.com
15-Nov-2007
TAPE AND REEL BOX INFORMATION
Device
Package Pins
Site
Reel
Diameter
(mm)
Reel
Width
(mm)
A0 (mm)
B0 (mm)
K0 (mm)
P1
(mm)
W
Pin1
(mm) Quadrant
DCP020505U/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP020507U/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP020515DU/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP021205U/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP021212DU/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP021212U/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP021515U/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP022405U/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
DCP022415DU/1K
DVB
12
SITE 35
330
24
10.9
18.3
3.2
12
24
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
15-Nov-2007
Device
Package
Pins
Site
Length (mm)
Width (mm)
Height (mm)
DCP020505U/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP020507U/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP020515DU/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP021205U/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP021212DU/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP021212U/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP021515U/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP022405U/1K
DVB
12
SITE 35
406.0
348.0
63.0
DCP022415DU/1K
DVB
12
SITE 35
406.0
348.0
63.0
Pack Materials-Page 2
MECHANICAL DATA
MPDS106A – AUGUST 2001 – REVISED NOVEMBER 2001
DVB(R-PDSO-G12/28)
–A–
28
PLASTIC SMALL-OUTLINE
18,10
17,70
11,20
10,82
C
0°–8°
15
1,27
0,40
F
7,60
7,40
–B–
D
10,65
10,01
0,25 M B M
Index
Area
1
14
0,30
0,10
2,65
2,35
0,75
0,25 x 45°
Base
Plane
–C–
Seating
Plane
1,27
G
0,32
0,23
0,51
0,33
0,10
0,25 M C A M B S
4202104/B 11/01
G. Lead width, as measured 0,36 mm or greater
above the seating plane, shall not exceed a
maximum value of 0,61 mm.
H. Lead-to-lead coplanarity shall be less than
0,10 mm from seating plane.
I. Falls within JEDEC MS-013-AE with the exception
of the number of leads.
NOTES: A. All linear dimensions are in millimeters.
B. This drawing is subject to change without notice.
C.
Body length dimension does not include mold
flash, protrusions, or gate burrs. Mold flash, protrusions,
and gate burrs shall not exceed 0,15 mm per side.
D. Body width dimension does not include inter-lead flash
or portrusions. Inter-lead flash and protrusions
shall not exceed 0,25 mm per side.
E. The chamfer on the body is optional. If it is not present,
a visual index feature must be located within the
cross-hatched area.
F. Lead dimension is the length of terminal for soldering
to a substrate.
•
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443
•
1
IMPORTANT NOTICE
Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements,
improvements, and other changes to its products and services at any time and to discontinue any product or service without notice.
Customers should obtain the latest relevant information before placing orders and should verify that such information is current and
complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.
TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s
standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this
warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily
performed.
TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and
applications using TI components. To minimize the risks associated with customer products and applications, customers should
provide adequate design and operating safeguards.
TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask
work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services
are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such
products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under
the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI.
Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is
accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an
unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties
may be subject to additional restrictions.
Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service
voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business
practice. TI is not responsible or liable for any such statements.
TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would
reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement
specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications
of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related
requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any
applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its
representatives against any damages arising out of the use of TI products in such safety-critical applications.
TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are
specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military
specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is
solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in
connection with such use.
TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products
are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any
non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements.
Following are URLs where you can obtain information on other Texas Instruments products and application solutions:
Products
Applications
Amplifiers
amplifier.ti.com
Audio
www.ti.com/audio
Data Converters
dataconverter.ti.com
Automotive
www.ti.com/automotive
DSP
dsp.ti.com
Broadband
www.ti.com/broadband
Interface
interface.ti.com
Digital Control
www.ti.com/digitalcontrol
Logic
logic.ti.com
Military
www.ti.com/military
Power Mgmt
power.ti.com
Optical Networking
www.ti.com/opticalnetwork
Microcontrollers
microcontroller.ti.com
Security
www.ti.com/security
RFID
www.ti-rfid.com
Telephony
www.ti.com/telephony
Low Power
Wireless
www.ti.com/lpw
Video & Imaging
www.ti.com/video
Wireless
www.ti.com/wireless
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265
Copyright © 2007, Texas Instruments Incorporated
Similar pages