Datenblatt

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rev.
PART NUMBER: VPOL5A-12-SIP
page
1 of 12
date
08/2007
DESCRIPTION: point of load converter
features
* industry standard pin out
* high efficiency to 92%
* 300 KHz switching frequency
* 8.3-14 VDC wide input range
* 0.75-5.0 VDC wide output range
* over temperature protection
* continuous short circuit protection
* remote on/off
* cost-efficient open frame design
* UL/C-UL60950-1 (E222736) certified
1. INTRODUCTION
2. VPOL5A-12-SIP CONVERTER FEATURES
7. APPLICATIONS
7.1 Layout Design Challenges.
7.2 Convection Requirements for Cooling
3. GENERAL DESCRIPTION
3.1 Electrical Description
7.3 Thermal Considerations
3.2 Thermal Packaging and Physical Design.
7.4 Power De-Rating Curves
4. TECHNICAL SPECIFICATIONS
7.5 Efficiency vs Load Curves
5. MAIN FEATURES AND FUNCTIONS
5.1 Operating Temperature Range
7.6 Input Capacitance at the Power Module
5.2 Over-Temperature Protection (OTP)
7.8 VPOL5A-12-SIP Output Voltage Adustment.
5.3 Output Voltage Adjustment
7.9 Output Ripple and Noise Measurement
5.4 Safe Operating Area (SOA)
7.10 Output Capacitance
5.5 Over Current Protection
5.6 Remote ON/OFF
7.7 Test Set-Up
8. MECHANICAL OUTLINE DIAGRAMS
8.1 VPOL5A-12-SIP Mechanical Outline Diagrams
5.7 UVLO (Under-Voltage Lockout)
6. SAFETY
6.1 Input Fusing and Safety Considerations.
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
rev.
PART NUMBER: VPOL5A-12-SIP
page
2 of 12
date
08/2007
DESCRIPTION: point of load converter
If the converter is overloaded or the ambient temperature gets too
1. Introduction
high, the converter will shut down to protect the unit.
L1
Q1
This application note describes the features and functions of CUI INC's
+VIN
+VO
VPOL5A-12-SIP series of non-isolated dc-dc converters. These are
highly efficient, reliable and compact, high power density, single output
C1
Q2
D1
C2
DC/DC converters. These “Point of Load” modules serve the needs
specifically of the fixed and mobile telecommunications and computing
market, employing economical distributed Power Architectures. The
VPOL5A-12-SIP series provide precisely regulated output voltage range
COM
COM
R1
from 0.75V to 5.0Vdc over a wide range of input voltage (Vi=8.3 –
14Vdc) and can operate over an ambient temperature range of –40°C
to +85°C. Ultra-h igh efficiency operation is achieved through the use of
PWM IC
ON/OFF
R trim
ERR AMP
TRIM
R2
synchronous rectification and drive control techniques.
The modules are fully protected against short circuit and overtemperature conditions. CUI INC's world class automated
Figure 1. Electrical Block Diagram
manufacturing methods, together with an extensive testing and
qualification program, ensure that all VPOL5A-12-SIP series converters
3.2 Thermal Packaging and Physical Design.
are extremely reliable.
The VPOL5A-12-SIP series uses a multi-layer FR4 PCB construction.
All surface mount power components are placed on one side of the
2. VPOL5A-12-SIP Converter Features
PCB, and all low-power control components are placed on the other
side. Thus, the Heat dissipation of the power components is optimized,
High efficiency topology, typically 89% at 3.3Vdc
ensuring that control components are not thermally stressed. The
Industry standard footprint
converter is an open-frame product and has no case or case pin. The
Wide ambient temperature range, -40°C to +85°C
open-frame design has several advantages over encapsulated closed
Cost efficient open frame design
devices. Among these advantages are:
Programmable output voltage via external resistor from 0.75 to
5.0Vdc
No minimum load requirement (Stable at all loads)
Remote ON/OFF
Fixed switching frequency
Continuous short-circuit protection and over current protection
Over-temperature protection (OTP)
Monotonic Startup with pre-bias at the output.
UL/IEC/EN60950 Certified.
Efficient Thermal Management: the heat is removed from the
heat generating components without heating more sensitive, small
signal control components.
Environmental: Lead free open-frame converters are more easily
re-cycled.
Cost Efficient: No encapsulation. Cost efficient open-frame
construction.
Reliable: Efficient cooling provided by open frame construction
offers high reliability and easy diagnostics.
3. General Description
3.1 Electrical Description
A block diagram of the VPOL5A-12-SIP Series converter is shown in
Figure 1. Extremely high efficiency power conversion is achieved
through the use of synchronous rectification and drive techniques.
Essentially, the powerful VPOL5A-12-SIP series topology is based on a
non-isolated synchronous buck converter. The control loop is optimized
for unconditional stability, fast transient response and a very tight line
and load regulation. In a typical pre-bias application the VPOL5A-12SIP series converters do not draw any reverse current at start-up. The
output voltage can be adjusted from 0.75 to 5.0vdc, using the TRIM pin
with a external resistor. The converter can be shut down via a remote
ON/OFF input that is referenced to ground. This input is compatible with
popular logic devices; a 'positive' logic input is supplied as standard.
Positive logic implies that the converter is enabled if the remote
ON/OFF input is high (or floating), and disabled if it is low. The
converter is also protected against over-temperature conditions.
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
For more information, please visit the product page.
rev.
4 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
P A R A ME T E R
DYNAMIC CHARACTERISTICS
page
N O T E S a n d C O N D IT IO N S
Device
Er ror Brand
5 0 % Ste p L oa d Cha nge , di/dt=0 . 1 A /us
Setting Time (within 1% Vout nominal)
50% Step Load Change, di/dt=0.1A/us
Min.
Typical
Max.
Units
AL L
200
mV
AL L
200
us
Output Voltage Transient Response
EFFICIENCY
100% Load
Vo=0.75V
Vo=1.2V
Vo=1.5V
Vo=1.8V
Vo=2.0V
Vo=2.5V
Vo=3.3V
Vo=5.0V
ALL
N on-isolation
AL L
73
80
82
84
85
87
89
92
%
ISOLATION CHARACTERISTICS
I nput to O utput
0
Vdc
FEATURE CHARACTERISTICS
Switching Fre uency
ALL
300
ON/OFF Control, Positive Logic Remote On/O
Logic Low (Module O )
L ogic H igh ( Module O n)
or O pe n C irc uit
Standard Model
0
ON/OFF Control, Negative Logic Remote On/O
Logic Low (Module On)
Logic High (Module O )
or Open Circuit
Su x “N” Model
0
2.8
O N /O F F C urre nt ( for both re mote on/off logic )
L e a k a ge C urre nt ( for both re mote on/off logic )
Turn-On Delay and Rise Time
T urn -O n D e la y T ime , F rom O n/O ff C ontrol
T urn -O n D e la y T ime , F rom I nput
O utput V olta ge R is e T ime
Over Temperature Protection
Vin
KHz
0.4
Vdc
Vdc
0.4
Vin
Vdc
Vdc
1
1
mA
mA
I on/off a t V on/off =0 . 0 V
L ogic H igh, V on/off=1 4 V
AL L
AL L
V on/off to 1 0 % V o, s e t
V in, min. to 1 0 % V o, s e t
1 0 % V o, s e t to 9 0 % V o, s e t
AL L
AL L
AL L
ALL
3. 5
3. 5
3. 5
120
ms
ms
ms
°C
ALL
1.5
M hours
ALL
2.3
grams
GENERAL SPECIFICATIONS
MTBF
Weight
Dimensions
V P O L 5 A -1 2 -S I P pa c k a ge s
Io=100% of Io.max Ta=2 5°C per MIL- HDBK - 217F
0 . 9 x 0 . 4 x 0 . 2 2 inc he s ( 2 2 . 9 x 1 0 . 1 6 x 5 . 6 mm)
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
rev.
PART NUMBER: VPOL5A-12-SIP
page
5 of 12
date
08/2007
DESCRIPTION: point of load converter
5. Main Features and Functions
5.4 Safe Operating Area (SOA)
5.1 Operating Temperature Range
(SOA) of the converter. This representation assumes ambient
Figure 2 provides a graphical representation of the Safe Operating Area
CUI INC’s VPOL5A-12-SIP series converters highly efficient converter
operating conditions such as airflow are met as per thermal guidelines
design has resulted in its ability to operate over a wide ambient
provided in Sections 7.2 and 7.3.
temperature environment ( -40°C to 85°C). Due consideration must be
given to the de-rating curves when ascertaining maximum power that
Vo
can be drawn from the converter. The maximum power drawn is
influenced by a number of factors, such as:
Input voltage range.
Air velocity (forced or natural convection).
Mounting orientation of converter PCB with respect to the Airflow.
Motherboard PCB design, especially ground and power planes.
These can be effective heat sinks for the converter.
Vo,nom
VOLTAGE (V)
Output load current.
Safe Operating Area
5.2 Over-Temperature Protection (OTP)
Io,max Io,CL Io
The VPOL5A-12-SIP Series converters are equipped with non-latching
CURRENT (A)
over-temperature protection. A te mperature sensor monitors the
temperature of the hot spot (typically, top switch). If the temperature
exceeds a threshold of 120°C (t ypical) the converter will shut down,
disabling the output. When the temperature has decreased the
Figure 2. Maximum Output Current Safe Operating Area
converter will automatically restart.
5.5 Over Current Protection
The over-temperature condition can be induced by a variety of reasons
All different voltage models have a full continuous short-circuit
such as external overload condition or a system fan failure.
protection. The unit will auto recover once the short circuit is removed.
To provide pr otection in a fault condition, the unit is equipped with
5.3 Output Voltage Adjustment
Section 7.8 describes in detail as to how to trim the output voltage with
respect to its set point. The output voltage on all models is trimmable in
the range 0.75 – 5.0Vdc.
internal over-current protection. The unit operates normally once the
fault condition is removed. The power module will supply up to 150% of
rated current. In the event of an over current converter will go into a
hiccup mode protection.
5.6 Remote ON/OFF
The remote ON/OFF input feature of the converter allows external
circuitry to turn the converter ON or OFF. Active-high remote ON/OFF
is available as standard. The VPOL5A-12-SIP series converters are
turned on if the remote ON/OFF pin is high, or left open or floating.
Setting the pin low will turn the converter ‘Off’. The signal level of the
remote on/off input is defined with respect to ground. If not using the
remote on/off pin, leave the pin open (module will be on). The part
number suffix “N” is Negative remote ON/OFF version. The unit is
guaranteed OFF over the full temperature range if this voltage level
exceeds 2.8Vdc. The converters are turned on If the on/off pin input is
low or left open. The recommended VPOL5A-12-SIP remote on/off
drive circuit as shown as figure 3, 4.
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
rev.
6 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
+Vin
ON/OFF
Control
page
+Vo
7. Applications
7.1 Layout Design Challenges.
Remote ON/OFF
Q1
In optimizing thermal design the PCB is utilized as a heat sink. Also
VPOL5A-12-SIP
some heat is transferred from the VPOL5A-12-SIP module to the main
board through connecting pins. The system designer or the end user
Common
Common
must ensure that other components and metal in the vicinity of the
VPOL5A-12-SIP series meet the spacing requirements to which the
Figure 3. Positive Remote ON/OFF Input Drive Circuit
+Vin
Q1
ON/OFF
Control
+Vo
VPOL5A-12-SIP
system is approved.
Low resistance and low inductance PCB layout traces are the norm and
should be used where possible. Due consideration must also be given
to proper low impedance tracks between power module, input and
output grounds. The recommended VPOL5A-12-SIP footprint as shown
as figure 5.
Remote ON/OFF
Common
Common
Figure 4. Negative Remote ON/OFF Input Drive Circuit
5.7 UVLO (Under-Voltage Lockout)
1.1mm PLATED THR OUGH HOLE
1.6mm PAD SIZE
0.20(5.1)
LAYOUT PA TTERN
TOP VIEW
0.24(6.1)
All Dimmension In Inches(mm)
Tol erance :
.XX= ±0.02 ( ±0.5 )
.XXX= ±0.010 ( ±0.25 )
Figure 5. Recommended VPOL5A-12-SIP Footprint
The voltage on the Vcc pin determines the start of the operation of the
Converter. When the input Vcc rises and exceeds about 8.0V the
converter initiates a soft start. The UVLO function in the converter has a
hysteresis (about 100mV) built in to provide noise immunity at start-up.
6. Safety
6.1 Input Fusing and Safety Considerations.
Agency Approvals: The power Supply shall be submitted to and
receive formal approval from the following test agencies.
1.The power supply shall be approved by a nationally recognized
rd
testing laboratory to UL/CSA 60950 3 Edition (North America) and
EN60950 (International)
2. CB Certificate from an internationally recognized test house in
accordance with EN 60950.
The VPOL5A-12-SIP series converters do not have an internal fuse.
However, to achieve maximum safety and system protection, always
use an input line fuse. The safety agencies require a time-delay fuse
with a maximum rating of 7A.
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
rev.
page
7 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
7.2 Convection Requirements for Cooling
To predict the ap proximate cooling needed for the module, refer to the
Power De-rating curves in Figures 8 & 9 . These de-rating curves are
approximations of the ambient temperatures and airflows required to
keep the power module temperature below its maximum rating. Once
the module is assembled in the actual system, the module’s
temperature should be checked as shown in Figure 6 to ensure it does
not exceed 110°C.
Proper cooling can be verified by measuring the power module’s
temperature at Q1-pin 6 as shown in Figure 7.
W ind
Tunnel
25.4(1.0)
Bakelite
Figure 7. Temperature Measurement Location for
VPOL5A-12-SIP
Power Module
7.3 Thermal Considerations
The power module operates in a variety of thermal environments;
however, sufficient cooling should be provided to help ensure reliable
operation of the unit. Heat is removed by conduction, convection, and
radiation to the surrounding environment. The thermal data presented is
76.2(3.0)
based on measurements taken in a set-up as shown in Figure 6.
Figures 8 & 9 represent the test data. Note that the airflow is parallel to
the long axis of the module as shown in Figure 6 for the VPOL5A-12-
Thermocuple Location
for measuring
ambient temperature
and airflow
12.7(0.5)
SIP.
The temperature at either location should not exceed 110 °C. The
output power of the module should not exceed the rated power for the
module (VO, set x IO, max). The SMT05 thermal data presented is
based on measurements taken in a wind tunnel. The test setup shown
Air
flow
in Figure 7 and EUT need to solder on 33mm x 40.38mm(1.300'' x
1.59'') test pcb. Note that airflow is parallel to the long axis of the
module as shown in Fig 6.
Note : Dimensions are in millimeters and (inches)
Figure 6. Thermal Test Setup
20050 SW 112th Ave
A . Tualatin, Oregon 97062 phone 503.612.2300 fa x 503.612.2382
For more information, please visit the product page.
rev.
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
6.0
Output Current(A)
5.0
4.0
0LFM
3.0
100LFM
2.0
200LFM
1.0
0.0
0
10
20
30
40
50
60
70
80
90
100
Ambient Temperature( C)o
Figure 2. Typical Power De-rating for 12V IN 3.3Vout
NOTE
1. specific input & output derating curves available, please
contact CUI INC for detail
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
page
8 of 12
date
08/2007
For more information, please visit the product page.
rev.
VPOL5A-12-SIP Vo=1.8V (Eff Vs Io)
date
08/2007
VPOL5A-12-SIP Vo=1.5V (Eff Vs Io)
100%
95%
95%
90%
90%
Efficincy (%)
100%
Efficincy (%)
9 of 12
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
85%
80%
75%
8.3V
12V
14V
70%
65%
85%
80%
75%
8.3V
12V
14V
70%
65%
60%
60%
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
0
0.5
1
Current Load (A)
1.5
2
2.5
3
3.5
4
4.5
5
Current Load (A)
VPOL5A-12-SIP Vo=1.2V (Eff Vs Io)
VPOL5A-12-SIP Vo=0.75V (Eff Vs Io)
90%
95%
85%
90%
80%
Efficincy (%)
100%
Efficincy (%)
page
85%
80%
75%
8.3V
12V
14V
70%
65%
75%
70%
65%
8.3V
12V
14V
60%
55%
60%
50%
0
0.5
1
1.5
2
2.5
3
Current Load (A)
3.5
4
4.5
5
0
0.5
1
1.5
2
2.5
3
Current Load (A)
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
3.5
4
4.5
5
For more information, please visit the product page.
rev.
The VPOL5A-12-SIP converters must be connected to a low AC
source impedance. To avoid probl ems with loop stability source
Line.reg =
close to the converter input pins to de-couple distribution inductance.
However, the external input capacitors are chosen for suitable ripple
handling capability. Low ESR polymers are a good choice. They have
VLL is the output voltage of minimum input voltage at full load.
Current Meter
Electrolytic capacitors should be avoided. Circuit as shown in Figure 10
A
represents typical measurement methods for ripple current. Input
reflected-ripple current is measured with a simulated source Inductance
of 1uH. Current is measured at the input of the module.
VHL _ VLL
x 100%
VLL
Where: VHL is the output voltage of maximum input voltage at full load.
high capacitance, high ripple rating and low ESR (typical <100mohm).
Power
Supply
+Vin
+
47uF
10UF
V
VPOL5A-12-SIP
CERAMIC
+Vin
1uH
2*100uF
Tantalum
Figure 11. VPOL5A-12-SIP Test Setup
VPOL5A-12-SIP
220uF
ESR<0.1ohm
Common
Figure 10. Input Reflected-Ripple Test Setup
7.7 Test Set-Up
The basic test set-up to measure parameters such as efficiency and
load regulation is shown in Figure 11. Things to note are that this
converter is non-isolated, as such the input and output share a common
ground. These grounds should be connected together via low
impedance ground plane in the application circuit. When testing a
converter on a bench set-up, ensure that -Vin and -Vo are connected
together via a low impedance short to ensure proper efficiency and load
regulation measurements are being made. When testing the CUI INC’s
VPOL5A-12-SIP under any transient conditions please ensure that the
transient response of the source is sufficient to power the equipment
under test. We can calculate the
Efficiency
Load regulation and line regulation.
The value of efficiency is defined as:
Vo x Io
x 100%
Vin x Iin
Where:
Vo is output voltage,
Io is output current,
Vin is input voltage,
Iin is input current.
The value of load regulation is defined as:
Load .reg =
Common
Voltage Meter
L1
A
+Vo
+Sense
Common
To Oscilloscope
ç=
08/2007
The value of line regulation is defined as:
inductance should be low. Also, the input capacitors should be placed
Supply
date
VFL is the output voltage at full load
VNL is the output voltage at no load
Where:
7.6 Input Capacitance at the Power Module
+
10 of 12
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
Power
page
VFL _ VNL
x 100%
VNL
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
V
Load
For more information, please visit the product page.
rev.
page
11 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
7.8 VPOL5A-12-SIP Output Voltage Adustment.
7.9 Output Ripple and Noise Measurement
The output Voltage of the VPOL5A-12-SIP can be adjusted in the range
The test set-up for noise and ripple measurements is shown in Figure
0.75V to 5.0V by connecting a single resistor on the motherboard
13. a coaxial cable with a 50ohm termination was used to prevent
(shown as R trim) in Figure 12. When Trim resistor is not connected the
impedance mismatch reflections disturbing the noise readings at higher
output voltage defaults to 0.75V
frequencies.
+Vin
+Vin
+Vo
VPOL5A-12-SIP
Trim
R trim-up
Common
1uF
Ceramic
R-Load
Test Jack
Common
Common
Figure 13. Output Voltage Ripple and Noise Measurement Set-Up
Figure 12. Trim-up Voltage Setup
The value of Rtrim-up defined as:
7.10 Output Capacitance
CUI INC’s VPOL5A-12-SIP converters provide unconditional stability
10500 _
Rtrim = ( _
1000 )
Vo 0.75
Where:
10uF
Tant.
R-Load
VPOL5A-12-SIP
Common
+Vo
Rtrim-up is the external resistor in ohm,
Vo is the desired output voltage
To give an exa mple of the above calculation, to set a voltage of 3.3Vdc,
Rtrim is given by:
with or without external capacitors. For good transient response low
ESR output capacitors should be located close to the point of load.
For high current applications point has already been made in layout
considerations for low resistance and low inductance tracks.
Output capacitors with its associated ESR values have an impact on
loop stability and bandwidth. CUI INC’s converters are designed to
work with load capacitance up-to 3,000uF. It is reco mmended that any
additional capacitance, Maximum 3,000uF and low ESR, be connected
Rtrim = (
10500 _
1000 )
_
3 0.75
close to the point of load and outside the remote compensation point.
Rtrim = 3118 ohm
For various output values various resistors are calculated and provided
in Table 3 for co nvenience.
Vo,set (V)
0.75
1.2
1.5
1.8
2.0
2.5
3.3
5.0
Rtrim (Kohm)
Open
22.33
13.00
9.00
7.40
5.00
3.12
1.47
Table 3 – Trim Resistor Values
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
rev.
DESCRIPTION: point of load converter
PART NUMBER: VPOL5A-12-SIP
8. Mechanical Outline Diagrams
8.1 VPOL5A-12-SIP Mechanical Outline Diagrams
Dimensions are in millimeters and inches
Tolerance: x.xx ±0.02 in. (0.5mm) , x.xxx ±0.010 in. (0.25 mm) unless
otherwise noted
SIZE VPOL5A-12-SIP
0.90(22.9)
PIN CONNECTION
0.22(5.6)Max.
Pin
1 2 3
4 5
0.400(10.16)
0.14(3.6)
0.100(2.54)
0.200(5.08)
0.700(17.78)
0.025(0.64)
0.025(0.64)
FUNCTION
1
+Output
2
Trim
3
Common
4
+V Input
5
On/Off
0.19(4.7)
0.800(20.32)
Figure 14 VPOL5A-12-SIP Mechanical Outline Diagram
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
page
12 of 12
date
08/2007
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