Datasheet

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rev.
PART NUMBER: VPOL16A-12-SMT
page
1 of 12
date
08/2007
DESCRIPTION: point of load converter
features
* industry standard pin out
* high efficiency to 94%
* 300 KHz switching frequency
* 9.0-14 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. VPOL16A-12-SMT CONVERTER FEATURES
7. APPLICATIONS
7.1 Layout Design Challenges.
3. GENERAL DESCRIPTION
3.1 Electrical Description
7.2 Convection Requirements for Cooling
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 Remote Sense Compensation
5.3 Output Voltage Adjustment
7.8 VPOL16A-12-SMT Series Output Voltage Adustment.
5.4 Safe Operating Area (SOA)
7.9 Output Ripple and Noise Measurement
5.5 Over Current Protection
7.10 Output Capacitance
5.6 Remote ON/OFF
7.11 VPOL16A-12-SMT Reflow Profile
5.7 UVLO (Under-Voltage Lockout)
6. SAFETY
6.1 Input Fusing and Safety Considerations.
7.3 Thermal Considerations
7.7 Test Set-Up
8. MECHANICAL OUTLINE DIAGRAMS
8.1 VPOL16A-12-SMT Mechanical Outline Diagrams
8.2 VPOL16A-12-SMT Tape and Reel Dimensions
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
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rev.
PART NUMBER: VPOL16A-12-SMT
page
2 of 12
date
08/2007
DESCRIPTION: point of load converter
The converter is also protected against over-temperature conditions. If
1. Introduction
the converter is overloaded or the ambient temperature gets too high,
the converter will shut down to protect the unit.
This application note describes the features and functions of CUI INC's
VPOL16A-12-SMT series of non-isolated dc-dc converters. These are
L1
Q1
+VIN
+VO
highly efficient, reliable and compact, high power density, single output
dc-dc converters. These “Point of Load” modules serve the needs
Q2
C1
specifically of the fixed and mobile telecommunications and computing
D1
C2
R sense
+SENSE
market, employing economical distributed Power Architectures. The
VPOL16A-12-SMT series provide precisely regulated output voltage
range from 0.75V to 5.0Vdc over a wide range of input voltage (Vi=9.0 –
COM
COM
14Vdc) and can operate over an ambient temperature range of –40°C
PWM IC
to +85°C. Ultra-high efficiency operation is achieved through the use of
synchronous rectification and drive control techniques.
ON/OFF
R1
R trim
ERR AMP
TRIM
R2
The modules are fully protected against short circuit and overtemperature conditions. CUI INC's world class automated
manufacturing methods, together with an extensive testing and
Figure 1. Electrical Block Diagram
qualification program, ensure that all VPOL16A-12-SMT series
converters are extremely reliable.
3.2 Thermal Packaging and Physical Design.
2. VPOL16A-12-SMT Converter
Features
The VPOL16A-12-SMT series uses a multi-layer FR4 PCB
High efficiency topology, typically 94% at 5.0Vdc
Industry standard footprint
Wide ambient temperature range, -40°C to +85°C
Cost efficient open frame design
Programmable output voltage via external resistor from 0.75 to
construction. All surface mount power components are placed on one
side of the PCB, and all low-power control components are placed on
the other side. Thus, the heat dissipation of the power components is
optimized, ensuring that control components are not thermally stressed.
The converter is an open-frame product and has no case or case pin.
The open-frame design has several advantages over encapsulated
closed devices. Among these advantages are:
5.0Vdc
Efficient Thermal Management: the heat is removed from the
No minimum load requirement (Stable at all loads)
heat generating components without heating more sensitive, small
Remote ON/OFF
signal control components.
Remote sense compensation
Environmental: Lead free open-frame converters are more easily
Fixed switching frequency
re-cycled.
Continuous short-circuit protection and over current protection
Cost Efficient: No encapsulation. Cost efficient open-frame
Over-temperature protection (OTP)
construction.
Monotonic Startup with pre-bias at the output.
Reliable: Efficient cooling provided by open frame construction
UL/IEC/EN60950 Certified.
offers high reliability and easy diagnostics.
3. General Description
3.1 Electrical Description
A block diagram of the VPOL16A-12-SMT 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 VPOL16A-12-SMT 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
VPOL16A-12-SMT 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.
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
3 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
4. Technical Specifications
(All specifications are typical at nominal input, full load at 25°C unless otherwise noted.)
Device
PARAMETER
NOTES and CONDITIONS
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Continuous
Operating Temp erature
See Thermal Considerations Section
Min.
Typical Max.
Units
ALL
0
15
Vdc
ALL
-40
+85
°C
ALL
-55
+125
°C
ALL
9.0
14
Vdc
ALL
ALL
ALL
ALL
8.0
Storage Temperature
INPUT CHARACTERISTICS
Operating Input Voltage
Input Under-Voltage Lockout
Turn-On Voltage Threshold
Turn-Off Voltage Threshold
Lockout Hysteresis Voltage
12
Vdc
Vdc
Vdc
7.7
0.3
11
A
Maximum Input Current
Vin=0 to 14Vdc , Io=Io,max.
No-Load Input Current
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
Off Converter Input Current
Shutdown input idle current
ALL
10
mA
ALL
0.1
As
2
Inrush Current (I t)
Input Reflected-Ripple Current
P-P thru 1uH inductor, 5Hz to 20MHz
40
50
50
60
60
65
75
75
mA
ALL
300
-1.5% Vo,set +1.5%
2
mA
OUTPUT CHARACTERISTIC
Output Voltage Set Point
Vin=Nominal Vin , Io=Io.max, Tc=25°C
ALL
Output Voltage Trim Adjustment Range
Selected by an external resistor
ALL
0.75
5.0
Vdc
Vdc
Output Voltage Regulation
Load Regulation
Io=Io.min to Io.max
ALL
-0.5
+0.5
%
Line Regulation
Vin=low line to high line
ALL
-0.2
+0.2
%
Tempera ture Coefficient
Ta=-40°C to 85°C
ALL
-0.03
+0.03
%/°C
Output Voltage Ripple and Noise
5Hz to 20MHz bandwidth
Peak-to-Peak
Full Load, 1uF ceramic and 10uF tantalum
ALL
75
mV
RMS
Full Load, 1uF ceramic and 10uF tantalum
ALL
30
mV
Low ESR
ALL
8000
uF
ALL
0
Output DC Current-Limit Inception
Output Voltage =90% Nominal Output Voltage
ALL
18
Shout Circuit Protection
Continuous with Hiccup Mode
ALL
External Capacitive Load
Operating Output Current Range
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
23
16
A
28
A
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rev.
4 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
PARAMETER
DYNAMIC CHARACTERISTICS
page
NOTES and CONDITIONS
Device
Min.
Typical Max.
Units
Output Voltage Transient Response
Error Brand
50% Step Load Change, di/dt=0.1A/us
ALL
200
mV
Setting Time (within 1% Vout nominal)
50% Step Load Change, di/dt=0.1A/us
ALL
200
us
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
Non-isolation
ALL
77
83
86
88
89
90
92
94
%
ISOLATION CHARACTERISTICS
Input to Output
0
Vdc
FEATURE CHARACTERISTICS
Switching Frequency
ON/OFF Control, Positive Logic Remote On/Off
Logic Low (Module Off)
Logic High (Module On)
ALL
or Open Circuit
ON/OFF Control, Negative Logic Remote On/Off
Logic Low (Module On)
or Open Circuit
Logic High (Module Off)
ON/OFF Current (for both remote on/off logic)
Leakage Current (for both remote on/off logic)
Turn-On Delay and Rise Time
Turn-On Delay Time, From On/Off Control
Turn-On Delay Time, From Input
Output Voltage Rise Time
Over Temperature Protection
300
VPOL16A-12-SMT
0
VPOL16A-12-SMT
2.8
KHz
0.4
Vdc
Vdc
Vin
Vdc
1
1
mA
mA
Vin
Ion/off at Von/off =0.0V
Logic High, Von/off=14V
ALL
ALL
Von/off to 10 %Vo,set
Vin,min. to 10%V o,set
10%Vo,set to 90 %Vo,set
ALL
ALL
ALL
ALL
3.5
3.5
3.5
130
ms
ms
ms
°C
ALL
0.98
M hours
ALL
10
grams
GENERAL SPECIFICATIONS
MTBF
Weight
Dimensions
VPOL16A-12-SMT packages
Io=100%of Io.max;Ta=2 5°C per MIL-HDBK217F
1.3x0.53x0.366 inches(33.0x13.46x9.3 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.
page
5 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
5.5 Over Current Protection
5. Main Features and Functions
All different voltage models have a full continuous short-circuit
5.1 Operating Temperature Range
To provide pr otection in a fault condition, the unit is equipped with
CUI INC's VPOL16A-12-SMT series converters highly efficient
converter design has resulted in its ability to operate over a wide
ambient temperature environment ( -40°C to 85°C). Due consideration
must be given to the de-rating curves when ascertaining maximum
power that can be drawn from the converter. The maximum power
drawn is influenced by a number of factors, such as:
Input voltage range.
protection. The unit will auto recover once the short circuit is removed.
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
Output load current.
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.
5.2 Over-Temperature Protection (OTP)
The VPOL16A-12-SMT Series converters are equipped with nonlatching over-temperature protection. A temperat ure sensor monitors
the temperature of the hot spot (typically, top switch). If the temperature
exceeds a threshold of 130°C (t ypical) the converter will shut down,
is available as standard. The VPOL16A-12-SMT are turned on if the
remote ON/OFF pin is high(=Vin), or left open. Setting the pin
low(<0.4Vdc) 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
(<0.4Vdc) or left open. The recommended VPOL16A-12-SMT remote
on/off drive circuit as shown as figure 3, 4.
disabling the output. When the temperature has decreased the
converter will automatically restart.
The over-temperature condition can be induced by a variety of reasons
such as external overload condition or a system fan failure.
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.
5.4 Safe Operating Area (SOA)
Figure 2 provides a graphical representation of the Safe Operating Area
(SOA) of the converter. This representation assumes ambient
operating conditions such as airflow are met as per thermal guidelines
provided in Sections 7.2 and 7.3.
Vo
VOLTAGE (V)
Vo,nom
Safe Operating Area
Io,max Io,CL Io
CURRENT (A)
Figure 2. Maximum Output Current Safe Operating Area
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: VPOL16A-12-SMT
+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
VPOL16A-12-SMT
some heat is transferred from the VPOL16A-12-SMT module to the
main board through connecting pins. The system designer or the end
Common
Common
user must ensure that other components and metal in the vicinity of the
VPOL16A-12-SMT series meet the spacing requirements to which the
Figure 3. Positive Remote ON/OFF Input Drive Circuit
+Vin
Q1
ON/OFF
Control
+Vo
VPOL16A-12-SMT
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 VPOL16A-12-SMT footprint is
shown as figure 5.
Remote ON/OFF
Common
Common
Recommended Pad Layout
Dimensions are in millimetes and(inches)
Figure 4. Negative Remote ON/OFF Input Drive Circuit
7.54
(0.297)
4.83
4.83
4.83
(0.190) (0.190) (0.190)
7.87
(0.310)
5.7 UVLO (Under-Voltage Lockout)
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
+SENSE TRIM
10.29
(0.405)
0.64
(0.025)
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.
COM
10.92
(0.430)
Top View of Board
ON/OFF
hysteresis (about 300mV) built in to provide noise immunity at start-up.
6. Safety
+VO
+VIN
29.90
(1.177)
PAD SIZE
MIN:3.556x2.413(0.140x0.095)
MAX:4.19x2.79(0.165x0.110)
Figure 5. Recommended VPOL16A-12-SMT Footprint
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 VPOL16A-12-SMT 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 20A.
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: VPOL16A-12-SMT
TYPICAL POWER DERATING FOR 5 Vin 3.3 Vout
18
16
Output Current(A)
14
12
10
0LFM
100LFM
200LFM
300LFM
8
6
4
2
0
0
10
20
30
40
50
60
70
80
90
100
Ambient Temperature(oC)
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
7 of 12
date
08/2007
For more information, please visit the product page.
rev.
page
8 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
7.5 Efficiency vs Load Curves (Fig. 9)
VPOL16A-12-SMT Vo=5.0V (Eff Vs Io)
VPOL16A-12-SMT Vo=3.3V (Eff Vs Io)
95%
95%
90%
85%
9.0V
12V
14V
80%
75%
70%
Efficincy (%)
100%
Efficincy (%)
100%
90%
85%
9.0V
12V
14V
80%
75%
70%
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Current Load (A)
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Current Load (A)
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
rev.
VPOL16A-12-SMT Vo=2.5V (Eff Vs Io)
95%
95%
90%
85%
9.0V
12V
14V
80%
75%
Efficincy (%)
100%
Efficincy (%)
date
08/2007
VPOL16A-12-SMT Vo=2.0V (Eff Vs Io)
100%
90%
85%
9.0V
12V
14V
80%
75%
70%
70%
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
0
1
2
3
4
Current Load (A)
VPOL16A-12-SMT Vo=1.8V (Eff Vs Io)
95%
90%
90%
85%
80%
9.0V
12V
14V
65%
Efficincy (%)
95%
70%
6
7
8
9 10 11 12 13 14 15 16
VPOL16A-12-SMT Vo=1.5V (Eff Vs Io)
100%
75%
5
Current Load (A)
100%
Efficincy (%)
9 of 12
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
85%
80%
9.0V
12V
14V
75%
70%
65%
60%
60%
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
0
1
2
3
4
Current Load (A)
5
6
7
8
9 10 11 12 13 14 15 16
Current Load (A)
VPOL16A-12-SMT Vo=1.2V (Eff Vs Io)
VPOL16A-12-SMT Vo=0.75V (Eff Vs Io)
100%
100%
95%
95%
90%
85%
80%
9.0V
12V
14V
75%
70%
65%
60%
Efficincy (%)
90%
Efficincy (%)
page
85%
80%
75%
70%
9.0V
12V
14V
65%
60%
55%
50%
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Current Load (A)
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
Current Load (A)
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
For more information, please visit the product page.
rev.
Where:
7.6 Input Capacitance at the Power Module
The VPOL16A-12-SMT converters must be connected to a low AC
source impedance. To avoid probl ems with loop stability source
However, the external input capacitors are chosen for suitable ripple
handling capability. Low ESR polymers are a good choice. They have
Line.reg=
VLL is the output voltage of minimum input voltage at full load.
Current Meter
Electrolytic capacitors should be avoided. Circuit as shown in Figure 11
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.
Power
Supply
+Vin
+
V 100uF
Voltage Meter
VPOL16A-12-SMT
Common
L1
+Vin
A
+Vo
+Sense
To Oscilloscope
Supply
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).
2*100uF
Tantalum
08/2007
The value of line regulation is defined as:
close to the converter input pins to de-couple distribution inductance.
+
date
VFL is the output voltage at full load
VNL is the output voltage at no load
inductance should be low. Also, the input capacitors should be placed
Power
10 of 12
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
1uH
page
V
Load
Common
Figure 11. VPOL16A-12-SMT Series Test Setup
7.8 Remote Sense Compensation
VPOL16A-12-SMT
220uF
ESR<0.1ohm
Remote Sense regulates the output voltage at the point of load. It
minimizes the effects of distribution losses such as drops across the
connecting pin and PCB tracks (see Figure 12). Please note however,
the maximum drop from the output pin to the point of load should not
Common
exceed 500mV for remote compensation to work.
The amount of power delivered by the module is defined as the output
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
voltage multiplied by the output current (VO x IO).
When using TRIM UP, the output voltage of the module will increase
which, if the same output current is maintained, increases the power
output by the module. Make sure that the maximum output power of the
module remains at or below the maximum rated power.
When the Remote Sense feature is not being used, leave sense pin
disconnected.
Figure 12. Circuit Configuration for Remote Sense Operation
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
VPOL16A-12-SMT series 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
Distribution Losses
+Vin
Load regulation and line regulation.
+Vo
+Sense
The value of efficiency is defined as:
Vo x Io
x 100%
ç=
Vin x Iin
VPOL16A-12-SMT
Common
Where:
Vo is output voltage,
Common
R-Load
Distribution Losses
Io is output current,
Vin is input voltage,
Iin is input current.
The value of load regulation is defined as:
Load .reg=
VFL _ VNL
x 100%
VNL
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
11 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
7.8 VPOL16A-12-SMT Series Output Voltage
Adustment.
7.9 Output Ripple and Noise Measurement
The output voltage of the VPOL16A-12-SMTS05A can be adjusted in
17. a coaxial cable with a 50ohm termination was used to prevent
the range 0.75V to 5.0V by connecting a single resistor on the
impedance mismatch reflections disturbing the noise readings at higher
motherboard (shown as Rtrim) in Figure 13. When Trim resistor is not
frequencies.
The test set-up for noise and ripple measurements is shown in Figure
connected the output voltage defaults to 0.75V
+Vin
+Vin
+Vo
+Vo
10uF
Tant.
VPOL16A-12-SMT
1uF
Ceramic
R-Load
Test Jack
Trim
R-Load
VPOL16A-12-SMT
Common
Common
R trim-up
Figure 14. Output Voltage Ripple and Noise Measurement Set-Up
Common
Common
7.10 Output Capacitance
Figure 13. Trim-up Voltage Setup
The value of Rtrim-up defined as:
CUI INC's VPOL16A-12-SMT series converters provide unconditional
stability with or without external capacitors. For good transient response
low ESR output capacitors should be located close to the point of load.
Rtrim = (
Where:
10500 _
1000 )
Vo _ .750
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
Rtrim-up is the external resistor in ohm,
loop stability and bandwidth. CUI INC's converters are designed to
Vo is the desired output voltage
work with load capacitance up-to 8,000uF. It is reco mmended that any
To give an exa mple of the above calculation, to set a voltage of 3.3Vdc,
additional capacitance, Maximum 8,000uF and low ESR, be connected
Rtrim is given by:
close to the point of load and outside the remote compensation point.
Rtrim = (
10500 _
1000 )
_
3 . .75
30
Rtrim = 3117 ohm
7.11 VPOL16A-12-SMT Reflow Profile
An example of the VPOL16A-12-SMT reflow profile is given in Fig 15.
Equipment used: SMD HOT AIR REFLOW HD-350SAR
Alloy: AMQ-M293TA or N C-SMQ92 IND-82088 SN63
For various output values various resistors are calculated and provided
Rtrim (Kohm)
Open
22.33
13.0
9.0
7.4
5.0
3.12
1.47
Table 3 – Trim Resistor Values
200
TEMPERATURE (C)
Vo,set (V)
0.75
1.20
1.50
1.80
2.00
2.50
3.30
5.0
REFLOW PROFILE
240
in Table 3 for co nvenience.
160
120
80
40
0
0
30
60
90
120 150 180 210 240
TIME (SECONDS)
Figure 15 VPOL16A-12-SMT Reflow Profile
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
12 of 12
date
08/2007
DESCRIPTION: point of load converter
PART NUMBER: VPOL16A-12-SMT
8. Mechanical Outline Diagrams
8.2 VPOL16A-12-SMT Tape and Reel Dimensions
8.1 VPOL16A-12-SMT Mechanical Outline Diagrams
Dimensions are in millimeters and inches
The Ta pe Reel dimensions for the VPOL16A-12-SMT module is shown
in Figure 17.
Tolerance: x.xx ±0.02 in. (0.5mm) , x.xxx ±0.010 in. (0.25 mm) unless
otherwise noted
Po
P2
P
D
7.87
(0.310)
4.83
COM
1.60
(0.063)
4.83
4.83
(0.190) (0.190) (0.190)
+VO
7.54
1.65
(0.065)
(0.297)
TRIM +SENSE
W
9.30
(0.366)
max.
33.0
(1.30)
Bo
F
BOTTOM VIEW OF BOARD
t
E
Ao
10.29 13.46
(0.405) (0.530)
ON/OFF
+VIN
SURFACE MOUNT CONTACT
2.84
(0.112)
1.22
(0.048)
1.91 (0.075)
L1 INDUCTOR
Dimensions are in millimeters(Inches)
Tolerances :X.X ±0.5mm(0.02in),X.XX ±0.25mm(0.010in),unless
__
otherwise noted.
Figure 16 VPOL16A-12-SMT Mechanical Outline Diagram
W
Ao
Bo
Ko
P
F
E
D
D1
Po
P2
t
Figure 17 – VPOL16A-12-SMT Tape an d Reel
Dimensions
20050 SW 112th Ave. Tualatin, Oregon 97062 phone 503.612.2300 fax 503.612.2382
Ko
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