ENPIRION EN5366QI-E

EN5366QI
6A Voltage Mode Synchronous Buck PWM
DC-DC Converter with Integrated Inductor
External Output Voltage Programming
RoHS Compliant
Halogen Free
Description
Features
This Enpirion solution is a Power System on a
chip (PowerSoC). It is specifically designed to
meet the precise voltage and fast transient
requirements of present and future highperformance, low-power processor, DSP, FPGA,
ASIC, memory boards and system level
applications in a distributed power architecture.
Advanced circuit techniques, ultra high switching
frequency, and very advanced, high-density,
integrated circuit and proprietary inductor
technology deliver high-quality, ultra compact,
non-isolated DC-DC conversion. Operating this
converter requires as few as three external
components that include small value input and
output ceramic capacitors and a soft-start
capacitor.
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The Enpirion integrated inductor solution
significantly helps in low noise system design
and productivity by offering greatly simplified
board design, layout and manufacturing
requirements.
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All Enpirion products are RoHS compliant and
lead-free manufacturing environment compatible.
VIN
47µF
1Ω
PVIN
VOUT
AVIN
ENABLE
XOV
XFB
PGND
Applications
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•
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Typical Application Circuit
VOUT
47µF
Integrated INDUCTOR, MOSFETS, Controller
Footprint 1/3rd that of competing solutions.
Low Part Count: only 3 MLCC Capacitors.
Up to 20W continuous output power.
Low output impedance optimized for ≤ 90 nm
Master/slave configuration for paralleling.
5MHz operating frequency.
High efficiency, up to 93%.
Wide input voltage range of 2.375V to 5.5V.
External resistor divider output voltage select.
Output enable pin and Power OK signal.
Programmable soft-start time.
Optimized for low noise/EMI design.
Under-Voltage Lockout, Thermal Shutdown,
Output Overvoltage, Over Current, and Short
Circuit Protection
RoHS compliant, MSL level 3, 260C reflow.
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•
Point of load regulation for low-power
processors, network processors, DSPs,
FPGAs, and ASICs
≤ 90 nm advanced process loads
Notebook computers, servers, workstations
Broadband, networking, LAN/WAN, optical
Low voltage, distributed power architectures
with 2.5V, 3.3V or 5V rails
DSL, STB, DVR, DTV, Industrial PC
Ripple sensitive applications
SS
Ordering Information
15nF
AGND
PGND
Figure 1. Simple Layout.
Part Number
EN5366QI
EN5366QI-E
Temp Rating
Package
(°C)
-40 to +85
58-pin QFN T&R
QFN Evaluation Board
*Optimized PCB Layout file downloadable from the Enpirion Website to assure first pass design success.
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Rev:B
EN5366QI
Pin Configuration
Below is a top view diagram of the EN5366Q package.
NOTE: NC pins are not to be electrically connected to each other or to any external signal, ground, or voltage.
However, they must be soldered to the PCB. Failure to follow this guideline may result in part malfunction or
damage.
Figure 2. Pin Diagram, top view.
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EN5366QI
Pin Descriptions
PIN
NAME
1-3
NC
4-5
NC(SW)
6-13
NC
14-20
VOUT
21-22
NC(SW)
23
NC
24-29
PGND
30-35
PVIN
36-37
NC
38
ROCP
39
AVIN
40
AGND
41-42
NC
43
44
XFB
XOV
45
NC
46
POK
47
NC
48
SS
49
50
51
EAIN
EAOUT
COMP
FUNCTION
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
NO CONNECT – These pins are internally connected to the common drain output of
the internal MOSFETs. NC(SW) pins are not to be electrically connected to any
external signal, ground, or voltage. However, they must be soldered to the PCB.
Failure to follow this guideline may result in part malfunction or damage.
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
Regulated converter output. Decouple with output filter capacitor to PGND. Refer to
layout section for specific layout requirements
NO CONNECT – These pins are internally connected to the common drain output of
the internal MOSFETs. NC(SW) pins are not to be electrically connected to any
external signal, ground, or voltage. However, they must be soldered to the PCB.
Failure to follow this guideline may result in part malfunction or damage.
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
Output power ground. Refer to layout section for specific layout requirements.
Input power supply. Connect to input power supply. Decouple with input capacitor to
PGND. Refer to layout section for specific layout requirements
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
Optional Over Current Protection adjust pin. Used for diagnostic purposes only. Place
10kΩ resistor between this pin and AGND (pin 40) to raise the over current trip point
to approximately 200% of maximum rated current.
Analog voltage input for the controller circuits.
Connect this pin to PVIN using a 1 Ohm resistor.
Analog ground for the controller circuits.
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
Feedback pin for external voltage divider network.
Over voltage programming feedback pin.
NO CONNECT: This pin should not be electrically connected to any other NC pin, or
to any external signal, voltage, or ground. This pin may be connected internally.
Power OK is an open drain transistor for power system state indication. POK is a
logic high when VOUT is with -10% to +20% of VOUT nominal. Size pull-up resistor
to limit current to 4mA when POK is low.
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
Soft-Start node. The soft-start capacitor is connected between this pin and AGND.
The value of this capacitor determines the startup timing.
Optional Error Amplifier input. Allows for customization of the control loop.
Optional Error Amplifier output. Allows for customization of the control loop.
Optional Error Amplifier Buffer output. Allows for customization of the control loop.
©Enpirion 2009 all rights reserved, E&OE
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Rev:B
EN5366QI
PIN
NAME
52
ENABLE
53
PWM
54
NC
55
M/S
56-58
NC
FUNCTION
Input Enable. Applying a logic high, enables the output and initiates a soft-start.
Applying a logic low disables the output.
PWM input/output. Used for optional master/slave configuration. When M/S pin is
asserted “low”, PWM will output the gate-drive PWM waveform. When the M/S pin is
asserted “high”, the PWM pin is configured as an input for PWM signal from the
“master” device. PWM pin can drive up to 3 slave devices.
NOTE: Leave this pin open when not using parallel mode.
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
Optional Master/Slave select pin. Asserting pin “low” places device in Master Mode
for current sharing. PWM pin (53) will output PWM drive signal. Asserting pin “high”
will place the device in Slave Mode. PWM pin (53) will be configured to input (receive)
PWM drive signal from “Master” device.
NOTE: Leave this pin open when not using parallel mode.
NO CONNECT: These pins should not be electrically connected to each other or to
any external signal, voltage, or ground. One or more of these pins may be connected
internally.
Block Diagram
PVIN
POK
power
Good
Logic
UVLO
Thermal Limit
ROCP
Current Limit
XOV
Over
Voltage
VOUT
Over Voltage
NC(SW)
P-Drive
VOUT
(-)
N-Drive
PWM
Comp
(+)
PGND
Compensation
Network
Sawtooth
Generator
Voltage
Selector
(-)
Error
Amp
(+)
ENABLE
SS
XFB
Reference
Voltage
selector
Soft Start
Bandgap
Reference
EAIN
EAOUT
COMP
Figure 3. System block diagram.
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Rev:B
EN5366QI
Absolute Maximum Ratings
CAUTION: Absolute Maximum ratings are stress ratings only. Functional operation beyond
recommended operating conditions is not implied. Stress beyond absolute maximum ratings may
cause permanent damage to the device. Exposure to absolute maximum rated conditions for
extended periods may affect device reliability.
PARAMETER
SYMBOL
MIN
MAX
UNITS
VIN
-0.5
-0.5
-0.5
-0.5
-0.5
-0.5
-65
7.0
VIN
2.5
2.5
3.0
VIN + 0.3
150
260
2000
V
V
V
V
V
V
°C
°C
V
Input Supply Voltage
Voltages on: ENABLE,
Voltage on XFB, XOV
Voltages on: EAIN, EAOUT, COMP
Voltages on: SS, PWM
Voltages on: POK
Storage Temperature Range
Reflow Temp, 10 Sec, MSL3 JEDEC J-STD-020A
ESD Rating (based on Human Body Model)
TSTG
Recommended Operating Conditions
PARAMETER
SYMBOL
MIN
MAX
UNITS
VIN
VOUT
TA
TJ
2.375
0.75
-40
-40
5.5
3.3
+85
+125
V
V
°C
°C
SYMBOL
TYP
UNITS
θJA
θJC
TJ-TP
20
1.5
+150
20
°C/W
°C/W
°C
°C
Input Voltage Range
Output Voltage Range
Operating Ambient Temperature
Operating Junction Temperature
Thermal Characteristics
PARAMETER
Thermal Resistance: Junction to Ambient (0 LFM) (Note 1)
Thermal Resistance: Junction to Case (0 LFM)
Thermal Overload Trip Point
Thermal Overload Trip Point Hysteresis
NOTES:
1. Based on a four-layer board and proper thermal design in line with JEDEC EIJ/JESD 51 Standards.
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EN5366QI
Electrical Characteristics
NOTE: VIN=5.5V over operating temperature range unless otherwise noted.
Typical values are at TA = 25°C.
PARAMETER
SYMBOL
Input Voltage
Output Regulation
VIN
Feedback Pin
Voltage
VOUT
Feedback Pin
Voltage
VOUT
TEST CONDITIONS
MIN
TYP
2.375
2.375V ≤ VIN ≤ 5.5V,
ILOAD = 1A; TA = 25°C
2.375V ≤ VIN ≤ 5.5V,
0A ≤ ILOAD ≤ 6A
-40 ºC ≤ TA ≤ +85 ºC
Transient Response (IOUT = 0% to 100% or 100% to 0% of Rated Load)
VIN = 5V, 1.2V < VOUT < 3.3V
Peak Deviation
∆VOUT
COUT=50uF
Under Voltage Lockout
Under Voltage Lock
VIN Increasing
VUVLO
out threshold
VIN Decreasing
Switching Frequency
Switching
FSWITCH
Frequency
Load Characteristics
Maximum
IOUT
Continuous Output
(Note 2)
Current
Current Limit
IOCP_TH
Threshold
Supply Current
Shut-Down Supply
ENABLE=0V
IS
Current
MAX
UNITS
5.5
V
0.735
0.750
0.765
V
0.725
0.750
0.773
V
3
%
2.2
2.1
V
5
MHz
6
A
9
A
50
µA
Enable Operation
Disable Threshold
VDISABLE
Enable Threshold
Enable Pin Current
VENABLE
IEN
Max voltage to ensure the
converter is disabled
2.375V ≤ VIN ≤ 5.5V
VIN = 5.5V
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0.8
1.8
50
V
V
µA
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Rev:B
EN5366QI
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
0.8
V
VIN
V
Voltage Select Operation
Logic Low
Threshold
VSX-Low
Logic High
Threshold
VSX-High
VSx Pin Current
Threshold voltage for Logic Low
Threshold voltage for Logic High
(internally pulled high; can be left
floating to achieve logic high)
VIN = 5.5V
VSx = GND
VSx = VIN
VSx = Open
IVSX
1.8
50
0
0
µA
Power OK Operation (Open Drain)
POK threshold High
POK threshold low
POK Low Voltage
POK High Voltage
Output Rise Time
Percentage of VOUT Nominal
Percentage of VOUT Nominal
IPOK = 4 mA (Max sink Current)
VOUT Rise Time
Accuracy
120
90
TRISE = Css* 75KΩ;
∆TRISE
-25
10nF ≤ CSS ≤30nF
0.4
VIN
%
%
V
%
+25
%
(Note 3)
Parallel Operation
With 2 – 4 converters in parallel,
the difference between any 2 parts.
∆VIN < 50mV; RTRACE < 10mΩ.
∆IOUT
Current Balance
+/-10
%
NOTES:
2. Maximum output current may need to be de-rated, based on operating condition, to meet TJ requirements.
3. Parameter not production tested but is guaranteed by design. Rise time begins when AVIN > VUVLO and
Enable=HIGH.
Typical Performance Characteristics
95
95
90
VOUT=3.3V
85
VOUT=2.5V
VOUT=2.5V
85
VOUT=1.8V
80
VOUT=1.5V
75
VOUT=1.2V
70
VOUT=1.2V
70
65
60
60
VIN=3.3V
VOUT=1.5V
75
65
55
VOUT=1.8V
80
Efficiency (%)
Efficiency (%)
90
55
VIN=5.0V
50
50
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
0
0.5
1
©Enpirion 2009 all rights reserved, E&OE
03817
2
2.5
3
3.5
4
4.5
5
5.5
Load Current (A)
Load Current (A)
Efficiency vs. Load, VIN = 3.3V.; Load = 0-6A.
1.5
Efficiency vs. Load, VIN = 5.0V.; Load = 0-6A.
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Rev:B
EN5366QI
Ripple Voltage, 5.0VIN/1.2VOUT, IOUT=6A,
COUT = 3x22uF.
Ripple Voltage, 3.3VIN/1.2VOUT, IOUT=6A,
COUT = 3x22uF.
Transient Response 5.5VIN/1.2VOUT, 0-6A, 10A/uS.
COUT=50uF.
Transient Response 5.5VIN/3.3VOUT, 0-6A, 10A/uS.
COUT=50uF
Start up waveforms VIN=5.0V, VOUT=1.2V, CSS=15nF,
Ch 1 = VOUT, Ch 3 = ENABLE, Ch 4 = POK.
©Enpirion 2009 all rights reserved, E&OE
03817
Start up waveforms VIN=5.0V, VOUT=3.3V, CSS=15nF,
Ch 1 = VOUT, Ch 3 = ENABLE, Ch 4 = POK.
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Rev:B
EN5366QI
Theory of Operation
Synchronous Buck Converter
It is recommended that Rb1 and Rb2 resistor
values be ~2kΩ. Use the following equation to
set the resistor Ra1 for the desired output
voltage:
The EN5366 is a synchronous, programmable
power supply with integrated power MOSFET
switches and integrated inductor. The nominal
input voltage range is 2.4-5.5V. The output
voltage is programmed using an external resistor
divider network. The feedback control loop is a
type III voltage-mode and the part uses a lownoise PWM topology. Up to 6A of continuous
output current can be drawn from this converter.
The 5MHz operating frequency enables the use
of small-size input and output capacitors.
(Vout − 0.75V ) * Rb1
0.75V
Ra1 =
If over-voltage protection is desired, use the
following equation to set the resistor Ra2 for the
desired OVP trip-point:
Ra 2 =
The power supply has the following protection
features:
• Programmable over-current protection (to
protect the IC from excessive load
current).
• Short Circuit protection.
• Thermal shutdown with hysteresis.
• Programmable over-voltage protection.
• Under-voltage lockout circuit to disable the
converter output when the input voltage is
less than approximately 2.2V
By design, if both resistor dividers are the same,
the OV trip-point will be 20% above the nominal
output voltage.
VIN
PVIN
47µF
•
Ra2
AGND
Ra1
47µF
XFB
Rb2
CSS
Rb1
PGND
Figure 4. VOUT and OVP resistor divider networks.
Input Capacitor Selection
The EN5366QI requires about 40-50uF of input
capacitance. Low ESR ceramic capacitors are
required with X5R or X7R dielectric formulation.
Y5V or equivalent dielectric formulations must
not be used as they lose capacitance with
frequency, temperature and bias voltage.
Output Voltage Programming
The EN5366 output voltage is programmed using
a simple resistor divider network. Figure 4 shows
the resistor divider configuration.
In some applications, lower value ceramic
capacitors maybe needed in parallel with the
larger capacitors in order to provide high
frequency decoupling.
The EN5366 output voltage and over voltage
thresholds are determined by the voltages
presented at the XFB and XOV pins respectively.
These voltages are set by way of resistor dividers
between VOUT and AGND with the midpoint going
to XFB and XOV.
03817
VOUT
VOUT
SS
Soft-start circuit, to limit the in-rush current
when the converter is powered up.
Power good circuit (POK) indicating
whether the output voltage is between
90% of nominal VOUT and the OVP trip
point.
©Enpirion 2009 all rights reserved, E&OE
POK
XOV
AVIN
Additional features include:
•
(OVPtrip − 0.90V ) * Rb 2
0.90V
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Rev:B
EN5366QI
Output Ripple vs Capacitor Configuration.
Recommended Input Capacitors.
Description
22uF, 10V,
X5R, 1206
(2 capacitors needed)
47uF, 10V,
X5R, 1210
(1 capacitor needed)
MFG
Murata
P/N
GRM31CR61A226ME19L
Taiyo Yuden
Murata
1 x 47uF
3 x 22 uF
LMK316BJ226ML-T
Typical Output Ripple (mVp-p)
(as measured on EN5366QI
Evaluation Board)
30
15
GRM32ER61A476KE20L
Taiyo Yuden
LMK325BJ476MM-T
Output Capacitor Selection
The EN5366QI has been optimized for use with
approximately 50µF of output capacitance. Low
ESR ceramic capacitors are required with X5R or
X7R dielectric formulation. Y5V or equivalent
dielectric formulations must not be used as these
lose capacitance with frequency, temperature
and bias voltage.
Recommended Output Capacitors.
Description
22uF, 6.3V, 10%
X5R, 1206
(3 capacitors needed)
47uF, 10V, 10%
X5R, 1210
47uF, 6.3V, 10%
X5R, 1210
(1 capacitor needed)
Output Capacitor
Configuration
MFG
Murata
P/N
GRM31CR60J226KE19L
Taiyo Yuden
JMK316BJ226KL-T
Murata
GRM32ER61A476KE20L
AVX
12106D476KAT2
Compensation
The EN5366 is internally compensated through
the use of a type 3 compensation network and is
optimized for use with about 50µF of output
capacitance and will provide excellent loop
bandwidth and transient performance for most
applications. Voltage mode operation provides
high noise immunity at light load.
Further,
Voltage mode control provides superior
impedance matching to sub 90nm loads.
In some cases modifications to the compensation
may be required. The EN5366QI provides the
capability to modify the control loop to allow for
customization for a given application. For more
information, contact Enpirion Applications
Engineering support.
Enable Operation
Output ripple voltage is primarily determined by
the aggregate output capacitor impedance. At
the 5MHz switching frequency output impedance,
denoted as Z, is comprised mainly of effective
series resistance, ESR, and effective series
inductance, ESL:
The ENABLE pin provides a means to shut down
the device, or enable normal operation. A logic
low will disable the converter and cause it to shut
down. A logic high will enable the converter into
normal operation. When the ENABLE pin is
asserted high, the device will undergo a normal
soft start.
Z = ESR + ESL.
Soft-Start Operation
Placing output capacitors in parallel reduces the
impedance and will hence result in lower ripple
voltage.
The SS pin in conjunction with a small capacitor
between this pin and AGND provides the soft
start function to limit the in-rush current during
start-up. During start-up of the converter the
reference voltage to the error amplifier is
gradually increased to its final level by an internal
current source of typically 10uA charging the soft
start capacitor. The typical soft-start time for the
output to reach regulation voltage, from when
AVIN > VUVLO and Enable crosses its logic high
threshold, is given by:
1
Z Total
=
1
1
1
+
+ ... +
Z1 Z 2
Zn
Typical ripple versus capacitor arrangement is
given below:
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EN5366QI
TSS = CSS * 75KΩ (seconds)
Where the soft-start time TSS is in seconds and
the soft-start capacitance CSS is in Farads.
Typically, a capacitor of around 15nF is
recommended.
During the soft-start cycle, when the soft-start
capacitor reaches 0.75V, the output has reached
its programmed regulation range. Note that the
soft-start current source will continue to operate,
and during normal operation, the soft-start
capacitor will charge up to a final value of 2.5V.
POK Operation
The POK signal is an open drain signal from the
converter indicating the output voltage is within
the specified range. The POK signal will be a
logic high when the output voltage is within 90% 120% of the programmed output voltage. If the
output voltage goes outside of this range, the
POK signal will be a logic low until the output
voltage has returned to within this range. In the
event of an over-voltage condition the POK
signal will go low and will remain in this condition
until the output voltage has dropped to 95% of
the programmed output voltage before returning
to the high state.
The internal POK FET is designed to tolerate up
to 4mA. The pull-up resistor value should be
chosen to limit the current from exceeding this
value when POK is logic low.
Over-Current Protection
The OCP trip point is nominally set to 150% of
maximum rated load. For diagnostic purposes, it
is possible to increase the OCP trip point to
approximately 200% of the maximum rated load
by connecting a 10kΩ resistor between the
ROCP pin (pin 38) and AGND (pin 39). This is
intended for troubleshooting purposes only and
the specification is not guaranteed.
Over-Voltage Protection
When the output voltage exceeds 120% of the
programmed output voltage, the PWM operation
stops, the lower N-MOSFET is turned on and the
POK signal goes low. When the output voltage
drops below 95% of the programmed output
voltage, normal PWM operation resumes and
POK returns to its high state.
Thermal Overload Protection
Thermal shutdown will disable operation when
the Junction temperature exceeds approximately
150ºC. Once the junction temperature drops by
approx 20ºC, the converter will re-start with a
normal soft-start.
Input Under-Voltage Lock-Out
Circuitry is provided to ensure that when the
input voltage is below the required voltage level
(VUVLO) for normal operation, the converter will
not start-up. Circuits for hysteresis and input deglitch are included to ensure high noise immunity
and to prevent false tripping.
Parallel Device Operation
The current limit function is achieved by sensing
the current flowing through a sense P-MOSFET.
When the sensed current exceeds the current
limit, both NFET and PFET switches are turned
off. If the over-current condition is removed, the
over-current protection circuit will re-enable the
PWM operation. If the over-current condition
persists, the circuit will continue to protect the
load.
©Enpirion 2009 all rights reserved, E&OE
03817
The EN5366QI is capable of paralleling up to a
total of four converters to provide up to 24A of
continuous current. Please refer to the Parallel
Operation Application note, available on the
Enpirion website www.enpirion.com, for details
on parallel operation.
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EN5366QI
Layout Recommendations
Compensation
Test Points
AGND
Test
Points
High-Frequency
Noise Suppression
Vias
VOUT(+)
Copper
Local
Ground
Copper
Thermal Pad
Vias and
Soldermask
Opening
VIN(+)
Copper
Vout
Slit separating
input local ground
from output
local ground
PGND
Copper
Slit
Vin
Figure 5. Layout of power and ground copper.
Figure 6. Use of thermal & noise suppression vias.
Recommendation 1: Input and output filter
capacitors should be placed as close to the
EN5366QI package as possible to reduce EMI
from input and output loop currents. This
reduces the physical area of the Input and
Output AC current loops.
These vias can be the same size as the
thermal vias discussed in recommendation 3.
Recommendation 5: The system ground
plane referred to in recommendations 3 and 4
should be the first layer immediately below the
surface layer. This ground plane should be
continuous and un-interrupted below the
converter and the input/output capacitors
shown in figure 6.
Recommendation 2: Place a slit in the
input/output capacitor ground copper starting
just below the common connection point of the
device GND pins as shown in figures 5 and 6.
Recommendation 6: As with any switch-mode
DC/DC converter, do not run sensitive signal or
control lines underneath the converter
package.
Recommendation 3: The large thermal pad
underneath the component must be connected
to the system ground plane through as many
vias as possible. The drill diameter of the vias
should be less than 0.33mm, and the vias must
have at least 1 oz. copper plating on the inside
wall, making the finished hole size around
0.26mm. This connection provides the path for
heat dissipation from the converter. Please see
figures 6, 7, and 8.
Please refer to the Gerber files and
summarized layout notes available on the
Enpirion website www.enpirion.com for more
layout details.
NOTE: Figures 5 and 6 show only the critical
components and traces for a minimum footprint
layout. ENABLE, Vout-programming, and
other small signal pins need to be connected
and routed according to the specific
application.
Recommendation 4: Multiple small vias
should be used to connect ground terminal of
the input capacitor and output capacitors to the
system ground plane as shown in figure 6.
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EN5366QI
Design Considerations for Lead-Frame Based Modules
Exposed Metal on Bottom Of Package
Lead frame offers many advantages in thermal performance, in reduced electrical lead resistance, ,
and in overall foot print. However, they do require some special considerations.
In the assembly process lead frame construction requires that, for mechanical support, some of the
lead-frame cantilevers be exposed at the point where wire-bond or internal passives are attached.
This results in several small pads being exposed on the bottom of the package.
Only the large thermal pad and the perimeter pads are to be mechanically or electrically connected to
the PC board. The PCB top layer under the EN5366QI should be clear of any metal except for the
large thermal pad. The “grayed-out” area in Figure 7 represents the area that should be clear of any
metal (traces, vias, or planes), on the top layer of the PCB.
Figure 8 demonstrates the recommended PCB footprint for the EN5366QI. Figure 9 shows the shape
and location of the exposed metal pads as well as the mechanical dimension of the large thermal pad
and the pins.
Ground copper my extend under this pad.
However, DO NOT CONNECT (NC)
Figure 7. Lead-Frame exposed metal. Grey area highlights exposed metal that is not to be mechanically or
electrically connected to the PCB.
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Rev:B
EN5366QI
Figure 8. Recommended footprint for PCB.
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EN5366QI
Package Dimensions
Figure 9. Package dimensions.
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EN5366QI
Contact Information
Enpirion, Inc.
Perryville III
53 Frontage Road, Suite 210
Hampton, NJ 08827
Phone: 908-894-6000
Fax: 908-894-6090
www.enpirion.com
Enpirion reserves the right to make changes in circuit design and/or specifications at any time without notice. Information furnished by Enpirion is
believed to be accurate and reliable. Enpirion assumes no responsibility for its use or for infringement of patents or other third party rights, which may
result from its use. Enpirion products are not authorized for use in nuclear control systems, as critical components in life support systems or equipment
used in hazardous environment without the express written authority from Enpirion.
©Enpirion 2009 all rights reserved, E&OE
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Rev:B