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EN5329QI 2A PowerSoC
Step-Down DC-DC Switching Converter with Integrated Inductor
DESCRIPTION
The EN5329QI is an Intel® Enpirion® Power System on
a Chip (PowerSoC) DC-DC converter. The device
features an advance integrated inductor, integrated
MOSFETs, a PWM voltage-mode controller, and
internal compensation providing the smallest
possible solution size.
The EN5329QI is a member of the EN53x9QI family
of pin compatible and interchangeable devices. The
pin compatibility enables an easy to use scalable
family of products covering the load range from 1.5A
up to 3A in a low profile 4mm x 6mm x 1.1mm QFN
package.
The EN5329QI operates at high switching frequency
and allows for the use of tiny MLCC capacitors. It also
enables a very wide control loop bandwidth providing
excellent transient performance and reduced output
impedance. The internal compensation is designed
for unconditional stability across all operating
conditions.
Intel Enpirion integrated inductor solution
significantly helps to reduce noise. The complete
power converter solution enhances productivity by
offering greatly simplified board design, layout and
manufacturing requirements.
All Enpirion products are RoHS compliant and lead-
free manufacturing environment compatible.
FEATURES
Integrated Inductor
Solution Footprint as Small as 50 mm2
Low Profile, 1.1mm
High Reliability Solution: 42,000 Years MTBF
High Efficiency, up to 95 %
Low Output Ripple Voltage; <5mVP-P Typical
2.4 V to 5.5 V Input Voltage Range
2A Continuous Output Current Capability
Pin Compatible w/ EN5319 1.5A and EN5339 3A
Output Enable and Power OK Signal
Under Voltage Lockout, Over Current, Short Circuit,
and Thermal Protection
RoHS Compliant; Halogen Free; 260°C Reflow
APPLICATIONS
Applications with Low Profile Requirement such as
SSD and Embedded Computing
SAN/NAS Accelerator Appliances
Controllers, Raid, Processors, Network Processors,
DSPs’ FPGAs, and ASICs
Noise Sensitive Applications
Figure 1: Simplified Applications Circuit
Figure 2. Highest Efficiency in Smallest Solution Size
DataSheeT enpirion® power solutions
0
10
20
30
40
50
60
70
80
90
100
0 0.5 1 1.5 2
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency vs. Output Current
VOUT = 2.5V
VOUT = 1.2V
EN5329QI
VOUT
PVIN
AGND
VIN
POK
TST0
TST1
TST2
ENABLE
AVIN PGND
CIN
22µF
COUT
2x 22µF
or
1x 47µF
100k
VOUT
PGND
Ra
Rb
VFB
POK
Ca
1µF
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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ORDERING INFORMATION
Part Number
Package Markings
TJ Rating
Package Description
EN5329QI
EN5329
-40°C to +125°C
24-pin (4mm x 6mm x 1.1mm) QFN
EVB-EN5329QI
EN5329
QFN Evaluation Board
Packing and Marking Information: https://www.altera.com/support/quality-and-reliability/packing.html
PIN FUNCTIONS
NC(SW)
NC(SW)
NC(SW)
NC(SW)
NC(SW)
PGND
PGND
VOUT
VOUT
VOUT
VOUT
PGND
PGND
NC
VFB
AGND
AVIN
POK
ENABLE
PVIN
PVIN
26
PGND
25
PGND
1
2
3
4
5 6 7 8 9 10 11 12
13
14
15
16
17
181920
21
22
2324
Keep-Out
Keep-Out
TST2
TST1
TST0
Figure 3: Pin Diagram (Top View)
NOTE A: 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.
NOTE B: Grey area highlights exposed metal on the bottom of the package that is not to be mechanically or electrically
connected to the PCB. There should be no traces on PCB top layer under these keep out areas.
NOTE C: White ‘dot’ on top left is pin 1 indicator on top of the device package.
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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PIN DESCRIPTIONS
PIN
NAME
TYPE
FUNCTION
1, 21-
24
NC(SW)
-
NO CONNECT: These pins are internally connected to the common
switching node of the internal MOSFETs. They must be soldered to PCB
but not be electrically connected to any external signal, ground, or
voltage. Failure to follow this guideline may result in device damage.
2-3, 8-
9
PGND
Power
Input and output power ground. Connect these pins to the ground
electrode of the input and output filter capacitors. See VOUT, PVIN
descriptions and Layout Recommendation for more details.
4-7
VOUT
Power
Regulated converter output. Connect to the load and place output filter
capacitor(s) between these pins and PGND pins 8 and 9. See layout
recommendation for details
10
TST2
-
Test Pin. For Intel Enpirion internal use only. Connect to AVIN at all times.
11
TST1
-
Test Pin. For Intel Enpirion internal use only. Connect to AVIN at all times.
12
TST0
-
Test Pin. For Intel Enpirion internal use only. Connect to AVIN at all times.
13
NC
-
NO CONNECT: This pin must be soldered to PCB but not electrically
connected to any other pin or to any external signal, voltage, or ground.
This pin may be connected internally. Failure to follow this guideline may
result in device damage.
14
VFB
Analog
This is the external feedback input pin. A resistor divider connects from
the output to AGND. The mid-point of the resistor divider is connected to
VFB. A feed-forward capacitor is required parallel to the upper feedback
resistor (RA). The output voltage regulation is based on the VFB node
voltage equal to 0.600V.
15
AGND
Power
The quiet ground for the control circuits. Connect to the ground plane
with a via right next to the pin.
16
AVIN
Power
Analog input voltage for the control circuits. Connect this pin to the input
power supply (PVIN) at a quiet point. Decouple with a 1uF capacitor to
AGND.
17
POK
Digital
POK is an open drain output. Refer to Power OK section for details. Leave
POK open if unused.
18
ENABLE
Analog
Output Enable. A logic high level on this pin enables the output and
initiates a soft-start. A logic low signal disables the output and discharges
the output to GND. This pin must not be left floating.
19-20
PVIN
Power
Input power supply. Connect to input power supply and place input filter
capacitor(s) between these pins and PGND pins 2 to 3.
25,26
PGND
Ground
Not a perimeter pin. Device thermal pad to be connected to the system
GND plane for heat-sinking purposes. See Layout Recommendation
section.
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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ABSOLUTE MAXIMUM RATINGS
CAUTION: Absolute Maximum ratings are stress ratings only. Functional operation beyond the recommended
operating conditions is not implied. Stress beyond the absolute maximum ratings may impair device
life. Exposure to absolute maximum rated conditions for extended periods may affect device reliability.
Absolute Maximum Pin Ratings
PARAMETER
SYMBOL
MIN
MAX
UNITS
PVIN, AVIN, VOUT
-0.3
6.5
V
ENABLE, POK, TST0, TST1, TST2
-0.3
VIN+0.3
V
VFB
-0.3
2.7
V
Absolute Maximum Thermal Ratings
PARAMETER
CONDITION
MIN
MAX
UNITS
Maximum Operating Junction
Temperature
+150
°C
Storage Temperature Range
-65
+150
°C
Reflow Peak Body Temperature
(10 Sec) MSL3 JEDEC J-STD-
020A
+260
°C
Absolute Maximum ESD Ratings
PARAMETER
CONDITION
MIN
MAX
UNITS
HBM (Human Body Model)
±2000
V
CDM (Charged Device Model)
±500
V
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
MIN
MAX
UNITS
Input Voltage Range
VIN
2.4
5.5
V
Output Voltage Range
VOUT
0.6
VIN VDO (1)
V
Output Current Range
IOUT
0
2
A
Operating Ambient Temperature Range
TA
-40
+85
°C
Operating Junction Temperature
TJ
-40
+125
°C
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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THERMAL CHARACTERISTICS
PARAMETER
SYMBOL
TYPICAL
UNITS
Thermal Shutdown
TSD
150
°C
Thermal Shutdown Hysteresis
TSDHYS
15
°C
Thermal Resistance: Junction to Ambient (0 LFM) (2)
JA
36
°C/W
Thermal Resistance: Junction to Case (0 LFM)
JC
6
°C/W
ELECTRICAL CHARACTERISTICS
NOTE: VIN = PVIN = AVIN = 5V, Minimum and Maximum values are over operating ambient temperature range
unless otherwise noted. Typical values are at TA = 25°C.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Operating Input
Voltage
VIN
2.4
5.5
V
Feedback Node Initial
Accuracy
VVFB
TA = 25°C; VIN = 5V
ILOAD = 100 mA
0.588
0.600
0.612
V
Output Variation (3)
(Line, Load,
Temperature)
VOUT
2.4V VIN 5.5V
0 ILOAD ≤ 2A
-3
+3
%
VFB, ENABLE, TST0/1/2
Pin Input Current (4)
+/-40
nA
Shutdown Current
ENABLE Low
20
A
Under Voltage Lock-
out VIN Rising
VUVLOR
Voltage Above Which UVLO
is Not Asserted
2.2
V
Under Voltage Lock-
out tVIN Falling
VUVLOF
Voltage Below Which UVLO
is Asserted
2.1
V
Soft-start Time
Time from Enable High (4)
0.91
1.40
1.89
ms
Dropout Resistance
150
300
m
ENABLE Voltage
Threshold
Logic Low
0.0
0.4
V
Logic High
1.4
VIN
V
POK Threshold
VOUT Rising
92
%
POK Threshold
VOUT Falling
90
%
POK Low Voltage
ISINK = 1 mA
0.15
0.4
V
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
POK Pin VOH Leakage
Current
POK High
0.5
2
µA
Current Limit
Threshold
2.4V VIN 5.5V
3.2
5
A
Operating Frequency
FOSC
3.2
MHz
Output Ripple Voltage
VRIPPLE
COUT = 2 x 22 F 0603 X5R
MLCC, VOUT = 3.3 V, ILOAD = 2A
5
mVP-P
COUT = 2 x 22 F 0603 X5R
MLCC, VOUT = 1.8 V, ILOAD = 2A
5
mVP-P
(1) VDO (dropout voltage) is defined as (ILOAD x Droput Resistance). Please refer to Electrical Characteristics Table.
(2) Based on 2oz. external copper layers and proper thermal design in line with EIJ/JEDEC JESD51-7 standard for high
thermal conductivity boards.
(3) The VFB pin is a sensitive node. Do not touch VFB while the device is in regulation.
(4) Parameter not production tested but is guaranteed by design.
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TYPICAL PERFORMANCE CURVES
0
10
20
30
40
50
60
70
80
90
100
0 0.5 1 1.5 2
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency vs. Output Current
VOUT = 2.5V
VOUT = 1.8V
VOUT = 1.2V
VOUT = 1.0V
CONDITIONS
VIN = 3.3V
0
10
20
30
40
50
60
70
80
90
100
0 0.5 1 1.5 2
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency vs. Output Current
VOUT = 3.3V
VOUT = 2.5V
VOUT = 1.8V
VOUT = 1.2V
VOUT = 1.0V
CONDITIONS
VIN = 5V
2.8
2.9
3
3.1
3.2
3.3
3.4
3.5
3.6
3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4
OUTPUT VOLTAGE (V)
INPUT VOLTAGE(V)
Dropout Voltage
IOUT = 1A
IOUT = 2A
CONDITIONS
VOUT = 3.3V
3.24
3.26
3.28
3.3
3.32
3.34
3.36
0 0.5 1 1.5 2
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VOUT = 3.3V
CONDITIONS
VIN = 5V
2.44
2.46
2.48
2.5
2.52
2.54
2.56
0 0.5 1 1.5 2
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VOUT = 2.5V
CONDITIONS
VIN = 5V
1.74
1.76
1.78
1.8
1.82
1.84
1.86
0 0.5 1 1.5 2
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VOUT = 1.8V
CONDITIONS
VIN = 5V
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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TYPICAL PERFORMANCE CURVES (CONTINUED)
1.14
1.16
1.18
1.2
1.22
1.24
1.26
0 0.5 1 1.5 2
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VOUT = 1.2V
CONDITIONS
VIN = 5V
2.44
2.46
2.48
2.5
2.52
2.54
2.56
0 0.5 1 1.5 2
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VOUT = 2.5V
CONDITIONS
VIN = 3.3V
1.74
1.76
1.78
1.8
1.82
1.84
1.86
0 0.5 1 1.5 2
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VOUT = 1.8V
CONDITIONS
VIN = 3.3V
1.14
1.16
1.18
1.2
1.22
1.24
1.26
0 0.5 1 1.5 2
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VOUT = 1.2V
CONDITIONS
VIN = 3.3V
1.780
1.785
1.790
1.795
1.800
1.805
1.810
1.815
1.820
2.5 3.1 3.7 4.3 4.9 5.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage vs. Input Voltage
CONDITIONS
Load = 5mA
1.780
1.785
1.790
1.795
1.800
1.805
1.810
1.815
1.820
2.5 3.1 3.7 4.3 4.9 5.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage vs. Input Voltage
CONDITIONS
Load = 500mA
08326 September 24, 2018 Rev F
Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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TYPICAL PERFORMANCE CURVES (CONTINUED)
1.780
1.785
1.790
1.795
1.800
1.805
1.810
1.815
1.820
2.5 3.1 3.7 4.3 4.9 5.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage vs. Input Voltage
CONDITIONS
Load = 1A
1.780
1.785
1.790
1.795
1.800
1.805
1.810
1.815
1.820
2.5 3.1 3.7 4.3 4.9 5.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage vs. Input Voltage
CONDITIONS
Load = 2A
0.960
0.970
0.980
0.990
1.000
1.010
1.020
1.030
1.040
-40 -15 10 35 60 85
OUTPUT VOLTAGE (V)
AMBIENT TEMPERATURE ( C)
Output Voltage vs. Temperature
LOAD = 2A
LOAD = 100mA
CONDITIONS
VIN = 5V
VOUT_NOM = 1.0V
1.760
1.770
1.780
1.790
1.800
1.810
1.820
1.830
1.840
-40 -15 10 35 60 85
OUTPUT VOLTAGE (V)
AMBIENT TEMPERATURE ( C)
Output Voltage vs. Temperature
LOAD = 2A
LOAD = 100mA
CONDITIONS
VIN = 5V
VOUT_NOM = 1.8V
CONDITIONS
VIN = 5V
VOUT_NOM = 1.8V
0
0.5
1
1.5
2
2.5
3
3.5
-40 -15 10 35 60 85
GUARANTEED OUTPUT CURRENT (A)
AMBIENT TEMPERATURE( C)
No Thermal Derating
Conditions
VIN = 5.0V
VOUT = 3.3V
CONDITIONS
VIN = 5.0V
VOUT = 1.0V
0
0.5
1
1.5
2
2.5
3
3.5
-40 -15 10 35 60 85
GUARANTEED OUTPUT CURRENT (A)
AMBIENT TEMPERATURE( C)
No Thermal Derating
Conditions
VIN = 5.0V
VOUT = 3.3V
CONDITIONS
VIN = 5.0V
VOUT = 3.3V
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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TYPICAL PERFORMANCE CHARACTERISTICS
Output Ripple at 20MHz
CONDITIONS
VIN = 3.3V
VOUT = 1.8V
IOUT = 2A
CIN = 1x 22µF (0805)
COUT = 2 x 22µF (0603)
VOUT
(AC Coupled)
Output Ripple at 20MHz
CONDITIONS
VIN = 5V
VOUT = 3.3V
IOUT = 2A
CIN = 1x 22µF (0805)
COUT = 2 x 22µF (0603)
VOUT
(AC Coupled)
Output Ripple at 500MHz
CONDITIONS
VIN = 3.3V
VOUT = 1.8V
IOUT = 2A
CIN = 1x 22µF (0805)
COUT = 2 x 22µF (0603)
VOUT
(AC Coupled)
Output Ripple at 500MHz
VOUT
(AC Coupled)
CONDITIONS
VIN = 5V
VOUT = 3.3V
IOUT = 2A
CIN = 1x 22µF (0805)
COUT = 2 x 22µF (0603)
VOUT
Startup Waveforms at 0A
VIN = 5V, VOUT = 1.8V
CIN = 1 X 22µF (0805), COUT = 2 x 22µF (0603), IOUT = 0A
LOAD
ENABLE
POK
VOUT
Startup Waveforms at 2A
VIN = 5V, VOUT = 1.8V
CIN = 1 X 22µF (0805), COUT = 2 x 22µF (0603), IOUT = 2A
LOAD
ENABLE
POK
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TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
VOUT
(AC Coupled)
Load Transient from 0 to 1A
CONDITIONS
VIN = 3.3V
VOUT = 1.8V
CIN = 1 X 22µF (0805)
COUT = 2 x 22µF (0603)
LOAD
VOUT
(AC Coupled)
Load Transient from 0 to 2A
CONDITIONS
VIN = 3.3V
VOUT = 1.8V
CIN = 1 X 22µF (0805)
COUT = 2 x 22µF (0603)
LOAD
VOUT
(AC Coupled)
Load Transient from 0 to 1A
CONDITIONS
VIN = 5V
VOUT = 2.5V
CIN = 1 X 22µF (0805)
COUT = 2 x 22µF (0603)
LOAD
VOUT
(AC Coupled)
Load Transient from 0 to 2A
CONDITIONS
VIN = 5V
VOUT = 2.5V
CIN = 1 X 22µF (0805)
COUT = 2 x 22µF (0603)
LOAD
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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FUNCTIONAL BLOCK DIAGRAM
DAC
VREF
(+)
(-)
Error
Amp
VFB
VOUT
Package Boundary
P-Drive
N-Drive
UVLO
Thermal Limit
Current Limit
Soft Start
Sawtooth
Generator
(+)
(-)PWM
Comp
PVIN
ENABLE
PGND
Logic
Compensation
Network
NC
(SW)
POK
POK
AVIN AGND
BIAS
TST
Figure 4: Functional Block Diagram
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FUNCTIONAL DESCRIPTION
Synchronous DC-DC Step-Down PowerSoC
The EN5329QI is a highly integrated synchronous buck converter with an internal inductor utilizing advanced
CMOS technology to provide high switching frequency, while also maintaining high efficiency. The EN5329QI
is a high power density device packaged in a tiny 4x6x1.1mm 24-pin QFN package. Its high switching frequency
allows for the use of very small MLCC input and output filter capacitors and results in a total solution size as
small as 50mm2.
The EN5329QI is a member of a family of pin compatible devices. This offers scalability for applications where
load currents may not be known apriori, and/or speeds time to market with a convenient common solution
footprint.
The EN5329QI buck converter uses Type III voltage mode control to provide pin-point output voltage
accuracy, high noise immunity, low output impedance and excellent load transient response. The EN5329QI
features include Power OK, under voltage lockout (UVLO), over current protection, short circuit protection, and
thermal overload protection.
Stability and Compensation
The EN5329QI utilizes an internal compensation network that is designed to provide stable operation over a
wide range of operating conditions. The output compensation circuit may be customized to improve transient
performance or reduce output voltage ripple with dynamic loads.
Soft-Start
The EN5329QI has an internal soft-start circuit that controls the ramp of the output voltage. The control
circuitry limits the VOUT ramp rate to levels that are safe for the Power MOSFETs and the integrated inductor.
The EN5329QI has a constant startup up time which is independent of the VOUT setting. The output rising
slew rate is proportional to the output voltage. The startup time is approximately 1.4ms from when the ENABLE
is first pulled high until VOUT reaches the regulated voltage level.
Excess bulk capacitance on the output of the device can cause an over-current condition at startup. Maximum
allowable output capacitance depends on the device’s minimum current limit as indicated in the Electrical
Characteristics Table, the output current at startup, the minimum soft-start time also in the Electrical
Characteristics Table and the output voltage.
The total maximum capacitance on the output rail is estimated by the equation below:
COUT_MAX = 0.7 * (ILIMIT - IOUT) * tSS / VOUT
COUT_MAX = maximum allowable output capacitance
ILIMIT = minimum current limit = 3.2A
IOUT = output current at startup
tSS = minimum soft-start time = 0.91ms
VOUT = output voltage
NOTE: Device stability still needs to be verified in the application if extra bulk capacitors are added to the
output rail.
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Over Current/Short Circuit Protection
When an over current condition occurs, VOUT is pulled low and the device disables switching internally. This
condition is maintained for a period of 1.2ms and then a normal soft-start cycle is initiated. If the over current
condition still persists, this cycle will repeat.
Under Voltage Lockout
An under voltage lockout circuit will hold off switching during initial power up until the input voltage reaches
sufficient level to ensure proper operation. If the voltage drops below the UVLO threshold the lockout circuitry
will again disable switching. Hysteresis is included to prevent chattering between UVLO high and low states.
Enable
The ENABLE pin provides means to shut down the converter or initiate normal operation. A logic high on the
ENABLE pin will initiate the converter to start the soft-start cycle and regulate the output voltage to the desired
value. A logic low will allow the device to discharge the output and go into shutdown mode for minimal power
consumption. When the output is discharged, an auxiliary NFET turns on and limits the discharge current to
300mA or below.
The ENABLE pin should not be left floating as it could be in an unknown and random state. It is recommended
to enable the device after both PVIN and AVIN is in regulation. At extremely cold conditions below -30°C, the
controller may not be properly powered if ENABLE is tied directly to AVIN during startup. It is recommended
to use an external RC circuit to delay the ENABLE voltage rise so that the internal controller has time to startup
into regulation (see circuit below).
The RC circuit may be adjusted so that AVIN and PVIN are above UVLO before ENABLE is high. The startup
time will be delayed by the extra time it takes for the capacitor voltage to reach the ENABLE threshold.
Figure 5: ENABLE Delay Circuit
AVIN
ENABLE
1k
1µF
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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Thermal Shutdown
When excessive power is dissipated in the device, its junction temperature rises. Once the junction
temperature exceeds the thermal shutdown temperature of 150°C, the thermal shutdown circuit turns off the
converter, allowing the device to cool. When the junction temperature drops 15°C, the device will be re-
enabled and go through a normal startup process.
Power OK
The Power OK (POK) feature is an open drain output signal used to indicate if the output voltage is within 92%
of the set value. Within this range, the POK output is allowed to be pulled high. Outside this range, the POK
output is maintained low. During transitions such as power up and power down, the POK output will not change
state until the transition is complete for enhanced noise immunity.
The POK has 1mA sink capability. When POK is pulled high, the worst case pin leakage current is as low as
500nA over temperature. This allows a large pull up resistor such as 100k to be used for minimal current
consumption in shutdown mode.
The POK output can also be conveniently used as an enable input of the next stage for power sequencing of
multiple converters.
Power-Up/Down Sequencing
During power-up, ENABLE should not be asserted before PVIN, and PVIN should not be asserted before AVIN.
The PVIN should never be powered when AVIN is off. During power down, the AVIN should not be powered
down before the PVIN. Tying PVIN and AVIN or all three pins (AVIN, PVIN, ENABLE) together during power up
or power down meets these requirements.
Pre-Bias Start-up
The EN5329QI does not support startup into a pre-biased condition. Be sure the output capacitors are not
charged or the output of the EN5329QI is not pre-biased when the EN5329QI is first enabled.
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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APPLICATION INFORMATION
Output Voltage Setting
The EN5329 uses a simple and flexible resistor divider network to program the output voltage. A feed-forward
capacitor (Ca) is used to ensure the stability of the converter. Table 3 shows the required critical component
values as a function of VOUT. It is recommended to use 1% or better feedback resistors to ensure output
voltage accuracy. The Ra resistor value is fixed at 348k as shown in Table 3. Based on that value, the bottom
resistor Rb can be calculated below as:
V0.6V V0.6Ra
Rb
OUT
The VOUT is the nominal output voltage. The Rb and Ra resistors have the same units based on the above
equation.
EN5329QI
VOUT
PVIN
AGND
VIN
POK
TST0
TST1
TST2
ENABLE
AVIN PGND
CIN
22µF
COUT
2x 22µF
or
1x 47µF
100k VOUT
PGND
Ra
Rb
VFB
POK
Ca
1µF
Figure 6: Typical Application Circuit
NOTE: Enable can be separated from PVIN if the application requires it.
AVIN Filter Capacitor
A 1.0 F, 10V, 0402 MLCC capacitor should be placed between AVIN and AGND as close to the pins as possible.
This will provide high frequency bypass to ensure clean chip supply for optimal performance.
Input Filter Capacitor Selection
A single 22F, 0805 MLCC capacitor is needed on PVIN for all applications. Connect the input capacitor
between PVIN and PGND as close to the pins as possible. Placement of the input capacitor is critical to ensure
low conducted and radiated EMI.
Low ESR MLCC capacitors with X5R or X7R or equivalent dielectric should be used for the input capacitors.
Y5V or equivalent dielectrics lose too much capacitance with frequency, DC bias, and temperature. Therefore,
they are not suitable for switch-mode DC-DC converter filtering, and must be avoided.
Table 1: Recommened Input Capacitos
Description
MFG
P/N
22µF, 10V,
X5R, 0805
Taiyo Yuden
LMK212BBJ226MG-T
Murata
GRM21BR61A226ME51
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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Output Filter Capacitor Selection
The EN5329QI output capacitor selection may be determined based on two configurations. Table 3 provides
the allowed output capacitor configurations based on operating conditions. For lower output ripple, choose 2
x 22µF for the output capacitors. For smaller solution size, use one 47µF output capacitor. Table 2 shows the
recommended type and brand of output capacitors to use.
In some rare applications modifications to the compensation may be required. The EN5329QI provides the
capability to modify the control loop response to allow for customization for specific applications.
Table 2: Recommened Output Capacitos
Description
MFG
P/N
47µF, 6.3V,
X5R, 0805
Taiyo Yuden
JMK212BBJ476MG-T
Murata
GRM21BR60J476ME15
22µF, 6.3V,
X5R, 0805
Taiyo Yuden
JMK212ABJ226MG
Murata
GRM21BR60J226ME39
22µF, 6.3V,
X5R, 0603
Murata
GRM188R60J226MEA0
Table 3. Required Critical Components
VOUT (V)
Ca (pF)
Ra (kΩ)
Cout (µF)
Vout ≤ 2.5V
8.2
348
1x47uF/0805
2.5V < Vout ≤ 3.3V
6.8
Vout ≤ 2.5V
8.2
348
2x22uF/0603
2.5V < Vout ≤ 3.3V
6.8
Vout ≤ 2.5V
8.2
348
2x22uF/0805
Note: Follow Layout Recommendations
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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THERMAL CONSIDERATIONS
Thermal considerations are important power supply design facts that cannot be avoided in the real world.
Whenever there are power losses in a system, the heat that is generated needs to be accounted for. Intel’s
Enpirion PowerSoCTM helps alleviate some of those concerns.
Intel’s Enpirion EN5329QI DC-DC converter is packaged in a 4x6x1.1mm 24-pin QFN package. The QFN
package is constructed with exposed thermal pads on the bottom of the package. The exposed thermal pad
should be soldered directly on to a copper ground pad on the printed circuit board (PCB) to act as a heat sink.
The recommended maximum junction temperature for continuous operation is 125°C. Continuous operation
above 125°C may reduce long-term reliability. The device has a thermal overload protection circuit designed
to turn off the device at an approximate junction temperature value of 150°C.
The EN5329QI is guaranteed to support the full 2A output current up to 85°C ambient temperature. The
following example and calculations illustrate the thermal performance of the EN5329QI.
Example:
VIN = 5V
VOUT = 3.3V
IOUT = 2A
First calculate the output power.
POUT = 3.3V x 2A = 6.6W
Next, determine the input power based on the efficiency (η) shown in Figure 7.
Figure 7: Efficiency vs. Output Current
0
10
20
30
40
50
60
70
80
90
100
0 0.5 1 1.5 2
EFFICIENCY (%)
OUTPUT CURRENT (A)
VOUT = 3.3V
CONDITIONS
VIN = 5V
CONDITIONS
VIN = 5V
CONDITIONS
VIN = 5V
CONDITIONS
VIN = 5V
~92%
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For VIN = 5V, VOUT = 3.3V at 2A, η ≈ 92%
η = POUT / PIN = 92% = 0.92
PIN = POUT / η
PIN 6.6W / 0.92 14W
The power dissipation (PD) is the power loss in the system and can be calculated by subtracting the output
power from the input power.
PD = PIN POUT
7.2W 6.6W ≈ 0.6W
With the power dissipation known, the temperature rise in the device may be estimated based on the theta JA
value JA). The θJA parameter estimates how much the temperature will rise in the device for every watt of
power dissipation. The EN5329QI has a θJA value of 36°C/W without airflow.
Determine the change in temperature (ΔT) based on PD and θJA.
ΔT = PD x θJA
ΔT ≈ 0.6W x 36°C/W = 21.6°C ≈ 22°C
The junction temperature (TJ) of the device is approximately the ambient temperature (TA) plus the change in
temperature. We assume the initial ambient temperature to be 25°C.
TJ = TA + ΔT
TJ ≈ 25°C + 22°C ≈ 47°C
The maximum operating junction temperature (TJMAX) of the device is 125°C, so the device can operate at a
higher ambient temperature. The maximum ambient temperature (TAMAX) allowed can be calculated.
TAMAX = TJMAX PD x θJA
≈ 125°C – 22°C ≈ 103°C
The ambient temperature can actually rise by another 78°C, bringing it to 103°C before the device will reach
TJMAX. This indicates that the EN5329QI can support the full 2A output current range up to approximately
103°C ambient temperature given the input and output voltage conditions. Note that the efficiency will be
slightly lower at higher temperatures and these calculations are estimates.
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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ENGINEERING SCHEMATIC
Figure 8. Engineering Schematic with Critical Components
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LAYOUT RECOMMENDATIONS
This layout only shows the critical components and top layer traces for minimum footprint with ENABLE as a
separate signal. Alternate ENABLE configurations & the POK pin need to be connected and routed according
to customer application. Please see the Gerber files on EN5329QIs product page at www.altera.com/powersoc
for details on all layers.
Figure 9: Optimized Layout Rommendations
Recommendation 1: Input and output filter capacitors should be placed on the same side of the PCB, and as
close to the EN5329QI package as possible. They should be connected to the device with very short and wide
traces. Do not use thermal reliefs or spokes when connecting the capacitor pads to the respective nodes. The
Voltage and GND traces between the capacitors and the EN5329QI should be as close to each other as possible
so that the gap between the two nodes is minimized, even under the capacitors.
Recommendation 2: The system ground plane 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.
Recommendation 3: The 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 0.33mm, and the vias must
have at least 1 oz. copper plating on the inside wall, making the finished hole size around 0.20-0.26mm. Do
not use thermal reliefs or spokes to connect the vias to the ground plane. This connection provides the path
for heat dissipation from the converter.
Recommendation 4: Multiple small vias (the same size as the thermal vias discussed in recommendation 3)
should be used to connect ground terminal of the input capacitor and output capacitors to the system ground
plane. It is preferred to put these vias along the edge of the GND copper closest to the +V copper. These vias
connect the input/output filter capacitors to the GND plane, and help reduce parasitic inductances in the input
and output current loops.
Recommendation 5: AVIN is the power supply for the small-signal control circuits. It should be connected to
the input voltage at a quiet point. In Figure 9 this connection is made at the input capacitor. Place a 1µF
capacitor from the AVIN pin to AGND right next to device pins.
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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Recommendation 6: The layer 1 metal under the device must not be more than shown in Figure 8. See the
section regarding exposed metal on bottom of package. As with any switch-mode DC/DC converter, try not to
run sensitive signal or control lines underneath the converter package on other layers.
Recommendation 7: The VOUT sense point should be just after the last output filter capacitor. Keep the sense
trace short in order to avoid noise coupling into the node.
Recommendation 8: Keep RA, CA, RB close to the VFB pin (See Figures 6). The VFB pin is a high-impedance,
sensitive node. Keep the trace to this pin as short as possible. Whenever possible, connect RB directly to the
AGND pin instead of going through the GND plane.
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Datasheet | Intel® Enpirion® Power Solutions: EN5329QI
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DESIGN CONSIDERATIONS FOR LEAD-FRAME BASED MODULES
Exposed Metal on Bottom of Package
QFN lead-frame based package technology utilizes exposed metal pads on the bottom of the package that
provide improved thermal dissipation, lower package thermal resistance, smaller package footprint and
thickness, larger lead size and pitch, and excellent lead co-planarity. As the EN5329QI
package is a fully integrated module consisting of multiple internal devices, the lead-frame provides circuit
interconnection and mechanical support of these devices resulting in multiple exposed metal pads on the
package bottom.
Only the two large thermal pads and the perimeter leads are to be mechanically/electrically connected to the
PCB through a SMT soldering process. All other exposed metal is to remain free of any interconnection to the
PCB. Figure 9 shows the recommended PCB metal layout for the EN5329QI package. A GND pad with a solder
mask "bridge" to separate into two pads and 24 signal pads are to be used to match the metal on the package.
The PCB should be clear of any other metal, including traces, vias, etc., under the package to avoid electrical
shorting.
The Solder Stencil Aperture should be smaller than the PCB ground pad. This will prevent excess solder from
causing bridging between adjacent pins or other exposed metal under the package. Please consult EN5329QI
Soldering Guidelines for more details and recommendations.
Figure 10: Lead-Frame exposed metal (Top View)
Note: Grey area highlights exposed metal that is not to be mechanically or electrically connected to the PCB.
08326 September 24, 2018 Rev F