Page 1
EN6310QI 1A PowerSoC
Step-Down DC-DC Switching Converter with Integrated Inductor
DESCRIPTION
The EN6310QI is an Intel® Enpirion® Power System on
a Chip (PowerSoC) DC-DC converter. It integrates the
inductor, MOSFET switches, small-signal circuits and
compensation in an advanced 4mm x 5mm x 1.85mm
30-pin QFN package.
The EN6310QI is specifically designed to meet the
precise voltage and fast transient requirements of
present and future high-performance, low-power
processor, DSP, FPGA, memory boards and system
level applications in distributed power architectures.
The device’s advanced circuit techniques, high
switching frequency, and proprietary integrated
inductor technology deliver high-quality, ultra
compact, non-isolated DC-DC conversion.
Intel Enpirion Power Solutions significantly help in
system design and productivity by offering greatly
simplified board design, layout and manufacturing
requirements. In addition, a reduction in the number
of components required for the complete power
solution helps to enable an overall system cost
saving.
All Enpirion products are RoHS compliant and lead-
free manufacturing environment compatible.
FEATURES
Integrated inductor, MOSFET and Controller
Small 4mm x 5mm x 1.85mm QFN
High Efficiency up to 96%
Solution Footprint Less than 65mm
2
1A Continuous Output Current
VIN Range of 2.7V to 5.5V
VOUT Range from 0.6V to 3.3V
Programmable Soft Start and Power OK Flag
Fast Transient Response and Recovery Time
Low Noise and Low Output Ripple; 4mV Typical
2.2MHz Switching Frequency
Under Voltage Lock-out (UVLO), Short Circuit, Over
Current and Thermal Protection
APPLICATIONS
Altera FPGAs (MAX, ARRIA, CYCLONE, STRATIX)
Low Power FPGA Applications
All SERDES and IO Supplies Requiring Low Noise
Applications Requiring High Efficiency
Enterprise Grade Solid State Drive (SSD)
Noise Sensitive Wireless and RF Application
Figure 1: Simplified Applications Circuit
Figure 2: Efficiency at V
IN
= 5V
V
OUT
V
IN
VOUT
ENABLE
AGND
PVIN
PGND PGND
C
SS
10nF
VFB
R
A
R
B
R
CA
C
A
C
OUT
47
µF
0805
AVIN
EN6310QI
SS
R
AVIN
20
Ω
C
AVIN
0.47F
OFF
ON
C
IN1
100pF
C
IN2
4.7F
60
65
70
75
80
85
90
95
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency vs. Output Current
VOUT = 2.5V
VOUT = 1.0V
CONDITIONS
V
IN
= 3.3V
DataSheeT – enpirion® power solutions
09644 May 15, 2018 Rev G
Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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ORDERING INFORMATION
Part Number Package Markings T
J
Rating Package Description
EN6310QI N6310QI -40°C to +125°C 30-pin (4mm x 5mm x 1.85mm) QFN
EVB-EN6310QI N6310QI QFN Evaluation Board
Packing and Marking Information: https://www.altera.com/support/quality-and-reliability/packing.html
PIN FUNCTIONS
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: White ‘dot’ on top left is pin 1 indicator on top of the device package.
NOTE C: Keep-Out are No Connect pads that should not to be electrically connected to each other or to any external
signal, ground or voltage. They do not need to be soldered to the PCB.
Keep out
1415
1
2
3
4
5
6
87
21
20
19
18
17
16
NC(SW) PGND
POK
PGND
PGND
PVIN
VFB
AGND
CSS
ENABLE
AVIN
VOUT
VOUT
NC(SW)
NC(SW)
NC(SW)
VOUT
1312
11109
2228 27262524 2330 29
VOUT
VOUT
VOUT
VOUT
VOUT
NC
PGND
PVIN
NC(SW)
NC(SW)
NC(SW)
NC(SW)
NC(SW)
31
PGND
Bottom Pad
Keep out
Keep out
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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PIN DESCRIPTIONS
PIN NAME TYPE FUNCTION
1, 2,
24-30 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.
3, 4, 20,
21 PGND Ground
Input/Output power ground. Connect to the ground electrode of the input
and output filter capacitors. See VOUT and PVIN pin descriptions for more
details.
5-12 VOUT Power
Regulated converter output. Connect to the load and place output filter
capacitor(s) between these pins and PGND pins. Refer to the Layout
Recommendation section.
13 VFB Analog
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 (C
A
) and resistor (R
C
) are required in parallel to the upper
feedback resistor (R
A
). The output voltage regulation is based on the VFB
node voltage being equal to 0.6V.
14 AGND Power Ground for internal control circuits. Connect to the power ground plane
with a via right next to the pin.
15 NC -
No Connect. These pins must be soldered to PCB but not electrically
connected to each other or to any external signal, voltage, or ground.
These pins may be connected internally. Failure to follow this guideline
may result in device damage.
16 SS Analog
A soft-start capacitor is connected between this pin and AGND. The value
of the capacitor controls the soft-start interval. Refer to Soft-Start
Operation in the Functional Description section for more details.
17 POK Digital
Power OK is an open drain transistor (pulled up to AVIN or similar voltage)
used for power system state indication. POK is logic high when VOUT is
above 90% of VOUT nominal. Leave this pin floating if not used.
18 ENABLE Analog Input Enable. Applying logic high will enable the device and initiate a soft-
start. Applying logic low disables the output and switching stops.
19 AVIN Power Input power supply for the controller. Connect to input voltage at a quiet
point. Refer to the Layout Recommendation section.
22, 23 PVIN Power Input power supply. Connect to input power supply. Decouple with input
capacitor to PGND pin. Refer to the Layout Recommendation section.
31 PGND Ground
Power ground thermal pad. Not a perimeter pin. Connect thermal pad to
the system GND plane for heat-sinking purposes. Refer to the Layout
Recommendation section.
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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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 6.6 V
ENABLE, POK -0.3 V
IN
+0.3 V
VFB, SS -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
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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RECOMMENDED OPERATING CONDITIONS
PARAMETER SYMBOL MIN MAX UNITS
Input Voltage Range V
IN
2.7 5.5 V
Output Voltage Range V
OUT
0.6 3.3 V
Output Current Range I
OUT
1 A
Operating Ambient Temperature Range T
A
-40 +85 °C
Operating Junction Temperature T
J
-40 +125 °C
THERMAL CHARACTERISTICS
PARAMETER SYMBOL TYPICAL UNITS
Thermal Shutdown T
SD
140 °C
Thermal Shutdown Hysteresis T
SDHYS
20 °C
Thermal Resistance: Junction to Ambient (0 LFM)
(1)
JA
60 °C/W
Thermal Resistance: Junction to Case (0 LFM)
JC
3 °C/W
(1) Based on 2oz. external copper layers and proper thermal design in line with EIJ/JEDEC JESD51-7 standard for high
thermal conductivity boards.
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ELECTRICAL CHARACTERISTICS
NOTE: V
IN
= PVIN = AVIN = 5V, Minimum and Maximum values are over operating ambient temperature range
unless otherwise noted. Typical values are at T
A
= 25°C.
PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNITS
Operating Input Voltage V
IN
PVIN = AVIN 2.7 5.5 V
Under Voltage Lock-Out
– V
IN
Rising V
UVLOR
Voltage above which UVLO is
not asserted 2.3 V
Under Voltage Lock-Out
– V
IN
Falling V
UVLOF
Voltage below which UVLO is
asserted 1.9 V
Output Voltage Range V
OUT
0.6 3.3 V
Maximum Duty Cycle D
MAX
85 %
Feedback Pin Voltage
Intial Accuracy
(2)
V
FB
T
A
= 25°C, V
IN
= 5.0V,
I
LOAD
= 100mA
0.591 0.6 0.609 V
Output Voltage DC
Accuracy
VIN = 3.3V; 0A ≤ I
OUT
≤ 1.0A;
-40°C ≤ T
A
≤ +85°C
-2.0 +2.25 %
VIN = 5.0V; 0A ≤ I
OUT
≤ 1.0A;
-20°C ≤ T
A
≤ +85°C
-2.0 +2.0 %
VIN = 5.0V; 0A ≤ I
OUT
≤ 1.0A;
-40°C ≤ T
A
≤ +85°C
-3.0 +2.0 %
Feedback pin Input
Leakage Current
(3)
I
FB
VFB pin input leakage
current 100 nA
Continuous Output
Current I
OUT
1 A
Over Current Trip Level I
OCP
1.2 1.8 A
OCP Threshold I
OCP
2.7 VIN 5.5V 1.2 A
AVIN Shut-Down Current I
SD
ENABLE = Low 175 A
PVIN Shut-Down Current I
SD
ENABLE = Low 175 A
ENABLE Pin Logic
Threshold
EN
LOW
Pin = Low 0.0 0.4 V
EN
HIGH
Pin = High 1.8 VIN V
ENABLE Pin Input
Current I
ENABLE
ENABLE = High 5 A
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNITS
ENABLE Lock-out ENLO
Time before enable will re-
assert internally after being
pulled low
12.5 ms
Switching Frequency f
SW
2.2 MHz
Soft Start Time
(2) (3)
T
SS
CSS = 10nF (Note 2 and 3) 5.2 6.5 7.8 ms
Allowable Soft Start
Capacitor Range
(3)
C
SS
(Note 3) 0.47 10 nF
(2) Parameter not production tested but is guaranteed by design.
(3) Soft Start Time range does not include capacitor tolerances.
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TYPICAL PERFORMANCE CURVES
50
55
60
65
70
75
80
85
90
95
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency vs. Output Current
VOUT = 3.3V
VOUT = 2.5V
VOUT = 1.8V
VOUT = 1.5V
VOUT = 1.2V
VOUT = 1.0V
CONDITIONS
V
IN
= 5.0V
50
55
60
65
70
75
80
85
90
95
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency vs. Output Current
VOUT = 2.5V
VOUT = 1.8V
VOUT = 1.5V
VOUT = 1.2V
VOUT = 1.0V
CONDITIONS
V
IN
= 3.3V
0.970
0.980
0.990
1.000
1.010
1.020
1.030
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VIN = 3.3V
VIN = 5V
CONDITIONS
V
OUT
= 1.0V
1.170
1.180
1.190
1.200
1.210
1.220
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VIN = 3.3V
VIN = 5.0V
CONDITIONS
V
OUT
= 1.2V
1.470
1.480
1.490
1.500
1.510
1.520
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VIN = 3.3V
VIN = 5.0V
CONDITIONS
V
OUT
= 1.5V
1.750
1.760
1.770
1.780
1.790
1.800
1.810
1.820
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VIN = 3.3V
VIN = 5.0V
CONDITIONS
V
OUT
= 1.8V
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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TYPICAL PERFORMANCE CURVES (CONTINUED)
2.470
2.480
2.490
2.500
2.510
2.520
2.530
2.540
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VIN = 3.3V
VIN = 5.0V
CONDITIONS
V
OUT
= 2.5V
3.270
3.280
3.290
3.300
3.310
3.320
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
1
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (A)
Output Voltage vs. Output Current
VIN = 5.0V
CONDITIONS
V
OUT
= 3.3V
0.980
0.985
0.990
0.995
1.000
1.005
1.010
1.015
1.020
-40 -15 10 35 60 85
OUTPUT VOLTAGE (V)
AMBIENT TEMPERATURE (°C)
Output Voltage vs. Temperature
LOAD = 0.05A
LOAD = 0.2A
LOAD = 0.4A
LOAD = 0.8A
LOAD = 1A
CONDITIONS
V
IN
= 3.3V
V
OUT_NOM
= 1.0V
0.980
0.985
0.990
0.995
1.000
1.005
1.010
1.015
1.020
-40 -15 10 35 60 85
OUTPUT VOLTAGE (V)
AMBIENT TEMPERATURE (°C)
Output Voltage vs. Temperature
LOAD = 0.05A
LOAD = 0.2A
LOAD = 0.4A
LOAD = 0.8A
LOAD = 1A
CONDITIONS
V
IN
= 5.0V
V
OUT_NOM
= 1.0V
2.400
2.420
2.440
2.460
2.480
2.500
2.520
2.540
2.560
-40 -15 10 35 60
85
OUTPUT VOLTAGE (V)
AMBIENT TEMPERATURE (°C)
Output Voltage vs. Temperature
LOAD = 0.05A
LOAD = 0.2A
LOAD = 0.4A
LOAD = 0.8A
LOAD = 1A
CONDITIONS
V
IN
= 3.3V
V
OUT_NOM
= 2.5V
3.220
3.240
3.260
3.280
3.300
3.320
3.340
3.360
-40 -15 10 35 60 85
OUTPUT VOLTAGE (V)
AMBIENT TEMPERATURE (°C)
Output Voltage vs. Temperature
LOAD = 0.05A
LOAD = 0.2A
LOAD = 0.4A
LOAD = 0.8A
LOAD = 1A
CONDITIONS
V
IN
= 5.0V
V
OUT_NOM
= 3.3V
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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TYPICAL PERFORMANCE CURVES (CONTINUED)
1.770
1.775
1.780
1.785
1.790
1.795
1.800
1.805
1.810
1.815
1.820
2.5 3 3.5 4 4.5 5 5.5
OUTPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Output Voltage vs. Input Voltage
LOAD = 0A
LOAD = 0.05A
LOAD = 0.25A
LOAD = 0.5A
LOAD = 1A
CONDITIONS
V
OUT_NOM
= 1.8V
T
A
= 25°C
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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TYPICAL PERFORMANCE CHARACTERISTICS
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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TYPICAL PERFORMANCE CHARACTERISTICS (CONTINUED)
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
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FUNCTIONAL BLOCK DIAGRAM
(+)
(-)
Error
Amp
VFB
VOUT
P-Drive
N-Drive
UVLO
Thermal Limit
Current Limit
Soft Start
PLL/
Sawtooth
Generator
(+)
(-)
PWM
Comp
ENABLE
PGND
Logic
Compensation
Network
NC(SW)
AVIN
AGND
Internal
Regulator
Internal
Reference
CSS
Power
OK
POK
PVIN
Figure 4: Functional Block Diagram
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FUNCTIONAL DESCRIPTION
Synchronous DC-DC Step-Down PowerSoC
The EN6310QI is a synchronous buck converter with integrated MOSFET switches and Inductor. The device
can deliver up to 1A of continuous load current. The EN6310QI has a programmable soft start rise time and a
power OK (POK) signal. The device operates in a fixed 2.2MHz PWM mode to eliminate noise associated with
pulse frequency modulation schemes. The control topology is a low complexity type IV voltage mode
providing high noise immunity and stability over the entire operating range. Output voltage is set with a simple
resistor divider. The high switching frequency enables the use of small MLCC input and output filter capacitors.
Figure 4 shows the EN6310QI block diagram.
Operational Features:
The EN6310QI has the following protection features.
Over-current protection (to protect the IC from excessive load current)
Short-Circuit protection
Thermal shutdown with hysteresis
Under-voltage lockout circuit to disable the converter output when the input voltage is below a pre-
defined level
Protection Features:
Soft-start circuit, limiting the in-rush current when the converter is initially powered up. The soft start time
is programmable with appropriate choice of soft start capacitor value.
High Efficiency Technology
The key enabler of this revolutionary integration is Enpirion’s proprietary power MOSFET technology. The
advanced MOSFET switches are implemented in deep-submicron CMOS to supply very low switching loss at
high switching frequencies and to allow a high level of integration. The semiconductor process allows seamless
integration of all switching, control, and compensation circuitry.
The proprietary magnetics design provides high-density/high-value magnetics in a very small footprint.
Enpirion magnetics are carefully matched to the control and compensation circuitry yielding an optimal
solution with assured performance over the entire operating range.
Integration for Low-Noise Low-EMI
The EN6310QI utilizes a proprietary low loss integrated inductor. The integration of the inductor greatly
simplifies the power supply design process. The inherent shielding and compact construction of the integrated
inductor reduces the conducted and radiated noise that can couple into the traces of the printed circuit board.
Furthermore, the package layout is optimized to reduce the electrical path length for the high di/dt input AC
ripple currents that are a major source of radiated emissions from DC-DC converters. Careful package and IC
design minimize common mode noise that can be difficult to mitigate otherwise. The integrated inductor
provides the optimal solution to the complexity, output ripple, and noise that plague low power DCDC
converter design.
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Control Topology
The EN6310QI utilizes an internal type IV voltage mode compensation scheme. Voltage mode control provides
a high degree of noise immunity at light load currents so that low ripple and high accuracy are maintained over
the entire load range. The high switching frequency allows for a very wide control loop bandwidth and hence
excellent transient performance. The EN6310QI is optimized for fast transient recovery for applications with
demanding transient performance. Voltage mode control enables a high degree of stability over the entire
operating range.
Enable
The EN6310QI ENABLE pin enables and disables operation of the device. A logic low will disable the converter
and cause it to shut down. A logic high will enable the converter and initiate a normal soft start operation.
When ENABLE is pulled low, the Power MOSFETs stop switching and the output is discharged in a controlled
manner with a soft pull down MOSFET. Once the enable pin is pulled low, there is a lockout period before the
device can be re-enabled. The lock out period can be found in the Electrical Characteristics Table. Do not leave
ENABLE pin floating or it will be in an unknown random state.
The EN6310QI supports startup into a pre-biased output of up to 1.5V. The output of the EN6310QI can be
pre-biased with a voltage up to 1.5V when it is first enabled.
POK Operation
The POK signal is an open drain signal (requires a pull up resistor to AVIN or similar voltage) from the converter
indicating the output voltage is within the specified range. Typically, a 100kΩ or lower resistance is used as the
pull-up resistor. The POK signal will be logic high (AVIN) when the output voltage is above 90% of the
programmed voltage level.
If the output voltage is below this point, the POK signal will be a logic low. The POK
will also be a logic low if the input voltage is in UVLO or if the ENABLE is pulled low. The POK signal can be
used to sequence down-stream converters by tying to their enable pins.
Programmable Soft Start Operation
Soft start is externally programmable by adjusting the value of the C
SS
capacitor, which is placed between the
respective C
SS
pin and AGND pin. When the enable pin is pulled high, the output will ramp up monotonically
at a rate determined by the CSS capacitor.
Soft start ramp time is programmable over a range of 0.5ms to 10ms. The longer ramp times allow startup
into very large bulk capacitors that may be present in applications such as wireless broadband or solid state
storage, without triggering an Over Current condition. The rise time is given as:
T
RISE
[ms] = C
SS
[nF] x 0.65 ± 25%
NOTE: Rise time does not include capacitor tolerances.
If a 10nF soft-start capacitor is used, then the output voltage rise time will be around 6.5ms. The rise time is
measured from when V
IN
≥ V
UVLOR
and ENABLE pin voltage crosses its logic high threshold to when V
OUT
reaches
its programmed value.
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Over Current/Short Circuit Protection
The current limit and short-circuit protection is achieved by sensing the current flowing through a sense PFET.
When the sensed current exceeds the current limit, both NFET and PFET switches are turned off and the output
is discharged. After 1.6ms the device will be re-enabled and will then go through a normal soft-start cycle. If
the over current condition persists, the device will enter a hiccup mode.
Under Voltage Lockout
During initial power up an under voltage lockout circuit will hold-off the switching circuitry until the input
voltage reaches a sufficient level to insure proper operation. If the voltage drops below the UVLO threshold,
the lockout circuitry will again disable the switching. Hysteresis is included to prevent chattering between
states.
Thermal Shutdown
When excess power is dissipated in the EN6310QI the junction temperature will rise. Once the junction
temperature exceeds the thermal shutdown temperature the thermal shutdown circuit turns off the converter
output voltage thus allowing the device to cool. When the junction temperature decreases to a safe operating
level, the part will go through the normal startup process. The thermal shutdown temperature and hysteresis
values can be found in The electrical characteristics table.
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APPLICATION INFORMATION
Output Voltage Setting
The EN6310QI output voltage is programmed using a simple resistor divider network (R
A
and R
B
). The feedback
voltage at VFB is nominally 0.6V. R
A
is fixed at 200kΩ and R
B
can be calculated based on Figure 5. The values
recommended for C
OUT
, C
A
, and R
CA
make up the external compensation of the EN6310QI. It will vary with each
VIN and VOUT combination to optimize on performance. Please see Table 1 for a list of recommended R
A
, C
A
,
R
CA
, and C
OUT
values for each solution. Since VFB is a sensitive node, do not touch the VFB node while the
device is in operation as doing so may introduce parasitic capacitance into the control loop that causes the
device to behave abnormally and damage may occur.
VOUT
VOUT
PGND
VFB
RA
RB
RCA
CA
COUT
RA
VFB
VFB
VOUT
x
-
=
VFB = 0.6V
EN6310QI
Figure 5: V
OUT
Resistor Divider & Compensation Capacitor
The output voltage is set by the following formula:
 =  ∗ 1 +
Rearranging to solve for R
B
:
=
∗ 
− Ω
Where:
R
A
= 200k, VREF = 0.60V
Then R
B
is given as:
= 120
−0.6 Ω
R
A
is chosen as 200k to provide constant loop gain. The output voltage can be programmed over the range
of 0.6V to 3.3V.
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 19
Table 1: Compensation values. For output voltages in between, use the values from the higher output voltage
CIN = 4.7µF/0603 + 100pF
CAVIN = 20Ω + 0.47µF
COUT = 47µF/0805 or 2x22µF/0603
R
A
= 200kΩ, R
CA
= 1kΩ, R
B
= 0.6R
A
/(V
OUT
– 0.6)
V
IN
V
OUT
C
A
V
IN
V
OUT
C
A
5.5V
3.3V 15pF
5.5V
1.2V
27pF
5.0V 5.0V
4.5V 4.5V
33pF
5.5V
2.5V 15pF
3.3V
5.0V 2.7V 39pF
4.5V 5.5V
1.0V
39pF
3.3V 5.0V
5.5V
1.8V
15pF
4.5V
5.0V 3.3V
47pF
4.5V 2.7V
3.3V
22pF
5.5V
0.6V
39pF
2.7V 5.0V
5.5V
1.5V
22pF
4.5V 47F
5.0V 3.3V
56pF
4.5V 2.7V
3.3V 27pF
2.7V 33pF
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 20
Input Filter Capacitor
The EN6310QI requires at least a 4.7µF/0603 and a 100pF input capacitor near the PVIN pins. Low-cost, low-
ESR ceramic capacitors should be used as input capacitors for this converter. The dielectric must be X5R or
X7R rated. Y5V or equivalent dielectric formulations must not be used as these lose too much capacitance
with frequency, temperature and bias voltage. In some applications, lower value capacitors are needed in
parallel with the larger capacitors in order to provide high frequency decoupling. Table 2 contains a list of
recommended input capacitors.
Table 2: Recommended Input Capacitors
DESCRIPTION MFG P/N
4.7µF, 10V, X5R, 10%, 0603 Murata GRM185R61A475KE11#
4.7µF, 10V, X5R, 10%, 0603 Taiyo Yuden LMK107BJ475KA-T
Output Capacitor Selection
The EN6310QI requires at least a 47µF/0805 or two 22µF/0603 output filter capacitors. Low ESR ceramic
capacitors are required with X5R or X7R rated dielectric formulation. Y5V or equivalent dielectric formulations
must not be used as these lose too much capacitance with frequency, temperature and bias voltage. Table 3
contains a list of recommended output capacitors.
Table 3: Recommended Output Capacitors
DESCRIPTION MFG P/N
47µF, 6.3V, X5R, 20%, 0805 Murata GRM21BR60J476ME15#
47µF, 6.3V, X5R, 20%, 0805 Taiyo Yuden JMK212BBJ476MG-T
22µF, 10V, X5R, 20%, 0603 Murata GRM188R60J226MEA0#
22µF, 10V, X5R, 20%, 0603 Taiyo Yuden JMK107BBJ226MA-T
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 21
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 by the power dissipation needs to be
accounted for. The Enpirion PowerSoC helps alleviate some of those concerns.
The Enpirion EN6310QI DC-DC converter is packaged in a 4x5x1.85mm 30-pin QFN package. The QFN
package is constructed with copper lead frames that have exposed thermal pads. The exposed thermal pad
on the package 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 140°C.
The following example and calculations illustrate the thermal performance of the EN6310QI.
Example:
V
IN
= 5V
V
OUT
= 3.3V
I
OUT
= 1A
First calculate the output power.
P
OUT
= 3.3V x 1A = 3.3W
Next, determine the input power based on the efficiency (η) shown in Figure 6.
Figure 6: Efficiency vs. Output Current
50
55
60
65
70
75
80
85
90
95
100
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
EFFICIENCY (%)
OUTPUT CURRENT (A)
Efficiency vs. Output Current
VOUT = 3.3V
CONDITIONS
V
IN
= 5.0V
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 22
For V
IN
= 5V, V
OUT
= 3.3V at 1A, η ≈ 91%
η = P
OUT
/ P
IN
= 91% = 0.91
P
IN
= P
OUT
/ η
P
IN
≈ 3.3W / 0.91 ≈ 3.63W
The power dissipation (P
D
) is the power loss in the system and can be calculated by subtracting the output
power from the input power.
P
D
= P
IN
– P
OUT
≈ 3.63W – 3.3W ≈ 0.33W
With the power dissipation known, the temperature rise in the device may be estimated based on the theta JA
value (θ
JA
). The θ
JA
parameter estimates how much the temperature will rise in the device for every watt of
power dissipation. The EN6310QI has a θ
JA
value of 60 °C/W without airflow.
Determine the change in temperature (ΔT) based on P
D
and θ
JA
.
ΔT = P
D
x θ
JA
ΔT ≈ 0.33W x 60°C/W ≈ 19.8°C ≈ 20°C
The junction temperature (T
J
) of the device is approximately the ambient temperature (T
A
) plus the change in
temperature. We assume the initial ambient temperature to be 25°C.
T
J
= T
A
+ ΔT
T
J
≈ 25°C + 20°C ≈ 45°C
The maximum operating junction temperature (T
JMAX
) of the device is 125°C, so the device can operate at a
higher ambient temperature. The maximum ambient temperature (T
AMAX
) allowed can be calculated.
T
AMAX
= T
JMAX
– P
D
x θ
JA
≈ 125°C – 20°C ≈ 105°C
The maximum ambient temperature the device can reach is 105°C given the input and output conditions. Note
that the efficiency will be slightly lower at higher temperatures and this calculation is an estimate.
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 23
APPLICATION CIRCUITS
Figure 7: Typical Engineering Schematic
VOUT
VINVOUT
ENABLE
AGND
PVIN
PGND PGND
CSS
10nF
VFB
RA
RB
RCA
CA
COUT
47µF
0805
AVIN
EN6310QI
SS
RAVIN
20Ω
CAVIN
F
OFF
ON
CIN1
100pF
CIN2
4.7 F
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 24
LAYOUT RECOMMENDATIONS
Figure 8: Drop-In Board Layout Recommendations
Recommendation 1: Input and output filter capacitors should be placed on the same side of the PCB, and as
close to the EN6310QI 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 EN6310QI 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. Please see the Gerber files on EN6310QI’s product page at www.altera.com/enpirion.
09644 May 15, 2018 Rev G
Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 25
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 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. See Figure 8.
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 under the capacitors along the edge of the GND copper closest to the
+V copper. Please see Figure 8. These vias connect the input/output filter capacitors to the GND plane, and
help reduce parasitic inductances in the input and output current loops. If the vias cannot be placed under C
IN
and C
OUT
, then put them just outside the capacitors along the GND slit separating the two components. Do not
use thermal reliefs or spokes to connect these vias to the ground plane. AVIN is the power supply for the
internal small-signal control circuits. It should be connected to the input voltage at a quiet point. A good
location is to place the AVIN connection on the source side of the input capacitor, away from the PVIN pins.
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 V
OUT
sense point should be just after the last output filter capacitor. Keep the sense
trace as short as possible in order to avoid noise coupling into the control loop.
Recommendation 8: Keep R
A
, C
A
, and R
B
close to the VFB pin (see Figures 6 and 7). The VFB pin is a high-
impedance, sensitive node. Keep the trace to this pin as short as possible. Whenever possible, connect R
B
directly to the AGND pin instead of going through the GND plane.
09644 May 15, 2018 Rev G
Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 26
RECOMMENDED PCB FOOTPRINT
Figure 9: EN6310QI PCB Footprint (Top View)
Note: Don’t use the layer underneath the device keep out area as it contains the exposed metal below the package that
is not to be mechanically or electrically connected to the PCB.
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Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
Page 27
PACKAGE AND MECHANICAL
Figure 10: EN6310QI Package Dimensions
Packing and Marking Information:
https://www.altera.com/support/quality-and-reliability/packing.html
09644 May 15, 2018 Rev G
Datasheet | Intel® Enpirion® Power Solutions: EN6310QI
WHERE TO GET MORE INFORMATION
For more information about Intel® and Enpirion® PowerSoCs, visit:
www.altera.com/enpirion
© 2017 Intel Corporation. All rights reserved. Intel, the Intel logo, Altera, ARRIA, CYCLONE, ENPIRION, MAX, MEGACORE, NIOS, QUARTUS, and STRATIX words and logos are trademarks of Intel
Corporation or its subsidiaries in the U.S. and/or other countries. Other marks and brands may be claimed as the property of others. Intel reserves the right to make changes to any products and
services at any time without notice. Intel assumes no responsibility or liability arising out of the application or use of any information, product, or service described herein except as expressly agreed to
in writing by Intel. Intel customers are advised to obtain the latest version of device specifications before relying on any published information and before placing orders for products or services.
* Other marks and brands may be claimed as the property of others.
Page 28
REVISION HISTORY
Rev Date Change(s)
A March 2014 Introductory production datasheet.
B March 2015 Pin 12 changed to VOUT instead of NC.
C June 2015 Updated the pre-bias section adding the capability of pre-biasing to voltage up
to 1.5V.
D Feb 2016
Changed Feedback Pin Voltage Initial Accuracy on Electrical Characteristics
Table.
Corrected thermal hysteresis value in thermal shutdown section.
Added section on "Design considerations for lead-frame based modules" i.e.
keepout area.
Modified PCB Footprint and package drawings.
Formatting changes.
E June 2016
Added EMI scan data.
Clarified location of Gerber files in layout recommendation section.
F Feb 2017
Updating the device package drawings with the keep-out area drawing.
Drawing the Keep-out Pins in figure 3.
G April 2018 Changed datasheet into Intel format.
09644 May 15, 2018 Rev G