ENPIRION
EN5312Q
Fully Integrated Voltage Mode Synchronous
Buck PWM DC-DC Converter Module
Rev 0.87 January , 2006
RoHS Compliant
Preliminary
Voltage
Select
DAC
Switch
VREF
(+)
(-)
Error
Amp
V
SENSE
V
FB
V
OUT
VS0 VS1 VS2
Package Boundry
P-Drive
N-Drive
UVLO
Thermal Limit
Current Limit
Soft Start
Sawtooth
Generator
(+)
(-)
PWM
Comp
V
IN
ENABLE
Product Highlights
Revolutionary integrated inductor
Total footprint as small as 28mm
2
Only two low cost MLCC caps required.
Very low solution profile at 1.1mm.
4mm x 5mm x1.1mm QFN package
Wide 2.4V to 5.5V input range.
1000mA output current.
Less than 1
A standby current.
High efficiency, up to 95%.
Very low ripple voltage; < 10mV
3 Pin VID Voltage select scheme.
External divider option.
5 MHz switching frequency
2% accuracy over line, load, & temp.
Short circuit, UVLO, and thermal protection.
Stable with up to 100uF output
capacitance.
Product Overview
The Ultra-Low-Profile EN5312Q is targeted to
applications where board area and profile are
critical. EN5312Q is a complete power
conversion solution requiring only two low cost
ceramic MLCC caps. Inductor, MOSFETS,
PWM, and compensation are integrated into a
tiny 4mm x 5mm x 1.1mm QFN package.
Engineered to minimize all sources of converter
noise, the EN5312Q eases design and layout
constraints. 5 MHz switching frequency and
internal type III compensation provides superior
transient response. With a 1.1 mm profile, the
entire layout can occupy as little as 28mm
2
of
board area.
A 3-pin VID output voltage select scheme
provides seven pre-programmed output voltages
along with an option for external resistor divider.
Output voltage can be programmed on-the-fly to
provide fast, dynamic voltage scaling.
Typical Application Circuit
V
IN
V
Sense
V
in
V
S1
V
S2
V
S0
E
N
53
12
Q
10
F
4.7
F
V
OUT
V
out
GND
ENABLE
V
FB
Voltage
Select
PFM
Figure 1. Typical application circuit.
Applications
Area constrained applications
Set top box/home gateway
Smart phones and PDAs.
VoIP and Video phones
Personal Media Players.
Advanced Mobile Processors, DSP, IO,
Memory, Video, Multimedia Engines.
Rev. 0.87 January 2006
EN5312Q
2
Absolute Maximum Ratings
Maximum Electrical Ratings
Min
Max
Voltages on: V
IN
, V
OUT
-0.3V 7.0V
Voltages on: V
SENSE
-0.3V V
IN
+ 0.3V
Voltages on: V
S0
-V
S2
-0.3V V
IN
+ 0.3V
Voltages on: ENABLE
-0.3V
V
IN
+ 0.3V
Voltages on: V
FB
-0.3V 1.5V
Maximum Thermal Ratings
Ambient operating range (Industrial Rated)
-40C
+85C
Max Junction Temperature
+125C
Storage Temperature Range
-65C
+125C
Solder Temperature Range MSL3 (10 Sec)
+260C
Reflow Peak Body Temperature
+260C
Electrical Characteristics
NOTE: V
IN
= 3.6V and T
A
= -40C to +85C unless otherwise noted. Typical values are at T
A
= 25C.
C
IN
= 4.7uF, C
OUT
=10uF
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Operating Input Voltage
V
IN
2.4 5.5 V
Output Voltage
V
o
VS2 VS1 VS0
0
0
0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
V
out
3.3
2.5
1.8
1.5
1.25
1.2
0.8
User Sel
V
Maximum Output Current
V
IN
= 5V, 0.6V <V
OUT
< 3.3V
Output Current
I
OUT
1000
mA
Shut-Down Current
I
SD
Enable = Low
<1
A
PFET Current Limit
I
LIM
1.4
A
Feedback Pin Voltage
V
FB
0.6
V
Feedback Pin Input
Current
I
FB
nA
VS0-VS1, Enable
Voltage Threshold
V
TH
Pin = Low
Pin = High
0.0
1.4
0.4
V
IN
VS0-VS2 Pin Input
Current
I
VSX
nA
Operating Frequency
F
OSC
5
MHz
PFET On Resistance
R
DS(ON)
300 m
NFET On Resistance
R
DS(ON)
300 m
Ripple Voltage
V
Ripple
COUT=4.7uF 1206 MLCC
10
mV
Operating Junction
Temperature
T
J
125
C
Thermal Shutdown
T
SD
150 C
Thermal Shutdown
T
SDH
15 C
Rev. 0.87 January 2006
www.enpirion.com
Rev. 0.87 January 2006
EN5312Q
3
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
Hysteresis
Voltage Accuracy
All parts over line, load and
Temp
2
%
Voltage Regulation
Any given part, Over load, line,
temp
1
%
Soft-Start Operation
Time to 90% V
out
T
ss
Vout = 3.3V
1.6
mSec
Pin Description
V
OUT
NC
NC
NC
V
OUT
V
FB
V
SENSE
NC
NC
NC
NC
V
OUT
GND
GND
V
IN
EN
AB
L
E
VS0
VS1
VS2
1
2
6
5
4
3
10
9
8
7
11
12
13
14
15
16
20
19
18
17
V
IN
EN5312Q
V
OUT
NC
NC
NC
V
OU
T
V
FB
V
SENSE
NC
NC
NC
NC
V
OUT
GND
GND
V
IN
ENA
B
L
E
VS
0
VS
1
VS2
1
2
5
4
3
10
9
8
7
11
12
13
14
15
16
20
19
18
17
V
IN
EN5312Q
AGND
6
Figure 3. Pin description, bottom view.
Figure 2. Pin description, top view.
V
IN
(Pin 1,2): Input voltage pin. Supplies power to
the IC. VIN can range from 2.4V to 5.5V.
GND: (Pin 3,4): Power ground. This pin is
internally connected to bottom thermal/ground pad
(AGND). Input and output filter capacitors should
be connected to this pin. Good EMI design practice
dictates that these pins not be connected to other
ground connections. The large thermal pad on the
bottom of the package should be the single point of
contact to system ground. (refer to section on EMI
layout consideration for more detail).
V
OUT
(Pin 5,6,7): Regulated output voltage.
NC (Pin 8,9,10,11,12,13,14): 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.
V
SENSE
(Pin 15): Sense pin for preset output
voltages. When using preset voltages connect this
to V
LOAD
or as close to V
LOAD
as possible to ensure
the best regulation. When using external divider,
connect this pin to V
OUT.
V
FB
(Pin 16): Feed back pin for external divider
option. When using the external divider option
(VS0=VS1=VS2= high) connect this pin to the
center of the external divider. Set the divider such
that V
FB
= 0.6V.
VS0,VS1,VS2 (Pin 17,18,19): Output voltage
select. VS0=pin19, VS1=pin18, VS2=pin17.
Selects one of seven preset output voltages or
choose external divider by connecting pins to logic
high or low. Logic low is defined as V
LOW
0.4V.
Logic high is defined as V
HIGH
1.4V. Any level
between these two values is indeterminate. (refer to
section on output voltage select for more detail).
ENABLE (Pin 20): Output enable. Enable = logic
high, disable = logic low. Logic low is defined as
V
LOW
0.4V. Logic high is defined as V
HIGH
Rev. 0.87 January 2006
www.enpirion.com
Rev. 0.87 January 2006
EN5312Q
1.4V. Any level between these two values is
indeterminate.
AGND (Bottom thermal/ground pad): System
ground for single point grounding. Also functions
as thermal pad to remove heat from package.
Connect to surface or PWB internal ground plane.
Functional Block Diagram
Voltage
Select
DAC
Switch
VREF
(+)
(-)
Error
Amp
V
SENSE
V
FB
V
OUT
VS0 VS1 VS2
Package Boundry
P-Drive
N-Drive
UVLO
Thermal Limit
Current Limit
Ramp Control
Soft Start
Sawtooth
Generator
(+)
(-)
PWM
Comp
V
IN
ENABLE
Figure 4. Functional block diagram.
Rev. 0.87 January 2006
www.enpirion.com
4
Rev. 0.87 January 2006
EN5312Q
Typical Performance Characteristics
Vin = 3.6V
60
70
80
90
100
100
200
300
400
500
600
700
800
900
1000
Load Current (mA)
E
f
f
i
ci
e
n
c
y (
%
)
3.3V
2.5V
1.8V
1.2V
Figure 5. Efficiency -vs- Load, Vin = 3.6V.
Detailed Description
Functional Overview
The EN5312Q is a complete DCDC converter
solution requiring only two low cost MLCC
capacitors. MOSFET switches, PWM controller,
Gate-drive, compensation, and inductor are
integrated into the tiny 4mm x 5mm x 1.1mm
package to provide the smallest footprint possible
while maintaining high efficiency, low quiescent
current, and high performance. The converter uses
voltage mode control to provide the simplest
implementation while also providing excellent
transient response. The device operates at a 5 MHz
switching frequency to make possible the very
small components required to enable this
unprecedented level of integration.
Enpirion's proprietary power MOSFET technology
provides very low switching loss at frequencies of 5
MHz and higher, allowing for the use of very small
internal components, and very wide control loop
bandwidth. Unique magnetics allow for high value
inductor integrated into a low profile 1.1mm
package. Integration of the inductor substantially
reduces switching noise and design/layout issues
normally associated with switch-mode DCDC
converters. All of this enables much easier and
faster integration into various applications to meet
demanding EMI requirements.
Output voltage is chosen from seven preset values
via a three pin VID voltage select scheme. An
external divider option enables the selection of any
voltage in the 3.3V to 0.6V range. This reduces the
number of components that must be qualified and
reduces inventory problems. The VID pins can be
toggled on the fly to implement glitch free dynamic
voltage scaling.
Protection features include under-voltage lock-out
(UVLO), over-current protection (OCP), short
circuit protection, and thermal overload protection.
Integrated Inductor for Low Noise
Design
Enpirion has introduced the world's first product
family featuring integrated inductors. The
EN5312Q family utilizes a low loss, planar
construction inductor. The use of an internal
inductor reduces noise associated with pulsed
switching currents that would otherwise be present
on the user circuit board. Integration minimizes the
path impedance between the MOSFET switches and
the inductor electrode, thereby reducing one of the
Rev. 0.87 January 2006
www.enpirion.com
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