EUTECH EUP3020JIR1

EUP3020
Dual High-Efficiency 1.5MHz 1A PWM
Step-Down DC-DC Converter
DESCRIPTION
FEATURES
The EUP3020 contains two independent 1.5MHz
constant frequency, current mode, PWM step-down
converters. Each converter integrates a main switch and
a synchronous rectifier for high efficiency without an
external Schottky diode. The EUP3020 is ideal for
powering portable equipment that runs from a single
cell Lithium-Ion (Li+) battery. Each converter can
supply 1A of load current from a 2.5V to 5.5V input
voltage. The output voltage can be regulated as low as
0.6V. The EUP3020 can also run at 100% duty cycle
for low dropout applications.
EUP3020 is available in an adjustable output or fixed
output 1.2V, 1.8V and 3.3V.
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Up to 96% Efficiency
1.5MHz Constant Switching Frequency
1A Load Current on Each Channel
2.5V to 5.5V Input Voltage Range
Output Voltage as Low as 0.6V
100% Duty Cycle in Dropout
Current Mode Operation
Short Circuit Protection
Thermal Fault Protection
<1µA Shutdown Current
Soft Start Function
Space Saving 3mm × 3mm 12-Pin TDFN
Package
RoHS Compliant and 100% Lead(Pb)-Free
APPLICATIONS
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Cellular and Smart Phones
Microprocessors and DSP Core Supplies
PDAs and Portable Media Players
Wireless and DSL Modems
Digital Still and Video Cameras
Typical Application Circuit
Figure 1. Adjustable Output Regulators
DS3020
Ver1.2
Feb. 2009
1
EUP3020
Typical Application Circuit (continued)
Figure 2. Fixed Output Regulators
Pin Configurations
Package
Type
Package
Type
Pin Configurations
TDFN-12
TDFN-12
ADJ Voltage
Fixed Voltage
Pin Description
PIN
Pin
VIN2
1
Power Input of Channel 2.
SW2
2
Pin for Switching of Channel 2.
GND
3,9
FB1/VOUT1
4
NC1,NC2
5,11
EN1
6
Chip Enable of Channel 1 (Active High).VEN1 ≤ VIN1.
VIN1
7
Power Input of Channel 1.
SW1
8
Pin for Switching of Channel1.
FB2/VOUT2
10
Feedback/Output Voltage Pin of Channel 2.
EN2
12
Chip Enable of Channel 2 (Active High).VEN2 ≤ VIN2.
DS3020
Ver1.2
Feb. 2009
DESCRIPTION
Ground.
Feedback/Output Voltage Pin of Channel 1.
No Connection or Connect to VIN.
2
Pin Configurations
EUP3020
Ordering Information
Order Number
Package Type
EUP3020-1.8/1.2JIR1
TDFN-12
EUP3020-3.3/1.2JIR1
TDFN-12
EUP3020-3.3/1.8JIR1
TDFN-12
EUP3020JIR1
TDFN-12
Marking
xxxxx
P3020
BK
xxxxx
P3020
BN
xxxxx
P3020
BL
xxxxx
P3020
1A
EUP3020-□□/□□ □ □ □ □
Lead Free Code
1: Lead Free 0: Lead
Packing
R: Tape & Reel
Operating temperature range
I: Industry Standard
Package Type
J: TDFN
Output Voltage Option
*EUP3020-VOUT1/VOUT2 JIR1
Blank: Adjustable
Block Diagram
Figure 3.
DS3020
Ver1.2
Feb. 2009
3
Operating Temperature Range
-40 °C to +85°C
-40 °C to +85°C
-40 °C to +85°C
-40 °C to +85°C
EUP3020
Absolute Maximum Ratings (1)
„
„
„
„
„
„
VIN1/IN2 to GND ---------------------------------------------------------------------- -0.3V to 6V
VSW1/SW2 to GND ------------------------------------------------------------ -0.3V to VIN+0.3V
VFB1/FB2 ,VEN1/EN2 to GND -------------------------------------------------------- -0.3V to VIN
Junction Temperature --------------------------------------------------------------------- 125°C
Storage Temperature --------------------------------------------------------- -65°C to +150°C
Lead Temp (Soldering, 10sec) ------------------------------------------------------260°C
Recommended Operating Conditions (2)
„
„
„
Supply Voltage, VIN1/IN2 ---------------------------------------------------------- 2.5V to 5.5V
Output Voltage, VOUT1/OUT2 -----------------------------------------------------0.6V to 5V
Operating Temperature -------------------------------------------------------- -40°C to +85°C
Note (1): Stress beyond those listed under “Absolute Maximum Ratings” may damage the device.
Note (2): The device is not guaranteed to function outside the recommended operating conditions.
Electrical Characteristics
VIN1/IN2 =VEN1/EN2 =3.6V, TA=+25°C, Unless otherwise specified.
Symbol
Parameter
VIN
Input Voltage Range
IFB
Feedback Current
IQ
Each converter Supply Current
ISHDN
Conditions
Min
EUP3020
Typ
Max.
2.5
5.5
VFB1/FB2=0.5V, SW1/SW2 Open
IPK
Peak Inductor Current
VIN1/IN2=3V,VFB1/FB2=0.5V
VFB
Regulator Feedback Voltage
(Note 3)
VOUT
Regulation Output Voltage
IOUT=200mA
Output Voltage Line Regulation
Reference Voltage Line
Regulation
Output Voltage Load Regulation
VIN=2.5V to 5.5V, ILOAD=0
∆VFB
∆VLOADREG
V
±30
270
Each converter Shutdown Current VEN1/EN2=0V, VIN1/IN2=4.2V
∆VOUT
Unit
nA
370
µA
1
µA
1.2
1.5
TA=+25℃
0.588
0.6
0.612
-40℃≤ TA≤ +85℃
0.585
0.6
0.615
-3
A
V
3
%
0.25
0.4
%/V
VIN=2.5V to 5.5V
0.25
0.4
%/V
ILOAD=0 to 1A
0.5
1.2
fOSC
Each converter Oscillator
Frequency
VFB1/FB2=0.6V
VFB1/FB2=0
0.7
RPFET
RDS(ON) of P-Channel FET
ISW1/SW2=200mA
0.28
0.4
Ω
RNFET
RDS(ON) of N-Channel FET
0.3
0.4
Ω
ILSW
SW Leakage Current
±1
µA
VEN
EN Threshold
ISW1/SW2= -200mA
VEN1/EN2=0V, VSW1/SW2=0 or 5V,
VIN1/IN2=5V
-40℃≤ TA ≤ +85℃
1.5
V
0.3
1.5
%
1.0
1.8
MHz
Note (3): The EUP3020 is tested in a proprietary test mode that connects FB1/FB2 to the output of the error amplifier.
DS3020
Ver1.2
Feb. 2009
4
EUP3020
Typical Operating Characteristics
DS3020
Ver1.2
Feb. 2009
5
EUP3020
DS3020
Ver1.2
Feb. 2009
6
EUP3020
DS3020
Ver1.2
Feb. 2009
7
EUP3020
Operation
Short Circuit Protection
The EUP3020 has dual independent constant frequency
current mode PWM step-down converters. The
EUP3020 is optimized for low voltage, Li-Ion battery
powered applications where high efficiency and small
size are critical. The EUP3020 uses resistor dividers to
set two output voltages independently from 0.6V to 5V.
The device integrates both main switches and
synchronous rectifiers, which provides high efficiency
and eliminates the need for an external Schottky diode.
The EUP3020 can achieve 100% duty cycle. The duty
cycle D of each step-down converter is defined as:
The EUP3020 has short circuit protection. When any
output is shorted to ground, the own oscillator frequency
is reduced to prevent the inductor current from
increasing beyond the PFET current limit. The PFET
current limit is also reduced to lower the short circuit
current. The frequency and current limit will return to
the normal values once the short circuit condition is
removed and the feedback voltage reaches 0.6V.
VOUT
D = TON × f OSC × 100% =
× 100%
VIN
Where TON is the main switch on time, fOSC is the
oscillator frequency (1.5MHz), VOUT is the output
voltage and VIN is the input voltage.
Current Mode PWM Control
Slope compensated current mode PWM control provides
stable switching and cycle-by-cycle current limit for
superior load and line response and protection of the
internal main switch and synchronous rectifier. Each
channel switches at a constant frequency (1.5MHz) and
regulates the output voltage. During each cycle the
PWM comparator modulates the power transferred to the
load by changing the inductor peak current based on the
feedback error voltage. During normal operation, the
main switch is turned on for a certain time to ramp the
inductor current at each rising edge of the internal
oscillator, and switched off when the peak inductor
current is reached. When the main switch is off, the
synchronous rectifier will be turned on immediately and
stay on until the next cycle starts or the inductor current
starts to reverse.
Dropout Operation
Each channel of the EUP3020 allows the main switch to
remain on for more than one switching cycle and
increases the duty cycle while the input voltage is
dropping close to the output voltage. When the duty
cycle reaches 100%, the main switch is held on
continuously to deliver current to the output up to the
PFET current limit. The output voltage then is the input
voltage minus the voltage drop across the main switch
and the inductor.
DS3020
Ver1.2
Feb. 2009
8
Maximum Load Current
The EUP3020 can operate down to 2.5V input voltage,
however the maximum load current decreases at lower
input due to large IR drop on the main switch and
synchronous rectifier. The slope compensation signal
reduces the peak inductor current as a function of the
duty cycle to prevent sub-harmonic oscillations at duty
cycles greater than 50%. Conversely the current limit
increases as the duty cycle decreases.
EUP3020
Application Information
Output Voltage Programming
Inductor Selection
The output voltage is set by a resistive divider according
to the following formula:
The output inductor is selected to limit the ripple current
to some predetermined value, typically 20%~40% of the
full load current at the maximum input voltage. Large
value inductors lower ripple currents. Higher VIN or
VOUT also increases the ripple current as shown in
equation. A reasonable starting point for setting ripple
current is ∆IL=400mA (40% of 1A).
 V

× VOUT ×  1 − OUT 

(f)(L)
VIN 

The DC current rating of the inductor should be at least
equal to the maximum load current plus half the ripple
current to prevent core saturation. Thus, a 1.2A rated
inductor should be enough for most applications
(1A+200mA). For better efficiency, choose a low
DC-resistance inductor.
∆I L =
1
CIN and COUT Selection
In continuous mode, the source current of the top
MOSFET is a square wave of duty cycle VOUT/VIN. The
primary function of the input capacitor is to provide a
low impedance loop for the edges of pulsed current
drawn by the EUP3020. A low ESR input capacitor sized
for the maximum RMS current must be used. The size
required will vary depending on the load, output voltage
and input voltage source impedance characteristics. A
typical value is around 4.7µF.
The input capacitor RMS current varies with the input
voltage and the output voltage. The equation for the
maximum RMS current in the input capacitor is:
I
RMS
=I
O
×

V
V
O × 1 − O
 V
V
IN 
IN









OUT 
1
When choosing the input and output ceramic capacitors,
choose the X5R or X7R dielectric formulations. These
dielectrics have the best temperature and voltage
characteristics of all the ceramics for a given value and
size.
DS3020
Ver1.2
Feb. 2009
For adjustable voltage package, the external resistive
divider is connected to the output, allowing remote
voltage sensing as shown in below figure.
CX1 is a feedforward cap which can speed loop response
and reduce output ripple during load transient. Choose
CX1 value between 220pF and 680pF for most
applications.
Thermal Dissipation
To avoid the EUP3020 from exceeding the maximum
junction temperature, the user will need to do a thermal
analysis. The goal of the thermal analysis is to determine
whether the operating conditions exceed the maximum
junction temperature of the part. The temperature rise is
given by:
TR=(PD)(θJA)
The output capacitor COUT has a strong effect on loop
stability.
The selection of COUT is driven by the required effective
series resistance (ESR).
ESR is a direct function of the volume of the capacitor;
that is, physically larger capacitors have lower ESR.
Once the ESR requirement for COUT has been met, the
RMS current rating generally far exceeds the IRIPPLE(P-P)
requirement. The output ripple ∆VOUT is determined by:
∆VOUT ≅ ∆I L ×  ESR +

8fC
 R 
VOUTX = 0.6V ×  1 + X1 
 R 

X2 
9
Where PD=ILOAD2 × RDS(ON) is the power dissipated by
the regulator ; θJA is the thermal resistance from the
junction of the die to the ambient temperature.
The junction temperature, TJ, is given by:
TJ=TA+TR
Where TA is the ambient temperature.
TJ should be below the maximum junction temperature
of 125°C.
PC Board Layout
The high current paths (GND1/GND2, VIN1/VIN2 and
SW1/SW2) should be placed very close to the device
with short, direct and wide traces. Input capacitors
should be placed as close as possible to the respective
VIN and GND pins. For adjustable voltage package, the
external feedback resistors shall be placed next to the FB
pins. Keep the switching nodes SW1/SW2 short and
away from the feedback network.
EUP3020
Packaging Information
TDFN-12
SYMBOLS
A
A1
b
E
D
D1
E1
e
L
DS3020
Ver1.2
Feb. 2009
MILLIMETERS
MIN.
MAX.
0.70
0.80
0.00
0.05
0.18
0.30
2.90
3.10
2.90
3.10
2.40
1.70
0.45
0.30
0.50
10
INCHES
MIN.
0.028
0.000
0.007
0.114
0.114
MAX.
0.031
0.002
0.012
0.122
0.122
0.094
0.067
0.018
0.012
0.020