SP 6 6 6 9
6 0 0 m A 1 . 5 M H z S y n c h r o n o u s S t e p D o w n Co n v e r t e r
November 2012
Rev. 2. 2.0
GENERAL DESCRIPTION
The SP6669 is a synchronous current mode
PWM step down (buck) converter capable of
delivering up to 600mA of current. It features
a pulse skip mode (PSM) for light load
efficiency and a LDO mode for 100% duty
cycle.
With a 2.5V to 5.5V input voltage range and a
1.5MHz switching frequency, the SP6669
allows the use of small surface mount
inductors and capacitors ideal for battery
power ed portable applications. The internal
synchronous switch increases efficiency and
eliminates the need for an external Schottky
diode. Low output voltages are easily
supported with the 0.6V feedback reference
voltage. The SP6669 is available in an
adjustab le output voltage version, using an
external resistor divider circuit, as well as
fixed output voltage v
ersions of 1.2V, 1.5V
and 1.8V.
Built - in over temperature and output over
voltage lock - out protections insure safe
operations
under
abnormal
operating
conditions.
The SP6669 is offered in a RoHS compliant,
- pin SOT23 package.
APPLICATIONS
Portable Equipments
Battery Operated Equipments
Audio - Video Equipments
Networking & Telecom Equipments
FEATURES
Guaranteed 600mA Output Current
In put Voltage: 2.5V to 5.5V
1.5MHz PWM Current Mode Control
100% Duty Cycle LDO Mode Operations
Achieves 95% Efficiency
Fixed/Adjustable Output Voltage
Range
As Low as 0.6V with ±3% Accuracy
1.2V, 1.5V, 1.8V Fixed Voltage Options
Excellent Line/Load
Response
Transient
200 µA Quiescent Current
Over Temperature Protection
5 - Pin SOT23 Package
TYPICAL APPLICATION
DIAGRAM
Fig. 1: SP6669 Application Diagram
(Adj. version shown)
Exar Corporation
48720 Kato Road, Fremont CA 94538, USA
Tel. +1 510 668
- 70 00
www.exar.com
Fax. +1 510 668 - 70 01
SP 6 6 6 9
6 0 0 m A 1 . 5 M H z S y n c h r o n o u s S t e p D o w n Co n v e r t e r
ABSOLUTE MAXIMUM RAT
INGS
OPERATING RATINGS
Input Voltage Range V
IN
...............................
Operating Temperature Range ...................
JA
................................
Jc
................................
2.7V to 5.5V
- 40°C to 85 °C
..... 250 °C/W
....... 90 °C/W
These are stress ratings only and functional operation of
the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolut
e maximum
rating conditions for extended periods of time may affect
reliability.
Input Voltage V
IN
................................
....... - 0.3V to 6.0V
Enable V
FB
Voltage ................................
....... - 0.3V to V
IN
SW Voltage ................................
...... - 0.3V to ( V
IN
+0.3V)
PMOS Switch Source Current (DC)
........................
800mA
NMOS Switch Sink Current
................................
.. 800mA
Peak Switch Sink/Source Current
............................
1.3A
1
Operating Junction Temperature
..........................
125 °C
Storage Temperature ..............................
- 65°C to 150°C
Lead Temperature (Soldering, 10 sec)
....................
260°C
ESD Rating (HBM - Human Body Model) ....................
2kV
ESD Rating (MM - Machine Model) ...........................
200V
Note 1: T
J
is a function of the ambient temperature T
power dissipation P
D
(T
J
= T
A
+ P
D
x 250°C/W).
A
and
ELECTRICAL SPECIFICA
Specifications with standard type
TIONS
are for an Operating Junction Temperature of T
J
= 25°C only; limits applying over the full
A
design, or statistical correlation. Typical values
represent the most likely parametric norm at T
for reference purposes only. Unless otherwise indicated, V
IN
= 3.6 V.
Parameter
Feedback Current I
VFB
FB
= 25°C, and are provided
Min.
0.588
Typ.
0.600
Max.
±30
0.612
0.4
Units
nA
V
%/V
%
mV
%
%/V
A
%
OVL
OVL
Conditions
T
A
=25°C
V
IN
=2.5V to 5.5V
=V
=V
V
FB
(Adj.)
V
OUT
(Fixed)
Regulated Feedback Voltage V
Reference Voltage Line
FB
OUT
%
-3
20
2.5
50
7.8
+3
80
13
0.4
1.0
0.5
200
0.1
340
1
1.8
0.55
0.50
±1
Output Over - Voltage Lockout
OVL
OVL
OVL
Output Voltage Line Regulation
OUT
V
IN
=2.5V to 5.5V
V
IN
=3V, V
FB
=0.5V or V
cycle <35%
OUT
=90%,
Peak Inductor Current I
PK
Duty
Output Voltage Load Regulation
V
LOADREG
Quiescent Current
Shutdown Current I
Oscillator Frequency f
RDS(ON) of PMOS R
RDS(ON) of NMOS R
SW Leakage I
LSW
EN
EN
EN
2
I
Q
SHTDWN
OSC
PFET
NFET
µA
µA
MHz
Hz
V
FB
=0.5V or
V
EN
=0V, V
V
FB
=0.6V or V
V
FB
=0V or V
I
SW
=100mA
I
SW
=100mA
V
OUT
=90%
OUT
=100%
IN
=4.2V
1.2
1.5
290
0.45
0.40
OUT
=0V
µA
V
V
µA
V
EN
=0V, V
SW
=0V
or 5V, V
IN
=5V
Enable Threshold V
1.2
0.4
±1
Shutdown Threshold V
EN Leakage Current I
Note 1: The Switch Current Limit is related to the Duty Cycle. Please refer to figure 15 for
details.
Note 2: Dynamic quiescent current is higher due to the gate charge being delivered at the switching frequency.
© 2012 Exar Corporation
2/ 11
Rev. 2. 2.0
SP 6 6 6 9
6 0 0 m A 1 . 5 M H z S y n c h r o n o u s S t e p D o w n Co n v e r t e r
BLOCK DIAGRAM
Fig. 2: SP6669 Block Diagram
PIN ASSIGNMENT
Fig. 3: SP6669 Pin Assignment
© 2012 Exar Corporation
3/ 11
Rev. 2. 2.0
SP 6 6 6 9
6 0 0 m A 1 . 5 M H z S y n c h r o n o u s S t e p D o w n Co n v e r t e r
PIN DESCRIPTION
Name
EN
GND
SW
VIN
VFB
5
VOUT
Pin Number
1
2
3
4
Enable Pin. Do not leave the pin floating.
V
EN
<0.4V: Shutdown mode
V
EN
>1.2V: Device enabled
Ground Signal
Switching Node
Power Supply Pin.
Must be decoupled to ground with a 4.7µF or greater ceramic capacitor.
Adjustable Version Feedback Input Pin.
Connect VFB to the center point of the resistor divider.
Fixed Output Voltage Version, Output Voltage Pin.
An internal resistive divider divides the output voltage down for comparison to the
internal reference voltage.
Description
ORDERING INFORMATION
Part Number
SP6669AEK - L/TRR3
SP6669BEK - L/TRR3
SP6669CEK - L/TRR3
SP6669DEK - L/TRR3
SP6669EB
-
-
-
-
Temperature
Range
A
Marking
QBWW
RBWW
SBWW
TBWW
Package
SOT23 - 5
SOT23 - 5
SOT23 - 5
SOT23 - 5
Packing
Quantity
3K/Tape & Reel
3K/Tape & Reel
3K/Tape & Reel
3K/Tape & Reel
Note 1
Halogen Free
Halogen Free
Halogen Free
Halogen Free
Note 2
Adjustable
output voltage
1.2V fixed output
voltage
1.5V fixed output
voltage
1.8V fixed output
voltage
A
A
A
SP6669 Evaluation Board
; when applicable.
Note that the SP6669 series is packaged in Tape and Reel with a reverse part orientation as per the
following diagram
© 2012 Exar Corporation
4/ 11
Rev. 2. 2.0
SP 6 6 6 9
6 0 0 m A 1 . 5 M H z S y n c h r o n o u s S t e p D o w n Co n v e r t e r
TYPICAL PERFORMANCE
CHARACTERISTICS
J
All data taken at V
IN
= 2.7V to 5.5V, T
Information section of this datasheet.
= T
A
= 25°C, unless otherwise specified
- Schematic and
BOM from Application
Fig. 4: Efficiency vs Output Current (mA)
Fig. 5: Efficiency vs Output Current (mA)
Fig. 6: Efficiency vs
Output Current (mA)
Fig. 7: Efficiency vs Output Current (mA)
Fig. 8: Output Voltage vs Load Current
Fig. 9: Reference Voltage vs Temperature
© 2012 Exar Corporation
5/ 11
Rev. 2. 2.0
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