Synchronous rectification with inhibit, 1.5 A, 1.5 MHz fixed or
adjustable, step-down switching regulator
Features
■ Step-down current mode PWM (1.5 MHz) DC-
DC converter
■ 2% DC output voltage tolerance
■ Synchronous rectification
■ Inhibit function
■ Internal soft start
■ Typical efficiency: > 90 %
■ 1.5 A output current capability
■ Not switching quiescent current: max 1.5 mA
over temperature range
■ R
■ Uses tiny capacitors and inductors
■ Operative junction temp. - 30 °C to 125 °C
■ Available in DFN6D (3x3 mm) exposed pad
Description
DS(ON)
typ.150 mΩ
ST1S06xx
DFN6D (3x3 mm)
Besides, a low output ripple is guaranteed by the
current mode PWM topology and by the use of low
ESR SMD ceramic capacitors. The device is
thermal protected and current limited to prevent
damages due to accidental short circuit. The
ST1S06xx is available in DFN6D (3x3 mm)
package.
The ST1S06xx is a step down DC-DC converter
optimized for powering low-voltage digital core in
HDD applications and, generally, to replace the
high current linear solution when the power
dissipation may cause an high heating of the
application environment. It provides up to 1.5 A
over an input voltage range of 2.7 V to 6 V. An high
switching frequency (1.5 MHz) allows the use of
tiny surface-mount components: as well as the
resistor divider to set the output voltage value,
only an inductor and two capacitors are required.
Table 1. Device summary
Part numbers Marking Order codes Package
ST1S06 ST1S06 ST1S06PUR DFN6D (3 x 3 mm)
May 2009 Doc ID 12236 Rev 9 1/20
ST1S06A ST1S06A ST1S06APUR DFN6D (3 x 3 mm)
ST1S06XX12 1S0612 ST1S06PU12R DFN6D (3 x 3 mm)
ST1S06XX33 1S0633 ST1S06PU33R DFN6D (3 x 3 mm)
www.st.com
20
Contents ST1S06xx
Contents
1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
6 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7 Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2/20 Doc ID 12236 Rev 9
ST1S06xx Diagram
1 Diagram
Figure 1. Schematic diagram
Doc ID 12236 Rev 9 3/20
Pin configuration ST1S06xx
2 Pin configuration
Figure 2. Pin configuration (top view)
ST1S06
* Pin 1 is VFB for ADJ version and VO for Fixed version
Table 2. Pin description
Pin n° Symbol Note
1FB/V
2 GND System ground
3 SW Switching pin
4V
5V
6V
IN_SW
IN_A
INH
Feedback voltage / output voltage
O
Power supply for the mosfet switch
Power supply for analogic circuit
Inhibit pin to turn off the device
Exposed pad to be connected to GND
ST1S06A
4/20 Doc ID 12236 Rev 9
ST1S06xx Maximum ratings
3 Maximum ratings
Table 3. Absolute maximum ratings
Symbol Parameter Value Unit
V
IN_SW
V
IN_A
V
INH
SWITCH
voltage
VFB/V
V
O
T
J
T
STG
T
LEAD
Positive power supply voltage -0.3 to 7 V
Positive power supply voltage -0.3 to 7 V
Inhibit voltage -0.3 to VI + 0.3 V
Max. voltage of output pin -0.3 to 7 V
Feedback voltage -0.3 to 2.5 V
O
Output voltage (for VO > 1.6 V) -0.3 to 6 V
Max junction temperature -40 to 150 °C
Storage temperature range -65 to 150 °C
Lead temperature (soldering) 10 sec 260 °C
Note: Absolute maximum ratings are those values beyond which damage to the device may occur.
Functional operation under these conditions is not implied.
Table 4. Thermal data
Symbol Parameter Value Unit
R
R
thJA
thJC
Thermal resistance junction-ambient 55 °C/W
Thermal resistance junction-case 10 °C/W
Doc ID 12236 Rev 9 5/20
Electrical characteristics ST1S06xx
4 Electrical characteristics
V
125 °C unless otherwise specified. Typical values are referred to T
Table 5. Electrical characteristics for ST1S06
IN_SW
= V
IN_A
= V
= 5 V, VO = 1.2 V, CI = 4.7 µF, CO = 22 µF, L1 = 3.3 µH, TJ = -30 °C to
INH
= 25 °C.
J
Symbol Parameter Test conditions Min. Typ. Max. Unit
FB Feedback voltage 784 800 816 mV
I
FB
V
I
I
V
INH
VFB pin bias current 600 nA
Minimum input voltage IO = 10mA to 1.5A 2.7 V
I
V
> 1.2V 1.5 mA
Quiescent current
Q
Output current VI = 2.7 to 5.5V Note 1 1.5 A
O
Inhibit threshold
INH
< 0.4V, TJ = -30°C to 85°C 1 µA
V
INH
Device ON, V
= 2.7 to 5.5V 1.3
I
= 2.7 to 5V 1.2
I
Device OFF 0.4
I
INH
Inhibit pin current 2µA
%VO/ΔVIReference line regulation VI = 2.7V to 5.5V Note 1 0.2 0.3
%VO/ΔIOReference load regulation IO = 10mA to 1.5A Note 1 0.2 0.3
PWMfSPWM switching frequency VFB = 0.8V 1.2 1.5 1.8 MHz
%V
ΔV
%V
ΔI
VDevice ON, V
/
O
I
/
O
O
D
MAX
R
DSON
R
DSON
I
SWL
T
SHDN
T
HYS
%VO/ΔIOLoad transient response
%VO/ΔIOShort circuit removal response
Note: 1 Guaranteed by design, but not tested in production
Maximum duty cycle 80 87 %
-N NMOS switch on resistance ISW = 750 mA 0.12 Ω
-P PMOS switch on resistance ISW = 750 mA 0.15 Ω
Switching current limitation Note 1 2.3 A
I
= 10mA to 100mA, VO = 3.3V 65
ν
Efficiency Note 1
O
= 100mA to 1.5A, VO = 3.3V 85 90
I
O
Thermal shutdown 130 150 °C
Thermal shutdown hysteresis 15 °C
I
= 100mA to 750mA, TJ =
O
25°C t
I
T
= tF ≥ 200ns, Note 1
R
= 10mA to IO = short,
O
= 25°C Note 1
J
%
-5 +5 %V
-10 +10 %V
O
O
6/20 Doc ID 12236 Rev 9
ST1S06xx Electrical characteristics
V
125 °C unless otherwise specified. Typical values are referred to T
Table 6. Electrical characteristics for ST1S06PM12
IN_SW
= V
IN_A
= V
= 5 V, VO = 1.2 V, CI = 4.7 µF, CO = 22 µF, L1 = 3.3 µH, TJ = -30 °C to
INH
= 25 °C.
J
Symbol Parameter Test conditions Min. Typ. Max. Unit
OUT Output feedback pin 1.176 1.2 1.224 V
I
V
I
I
V
INH
IO pin bias current VO = 1.5V 15 20 µA
O
Minimum input voltage IO = 10mA to 1.5A 2.7 V
I
V
> 1.2V 1.5 mA
Quiescent current
Q
Output current VI = 2.7 to 5.5V Note 1 1.5 A
O
Inhibit threshold
INH
< 0.4V, TJ = -30°C to 85°C 1 µA
V
INH
Device ON, V
= 2.7 to 5.5V 1.3
I
= 2.7 to 5V 1.2
I
Device OFF 0.4
I
INH
Inhibit pin current 2µA
%VO/ΔVIReference line regulation VI = 2.7V to 5.5V Note 1 0.2 0.3
%VO/ΔIOReference load regulation IO = 10mA to 1.5A Note 1 0.2 0.3
PWMfSPWM switching frequency VFB = 0.8V 1.2 1.5 1.8 MHz
D
MAX
R
DSON
R
DSON
I
SWL
T
SHDN
T
HYS
%VO/ΔIOLoad transient response
Maximum duty cycle 80 87 %
-N NMOS switch on resistance ISW = 750 mA 0.12 Ω
-P PMOS switch on resistance ISW = 750 mA 0.15 Ω
Switching current limitation Note 1 2.3 A
I
= 10mA to 100mA, VO = 1.2V 60
ν
Efficiency Note 1
O
= 100mA to 1.5A, VO = 1.2V 80 85
I
O
Thermal shutdown 130 150 °C
Thermal shutdown hysteresis 15 °C
I
= 100mA to 750mA, TJ =
O
25°C tR = tF ≥ 200ns, Note 1
-5 +5 %V
%V
ΔV
%V
ΔI
%
VDevice ON, V
/
O
I
/
O
O
O
I
= 10mA to IO = short,
%VO/ΔIOShort circuit removal response
O
= 25°C Note 1
T
J
Note: 1 Guaranteed by design, but not tested in production
Doc ID 12236 Rev 9 7/20
-10 +10 %V
O
Electrical characteristics ST1S06xx
V
125 °C unless otherwise specified. Typical values are referred to T
Table 7. Electrical characteristics for ST1S06PM33
IN_SW
= V
IN_A
= V
= 5 V, VO = 3.3 V, CI = 4.7 µF, CO = 22 µF, L1 = 3.3 µH, TJ = -30 °C to
INH
= 25 °C.
J
Symbol Parameter Test conditions Min. Typ. Max. Unit
OUT Output feedback pin 3.23 3.3 3.37 V
I
V
I
I
V
INH
IO pin bias current VO = 3.5V 15 20 µA
O
Minimum input voltage IO = 10mA to 1.5A 4.2 V
I
V
> 1.2V 1.5 mA
Quiescent current
Q
Output current VI = 4.2 to 5.5V Note 1 1.5 A
O
Inhibit threshold
INH
< 0.4V, TJ = -30°C to 85°C 1 µA
V
INH
Device ON, V
= 4.2 to 5.5V 1.3
I
= 4.2 to 5V 1.2
I
Device OFF 0.4
I
INH
Inhibit pin current 2µA
%VO/ΔVIReference line regulation VI = 4.2V to 5.5V Note 1 0.2 0.3
%VO/ΔIOReference load regulation IO = 10mA to 1.5A Note 1 0.2 0.3
PWMfSPWM switching frequency VFB = 0.8V 1.2 1.5 1.8 MHz
D
MAX
R
DSON
R
DSON
I
SWL
T
SHDN
T
HYS
%VO/ΔIOLoad transient response
Maximum duty cycle 80 87 %
-N NMOS switch on resistance ISW = 750 mA 0.12 Ω
-P PMOS switch on resistance ISW = 750 mA 0.15 Ω
Switching current limitation Note 1 2.3 A
I
= 10mA to 100mA, VO = 3.3V 65
ν
Efficiency Note 1
O
= 100mA to 1.5A, VO = 3.3V 85 90
I
O
Thermal shutdown 130 150 °C
Thermal shutdown hysteresis 15 °C
I
= 100mA to 750mA, TJ =
O
25°C tR = tF ≥ 200ns, Note 1
-5 +5 %V
%V
ΔV
%V
ΔI
%
VDevice ON, V
/
O
I
/
O
O
O
I
= 10mA to IO = short,
%VO/ΔIOShort circuit removal response
O
= 25°C Note 1
T
J
Note: 1 Guaranteed by design, but not tested in production
8/20 Doc ID 12236 Rev 9
-10 +10 %V
O
ST1S06xx Typical performance characteristics
5 Typical performance characteristics
V
IN_SW
= V
IN_A
= V
= 5 V, CI = 4.7 µF, CO = 22 µF, L1 = 3.3 µH, unless otherwise
INH
specified. Typical values are referred to 25 °C.
Figure 3. Efficiency vs. output current Figure 4. Efficiency vs. output current
Figure 5. Efficiency vs. output current Figure 6. Efficiency vs. output current
Figure 7. Efficiency vs. output current Figure 8. Efficiency vs. inductor
Doc ID 12236 Rev 9 9/20
Typical performance characteristics ST1S06xx
Figure 9. Voltage feedback vs. temperature Figure 10. Input voltage vs. output voltage
Figure 11. Feedback pin bias current vs.
Figure 13. Quiescent current vs. temperature Figure 14. Inhibit voltage vs. input voltage
temperature
Figure 12. Quiescent current vs. temperature
10/20 Doc ID 12236 Rev 9
ST1S06xx Typical performance characteristics
Figure 15. Inhibit voltage vs. temperature Figure 16. Inhibit voltage vs. temperature
Figure 17. Line regulation vs. temperature Figure 18. Load regulation vs. temperature
Figure 19. PWM switching frequency vs.
temperature
Figure 20. NMOS switch on resistance vs.
temperature
Doc ID 12236 Rev 9 11/20
Typical performance characteristics ST1S06xx
Figure 21. PMOS switch on resistance vs.
Figure 23. Inhibit transient
temperature
Figure 22. Inhibit transient
VI = 5 V, V
= 0 to 2 V, IO = 1.5 A
INH
VI = 5 V, V
= 0 to 2 V, IO = 10 mA
INH
12/20 Doc ID 12236 Rev 9
ST1S06xx Typical application
6 Typical application
Figure 24. Application circuit
Doc ID 12236 Rev 9 13/20
Application notes ST1S06xx
7 Application notes
The ST1S06xx is an adjustable current mode PWM step-down DC-DC converter with
internal 1.5 A power switch, packaged in a 6-lead DFN 3x3.
It’s a complete 1.5 A switching regulator with its internal compensation eliminating additional
component.
The constant frequency, current mode, PWM architecture and stable operation with ceramic
capacitors results in low, predictable output ripple. However, in order to maximize the power
conversion efficiency with light load, the regulator reduces automatically the switching
frequency when the output load becomes less than 250 mA typically.
To clamp the error amplifier reference voltage a soft start control block generating a voltage
ramp, has been implemented. Besides an on-chip power on reset of 50 = 100 µs ensure the
proper operation when switching on the power supply. Other circuits fitted to the device
protection are the thermal shut down block which turn off the regulator when the junction
temperature exceeds 150 °C typically and the cycle-by-cycle current limiting that provides
protection against shorted outputs.
Being the ST1S06xx an adjustable regulator, the output voltage is determined by an
external resistor divider. The desired value is given by the following equation:
V
= V
O
[1 + R1 / R2]
FB
To make the device working, only few component are required: an inductor and two
capacitors and the resistor divider. The chosen inductor must be able to not saturate at the
peak current level. Besides, its value can be selected keeping in account that a large
inductor value increases the efficiency at low output current and reduces output voltage
ripple, while a smaller inductor can be chosen when it is important to reduce the package
size and the total cost of the application. Finally, the ST1S06xx has been designed to work
properly with X5R or X7R SMD ceramic capacitors both at the input and at the output. this
kind of capacitors, thanks to their very low series resistance (ESR), minimize the output
voltage ripple. Other low ESR capacitors can be used according to the need of the
application without invalidate the right functioning of the device.
14/20 Doc ID 12236 Rev 9
ST1S06xx Package mechanical data
8 Package mechanical data
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK
®
packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com. ECOPACK
is an ST trademark.
Doc ID 12236 Rev 9 15/20
Package mechanical data ST1S06xx
DFN6D (3x3 mm) mechanical data
mm. inch.
Dim.
Min. Typ. Max. Min. Typ. Max.
A0.80 1.00 0.031 0.039
A1 0 0.02 0.05 0 0.001 0.002
A3 0.20 0.008
b 0.23 0.45 0.009 0.018
D2.90 3.00 3.10 0.114 0.118 0.122
D2 2.23 2.50 0.088 0.098
E2.90 3.00 3.10 0.114 0.118 0.122
E2 1.50 1.75 0.059 0.069
e0.950.037
L0.30 0.40 0.50 0.012 0.016 0.020
16/20 Doc ID 12236 Rev 9
7946637B
ST1S06xx Package mechanical data
Tape and reel QFNxx/DFNxx (3x3 mm) mechanical data
mm. inch.
Dim.
Min. Typ. Max. Min. Typ. Max.
A 330 12.992
C 12.8 13.2 0.504 0.519
D 20.2 0.795
N60 2.362
T18.4 0.724
Ao 3.3 0.130
Bo 3.3 0.130
Ko 1.1 0.043
Po 4 0.157
P 8 0.315
Doc ID 12236 Rev 9 17/20
Package mechanical data ST1S06xx
Figure 25. DFN6 (3x3 mm) footprint recommended data
18/20 Doc ID 12236 Rev 9
ST1S06xx Revision history
9 Revision history
Table 8. Document revision history
Date Revision Changes
08-May-2006 1 Initial release.
06-Jun-2006 2 Tab l e 3 updated.
16-Oct-2006 3 Add new mechanical data DFN6D.
09-Nov-2006 4 Mechanical data information for DFN6 update.
03-Apr-2007 5 Tape and reel updated.
12-Mar-2008 6 Added: Table 1 on page 1.
15-Apr-2008 7 Modified: Figure 6 on page 9.
10-Apr-2009 8 Modified: Table 3 on page 5.
06-May-2009 9 Added: marking Table 1 on page 1.
Doc ID 12236 Rev 9 19/20
ST1S06xx
Please Read Carefully:
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the
right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any
time, without notice.
All ST products are sold pursuant to ST’s terms and conditions of sale.
Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no
liability whatsoever relating to the choice, selection or use of the ST products and services described herein.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this
document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products
or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such
third party products or services or any intellectual property contained therein.
UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED
WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS
OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.
UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT
RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING
APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY,
DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE
GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK.
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void
any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any
liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries.
Information in this document supersedes and replaces all information previously supplied.
The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.
© 2009 STMicroelectronics - All rights reserved
Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan -
STMicroelectronics group of companies
Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America
www.st.com
20/20 Doc ID 12236 Rev 9
Loading...