ST1S12XX12

Manufacturer Part NumberST1S12XX12
DescriptionSynchronous rectification with inhibit, 0.7 A, 1.7 MHz fixed, step-down switching regulator
ManufacturerSTMicroelectronics
ST1S12XX12 datasheet
 


Specifications of ST1S12XX12

Typical Efficiency> 90%Not Switching Quiescent Currentmax 650 μA over temperature range
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Synchronous rectification with enable, 0.7 A, 1.7 MHz fixed or
adjustable step-down switching regulator in TSOT23-5L
Features
Step-down current mode PWM (1.7 MHz) DC-
DC converter
3% DC output voltage tolerance
Synchronous rectification
Fixed output voltage 1.2 V, 1.8 V, and ADJ
(available on request 1.5 V, 2.5 V and 3.3 V)
Enable function
Internal soft start
Typical efficiency: > 90%
0.7 A output current capability
Not switching quiescent current: max 650 µA
over temperature range
R
typ. 250 mΩ and 400 mΩ
DSON
Uses tiny capacitors and inductors
Operative junction temp. -40 °C to 125 °C
Available in TSOT23-5L package
Description
The ST1S12 is a step down DC-DC converter
optimized for powering low-voltage digital cores in
HDD applications and, generally, to replace the
high current linear solution when the power
dissipation may cause high heating of the
application environment. It provides up to 0.7 A
over an input voltage range of 2.5 V to 5.5 V. A
high switching frequency (1.7 MHz) allows the
use of tiny surface-mount components. In addition
to the resistor divider to set the output voltage
value, only an inductor and two capacitors are
required. Moreover, a low output ripple is
Table 1.
Device summary
Part numbers
ST1S12XX
ST1S12XX12
ST1S12XX18
February 2012
ST1S12XX12, ST1S12XX18
guaranteed by the current mode PWM topology
and by the use of low ESR SMD ceramic
capacitors. The device is thermally protected and
the current is limited to prevent damage due to
accidental short-circuit. The ST1S12 is available
in the TSOT23-5L package.
Order codes
ST1S12GR
ST1S12G12R
ST1S12G18R
Doc ID 14314 Rev 5
ST1S12XX
TSOT23-5L
Package
TSOT23-5L
TSOT23-5L
TSOT23-5L
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www.st.com
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ST1S12XX12 Summary of contents

  • Page 1

    ... Device summary Part numbers ST1S12XX ST1S12XX12 ST1S12XX18 February 2012 ST1S12XX12, ST1S12XX18 guaranteed by the current mode PWM topology and by the use of low ESR SMD ceramic capacitors. The device is thermally protected and the current is limited to prevent damage due to accidental short-circuit. The ST1S12 is available in the TSOT23-5L package ...

  • Page 2

    ... Contents Contents 1 Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 5 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6 Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2/20 ST1S12XX, ST1S12XX12, ST1S12XX18 Doc ID 14314 Rev 5 ...

  • Page 3

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 1 Schematic Figure 1. Schematic diagram Doc ID 14314 Rev 5 Schematic 3/20 ...

  • Page 4

    ... Pin configuration 2 Pin configuration Figure 2. Pin connections (top view) Table 2. Pin description Pin n° Symbol GND FB/V O 4/20 Name and function Enable pin System ground Switching pin Input supply pin Feedback voltage / or output voltage Doc ID 14314 Rev 5 ST1S12XX, ST1S12XX12, ST1S12XX18 ...

  • Page 5

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 3 Maximum ratings Table 3. Absolute maximum ratings Symbol V Positive power supply voltage IN V Enable voltage EN SWITCH Voltage Max. voltage of output pin V /V Feedback voltage Output voltage (for Max junction temperature J T Storage temperature range STG T Lead temperature (soldering) 10 sec ...

  • Page 6

    ... 100mA to 700mA ≥ 200ns =22µ 10mA short ( 25°C A Doc ID 14314 Rev 5 ST1S12XX, ST1S12XX12, ST1S12XX18 = - 40 to 125 °C (unless J Min. Typ. Max. 582 600 618 -50 50 2.5 500 650 1 0.7 1.5 0.5 1 0.05 0.1 0.0025 0.005 %V 1.16 1.7 2.08 100 0 ...

  • Page 7

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 specified. Typical values are referred to 25 °C). Table 7. Electrical characteristics for ST1S12G12 Symbol Parameter OUT Output feedback pin I V pin bias current Minimum input voltage IN I Quiescent current Q I Output current O V Enable threshold ...

  • Page 8

    ... 100mA to 0. 100mA to 700mA ≥ 200ns =22µ 10mA short ( 25°C A Doc ID 14314 Rev 5 ST1S12XX, ST1S12XX12, ST1S12XX18 = -40 to 125 °C (unless otherwise J Min. Typ. Max. 1.746 1.8 1.854 15 20 2.5 500 650 1 0.7 1.5 0.5 1 0.05 0.1 0.0025 0.005 %V 1.16 1.7 2 ...

  • Page 9

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 5 Typical application Figure 3. Application circuit Doc ID 14314 Rev 5 Typical application 9/20 ...

  • Page 10

    ... SMD ceramic capacitors both at the input and at the output. These types of capacitors, due 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 compromising the correct functioning of the device. 10/ Doc ID 14314 Rev 5 ST1S12XX, ST1S12XX12, ST1S12XX18 ...

  • Page 11

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 7 Typical performance characteristics Unless otherwise specified, refer to the typical application circuit under the following conditions 4.7 µ Figure 4. Voltage feedback vs. temperature 650 650 =3.6V, I =3.6V, I =10mA, V =10mA OUT OUT 630 630 610 610 590 590 ...

  • Page 12

    ... V =10µF, V =1.8V =1.8V OUT OUT OUT OUT -0.6 -0.6 -75 - 100 100 125 125 150 150 175 175 Doc ID 14314 Rev 5 ST1S12XX, ST1S12XX12, ST1S12XX18 =3V, V =3V, V =1.2V, No Load =1.2V, No Load OUT OUT -50 -50 -25 - 100 100 T [° ...

  • Page 13

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 Figure 16. Reference load regulation vs. temperature 0.005 0.005 V V =3.6V, I =3.6V, I from 10mA to 0.7A, V from 10mA to 0.7A OUT OUT 0.004 0.004 0.003 0.003 0.002 0.002 0.001 0.001 0 0 -75 -75 -50 -50 -25 - [°C] T [°C] Figure 18. PMOS switch on resistance vs. ...

  • Page 14

    ... V IN OUT OUT Figure 24. Start-up transient from 350 mA OUT µ 1 OUT OUT 14/20 ST1S12XX, ST1S12XX12, ST1S12XX18 Figure 23. Load transient OUT 100 mA to 700 mA OUT Figure 25. Enable transient OUT V = 3.6, V from ...

  • Page 15

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 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: ® ECOPACK trademark. Doc ID 14314 Rev 5 Package mechanical data ® ...

  • Page 16

    ... Package mechanical data Dim. Min 0.7 b 0 0.3 16/20 TSOT23-5L mechanical data mm. Typ. Max. 1.1 0.1 1.0 0.5 0.2 2.9 2.8 1.6 0.95 1.9 0.6 Doc ID 14314 Rev 5 ST1S12XX, ST1S12XX12, ST1S12XX18 mils. Min. Typ. 27.6 11.8 3.1 114.2 110.2 63.0 37.4 74.8 11.8 7282780B Max. 43.3 3.9 39.4 19.7 7.9 23.6 ...

  • Page 17

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 Tape & reel TSOT23-5L mechanical data Dim. Min 12 3.13 Bo 3.07 Ko 1.27 Po 3.9 P 3.9 mm. Typ. Max. Min. 180 13.0 13.2 0.504 0.795 2.362 14.4 3.23 3.33 0.123 3.17 3.27 0.120 1.37 1.47 0.050 4.0 4.1 0.153 4.0 4.1 0.153 Doc ID 14314 Rev 5 Package mechanical data inch. Typ. Max. 7.086 0.512 0.519 ...

  • Page 18

    ... Package mechanical data Figure 26. TSOT23-5L footprint recommended data Table 9. Footprint data 18/20 ST1S12XX, ST1S12XX12, ST1S12XX18 Values mm. 3.50 1.10 0.60 0.95 1.20 2.30 Doc ID 14314 Rev 5 inch. 0.138 0.043 0.024 0.037 0.047 0.090 ...

  • Page 19

    ... ST1S12XX, ST1S12XX12, ST1S12XX18 9 Revision history Table 10. Document revision history Date Revision 10-Jan-2008 1 01-Feb-2008 2 23-Feb-2010 3 23-Jun-2011 4 17-Feb-2012 5 Initial release. Modified: Figure 3 on page 9 . Modified: V value Table 3 on page 5 IN Table 6 on page 6 Modified: FB unit Modified: quiescent current max value 600 ==> 650 Table 7 on page 7 ...

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    ... Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America 20/20 ST1S12XX, ST1S12XX12, ST1S12XX18 Please Read Carefully: © 2012 STMicroelectronics - All rights reserved STMicroelectronics group of companies www ...