ST1S03
1.5 A, 1.5 MHz adjustable, step-down switching regulator
Datasheet
-
production data
Description
The ST1S03 is a step-down DC-DC converter
optimized for powering a low voltage digital core
in HDD applications and, generally, to replace the
high current linear solution when the power
dissipation may cause a high heating of the
application environment. It provides up to 1.5 A
over an input voltage range of 3 V to 16 V. A 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, a Schottky diode and two
capacitors are required. 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 an
accidental short-circuit. The ST1S03 device is
available in a DFN6D package.
Table 1. Device summary
Order code
ST1S03PUR
Package
DFN6D (3 x 3 mm)
Packaging
Tape and reel
DFN6D (3 x 3 mm)
Features
Step-down current mode PWM (1.5 MHz)
DC-DC converter
2% DC output voltage tolerance
Internal soft-start for STARTUP current
limitation and power on delay of 50 - 100 µs
Typical efficiency: > 70% over all operating
conditions
1.5 A output current capability
Not switching quiescent current: max 2.5 mA
over temperature range
Switch V
DS
: max. 350 mV at I
SW
= 750 mA
Uses tiny capacitors and inductors
Available in DFN6D 3 x 3 mm package with
exposed pad
November 2014
This is information on a product in full production.
DocID10992 Rev 7
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Contents
ST1S03
Contents
1
2
3
4
5
6
7
8
9
Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Application notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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Pin configuration
ST1S03
2
Pin configuration
Figure 2. Pin connections (top view)
Table 2. Pin description
Pin no.
1
2
3
4
5
6
7
Symbol
V
FB
GND
SW
V
IN_SW
V
IN_A
N.C.
EP
Voltage of feedback
System ground
Output of the internal power switch
Power supply for the MOSFET switch
Power supply for the analog circuit
Not connected
Exposed pad should be connected to GND
Name and function
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ST1S03
Maximum ratings
3
Maximum ratings
Table 3. Absolute maximum ratings
Symbol
V
IN_SW
V
IN_A
Parameter
Positive power supply voltage
Positive power supply voltage
Max voltage of output pin
Feedback voltage
Common mode input voltage
Max junction temperature
Storage temperature range
Lead temperature (soldering) 10 s
Value
-0.3 to 16
-0.3 to 16
-0.3 to 16
2.5
±1
150
-25 to 150
300
Unit
V
V
V
V
mA
°C
°C
°C
SWITCH voltage
V
FB
I
VFB
T
J
T
STG
T
LEAD
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
R
thJC
R
thJA
Parameter
Thermal resistance junction case
Thermal resistance junction ambient
Value
10
55
Unit
°C/W
°C/W
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