SGS Thomson Microelectronics ST5R50U, ST5R50MTR, ST5R50M, ST5R33U, ST5R33MTR Datasheet

ST5R00

®

MICROPOWER VFM STEP-UP DC/DC CONVERTER

■

VERY LOW SUPPLY CURRENT

■

REGULATED OUTPUT VOL TA GE

■

WIDE RA NGE OF OUT PU T V O LTA GE
AVAILABLE (2.5V, 2.8V, 3.0V, 3.3V, 5.0V)

■

OUTPUT VOLTAGE ACCURACY ±5%

■

OUTPUT CURRENT UP TO 100mA

■

LOW RIPP LE A ND LOW NOIS E

■

VERY LOW START-UP VOLTAGE

■

HIGH EFFICIENCY (VOUT=5V TYP . 87%)

■

FEW EXTERNAL COMPONENTS

■

VERY SMALL PACKAGE: SOT23-5L, SOT-89

DESCRIPTION

The ST5R00 is an high efficiency VFM Step-up
DC/DC converter for small, low input voltage or
battery powered systems with ult ra low quiescent
supply current. The ST5Rxx accept a positive
input voltage from start-up voltage to V
convert it to a higher output voltage in t he 2.5 to
5V range.

The ST5R00 combine ultra low quiescent supply
current and high efficiency to give maximum
battery life. The high switching frequency and
the internally limited peak inductor current,
permits the use of small, low cost inductors. Only
three external components are nedeed: an
inductor a diode and an output capacitor.

OUT

and

SERIES

SOT23-5L

The ST5R00 is suitable to be used in a battery
powered equipment where low noise, low ripple
and ultra low supply current are required. The
ST5R00 is available in very small packages:
SOT23-5L, SOT-89.

Typical applications are pagers, cameras &
video camera, cellular telephones, wireless
telephones, palmtop computer, battery backup
supplies, battery powered equipment.

SOT-89

SCHEMATIC DIAGRAM

June 2001

1/13

ST5R00

ABSOLUTE MAXIMUM RATING

Symbol Parameter Value Unit

V

(*) Reduced by 1.7 mW for increasing in TA of 1oC over 25oC

THERMAL DATA

Symbol Parameter SOT23-5L SOT-89 Unit

R

thj-case

Output Voltage 5.5 V

OUT

Input Voltage 5.5 V

V

IN

V

LX Pin Voltage 5.5 V

LX

LX Pin Output Current Internally limited

I

LX

P

Power Dissipation @ 25oC fo r S OT2 3-5L 170 (*) mW

tot

Storage Temperature Range - 55 to 125

T

stg

Operating Junction Temperature Range - 2 5 to 8 5

T

op

Therma l Resistance Junction-case 63 17 °C/W

o

C

o

C

OPERATION

The ST5Rxx architecture is built around a VFM
CONTROL logic core: switching frequency is set
through a built in oscillator: T
5µs) while T

time is determined by the error

OFF

time is fixed (Typ.

ON

amplifier output, a logic signal coming from the
comparison made by the Error Amplifier Stage
between the signal coming from the output
voltage divider network and the internal
Band-Gap voltage reference (V

ref

). T

reaches

OFF

a minimum (Typ. 1.7µs) when heavy load
conditions are met (Clock frequency 150KHz). An
over current conditions, through the internal
power switch, causes a voltage drop
V

LX=RDSONxISW

the internal switch to be off, so narrowing T

and the VLX limiter block forces

ON

case the switching frequency may be higher than
the 150KHz set by the internal clock generator.

VFM control ensures very low quiescent current
and high conversion efficiency even with very
light loads.

Since the Output Voltage pin is also used as the
device Supply Voltage, the versions with higher
output voltage present an higher internal supply
voltage that results in lower power switch R
slightly greater output power and higher
efficiency. Moreover, bootstrapping allows the
input voltage to sag to 0.6V (at I
the system is started.

If the input voltage exceeds the output voltage,
the output will follow the input, however, the input
or output voltage must not be forced above 5.5V.

time and limiting internal power dissipation. In this

Typical Application Circuit Typical Application Efficency

=1mA) once

OUT

DSON

,

(*) See application info

2/13

CONNECTION DIAGRAM (top view)

SOT23-5L SOT-89

ORDERING NUMBERS

SOT23-5L SOT-89 Output Voltage

ST5R25M
ST5R28M
ST5R30M
ST5R33M
ST5R50M

ST5R25U
ST5R28U
ST5R30U
ST5R33U
ST5R50U

ST5R00

2.5 V

2.8 V

3.0 V

3.3 V

5.0 V

TYPICAL DEMOBOARD

3/13

ST5R00

ELECTRICAL CHARACTERISTICS FOR ST5R25

(V

= 1.5V, I

IN

otherwise notes, refer to the typical operating circuit.

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

OUT

V

START-UP

V

HOLD

I

SUPPLY

R

LX(DSON)

I

LX(leak)

F

osc

Dty Oscillator Duty Cycle to be measure on Lx pin 77 %

ν

(1): The minimum input voltage for the IC start-up is strictly a function of the VF catch diode.

ELECTRICAL CHARACTERISTICS FOR ST5R28

= 1.7V, I

(V

IN

otherwise notes, refer to the typical operating circuit.

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

OUT

V

START-UP

V

HOLD

I

SUPPLY

R

LX(DSON)

I

LX(leak)

F

osc

Dty Oscillator Duty Cycle to be measure on Lx pin 77 %

ν

(1): The minimum input voltage for the IC start-up is strictly a function of the VF catch diode.

= 10mA TA = 25oC unless otherwise specified. For external components value, unless

OUT

Output Voltage 2.375 2.5 2.625 V
Start-up Voltage (VIN-VF) (1) I
Hold-on Voltage I

=1mA VIN rising from 0 to 2V 0.8 1.2 V

OUT

=1mA VIN falling from 2 to 0V 0.6 V

OUT

Supply Current To be measured at VIN, no load 16
Internal Switch R

DSON

Internal Leakage Current VLX=4V, forced V

ILX=150mA 850 m

=3V 0.5

OUT

Maximum oscillator Frequency 150 kHz

Efficency I

= 10mA TA = 25oC unless otherwise specified. For external components value, unless

OUT

=50mA 82 %

OUT

Output Voltage 2.66 2.8 2.94 V
Start-up Voltage (VIN-VF) (1) I
Hold-on Voltage I

=1mA VIN rising from 0 to 2V 0.8 1.2 V

OUT

=1mA VIN falling from 2 to 0V 0.6 V

OUT

Supply Current To be measured at VIN, no load 16
Internal Switch R

DSON

Internal Leakage Current VLX=4V, forced V

ILX=150mA 850 m

=3.3V 0.5

OUT

Maximum oscillator Frequency 150 kHz

Efficency I

=50mA 82 %

OUT

A

µ

Ω

A

µ

A

µ

Ω

A

µ

ELECTRICAL CHARACTERISTICS FOR ST5R30

(V

IN

= 1.8V, I

= 10mA TA = 25oC unless otherwise specified. For external components value, unless

OUT

otherwise notes, refer to the typical operating circuit.

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

OUT

V

START-UP

V

HOLD

I

SUPPLY

R

LX(DSON)

I

LX(leak)

F

Dty Oscillator Duty Cycle to be measure on Lx pin 77 %

(1): The minimum input voltage for the IC start-up is strictly a function of the VF catch diode.

4/13

Output Voltage 2.85 3 3.15 V
Start-up Voltage (VIN-VF) (1) I
Hold-on Voltage I

=1mA VIN rising from 0 to 2V 0.8 1.2 V

OUT

=1mA VIN falling from 2 to 0V 0.6 V

OUT

Supply Current To be measured at VIN, no load 17
Internal Switch R

DSON

Internal Leakage Current VLX=4V, forced V
Maximum oscillator Frequency 150 kHz

osc

Efficency I

ν

ILX=150mA 850 m

=3.5V 0.5

OUT

=50mA 83 %

OUT

A

µ

Ω

A

µ