SGS Thomson Microelectronics ST1534APT, ST1534AP2T Datasheet

■ GLITCH FREE TRANSITION BETWEEN

INPUT SOURCES

■ INTERNAL LOGIC SELECTS INPUT

SOURCE

■ GATE DRIVE FOR EXTERNAL PMOS

BYPASS SWITCH

■ 5V DETECTOR WITH HYSTERESIS

■ 1% 3.3V REGULATED OUTPUT VOLTAGE

■ 500mA GUARANTEED OUTPUT CURRENT

■ OPERATING TEMPERATURE RANGE

FROM 0°C TO 85°C

■ AVAILABLE IN P

■ PPAK AND SO-8 PACKAGES CAN BE

2

PAK PACKAGE

AVAILABLE ON REQUEST

APPLICATIONS

■ NETWORK INTERFACE CARDS

■ PCMCIA/PCI INTERFACE CARDS

■ DESKTOP COMPUTERS

■ POWER SUPPLY WITH MULTIPLE INPUT

SOURCES

DESCRIPTION

The ST1534A is intended for app lication such as
power managed PCI and network interface cards
(NICs), where operations from 3.3V V AUX supply

SCHEMATIC DIAGRAM

ST1534A

500mA SMART LDO

PPAKP2PAK

SO-8

may be required when the 5V supply has been
shut down.
During regular operation, 3.3V power f or the PCI
card is provided by the internal LDO regulator,
generated from 5V supply. When the 5V V
available, the IC connects thissupply directlyto its
output using an external P-Channel FET. This
ensures an uninterrupted 3. 3V out even if VIN falls
out of specificat ion.
When both supplies are available simultaneously,
the drive p in DR will be pulled high, turning off the
PMOS switch.
The device is available in the popular 5 leads

2

P

PAK and PPA K

AUX

is

+

5V Detect

-

GND

VIN

Reference

+

Error
Amp

-

VIN

Rpull_down

V

OUT

DR

1/15April 2003

ST1534A

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter² Value Unit

V

V

SHDN

I

T

T

Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is
not implied.

THERMAL DATA

DC Input Voltage

I

Shutdown Input Voltage
Output Current

O

Storage Temperature Range

stg

Operating Junction Temperature Range

op

-0.3 to 7 V

-0.3 to 7 V

Internally limited mA

-40 to +125 °C
0to+85 °C

Symbol Parameter PPAK

R

thj-case

R

thj-amb

Thermal Resistance Junction-case
Thermal Resistance Junction-ambient

CONNECTION DIAGRAM (top view)

2

PAK

P

PPAK

PIN DESCRIPTION

Pin PPAK/P

1 1 AUX Auxiliary Input port typically 3.3V
2 2 IN Input port typically 5V
3 5, 6, 7, 8 GND Ground
4 3 OUT LDO 3.3V Output Port
5 4 DR Drive Output for external P-Channel MOSFET pass element

2

PAK

Pin SO/8 Symbol Name and Function

2

PAK

P

SO-8 Unit

8320°C/W

100 50 55 °C/W

SO-8

ORDERING INFORMATION

TYPE PPAK (*)

ST1534A ST1534APT ST1534AP2T ST1534AD

(*) PPAK and SO-8 a re availablein Tape & Reel with the suffix"-TR".

2

(#) P

PAKisavailableinTape&Reelwiththesuffix"-R".

2/15

2

PAK (#)

P

SO-8 (*)

TYPICAL APPLICATION CIRCUIT

ST1534A

3.3V

0.1 µF

5V

4.7 µF 0.1 µF

ELECTRICAL CHARACTERISTICS (T

AUX

IN

GND

=25°C,VI=5V, V

j

DR

OUT

10 µF0.1 µF

=3.3V, IO=10mA, CO=2.2µF,

AUX

Vout=3.3V

unless otherwise spec ified)

Symbol Parameter Test Conditions Min. Typ. Max. Unit

Input Voltage Range 4.5 5 5.5 V

V

I

Input Supply Current VI≥ 4.5V IO= 0mA V

I

IN

I

Auxliary Supply Current VI= 0 V 2.2 mA

AUX

3.3V VOLTAGE REGULATOR BLOCK

V

Output Voltage Tj= 0 to 85 °C 3.18 3.3 3.42 V

O

∆V
∆V

Line Regulation VI= 4.5 to 5.5V 0.04 0.5 %

O

Load Regulation IO= 0 to 500mA 0.1 1 %

O

Dropout Voltage IO= 500 mA Tj= 0 to 85 °C 1.15 V

V

d

Output Current Limit Tj=0to85°C 550 mA

I

O

5V DETECT BLOCK

V

V

Low Threshold Voltage VIfalling, IO= 500 mA Tj= 0 to 85 °C 4.15 4.3 V

THL

Hysteresis 70 200 mV

HYST

DRIVE OUTPUT BLOCK

V

Note 1: Guaranteed by design
Note 2: See timing diagram

Drive Output Voltage VI= 4.5 to 5.5V IDR=200µA 3.6 VIN-0.8 V

DR

Drive Current Sinking: VI= 4.15V VDR= 1V 7 20 mA

I

DR

Drive High Delay (Note 1

t

DH

and 2)

Drive Low Delay (Note 1

t

DL

and 2)

≥4.5V IO= 0mA V

V

I

< 4.1V IO= 0mA V

V

I

< 4.1V IO= 0mA V

V

I

V

= 5V 200 µA

I

< 4.15V IDR=200µA 100 200 mV

V

I

Sourcing: V

= 4.5V VI-VDR= 2V 7 25 mA

I

CDR= 1.2nF,VINramping up, measured
from V

I=VTH(H)

=0to85°C

T

j

to VDR= 3.3V

CDR= 1.2nF,VINramping down, measured
from V

I=VTH(L)

T

=0to85°C

j

to VDR= 200mV

=0V 11 mA

AUX

= 3.3V 11 mA

AUX

=0V 2 mA

AUX

= 3.3V 2 mA

AUX

25µs

36µs

3/15

ST1534A

5V DETECT THRESHOLDS

VINrise and fall times (10% to 90%) to be > 100µs

TIMING DIAGRAM

VINrise and fall times (10% to 90%) to be > 100µs

4/15

TYPICAL CHARACTERISTICS (unless otherwise specified Tj=25°C)

ST1534A

Figure1 : Supply Currentvs Temperature

Figure2 : Aux Current vs Temperature

Figure4 : Aux Current vs Temperature

Figure5 : Drive Output Voltage vs Tem perature

Figure3 : Drive Current vs Temperature

Figure6 : Drive Current vs V

IN-VDR

5/15