US1206 Ver la hoja de datos (PDF) - Unisem

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US1206

1A ULTRA LOW DROPOUT POSITIVE ADJUSTABLE & FIXED REGULATOR

Unisem 

US1206/1207/1208/1209

US1207,1208

SYM

Ground Current-S.D Activated Iqsd

Enable pin input LO voltage Venl

Enable pin input HI voltage Venh

Enable pin input LO current

Enable pin input HI current

US1207,1209

Flag Output Threshold Voltage Vthfg

Flag Output Hysterises Voltage Vhys

Flag Output Saturation Voltage Vfsat

TEST CONDITION

Enable=0V

Regulator OFF (Note 4)

Regulator ON (Note 4)

Venl=0V to 0.8V (Note 4)

Venh=2V to Vin (Note 4)

Output Ramping Up

Io=5mA

Io=500uA

MIN TYP MAX

0.01 1

0.8

2

0.1

2

100 600

3.8

0.8

400

230

UNITS

uA

V

V

uA

uA

%Vo

%Vo

mV

mV

Note 1 : Low duty cycle pulse testing with Kelvin con-

nections are required in order to maintain accurate data.

Note 2 : Drop-out voltage is defined as the minimum

differential voltage between Vin and Vout required to main-

tain regulation at Vout. It is measured when the output

voltage drops 1% below its nominal value.

Note 3 : Ground current is the the regulator quiescent

current plus the pass transistor current. The total cur-

rent from the supply is the sum of the load current plus

the ground pin current.

Note 4 : The specification applies for the junction tem-

perature of 0 to +125°C.

Pin DescRIPTIONS

PIN SYMBOL

Adj

US1208,1209

Flag

US1208

Vout

All devices

GND

All devices

Enable

US1207,1209

Vin

All devices

Part Number

US1206-18

US1206-25

US1206-33

US1207-18

US1207-25

US1207-33

US1208

US1209

Output

Voltage

1.8V

2.5V

3.3V

1.8V

2.5V

3.3V

1.24V

1.24V

Table 1- Output voltage v.s. part number

Rev. 1.1

6/26/00

PIN DESCRIPTION

A resistor divider from this pin to the Vout pin and ground sets

the output voltage.

An open collector output that switches low when the output

voltage drops about 4% below its expected regulated voltage.

The output of the regulator .A minimum of 2.2uF capacitor

must be connected from this pin to ground.

Ground pin. This pin must be connected to the lowest poten-

tial in the system & all other pins must be at higher potential

with respect to this pin.

Enable pin. A low signal or left open on this pin shuts down the

output.This pin must be tied HI or to Vin for normal operation.

The input pin of the regulator. Typically a large storage

capacitor is connected from this pin to ground to insure that

the input voltage does not sag below the minimumdrop out

voltage during the load transient response. This pin must al-

ways be 0.6V higher than Vout in order for thedevice to regu-

late properly.

APPLICATION INFORMATION

Stability

The US120X series of regulators require the use of an

output capacitor as part of the frequency compensation

in order to make the regulator stable. A minimum of

2.2uF capacitance and the ESR in the range of 0.5 to 2

ohm insures the stability of the system.

2-3

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