Micrel MIC5256 User Manual

MIC5256 Micrel

查询MIC5256-2.6BM5供应商

MIC5256

150mA µCap LDO with Error Flag

Final Information

General Description

The MIC5256 is an efficient, precise CMOS voltage regula­tor. It offers better than 1% initial accuracy, extremely low­dropout voltage (typically 135mV at 150mA) and low ground
current (typically 90µA) over load. The MIC5256 features an
error flag that indicates an output fault condition such as
overcurrent, thermal shutdown and dropout.

Designed specifically for handheld and battery-powered de­vices, the MIC5256 provides a TTL-logic-compatible enable
pin. When disabled, power consumption drops nearly to zero.

The MIC5256 also works with low-ESR ceramic capacitors,
reducing the amount of board space necessary for power
applications, critical in hand-held wireless devices.

Key features include current limit, thermal shutdown, faster
transient response, and an active clamp to speed up device
turnoff. Available in the IttyBitty™ SOT-23-5 package and the
new Thin SOT-23-5, which offers the same footprint as the
standard IttyBitty™ SOT-23-5, but only 1mm tall. The MIC5256
offers a range of output voltages.

Features

• Input voltage range: 2.7V to 6.0V

• Thin SOT package: 1mm height

• Error flag indicates fault condition

• Stable with ceramic output capacitor

• Ultralow dropout: 135mV @ 150mA

• High output accuracy:

1.0% initial accuracy

2.0% over temperature

• Low quiescent current: 90µA

• Tight load and line regulation

• Thermal shutdown and current limit protection

•“Zero” off-mode current

• TTL logic-controlled enable input

Applications

• Cellular phones and pagers

• Cellular accesories

• Battery-powered equipment

• Laptop, notebook, and palmtop computers

• Consumer/personal electronics

T ypical Application

Ordering Information

Part Number Marking Voltage Junction Temp. Range Package

MIC5256-2.6BM5 LX26 2.6V –40°C to +125°C SOT-23-5
MIC5256-2.7BM5 LX27 2.7V –40°C to +125°C SOT-23-5
MIC5256-2.8BM5 LX28 2.8V –40°C to +125°C SOT-23-5
MIC5256-2.85BM5 LX2J 2.85V –40°C to +125°C SOT-23-5
MIC5256-3.0BM5 LX30 3.0V –40°C to +125°C SOT-23-5
MIC5256-3.3BM5 LX33 3.3V –40°C to +125°C SOT-23-5
MIC5256-2.85BD5 NX2J 2.85V –40°C to +125°C TSOT-23-5

Other voltages available. Contact Micrel for details.

MIC5256-x.xBM5

IN

15

2
34

V

OUT

C

= 1.0µF

OUT

Ceramic

FLG

= 1.0µF

C

IN

Ceramic

Enable

Shutdown

EN (pin 3) may be
connected directly
to IN (pin 1).

Low-Noise Regulator Application

V

EN

IttyBitty is a trademark of Micrel, Inc.

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com

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MIC5256 Micrel

Pin Configuration

GND

2

IN

13

EN

LXxx

45

FLG

OUT

MIC5256-x.xBM5

(SOT-23-5)

Pin Description

Pin Number Pin Name Pin Function

1 IN Supply Input.
2 GND Ground.
3 EN Enable/Shutdown (Input): CMOS compatible input. Logic high = enable;

4 FLG Error Flag (Output): Open-drain output. Active low indicates an output

5 OUT Regulator Output.

EN

MIC5256-x.xBD5

logic low = shutdown. Do not leave open.

undervoltage condition.

IN

GND

13

2

NWxx

45

OUTBYP

(TSOT-23-5)

MIC5256 2 June 2003

MIC5256 Micrel

Absolute Maximum Ratings (Note 1)

Supply Input Voltage (V
Enable Input Voltage (V
Power Dissipation (P

Junction Temperature (TJ) ....................... –40°C to +125°C

) .................................. 0V to +7V

IN

) ................................. 0V to +7V

EN

) ............... Internally Limited, Note 3

D

Operating Ratings (Note 2)

Input Voltage (V

Enable Input Voltage (VEN) .................................. 0V to V

Junction Temperature (TJ) ....................... –40°C to +125°C

Thermal Resistance

SOT-23 (θJA) .....................................................235°C/W

) ......................................... +2.7V to +6V

IN

Storage Temperature ............................... –65°C to +150°C

Lead Temperature (soldering, 5 sec.) ....................... 260°C

ESD, Note 4..................................................................2kV

Electrical Characteristics

VIN = V

Symbol Parameter Conditions Min Typical Max Units

V

O

∆V

LNR

∆V

LDR

VIN – V

I

Q

I

GND

PSRR Power Supply Rejection f = 10Hz, VIN = V

I

LIM

e

n

Enable Input

V

IL

V

IH

I

EN

Error Flag

V

FLG

V

OL

I

FL

Thermal Protection

+ 1V, VEN = V

OUT

Output Voltage Accuracy I

Line Regulation VIN = V
Load Regulation I

OUT

Dropout Voltage, Note 6 I

Quiescent Current VEN ≤ 0.4V (shutdown) 0.2 1 µA
Ground Pin Current, Note 7 I

Current Limit V
Output Voltage Noise tbd

Enable Input Logic-Low Voltage VIN = 2.7V to 5.5V, regulator shutdown 0.4 V
Enable Input Logic-High Voltage VIN = 2.7V to 5.5V, regulator enabled 1.6 V
Enable Input Current VIL ≤ 0.4V, regulator shutdown 0.01 µA

Shutdown Resistance Discharge 500 Ω

Low Threshold % of V
High Threshold % of V

Output Logic-Low Voltage IL = 100µA, fault condition 0.02 0.1 V
Flag Leakage Current flag off, V

Thermal Shutdown Temperature 150 °C
Thermal Shutdown Hysteresis 10 °C

= 100µA; TJ = 25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless noted.

IN; IOUT

= 100µA –1+1%

OUT

+ 1V to 6V 0.02 0.05 %/V

OUT

= 0.1mA to 150mA, Note 5 1.5 2.5 %

OUT

= 100µA 0.1 5.0 mV

OUT

I

= 100mA 90 150 mV

OUT

= 150mA 135 200 mV

I

OUT

= 0mA 90 150 µA

OUT

I

= 150mA 117 µA

OUT

+ 1V; C

OUT

f = 100Hz, VIN = V
f = 10kHz, VIN = V

= 0V 160 425 mA

OUT

+ 0.5V; C

OUT

+ 0.5V 45 dB

OUT

= 1µF60dB

OUT

= 1µF60dB

OUT

VIH ≥ 1.6V, regulator enabled 0.01 µA

(Flag ON) 90 %

OUT

(Flag OFF) 96 %

OUT

= 6V 0.01 µA

FLG

–2+2%

250 mV

µV(rms)

IN

Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3. The maximum allowable power dissipation of any TA (ambient temperature) is P

D(max)

= T

J(max)–TA/θJA

. Exceeding the maximum allowable

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MIC5256 Micrel

power dissipation will result in excessive die temperature, and the regulator will go into thermal shutdown. The θJA of the MIC5255-x.xBM5 (all
versions) is 235°C/W on a PC board (see “Thermal Considerations” section for further details).

Note 4. Devices are ESD sensitive. Handling precautions recommended.
Note 5. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load

Note 6. Dropout Voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V

Note 7. Ground pin current is the regulator quiescent current. The total current drawn from the supply is the sum of the load current plus the ground

range from 0.1mA to 150mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.

differential. For outputs below 2.7V, dropout voltage is the input-to-output voltage differential with the minimum input voltage 2.7V. Minimum
input operating voltage is 2.7V.

pin current.

MIC5256 4 June 2003