Bay Linear LM2931Z-90, LM2931Z-85, LM2931Z-33, LM2931Z-15, LM2931Z-10 Datasheet

Bay Linear, Inc

2478 Armstrong Street, Livermore, CA 94550 Tel: [phone], Fax: [phone] www.baylinear.com

100mA Low Dropout Voltage Regulator

LM2931

Pin Connection

Ordering Information

8SOIC (M)

Package Tolerance

SOT-89

LM2931R-XX

TO-92

LM2931Z-XX

8-SOIC

LM2931M-XX

“XX” Voltage Selection Guide

Vout XX Code

3.3V

33

5.0V

50

8.0V

80

8.5V

85

9.0V

90

10.0V

10

12.0V

12

15.0V

15

Adjustable

Left Blank

Description

The Bay Linear LM2931 are low power voltage regulators
designed for a wide range of applications. They are an
excellent choice for use in Battery Powered applications. The
LM2931 feature low quiescent current (100 µA Typ.) and low
dropout of only 60mV at light loads and 300mV (typ.) at
100mA. The LM2931 has tight initial tolerance of 0.5% typ.,
extremely good load and line regulation of 0.05% typ. and very
low output temperature coefficient.

The Bay Linear LM2931 is available as a fixed voltage
regulator and as an adjustable regulator in TO-92 and 8SOIC
packages. The Bay Linear LM2931 in an 8SOIC package has
an adjustable output voltage from 3V to 24V, programmed
with a pair of external resistor. The logic compatible shutdown
enables the regulator to be switched ON and OFF.

Features

•

Guaranteed 100mA Output

•

Fixed Versions 3.3V, 50.V, 8.0

•

Very Low Quiescent Current

•

Low Dropout Voltage

•

Extremely Tight Load and Line
Regulation

•

Very Low Temperature Coefficient

•

Current and Thermal Limiting

•

Reverse Battery Protection of –20V

•

Transient protection of 60V

•

Output programmable from 3V to 24V

Applications

• Battery Powered Systems

• Portable instrumentation

• Notebooks Computers

• Potable Consumer Equipment

• Automotive electronics

• SMPS Post-Regulator

Bay Linear

Bay LinearBay Linear

Bay Linear

Linear Excellenc e

1

2

4

3

5

6

7

8

Output

Input

GND

GND

GND

GND

Feedback

Shutdown

SOT-89

Front View

INPUT

GND

OUTPUT

BAY

LM2931

OUTPUT

GROUND

INPUT

13

2

TO-92

Bott om View

SOT-89

Front View

INPUT

GND

OUTPUT

BAY

LM2931

SOT-89

Front View

INPUT

GND

OUTPUT

BAY

LM2931

OUTPUT

GROUND

INPUT

13

2

TO-92

Bott om View

OUTPUT

GROUND

INPUT

13

2

TO-92

Bott om View

Bay Linear, Inc

2478 Armstrong Street, Livermore, CA 94550 Tel: [phone], Fax: [phone] www.baylinear.com

LM2931

Absolute Maximum Rating

Parameter

Power Dissipation Internally Limited
Lead Temperature ( Soldering 5 seconds )

260 °C

Storage Temperature Range

-65 °C to +150 °C

Operating Junction Temperature

-55 °C to +150 °C

Input Supply Voltage -20 to +35V

Electrical Characteristics

TJ = 25°C , IO = 100µA, VIN = 14V ( for 2931-15 VIN = 16V), CO = 100µF; unless otherwise specified)

Parameter Conditions MIN TYP MAX UNIT

Output Voltage
(Fixed Version)

-25 °C ≤ T

j

≤

85 °C

Full Operating Temperature

0.985 [ V

o

]

0.98 [ V

o

]

V

o

1.015 [ Vo ]

1.02 [ V

o

]

V

Output Voltage (Fixed Versi on)

100µA ≤ I

L

≤

100mA, T

j

≤ T

jmax

0.975 [Vo ] Vo 1.025 [ Vo ]

V

Input Supply Voltage 26 V
Output Voltage Temperature

Coefficient

(Note 1) 50 150

ppm / ° C

Line Regulation (Note 2)

13V ≤ V

IN

≤ 26V (Note 3)

0.1 0.4 %

Load Regulation (Note 2)

100µA ≤ I

L

≤

100mA

0.1 0.3 %

Dropout Voltage (Note 4)

I

L

= 100µA

IL = 100mA

60

300

200
600

mV

Ground Current (Note 5)

I

L

= 100µA
IL = 10mA
I

L

= 100mA

100

0.9
8

150

1.5
12

µ

A
mA
mA

Dropout Ground Current

V

IN

= (V

OUT

– 0.5V), IL = 100µA

110 170

µ

A

Current Limit V

OUT

= 0 160 200 mA
Thermal Regulation (Note 6) 0.05 0.2 % / W
Output Noise,
10Hz to 100KHz
I

L

= 10mA

C

L

= 2.2µF

C

L

= 3.3µF

C

L

= 33µF

500

350
120

µ

Vrms

Ripple Rejection Ratio

I

O

= 10mA, f = 120Hz, C0 = 100µF

VIN = VO + 3V+2Vpp

60 dB

8 pin Versions only (LP2951)

Reference Voltage

Over Temperature (Note 7)

1.21

1.185

1.235 1.26

1.285

V

Feedback Pin Bias Current 20 40

η

A
Reference Voltage Temperature
Coefficient

(Note 1) 50

ppm/°C

Feedback Pin Bias Current
Temperature Coefficient

0.1

ηA/°

C

Shutdown Input

Input Logic Vol tage Low (Regulator ON)

High (Regulator OFF)

2

1.3 0.7 V

Shutdown Pin Input Current VS = 2.4V

VS = 26V

30

450

50

600

µ

A

Regulator Output Current
in Shutdown

(Note 8)

5.0V ≤ V

OUT

≤

15.0V

3.3V ≤ V

OUT

≤

5.0V

2.0V ≤ V

OUT

≤

3.3V

10
20
30

µ

A

Bay Linear, Inc

2478 Armstrong Street, Livermore, CA 94550 Tel: [phone], Fax: [phone] www.baylinear.com

LM2931

Note 1:

Output or reference voltage temperature coefficient s defined as the worst case voltage change di vided by the total temperature range.

Note 2:

Unless otherwise sp ecified all limits guaranteed for T

J

= 25°C, VIN = VO +1V, IL = 100µA and CL = 1µF. Additional conditions for the 8-

pin versions are feedback tied to –XX Voltage tap and output tied to output Sense pin ( V

OUT

= XX V) and V

SHUTDOWN

≤ 0.8V

Note 2:

Regulation is meas ured at constant junction temperat ure , using pulse testing with a low dut y cycle. Changes in output voltage due to

heating effects are covered under sp ecification for therm al regulation.

Note 3:

Line regulation for is tested at 150°C for I

L

= 1mA. For IL = 100µA and TJ = 125°C, line regulation is guaranteed by design to 0.2%. for

B2931-15 16V ≤ V

IN

≤ 26V.

Note 4:

Dropout voltage is defined as the input to output differentia l at which the output voltage drops 2% below i ts nominal value measured at

1V differential .

Note 5:

Ground pin Current is the regulator quiescent current. The total current drawn from the source is the sum of the ground pin current and

output load current.

Note 6:

Thermal regulati on is the change in output voltage at a time T af ter a change in power dissipation, exclu ding load or line regulation

effects. Specifications are for a 50 mA load pulse (1.25W) for T = 10ms.

Note 7:

V

REF

≤ V

OUT

≤ (V

IN

–1V), 2.3V ≤ VIN ≤ 26V, 100µA ≤ IL ≤100mA, T

J

≤ T

JMAX

Note 8:

V

SHUTDOWN

≥ 2V, VIN ≤ 26V, V

OUT

= 0

Application Hints

The LM2931 requires an output capacitor for device
stability. The value required varies greatly
depending upon the application circuit and other
factors. The high frequency characteristics of
electrolytic capacitors depend greatly on the type and
also on the manufacturer. Sometimes only bench
testing is the only means to determine the proper
capacitor type and value. The high quality 100 µF
aluminum electrolytic covers all general application
circuits, this stability can be o btained with a ta ntal u m
electrolytic value of 47 µF.

Another critical point of electrolytic characteristics is
its performance over temperature. The LM2931 is
designed to operate starting at -40°C which may not
be true in the case of electrolytic. Higher
temperatures generally no problem. The electrolytic.
type in aluminum will freeze around -30°C. This
could cause an oscillation at output of regulator. At a
lower temperature requirement by many applications
the capacitor should maintain its performance. So as
a result, for an application which regulator junction
temperature does not exceed 25°C, the output
capacitor can be reduced by the

factor of two over the value needed for the entire
temperature range.

Other points with linear regulators are that the twitch
higher output current stability

decreases. In most
applications the LM2931 is operating at few
milliamps. In these applications the output capacitance
can be further reduced. For example, when the
regulator is running at 10mA output current the output
capacitance value is half compared to the same
regulator that is running at 100 mA.
With the LM2931 adjustable regulator, the minimum
value of output capacitance is a function of the output
voltage. The value decreases with higher output
voltages, since the internal loop gain is reduced.

The worst case occurs at the lower temperature and
maximum operating currents, the entire circuit and the
electrolytic, should be cooled down to the minimum
temperature. The minimum of 0.6 volts required at
the input of regulator above the output to keep the
power dissipation and die heating to its minimum.
After the value for the capacitor has been determined
for actual use, the value should be doubled.