Datasheet LD2985BM33R, LD2985BM32R, LD2985BM31R, LD2985BM30R, LD2985BM28R Datasheet (SGS Thomson Microelectronics)

LD2985

SERIES

VERY LOW DROP AND LOW NOISE VOLTAGE REGULATOR

LOW ESR CAP. COMPATIBLE, WITH INHIBIT FUNCTION

■ VERY LOW DRO PO UT VOLTAGE (280mV

AT 150mA AND 7mV AT 1mA LOAD)

■ VERY LOW QUIESCENT CURRE NT (2mA

TYP. AT 150mA LOAD AND 80µAATNO
LOAD)

■ OUTPUT CURRENT UP TO 150mA

■ LOGIC C ONTROLLED ELECTRONIC

SHUTDOWN

■ OUTPUT VOLTAGE OF 1.5, 1.8,2.5, 2.8,

2.85,3,3.1,3.2,3.3,3.5,3.6,3.8,4,4.7,5V

■ INTERNAL CURRENT AND THERMAL LIMIT

■ AVAILABLE IN ± 1% TOLLERANCE (AT25°C,

AVERSION)

■ LOW OUTPUT NOISE VOLTAGE 30µVrms

■ SMALLEST PACKAGESOT23-5L

■ TEMPERATURE RAN GE : -40°C TO 125°C

DESCRIPTION

The LD2985 is a 150mA fixed output voltage
regulator. The ultra low drop voltage and the low
quiescent current make them particularly suitable
for low noise , low power applications , and in
battery powered systems. In sleep mode
quiescent current is less than 1µA when INHIBIT
pin i s pulled low. Shut down Logic Control F unc tion

is av ailable on pin 3 (TTL c ompatible). This means
that when t he device is used as local regulator, it
is possible to put a part of the board in standby,
decreasing the total power consumption.
An external capacitor, C
between bypass pin and GND reduce the noise
to 30µV rms.
Typical application are in cellular phone, palmtop
laptop computer, personal digital assistant (PDA),
personal stereo, ca mcorder and camera.

SOT23-5L

BYP

=10nF, connected

SCHEMATIC DIAGRAM

1/13July 2003

LD2985 SERIES

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

V

INH

I
P
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

Symbol Parameter SOT23-5L Unit

R

thj-case

CONNECTION DIAGRAM (top view) PIN DESCRIPTION

DC Input Voltage

I

INHIBIT Input Voltage
Output Current

O

Power Dissipation

tot

Storage Temperature Range

stg

Operating Junction Temperature Range

op

Thermal Resistance Junction-case

SOT23-5L

16 V

16 V
Internally limited
Internally limited

-65 to +150 °C

-40 to +125 °C

81 °C/W

Pin N° Symbol Name and Function

1 IN Input Port
2 GND Ground Pin
3 INHIBIT Control switch ON/OFF. Inhibit is not

internally pulled-up; it cannot be left
floating. Disable the device when
connected to GND or to a positive
voltage less than 0.18V

4 Bypass Bypass Pin: Capacitor to be

connected to GND in order to
improve the thermal noise
performances.

5 OUT Output Port

ORDERING CODES

A VERSION B VERSION OUTPUT VOLTAGES

LD2985AM15R LD2985BM15R 1.5V
LD2985AM18R LD2985BM18R 1.8V
LD2985AM25R LD2985BM25R 2.5V
LD2985AM28R LD2985BM28R 2.8V

LD2985AM285R LD2985BM285R 2.85V

LD2985AM30R LD2985BM30R 3.0V
LD2985AM31R LD2985BM31R 3.1V
LD2985AM32R LD2985BM32R 3.2V
LD2985AM33R LD2985BM33R 3.3V
LD2985AM35R LD2985BM35R 3.5V
LD2985AM36R LD2985BM36R 3.6V
LD2985AM38R LD2985BM38R 3.8V
LD2985AM40R LD2985BM40R 4.0V
LD2985AM47R LD2985BM47R 4.7V
LD2985AM50R LD2985BM50R 5.0V

2/13

LD2985 SE RIE S

ELECTRICAL CHARACTERISTICS FOR LD2985A (TJ= 25°C, VI=VO+1V, IO=1mA, V

C

=1µF, CO=1µF, unless otherwise s pec ified)

I

SHDN

=2V,

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

Operating Input Voltage 2.5 16 V

Op

Output Voltage VI= 2.5V 1.485 1.5 1.515 V

V

O

= 1 to 50mA 1.462 1.538 V

I

O

I

=1to50mA TJ= -40 to 125°C

O

V

Output Voltage VI= 2.8V 1.782 1.8 1.818

O

= 1 to 150mA 1.755 1.845

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 3.5V 2.475 2.5 2.525

O

= 1 to 150mA 2.4375 2.5625

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 3.8V 2.772 2.8 2.828

O

= 1 to 150mA 2.730 2.870

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 3.85V 2.821 2.85 2.879 V

O

= 1 to 50mA 2.778 2.921 V

I

O

IO=1to50mA TJ= -40 to 125°C

V

Output Voltage VI= 4.0V 2.970 3.0 3.030

O

= 1 to 150mA 2.925 3.075

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.1V 3.069 3.1 3.131

O

= 1 to 150mA 3.022 3.1775

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.2V 3.168 3.2 3.232

O

= 1 to 150mA 3.120 3.280

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.3V 3.267 3.3 3.333

O

= 1 to 150mA 3.2175 3.3825

I

O

= 1 to 150mA TJ= -40 to 125°C

I

O

V

Output Voltage VI= 4.5V 3.465 3.5 3.535

O

= 1 to 150mA 3.412 3.587

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.6V 3.564 3.6 3.636

O

= 1 to 150mA 3.510 3.690

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.8V 3.762 3.8 3.838

O

= 1 to 150mA 3.705 3.895

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 5.0V 3.96 4 4.04

O

= 1 to 150mA 3.9 4.1

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

1.447 1.553 V

1.737 1.863

2.4125 2.5875

2.702 2.898

2.750 2.950 V

2.895 3.105

2.9915 3.2085

3.088 3.312

3.1845 3.4155

3.377 3.622

3.474 3.726

3.667 3.933

3.86 4.14

V
V
V
V
V
V
V
V
V

V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V

3/13

LD2985 SERIES

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

Output Voltage VI= 5.7V 4.653 4.7 4.747

O

= 1 to 150mA 4.582 4.817

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 6.0V 4.95 5 5.05

O

= 1 to 150mA 4.875 5.125

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

I

Short Circuit Current RL= 0 400 mA

SC

/∆VILine Regulation VI=VO+1V to 16V, IO= 1mA 0.003 0.014 %/V

∆V

O

VI=VO+1V to 16V, IO= 1mA

= -40 to 125°C

T

J

V

Dropout Voltage IO=0 1 3 mV

d

I

=0 TJ= -40 to 125°C

O

I

=1mA 7 10 mV

O

I

=1mA TJ= -40 to 125°C

O

I

= 10mA 40 60 mV

O

I

= 10mA TJ= -40 to 125°C

O

I

= 50mA 120 150 mV

O

I

= 50mA TJ= -40 to 125°C

O

I

= 150mA 280 350 mV

O

I

= 150mA TJ= -40 to 125°C

O

I

Quiescent Current IO= 0 80 100 µA

d

I

=0 TJ= -40 to 125°C

O

I

= 1mA 100 150 µA

O

I

=1mA TJ= -40 to 125°C

O

I

= 10mA 200 300 µA

O

I

= 10mA TJ= -40 to 125°C

O

I

= 50mA 600 900 µA

O

I

= 50mA TJ= -40 to 125°C

O

I

= 150mA 2000 3000 µA

O

I

= 150mA TJ= -40 to 125°C

O

SVR Supply Voltage Rejection C

Control Input Logic Low

V

IL

V

Control Input Logic High

IH

I

Control Input Current

iNH

OFF MODE V
OFF MODE V

T

= -40 to 125°C

J

= 0.01µFCO=10µF f = 1KHz 45 dB

BYP

T

= -40 to 125°C

J

T

= -40 to 125°C

J

T

= -40 to 125°C V

J

= -40 to 125°C V

T

J

<0.18V 0 µA

INH

<0.18V

INH

=5V

SHDN

=0V

SHDN

eN Output Noise Voltage B= 300Hz to 50KHz

= 0.01µFC

C

BYP

=10µF

O

4.5355 4.8645

4.825 5.175

0.032 %/V

5mV

15 mV

90 mV

225 mV

575 mV

150 µA

200 µA

400 µA

1200 µA

4000 µA

2 µA

0.15 V

2V

515µA
0-1µA

30 µV

V
V
V
V
V
V

I
I

4/13

LD2985 SE RIE S

ELECTRICAL CHARACTERISTICS FOR LD2985B (TJ= 25°C, VI=VO+1V, IO=1mA, V

C

=1µF, CO=1µF, unless otherwise s pec ified)

I

SHDN

=2V,

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

Operating Input Voltage 2.5 16 V

Op

Output Voltage VI= 2.5V 1.477 1.5 1.523 V

V

O

= 1 to 150mA 1.455 1.545 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 2.8V 1.773 1.8 1.827 V

O

= 1 to 150mA 1.746 1.854 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 3.5V 2.4625 2.5 2.5375 V

O

= 1 to 150mA 2.425 2.575 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 3.8V 2.758 2.8 2.842 V

O

= 1 to 150mA 2.716 2.884 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 3.85V 2.807 2.85 2.893 V

O

= 1 to 150mA 2.764 2.935 V

I

O

IO= 1 to 150mA TJ= -40 to 125°C

V

Output Voltage VI= 4.0V 2.955 3.0 3.045 V

O

= 1 to 150mA 2.91 3.09 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.1V 3.0535 3.1 3.1465 V

O

= 1 to 150mA 3.007 3.193 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.2V 3.152 3.2 3.248 V

O

= 1 to 150mA 3.104 3.296 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.3V 3.2505 3.3 3.3495 V

O

= 1 to 150mA 3.201 3.399 V

I

O

= 1 to 150mA TJ= -40 to 125°C

I

O

V

Output Voltage VI= 4.5V 3.447 3.5 3.552 V

O

= 1 to 150mA 3.395 3.605 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.6V 3.546 3.6 3.654 V

O

= 1 to 150mA 3.492 3.708 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 4.8V 3.743 3.8 3.857 V

O

= 1 to 150mA 3.686 3.914 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 5.0V 3.94 4 4.06 V

O

= 1 to 150mA 3.88 4.12 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

1.440 1.560 V

1.728 1.872 V

2.4 2.6 V

2.688 2.912 V

2.736 2.964 V

2.88 3.12 V

2.976 3.224 V

3.072 3.328 V

3.168 3.432 V

3.360 3.640 V

3.456 3.744 V

3.648 3.952 V

3.84 4.16 V

5/13

LD2985 SERIES

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

Output Voltage VI= 5.7V 4.6295 4.7 4.7705 V

O

= 1 to 150mA 4.559 4.841 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

V

Output Voltage VI= 6.0V 4.925 5 5.075 V

O

= 1 to 150mA 4.85 5.15 V

I

O

I

= 1 to 150mA TJ= -40 to 125°C

O

I

Short Circuit Current RL= 0 400 mA

SC

/∆VILine Regulation VI=VO+1V to 16V, IO= 1mA 0.003 0.014 %/V

∆V

O

VI=VO+1V to 16V, IO= 1mA

= -40 to 125°C

T

J

V

Dropout Voltage IO=0 1 3 mV

d

I

=0 TJ= -40 to 125°C

O

I

=1mA 7 10 mV

O

I

=1mA TJ= -40 to 125°C

O

I

= 10mA 40 60 mV

O

I

= 10mA TJ= -40 to 125°C

O

I

= 50mA 120 150 mV

O

I

= 50mA TJ= -40 to 125°C

O

I

= 150mA 280 350 mV

O

I

= 150mA TJ= -40 to 125°C

O

I

Quiescent Current IO= 0 80 100 µA

d

I

=0 TJ= -40 to 125°C

O

I

= 1mA 100 150 µA

O

I

=1mA TJ= -40 to 125°C

O

I

= 10mA 200 300 µA

O

I

= 10mA TJ= -40 to 125°C

O

I

= 50mA 600 900 µA

O

I

= 50mA TJ= -40 to 125°C

O

I

= 150mA 2000 3000 µA

O

I

= 150mA TJ= -40 to 125°C

O

SVR Supply Voltage Rejection C

Control Input Logic Low

V

IL

V

Control Input Logic High

IH

I

Control Input Current

iNH

OFF MODE V
OFF MODE V

T

= -40 to 125°C

J

= 0.01µFCO=10µF f = 1KHz 45 dB

BYP

T

= -40 to 125°C

J

T

= -40 to 125°C

J

T

= -40 to 125°C V

J

= -40 to 125°C V

T

J

<0.18V 0 µA

INH

<0.18V

INH

=5V

SHDN

=0V

SHDN

eN Output Noise Voltage B= 300Hz to 50KHz

= 0.01µFC

C

BYP

=10µF

O

4.512 4.888 V

4.8 5.2 V

0.032 %/V

5mV

15 mV

90 mV

225 mV

575 mV

150 µA

200 µA

400 µA

1200 µA

4000 µA

2 µA

0.15 V

2V

515µA
0-1µA

30 µV

I
I

6/13

LD2985 SE RIE S

TYPICAL CHARACTERISTICS (unless otherwise spec ified TJ= 25°C, CI=1µF, CO=2.2µF, C
Figure1 : Output Voltage vs Temperature

Figure2 : Dropout Voltage v s Temperature

Figure4 : Quiescent Current v s Load Current

Figure5 : Quiescent Current v s Temperature

BYP

=100nF)

Figure3 : Dropout Voltage v s Output Current

Figure6 : Supply Voltage Rejection vs

Temperature

7/13

LD2985 SERIES

V

I

C

C

t

t

V

I

C

C

Figure7 : Supply Voltage Rejection vs Output
Current

Figure8 : Supply Voltage Rejection vs Output
Current

Figure10 : Supply Voltage Rejection vs
Frequency

Figure11 : Line Transient

Figure9 : Supply Voltage Rejection vs

Frequency

8/13

=2.5V,

O

=50mA,no

O

,

I

=4.7µF,

O

Figure12 : Line Transient

=2.5V,

O

=50mA,no

O

,

=4.7µF,tr=tf=1µs

I

O

=

=2ns

r

f

Figure13 : Load Transient Figure14 : Load Transient

V

I

C

C

V

I

C

C

LD2985 SE RIE S

=2.5V,

O

=0to 50mA,no

O

,

=10µF,ts=tf=2ns

I

O

=2.5V,

O

=0to 50mA,no

O

,

=4.7µF,ts=tf=2ns

I

O

EXTERNAL CAPACITORS

Like any low-dropout regulator, the LD2985 requires e xternal c apacitors for regulator stability . This
capacitor must be selected to meet the requirements of m inimum capacitance and equivalent series
resistance. We suggest to solder input and output capacitors as close as possible to the relative pins.

INPUT CAPACITOR

An input capacitor whose value is 1µF is required with the LD2985 (amount of capacitance c an be
increased without limit). This capacitor must be located a distance of not more t han 0.5" from the input pin
of the device and returned to a clean analog ground. Any good quality ceramic , tantalum or film capacitors
can be used for this capacitor.

OUTPUT CAPACITOR

The LD2985 is designed specifically to work with c eramic output capacitors. It may also be possibl e to use
Tantalum capacitors, but t hes e are not as attractive for reasons of size and cost. By the way, the output
capacitor must meet both the requi re ment for mi nimum amount of capacitance and E.S.R. (equivalent
series resistance) v alue. Due to the different loop gain, the stability improv es for higher output versions
and so the sugg ested minimum output capacitor value, if low E.S.R. ceramic type is used, is 1µF for
output voltages equal or major than 3.8V, 2.2µF for V

going from 1.8 to 3.3V, an d 3. 3µF for the other

O

versions. However, if an output capacitor lower than the suggested one is used, it 's possible t o make
stable the regulator adding a resistor in series to the capacitor.

IMPORTANT:
The outp ut capacitor must maintain i ts ESR in the stable region over the full operating temperature to

assure stability. Also, capacitor tolerance and variation with temperature must be considered to assure
the minimum amount of capacitance is provided at all times. This capacitor should be located not more
than 0.5" from the output pin of the device and returned to a clean analog grou nd.

INHIBIT INPUT OPERATION

The inhibit pin can be used to turn OFF the regulator when pulled low, so drastically red uc ing the current
consumption down to less than 1µA. When the inhibit feature is not used, this p in m us t b e tied to V

to

I

keep the regulator output ON at all times. To assure proper operation, the signal source us ed to drive the
inhibit pin must be able to swing above and below the specified thresholds li sted in the electrical
characteristics section under V

.Anyslewratecanbeusedtodrivetheinhibit.

IHVIL

9/13

LD2985 SERIES

REVERSE CURRENT

The power transistor used in the LD2985 has not an inherent diode connected between the regulator input
and output. If the output is forced above the input, no current will flow from the output to the input across
the series pas s transistor. When a V
flows to the GND across the two feedback resistors. This current typical value is 160µA. R
resistors are implanted type; typical values are, respectively, 42.6 KΩ and 51.150 KΩ.

Figure15 : Reverse Current Test Circuit

voltage is applied on the output, t he reve rse current measured

REV

and R

1

2

10/13

LD2985 SE RIE S

SOT23-5L MECHANICAL DATA

mm. mils

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 0.90 1.45 35.4 57.1

A1 0.00 0.10 0.0 3.9

A2 0.90 1.30 35.4 51.2

b 0.35 0.50 13.7 19.7

C 0.09 0.20 3.5 7.8

D 2.80 3.00 110.2 118.1

E 1.50 1.75 59.0 68.8

e0.95 37.4

H 2.60 3.00 102.3 118.1

L 0.10 0.60 3.9 23.6

.

7049676C

11/13

LD2985 SERIES

Tape & Reel SOT23-xL MECHANICAL DATA

DIM.

MIN. TYP MAX. MIN. TYP. MAX.

A 180 7.086
C 12.8 13.0 13.2 0.504 0.512 0.519
D 20.2 0.795
N 60 2.362

T 14.4 0.567
Ao 3.13 3.23 3.33 0.123 0.127 0.131
Bo 3.07 3.17 3.27 0.120 0.124 0.128
Ko 1.27 1.37 1.47 0.050 0.054 0.0.58
Po 3.9 4.0 4.1 0.153 0.157 0.161

P 3.9 4.0 4.1 0.153 0.157 0.161

mm. inch

12/13

LD2985 SE RIE S

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use o f suc h inf ormat ion n or f or an y infr ingeme nt of paten ts or oth er ri gh ts of third part ies whic h may resul t f rom
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mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
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13/13