LD3985G122R - STMicroelectronics, Inc.

January 2011 Doc ID 9587 Rev 14 1/23

LD3985xx

Ultra low drop-low noise BiCMOS voltage

regulators low ESR capacitors compatible

Features

■Input voltage from 2.5 V to 6 V

■Stable with low ESR ceramic capacitors

■Ultra low dropout voltage (60 mV typ. at 150

mA load, 0.4 mV typ. at 1 mA load)

■Very low quiescent current (85 µA typ. at no

load, 170 µA typ. at 150 mA load; max 1.5 µA

in OFF mode)

■Guaranteed output current up to 150 mA

■Wide range of output voltage: 1.22 V; 1.8 V; 2.5

V; 2.6 V; 2.7 V; 2.8 V; 2.9 V; 3 V; 3.3 V; 4.7 V

■Fast turn-on time: typ. 200 µs [CO = 1 µF, CBYP

= 10 nF and IO = 1 mA]

■Logic-controlled electronic shutdown

■Internal current and thermal limit

■Output low noise voltage 30 µVRMS over 10 Hz

to 100 kHz

■SVR of 60 dB at 1 kHz, 50 dB at 10 kHz

■Temperature range: - 40 °C to 125 °C

Description

The LD3985xx provides up to 150 mA, from 2.5 V

to 6 V input voltage. The ultra low drop-voltage,

low quiescent current and low noise make it

suitable for low power applications and in battery

powered systems. Regulator ground current

increases only slightly in dropout, further

prolonging the battery life. Power supply rejection

is better than 60 dB at low frequencies and starts

to roll off at 10 kHz. High power supply rejection is

maintained down to low input voltage levels

common to battery operated circuits. Shutdown

logic control function is available, this means that

when the device is used as local regulator, it is

possible to put a part of the board in standby,

decreasing the total power consumption. The

LD3985xx is designed to work with low ESR

ceramic capacitors. Typical applications are in

mobile phone and similar battery powered

wireless systems.

Flip-chip TSOT23-5LSOT23-5L

(1.57 x 1.22)

Table 1. Device summary

Part numbers

LD3985XX122 LD3985XX28

LD3985XX18 LD3985XX29

LD3985XX25 LD3985XX30

LD3985XX26 LD3985XX33

LD3985XX27 LD3985XX47

www.st.com

         
Contents LD3985xx
2/23  Doc ID 9587 Rev 14
Contents
Diagram  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Typical application   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Electrical characteristics   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Typical performance characteristics  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Package mechanical data  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Order codes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Revision history   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

LD3985xx Diagram

Doc ID 9587 Rev 14 3/23

1 Diagram

Figure 1. Schematic diagram

Pin configuration LD3985xx

4/23 Doc ID 9587 Rev 14

2 Pin configuration

Figure 2. Pin connections (top view for SOT and TSOT, top through view for Flip-chip)

Flip-chip

SOT23-5L/TSOT23-5L

Table 2. Pin description

Pin n° for

SOT23-5L/

TSOT23-5L

Pin n° for

Flip-chip Symbol Name and function

14V

IInput voltage of the LDO

2 2 GND Common ground

31V

INH

Inhibit input voltage: ON MODE when VINH ≥ 1.2 V, OFF MODE when VINH

≤ 0.4 V (Do not leave floating, not internally pulled down/up)

4 5 BYPASS Bypass pin: connect an external capacitor (usually 10 nF) to minimize

noise voltage

53V

OOutput voltage of the LDO

LD3985xx Typical application

Doc ID 9587 Rev 14 5/23

3 Typical application

Figure 3. Typical application circuit

Maximum ratings LD3985xx

6/23 Doc ID 9587 Rev 14

4 Maximum ratings

Note: Absolute maximum ratings are those values beyond which damage to the device may occur.

Functional operation under these condition is not implied.

Table 3. Absolute maximum ratings

Symbol Parameter Value Unit

VIDC input voltage -0.3 to 6 (1)

1. The input pin is able to withstand non repetitive spike of 6.5 V for 200 ms.

VODC output voltage -0.3 to VI+0.3 V

VINH INHIBIT input voltage -0.3 to VI+0.3 V

IOOutput current Internally limited

PDPower dissipation Internally limited

TSTG Storage temperature range -65 to 150 °C

TOP Operating junction temperature range -40 to 125 °C

Table 4. Thermal data

Symbol Parameter SOT23-5L/

TSOT23 Flip-chip Unit

RthJC Thermal resistance junction-case 81 °C/W

RthJA Thermal resistance junction-ambient 255 170 °C/W

LD3985xx Electrical characteristics

Doc ID 9587 Rev 14 7/23

5 Electrical characteristics

TJ = 25 °C, VI = VO(NOM) +0.5 V, CI = 1 µF, CBYP = 10 nF, IO = 1 mA, VINH = 1.4 V, unless

otherwise specified.

Table 5. Electrical characteristics for LD3985

Symbol Parameter Test conditions Min. Typ. Max. Unit

VIOperating input voltage 2.5 6 V

VOOutput voltage < 2.5 V IO = 1 mA -50 50 mV

TJ= -40 to 125°C -75 75

VOOutput voltage ≥ 2.5 V IO = 1 mA -2 2 % of

VO(NOM)

TJ= -40 to 125°C -3 3

ΔVOLine regulation (1)

VI = VO(NOM) + 0.5 to 6 V

TJ= -40 to 125°C -0.1 0.1 %/V

VO = 4.7 to 5V -0.19 0.19

ΔVOLoad regulation IO = 1 mA to 150mA, VO < 2.5V

TJ= -40 to 125°C 0.002 0.008 %/mA

ΔVOLoad regulation

IO = 1 mA to 150mA, VO ≥ 2.5V

TJ= -40 to 125°C (for flip-chip) 0.0004 0.002

%/mA

IO = 1 mA to 150mA, TJ= -40 to 125°C

(for SOT23-5L/TSOT23-5L), VO ≥ 2.5V 0.0025 0.005

ΔVO

Output AC Line regulation

(2) VI = VO(NOM) + 1 V, IO = 150mA,

tR= tF = 30µs 1.5 mVPP

Quiescent current

ON MODE: VINH = 1.2 V

IO = 0 85

µA

IO = 0, TJ= -40 to 125°C 150

IO = 0 to 150mA 170

IO = 0 to 150mA, TJ= -40 to 125°C 250

OFF MODE: VINH = 0.4 V 0.003

TJ= -40 to 125°C 1.5

VDROP Dropout voltage (3)

IO = 1mA 0.4

IO = 1mA, TJ= -40 to 125°C 2

IO = 50mA 20

IO = 50mA, TJ= -40 to 125°C 35

IO = 100mA 45

IO = 100mA, TJ= -40 to 125°C 70

IO = 150mA 60

IO = 150mA, TJ= -40 to 125°C 100

ISC Short circuit current RL = 0 600 mA

Electrical characteristics LD3985xx

8/23 Doc ID 9587 Rev 14

SVR Supply voltage rejection

VI = VO(NOM)+0.25V ±

VRIPPLE = 0.1V, IO= 50mA

VO(NOM) < 2.5V, VI = 2.55V

f = 1kHz 60

f = 10kHz 50

IO(PK) Peak output current VO ≥ VO(NOM) - 5% 300 550 mA

VINH

Inhibit input logic low VI = 2.5V to 6V, TJ= -40 to 125°C 0.4 V

Inhibit input logic high 1.2

IINH Inhibit input current VINH = 0.4V, VI = 6V ±1 nA

eN Output noise voltage BW = 10 Hz to 100 kHz, CO = 1µF 30 µVRMS

tON Turn On time (4) CBYP = 10 nF 100 250 µs

TSHDN Thermal shutdown (5) 160 °C

COOutput capacitor Capacitance (6) 122µF

ESR 5 5000 mΩ

1. For VO(NOM) < 2 V, VI = 2.5 V

2. For VO(NOM) = 1.25 V, VI = 2.5 V

3. Dropout voltage is the input-to-output voltage difference at which the output voltage is 100 mV below its nominal value. This

specification does not apply for input voltages below 2.5 V

4. Turn-on time is time measured between the enable input just exceeding VINH High Value and the output voltage just

reaching 95 % of its nominal value

5. Typical thermal protection hysteresis is 20 °C

6. The minimum capacitor value is 1 µF, anyway the LD3985 is still stable if the compensation capacitor has a 30 % tolerance

in all temperature range

Table 5. Electrical characteristics for LD3985 (continued)

Symbol Parameter Test conditions Min. Typ. Max. Unit

LD3985xx Typical performance characteristics

Doc ID 9587 Rev 14 9/23

6 Typical performance characteristics

TJ = 25 °C, VI = VO(NOM) +0.5 V, CI = CO = 1 µF, CBYP = 10 nF, IO = 1 mA, VINH = 1.4 V,

unless otherwise specified.

Figure 4. Output voltage vs. temperature Figure 5. Output voltage vs. temperature

Figure 6. Output voltage vs. temperature Figure 7. Shutdown voltage vs. temperature

Figure 8. Shutdown voltage vs. temperature Figure 9. Line regulation vs. temperature

Typical performance characteristics LD3985xx

10/23 Doc ID 9587 Rev 14

Figure 10. Line regulation vs. temperature Figure 11. Line regulation vs. temperature

Figure 12. Load regulation vs. temperature Figure 13. Load regulation vs. temperature

Figure 14. Load regulation vs. temperature Figure 15. Quiescent current vs. temperature

LD3985xx Typical performance characteristics

Doc ID 9587 Rev 14 11/23

Figure 16. Quiescent current vs. temperature Figure 17. Quiescent current vs. temperature

Figure 18. Supply voltage rejection vs.

frequency

Figure 19. Load transient response

VI = 3.2V, IO = 1 to 150mA, Rise-Fall time = 1µsec

Figure 20. Line transient response Figure 21. Start-Up

VI = 3.8V to 4.4V, TJ = 25°C, IO = 150mA, CI = CO = 1µF

(X7R), CBYP = 10nF, Rise-Fall time = 1µsec, VO = 2.7V

VI = 3.3V, IO = 1mA, CI = CO = 1µF (cer), CBYP = 10nF,

Tr = 20ns, VO = 2.8V

Typical performance characteristics LD3985xx

12/23 Doc ID 9587 Rev 14

Figure 22. Turn-Off

VI = 3.3V, IO = 1mA, CI = CO = 1mF (cer), CBYP = 10nF,

Tf = 20ns, VO = 2.8V

LD3985xx Package mechanical data

Doc ID 9587 Rev 14 13/23

7 Package mechanical data

In order to meet environmental requirements, ST offers these devices in different grades of

ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®

specifications, grade definitions and product status are available at: www.st.com.

ECOPACK® is an ST trademark.

Package mechanical data LD3985xx

14/23 Doc ID 9587 Rev 14

Dim.

mm. mils.

Min. Typ. Max. Min. Typ. Max.

A0.90 1.45 35.4 57.1

A1 0.00 0.10 0.0 3.9

A2 0.90 1.3035.4 51.2

b0.35 0.50 13.7 19.7

C0.090.20 3.5 7.8

D2.803.00 110.2 118.1

E 1.50 1.75 59.0 68.8

e0.9537.4

H 2.60 3.00 102.3118.1

L 0.10 0.60 3.923.6

SOT23-5L mechanical data

7049676D

LD3985xx Package mechanical data

Doc ID 9587 Rev 14 15/23

Dim.

mm. mils.

Min. Typ. Max. Min. Typ. Max.

A1.143.3

A1 0 0.1 3.9

A2 0.7 1.0 27.6 39.4

b0.30.5 11.819.7

C0.080.2 3.1 7.9

D2.9114.2

E2.8110.2

E1 1.6 63.0

e0.9537.4

e1 1.974.8

L0.30.6 11.823.6

TSOT23-5L mechanical data

7282780B

Package mechanical data LD3985xx

16/23 Doc ID 9587 Rev 14

Table 6. Flip-chip 5 mechanical data

mm.

Dim. Min. Typ. Max.

A 0.54 0.65 0.66

A1 0.21 0.25 0.29

A2 0.33 0.35 0.37

b 0.265 0.315 0.365

D 1.54 1.59 1.64

D1 0.83 0.87 0.91

E 1.19 1.24 1.29

E1 0.46 0.5 0.54

eD 0.395 0.435 0.475

eE 0.21 0.25 0.29

fD 0.360

fE 0.370

ccc 0.080

$0.05

LD3985xx Package mechanical data

Doc ID 9587 Rev 14 17/23

Figure 23. Drawing dimension Flip-chip 5

7224716/N

Package mechanical data LD3985xx

18/23 Doc ID 9587 Rev 14

Dim.

mm. inch.

Min. Typ. Max. Min. Typ. Max.

A180 7.086

C 12.813.0 13.2 0.504 0.512 0.519

D 20.2 0.795

N60 2.362

T 14.4 0.567

Ao 3.133.233.33 0.1230.127 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 3.94.0 4.1 0.1530.157 0.161

P3.94.0 4.1 0.1530.157 0.161

Tape & reel SOT23-xL mechanical data

LD3985xx Package mechanical data

Doc ID 9587 Rev 14 19/23

Dim.

mm. inch.

Min. Typ. Max. Min. Typ. Max.

A 1786.926

C 12.813.2 0.504 0.519

D 20.2 0.795

N4950 51 1.9291.9692.008

T 12.4 0.488

Ao 1.60 1.65 1.70 0.0630.065 0.067

Bo 1.27 1.32 1.37 0.050 0.052 0.054

Ko 0.76 0.81 0.86 0.030 0.032 0.034

Po 3.94 4.1 0.1530.157 0.161

P3.94 4.1 0.1530.157 0.161

Tape & reel Flip-chip 5 mechanical data

Package mechanical data LD3985xx

20/23 Doc ID 9587 Rev 14

Dim.

mm. inch.

Min. Typ. Max. Min. Typ. Max.

A180 7.086

C 12.813.0 13.2 0.504 0.512 0.519

D 20.2 0.795

N60 2.362

T 14.4 0.567

Ao 3.133.233.33 0.1230.127 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 3.94.0 4.1 0.1530.157 0.161

P3.94.0 4.1 0.1530.157 0.161

Tape & reel TSOT23-5L mechanical data

LD3985xx Order codes

Doc ID 9587 Rev 14 21/23

8 Order codes

Table 7. Order codes

Packages

SOT23-5L TSOT23-5L Flip-chip Output voltage

LD3985M122R LD3985G122R (1)

1. Available on request.

1.22 V

LD3985M18R LD3985G18R LD3985J18R 1.8 V

LD3985M25R LD3985G25R LD3985J25R 2.5 V

LD3985M26R (1) LD3985G26R (1) LD3985J26R 2.6 V

LD3985M27R LD3985G27R 2.7 V

LD3985M28R LD3985G28R LD3985J28R 2.8 V

LD3985M29R LD3985J29R 2.9 V

LD3985M30R LD3985G30R LD3985J30R 3.0 V

LD3985M33R LD3985G33R LD3985J33R 3.3 V

LD3985M47R LD3985G47R 4.7 V

Revision history LD3985xx

22/23 Doc ID 9587 Rev 14

9 Revision history

Table 8. Document revision history

Date Revision Changes

07-May-2004 6 Part number status changed on table 3.

05-Oct-2004 7 tON values are changed on table 5.

27-Oct-2004 8 Order codes changed - table 3.

17-Mar-2005 9 Improved drawing quality for figures 19 - 20 - 21 - 22.

10-Apr-2007 10 Order codes updated.

08-Jun-2007 11 Order code change.

20-Dec-2007 12 Modified: Ta bl e 1, Ta bl e 7 , mechanical data for Flip-chip.

02-Dec-2008 13 Modified: Table 6 on page 16 and Figure 23 on page 17.

03-Jan-2011 14 Modified: Features on page 1 and Table 7 on page 21.

LD3985xx

Doc ID 9587 Rev 14 23/23

Please Read Carefully:

Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the

right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any

time, without notice.

All ST products are sold pursuant to ST’s terms and conditions of sale.

Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no

liability whatsoever relating to the choice, selection or use of the ST products and services described herein.

No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this

document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products

or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such

third party products or services or any intellectual property contained therein.

UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED

WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED

WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS

OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.

UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT

RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING

APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY,

DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE

GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK.

Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void

any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any

liability of ST.

ST and the ST logo are trademarks or registered trademarks of ST in various countries.

Information in this document supersedes and replaces all information previously supplied.

The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.

STMicroelectronics group of companies

Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan -

Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America