LD3985G125R - STMicroelectronics, Inc.

June 2007 Rev. 11 1/20

LD3985 series

Ultra low drop-low noise bicmos voltage

regulators low ESR capacitors compatible

Features

■Input voltage from 2.5V to 6V

■Stable with low ESR ceramic capacitors

■Ultra low dropout voltage (100mV typ. at

150mA load, 0.4mV typ. at 1mA load)

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

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

OFF mode)

■Guaranteed output current up to 150mA

■Wide range of output voltage: 1.22V; 1.25V;

1.35V; 1.5V; 1.8V; 2V; 2.1V; 2.2V; 2.4V, 2.5V;

2.6V; 2.7V; 2.8V; 2.85V; 2.9V; 3V; 3.1V; 3.2V;

3.3V; 4.4V; 4.7V; 4.8V; 4.9V; 5V

■Fast turn-on time: typ. 200µs

[CO=1µF, CBYP= 10nF and IO=1mA]

■Logic-controlled electronic shutdown

■Internal current and thermal limit

■Output low noise voltage 30µVRMS over 10Hz

to 100KHz

■S.V.R. of 60dB at 1KHz, 50dB at 10KHz

■Temperature range: -40°C to 125°C

Description

The LD3985 provides up to 150mA, from 2.5V to

6V 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 10KHz. 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 LD3985 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

(1.57x1.22)

www.st.com

Schematic diagram

LD3985 series

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Contents

1 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

6 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

7 Order codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

LD3985 series Pin configuration

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1 Pin configuration

Figure 1. Pin connections (top view for SOT and TSOT, top through view for Flip-Chip)

Flip-Chip

SOT23-5L/TSOT23-5L

Table 1. 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 ≥ 1.2V, OFF MODE when VINH

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

4 5 BYPASS Bypass Pin: Connect an external capacitor (usually 10nF) to minimize

noise voltage

53V

OOutput Voltage of the LDO

Typical application LD3985 series

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2 Typical application

Figure 2. Typical application circuit

LD3985 series Maximum ratings

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3 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 2. 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 6.5V for 200ms.

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 3. 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

Electrical characteristics LD3985 series

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4 Electrical characteristics

Table 4. Electrical characteristics for LD3985 (TJ = 25°C, VI = VO(NOM) +0.5V, CI = 1µF,

CBYP = 10nF, IO = 1mA, VINH = 1.4V, unless otherwise specified)

Symbol Parameter Test conditions Min. Typ. Max. Unit

VIOperating input voltage 2.5 6 V

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

TJ= -40 to 125°C -75 75

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

VO(NOM)

TJ= -40 to 125°C -3 3

ΔVOLine regulation (Note: 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

ΔVOOutput AC Line regulation VI = VO(NOM) + 1 V, IO = 150mA,

tR= tF = 30µs 1.5 mVPP

Quiescent current

ON MODE: VINH = 1.2V

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 = 0.4V 0.003

TJ= -40 to 125°C 1.5

VDROP Dropout voltage (Note: 1)

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

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

LD3985 series Electrical characteristics

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

2For V

O(NOM)= 1.25V, VI = 2.5V

3 Dropout voltage is the input-to-output voltage difference at which the output voltage is

100mV below its nominal value. This specification does not apply for input voltages below

2.5V.

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 1µF, anyway the LD3985 is still stable if the compensation

capacitor has a 30% tolerance in all temperature range.

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 (Note 4)C

BYP = 10 nF 100 250 µs

TSHDN Thermal shutdown Note 5 160 °C

COOutput capacitor Capacitance (Note 6) 1 22 µF

ESR 5 5000 mΩ

Table 4. Electrical characteristics for LD3985 (TJ = 25°C, VI = VO(NOM) +0.5V, CI = 1µF,

CBYP = 10nF, IO = 1mA, VINH = 1.4V, unless otherwise specified)

Symbol Parameter Test conditions Min. Typ. Max. Unit

Typical performance characteristics LD3985 series

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5 Typical performance characteristics

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

otherwise specified)

Figure 3. Output voltage vs temperature Figure 4. Output voltage vs temperature

Figure 5. Output voltage vs temperature Figure 6. Shutdown voltage vs temperature

Figure 7. Shutdown voltage vs temperature Figure 8. Line regulation vs temperature

LD3985 series Typical performance characteristics

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Figure 9. Line regulation vs temperature Figure 10. Line regulation vs temperature

Figure 11. Load regulation vs temperature Figure 12. Load regulation vs temperature

Figure 13. Load regulation vs temperature Figure 14. Quiescent current vs temperature

Typical performance characteristics LD3985 series

10/20

Figure 15. Quiescent current vs temperature Figure 16. Quiescent current vs temperature

Figure 17. Supply voltage rejection vs

frequency

Figure 18. Load transient response

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

Figure 19. Line transient response Figure 20. 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

LD3985 series Typical performance characteristics

11/20

Figure 21. Turn-Off

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

Tf = 20ns, VO = 2.8V

Package mechanical data LD3985 series

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6 Package mechanical data

In order to meet environmental requirements, ST offers these devices in ECOPACK®

packages. These packages have a Lead-free second level interconnect. The category of

second Level Interconnect is marked on the package and on the inner box label, in

compliance with JEDEC Standard JESD97. The maximum ratings related to soldering

conditions are also marked on the inner box label. ECOPACK is an ST trademark.

ECOPACK specifications are available at: www.st.com.

LD3985 series Package mechanical data

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DIM.

mm. mils

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

SOT23-5L MECHANICAL DATA

7049676C

Package mechanical data LD3985 series

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DIM.

mm. mils

MIN. TYP MAX. MIN. TYP. MAX.

A 1.1 43.3

A1 0 0.1 3.9

A2 0.7 1.0 27.6 39.4

b 0.3 0.5 11.8 19.7

C 0.08 0.2 3.1 7.9

D 2.9 114.2

E 2.8 110.2

E1 1.6 63.0

e0.95 37.4

e1 1.9 74.8

L 0.3 0.6 11.8 23.6

TSOT23-5L MECHANICAL DATA

7282780B

LD3985 series Package mechanical data

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DIM.

mm. mils

MIN. TYP MAX. MIN. TYP. MAX.

A 0.835 0.9 0.965 32.9 35.4 38.0

A1 0.21 0.25 0.29 8.3 9.8 11.4

A2 0.625 0.65 0.675 24.6 25.6 26.6

b 0.290 0.315 0.340 11.4 12.4 13.4

D 1.510 1.540 1.570 59.4 6.1 61.8

E 1.161.191.2245.746.848.0

e 0.45 0.5 0.55 17.7 19.7 21.7

e1 0.816 0.866 0.916 32.1 34.1 36.1

f 0.345 13.6

f1 0.337 13.3

Flip-Chip5 MECHANICAL DATA

Package mechanical data LD3985 series

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DIM.

mm. inch

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

Tape & Reel SOT23-xL MECHANICAL DATA

LD3985 series Package mechanical data

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DIM.

mm. inch

MIN. TYP MAX. MIN. TYP. MAX.

A 178 6.926

C 12.8 13.2 0.504 0.519

D 20.2 0.795

N 49 50 51 1.929 1.969 2.008

T 12.4 0.488

Ao 1.60 1.65 1.70 0.063 0.065 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 3.9 4 4.1 0.153 0.157 0.161

P 3.9 4 4.1 0.153 0.157 0.161

Tape & Reel Flip-Chip 5 MECHANICAL DATA

Order codes LD3985 series

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7 Order codes

Table 5. Order codes

Part number

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

LD3985M122R LD3985G122R (1)

1. Available on request.

LD3985J122R 1.22 V

LD3985M125R (1) LD3985G125R (1) LD3985J125R 1.25 V

LD3985M135R (1) LD3985G135R (1) LD3985J135R 1.35 V

LD3985M15R LD3985G15R (1) LD3985J15R (1) 1.5 V

LD3985M18R LD3985G18R LD3985J18R 1.8 V

LD3985M20R (1) LD3985G20R (1) LD3985J20R (1) 2.0 V

LD3985M21R (1) LD3985G21R (1) LD3985J21R (1) 2.1 V

LD3985M22R (1) LD3985G22R (1) LD3985J22R (1) 2.2 V

LD3985M24R (1) LD3985G24R (1) LD3985J24R 2.4 V

LD3985M25R LD3985G25R LD3985J25R 2.5 V

LD3985M26R (1) LD3985G26R (1) LD3985J26R 2.6 V

LD3985M27R LD3985G27R LD3985J27R 2.7 V

LD3985M28R (1) LD3985G28R (1) LD3985J28R 2.8 V

LD3985M285R (1) LD3985G285R (1) LD3985J285R (1) 2.85 V

LD3985M29R LD3985G29R LD3985J29R 2.9 V

LD3985M30R (1) LD3985G30R (1) LD3985J30R 3.0 V

LD3985G31R (1) LD3985J31R 3.1 V

LD3985M32R (1) LD3985G32R (1) LD3985J32R (*) 3.2 V

LD3985M33R LD3985G33R (1) LD3985J33R 3.3 V

LD3985M44R (1) LD3985G44R (1) LD3985J44R (1) 4.4 V

LD3985M47R LD3985G47R (1) LD3985J47R 4.7 V

LD3985M48R (1) LD3985G48R (1) LD3985J48R 4.8 V

LD3985M49R (1) LD3985G49R (1) LD3985J49R (1) 4.9 V

LD3985M50R (1) LD3985G50R (1) LD3985J50R (1) 5.0 V

LD3985 series Revision history

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8 Revision history

Table 6. 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 has been updated and the document has been reformatted.

08-Jun-2007 11 Order code change.

LD3985 series

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