LM2931AD33R - STMicroelectronics, Inc.

November 2011 Doc ID 6740 Rev 20 1/21

LM2931XX, LM2931AXX33

LM2931AXX50

Very low drop voltage regulators with inhibit function

Features

■Very low dropout voltage (0.15 V typ. at 10 mA

load)

■Low quiescent current (typ. 2.5 mA, at 100 mA

load)

■Output current up to 100 mA

■Adjustable (from VOUT = 2.5 V only SO-8) and

fixed (3.3 V and 5 V) output voltage version

■Internal current and thermal limit

■Load dump protection up to 60 V

■Reverse transient protection up to - 50 V

■Temperature range: - 40 to 125 °C

■Package available: TO-92, DPAK, SO-8 (with

inhibit control)

Description

The LM2931xx are very low drop regulators. The

very low drop voltage and the low quiescent

current make them particular suitable for low

noise, low power applications and in battery-

powered systems. In the 8-pin configuration

(SO-8), fully compatible with the older L78Lxx

family, a shutdown logic control function is

available. This means that when the device is

used as a local regulator it is possible to put a part

of the board in standby, decreasing total power

consumption. Ideal for automotive applications,

LM2931xx is protected from reverse battery

installations or 2 battery jumps. During the

transient, such as a 60 V load dump, when the

input voltage can exceed the specified maximum

operating input voltage of 26 V, the regulator

automatically shuts down to protect both internal

circuitry and the load.

TO-92

DPAK

SO-8

Table 1. Device summary

Order codes

Output voltages

DPAK TO-92 (Bag) SO-8

LM2931AD33R 3.3 V

LM2931ADT50R LM2931AZ50R LM2931AD50R 5.0 V

LM2931D-R 2.5 to 26 V

www.st.com

Contents LM2931XX, LM2931AXX33, LM2931AXX50

2/21 Doc ID 6740 Rev 20

Contents

1 Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

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

4 Application circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

5 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

6 Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

LM2931XX, LM2931AXX33, LM2931AXX50 Diagram

Doc ID 6740 Rev 20 3/21

1 Diagram

Figure 1. Schematic diagram

Pin configuration LM2931XX, LM2931AXX33, LM2931AXX50

4/21 Doc ID 6740 Rev 20

2 Pin configuration

(*) ADJ pin on the Adjustable version, Not Connected in the fixed output version.

Figure 2. Pin connections (top view)

SO-8

DPAK

PIN 1 = VOUT

PIN 2 = GND

PIN 3 = VIN

TO-92 BOTTOM VIEW

LM2931XX, LM2931AXX33, LM2931AXX50 Maximum ratings

Doc ID 6740 Rev 20 5/21

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 positive input voltage 40 V

VIDC reverse input voltage -15 V

VITransient input voltage (τ < 100 ms) 60 V

VITransient reverse input voltage (τ < 100 ms) -50 V

VINH Inhibit input voltage 40 V

IOOutput current 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 SO-8 DPAK TO-92 Unit

RthJC Thermal resistance junction-case 20 8 °C/W

RthJA Thermal resistance junction-ambient 55 (1) 100 200 °C/W

1. Considering 6 cm2 of copper board heat-sink.

Application circuits LM2931XX, LM2931AXX33, LM2931AXX50

6/21 Doc ID 6740 Rev 20

4 Application circuits

Note: R1 suggested value = 27 kΩ

VO = VREF (R1 + R2)/R1

Inhibit pin: regulator is enabled when VINH < 1.2 V , disabled when VINH > 3.25 V

Figure 3. Application circuit for fixed output

Figure 4. Application circuit for adjustable output

LM2931XX, LM2931AXX33, LM2931AXX50 Electrical characteristics

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5 Electrical characteristics

Refer to the application circuit Figure 3, TJ = 25 °C, CI = 0.1 µF, CO = 100 µF, VI = 14 V,

IO = 10 mA, VINH = 0 V, unless otherwise specified.

Table 4. Electrical characteristics of LM2931Axx33

Symbol Parameter Test conditions Min. Typ. Max. Unit

Maximum operating input

voltage IO = 10 mA, TJ = -40 to 125°C 26 V

VOOutput voltage 3.135 3.3 3.425 V

VOOutput voltage IO = 100 mA, VI = 6 to 26 V

TJ = -40 to 125°C 3.135 3.3 3.465 V

ΔVOLine regulation VI = 9 to 16 V 2 10 mV

VI = 6 to 26 V 4 33

ΔVOLoad regulation IO = 5 to 100 mA 10 33 mV

VdDropout voltage (1) (2) IO = 10 mA 90 250 mV

IO = 100 mA 250 600

Quiescent current

ON MODE IO = 100 mA 2.5 30 mA

OFF MODE VINH = 2.5 V, RLOAD = 330 Ω0.3 1 mA

ISC Short circuit current 100 300 mA

SVR Supply voltage rejection IO = 100 mA, VI = 14 ± 2 V

f = 120 Hz, TJ = -40 to 125°C 55 78 dB

VIL Control input voltage low TJ = -40 to 125°C 2 1.2 V

VIH Control input voltage high TJ = -40 to 125°C 3.25 2 V

IINH Inhibit input current VINH = 2.5 V 22 50 µA

VITransient input voltage RLOAD = 330 Ω, τ < 100ms 60 70 V

Reverse polarity input

voltage VO = ± 0.3 V, RLOAD = 330 Ω-15 -50 V

Reverse polarity input

voltage transient RLOAD = 330 Ω, τ < 100ms -50 V

eN Output noise voltage B =10 Hz to 100 kHz 330 µVRMS

1. Reference voltage is measured from VOUT to ADJ pin.

2. Vd measured when the output voltage has dropped 100 mV from the nominal value obtained at 14 V.

Electrical characteristics LM2931XX, LM2931AXX33, LM2931AXX50

8/21 Doc ID 6740 Rev 20

Refer to the application circuit Figure 3, TJ = 25 °C, CI = 0.1 µF, CO = 100 µF, VI = 14 V, IO =

10 mA, VINH = 0 V, unless otherwise specified.

Table 5. Electrical characteristics of LM2931Axx50

Symbol Parameter Test conditions Min. Typ. Max. Unit

Maximum operating input

voltage IO = 10 mA, TJ = -40 to 125°C 26 V

VOOutput voltage 4.81 5 5.19 V

VOOutput voltage IO = 100 mA, VI = 6 to 26 V

TJ = -40 to 125°C 4.75 5 5.25 V

ΔVOLine regulation VI = 9 to 16 V 2 10 mV

VI = 6 to 26 V 4 30

ΔVOLoad regulation IO = 5 to 100 mA 15 50 mV

VdDropout voltage (1) (2) IO = 10 mA 90 200 mV

IO = 100 mA 250 600

Quiescent current

ON MODE IO = 100 mA 2.5 30 mA

OFF MODE VINH = 2.5 V, RLOAD = 500 Ω0.3 1 mA

ISC Short circuit current 100 300 mA

SVR Supply voltage rejection IO = 100 mA, VI = 14 ± 2 V

f = 120 Hz, TJ = -40 to 125°C 55 75 dB

VIL Control input voltage low TJ = -40 to 125°C 2 1.2 V

VIH Control input voltage high TJ = -40 to 125°C 3.25 2 V

IINH Inhibit input current VINH = 2.5 V 22 50 µA

VITransient input voltage RLOAD = 500 Ω, τ < 100ms 60 70 V

Reverse polarity input

voltage VO = ± 0.3 V, RLOAD = 500 Ω-15 -50 V

Reverse polarity input

voltage transient RLOAD = 500 Ω, τ < 100ms -50 V

eN Output noise voltage B =10 Hz to 100 kHz 500 µVRMS

1. Reference voltage is measured from VOUT to ADJ pin.

2. Vd measured when the output voltage has dropped 100 mV from the nominal value obtained at 14 V.

LM2931XX, LM2931AXX33, LM2931AXX50 Electrical characteristics

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Refer to the application circuit Figure 4 with R1 = 27 KΩ and R2 = 40.5 kΩ, TJ = 25 °C,

CI = 0.1 µF, CO = 100 µF, VI = 14 V, IO = 10 mA, VINH = 0 V, unless otherwise specified.

Table 6. Electrical characteristics of LM2931xx

Symbol Parameter Test conditions Min. Typ. Max. Unit

Maximum operating input

voltage IO = 10 mA, TJ = -40 to 125°C 26 V

VREF Reference voltage (1) 1.14 1.2 1.26 V

VREF Reference voltage (1) IO = 100 mA, TJ = -40 to 125°C 1.08 1.2 1.32 V

ΔVOLine regulation VI = 3.6 to 26 V 0.6 4.5 mV

ΔVOLoad regulation IO = 5 to 100 mA 9 30 mV

VdDropout voltage (1) (2) IO = 10 mA 90 200 mV

IO = 100 mA 250 600

Quiescent current

ON MODE IO = 100 mA 2.5 30 mA

OFF MODE VINH = 2.5 V, RLOAD = 300 Ω0.3 1 mA

ISC Short circuit current 100 300 mA

SVR Supply voltage rejection IO = 100 mA, VI = 14 ± 2 V

f = 120 Hz, TJ = -40 to 125°C 55 80 dB

VIL Control input voltage low TJ = -40 to 125°C 2 1.2 V

VIH Control input voltage high TJ = -40 to 125°C 3.25 2 V

IINH Inhibit input current VINH = 2.5 V 22 50 µA

VITransient input voltage RLOAD = 300 Ω, τ < 100ms 60 70 V

Reverse polarity input

voltage VO = ± 0.3 V, RLOAD = 300 Ω-15 -50 V

Reverse polarity input

voltage transient RLOAD = 300 Ω, τ < 100ms -50 V

eN Output noise voltage B = 10 Hz to 100 kHz 330 µVRMS

1. Reference voltage is measured from VOUT to ADJ pin.

2. Vd measured when the output voltage has dropped 100 mV from the nominal value obtained at 14 V.

Typical characteristics LM2931XX, LM2931AXX33, LM2931AXX50

10/21 Doc ID 6740 Rev 20

6 Typical characteristics

Unless otherwise specified CI = 0.1 µF, CO = 100 µF.

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

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

Figure 9. Load regulation vs. temperature Figure 10. Dropout voltage vs. temperature

LM2931XX, LM2931AXX33, LM2931AXX50 Typical characteristics

Doc ID 6740 Rev 20 11/21

Figure 11. Dropout voltage vs. temperature Figure 12. Dropout voltage vs. output current

Figure 13. Output voltage vs. input voltage Figure 14. Short circuit current vs. drop

voltage

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

Typical characteristics LM2931XX, LM2931AXX33, LM2931AXX50

12/21 Doc ID 6740 Rev 20

Figure 17. Quiescent current vs. output

current

Figure 18. Supply voltage rejection vs.

temperature

Figure 19. Supply voltage rejection vs.

frequency

Figure 20. Supply voltage rejection vs. output

current

Figure 21. Stability vs. COFigure 22. Line transient

VI = 6 to 20 V, RL = 500 Ω, TJ = 25°C, CI = 0, CO = 100 µF,

Rise Fall-Time = 200 ns

LM2931XX, LM2931AXX33, LM2931AXX50 Typical characteristics

Doc ID 6740 Rev 20 13/21

Figure 23. Line transient

VI = 14 V, IO = 100 mA, TJ = 25°C, CI = 0.1 µF, CO = 100 µF,

Rise Time = 500 ns, Fall-Time = 1 µs

Package mechanical data LM2931XX, LM2931AXX33, LM2931AXX50

14/21 Doc ID 6740 Rev 20

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.

LM2931XX, LM2931AXX33, LM2931AXX50 Package mechanical data

Doc ID 6740 Rev 20 15/21

Dim.

mm. mils.

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

A4.324.95 170.1 194.9

b0.36 0.51 14.2 20.1

D 4.45 4.95 175.2 194.9

E3.303.94 129.9155.1

e 2.41 2.67 94.9105.1

e1 1.14 1.40 44.955.1

L 12.7 15.49500.0 609.8

R 2.16 2.41 85.0 94.9

S1 0.92 1.52 36.2 59.8

W 0.41 0.56 16.1 22.0

α5° 5°

TO-92 mechanical data

0102782/D

Package mechanical data LM2931XX, LM2931AXX33, LM2931AXX50

16/21 Doc ID 6740 Rev 20

Dim.

mm. inch.

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

A 2.2 2.4 0.086 0.094

A1 0.91.1 0.035 0.043

A2 0.030.230.001 0.009

B 0.64 0.90.025 0.035

b4 5.2 5.4 0.204 0.212

C 0.45 0.6 0.017 0.023

C2 0.480.6 0.0190.023

D 6 6.2 0.236 0.244

D1 5.1 0.200

E 6.4 6.6 0.252 0.260

E1 4.7 0.185

e2.280.090

e1 4.4 4.6 0.1730.181

H9.35 10.1 0.3680.397

L 1 0.039

(L1) 2.80.110

L2 0.80.031

L4 0.6 1 0.0230.039

R 0.2 0.008

V2 0° 8°0° 8°

DPAK mechanical data

0068772-F

LM2931XX, LM2931AXX33, LM2931AXX50 Package mechanical data

Doc ID 6740 Rev 20 17/21

Dim. mm. inch.

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

A1.35 1.75 0.0530.069

A1 0.10 0.25 0.04 0.010

A2 1.10 1.65 0.0430.065

B0.33 0.51 0.0130.020

C0.190.25 0.007 0.010

D4.80 5.00 0.189 0.197

E3.80 4.00 0.150 0.157

e 1.27 0.050

H5.80 6.20 0.2280.244

h 0.25 0.50 0.010 0.020

L 0.40 1.27 0.016 0.050

k8° (max.)

ddd 0.1 0.04

SO-8 mechanical data

0016023/C

Package mechanical data LM2931XX, LM2931AXX33, LM2931AXX50

18/21 Doc ID 6740 Rev 20

Dim.

mm. inch.

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

A330 12.992

C12.813.0 13.2 0.504 0.512 0.519

D 20.2 0.795

N60 2.362

T22.40.882

Ao 6.806.90 7.00 0.2680.272 0.2.76

Bo 10.40 10.50 10.60 0.4090.4130.417

Ko 2.55 2.65 2.75 0.100 0.104 0.105

Po 3.94.0 4.1 0.1530.157 0.161

P7.98.0 8.1 0.311 0.315 0.319

Tape & reel DPAK-PPAK mechanical data

LM2931XX, LM2931AXX33, LM2931AXX50 Package mechanical data

Doc ID 6740 Rev 20 19/21

Dim.

mm. inch.

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

A330 12.992

C 12.813.2 0.504 0.519

D 20.2 0.795

N60 2.362

T 22.4 0.882

Ao 8.1 8.5 0.3190.335

Bo 5.5 5.90.216 0.232

Ko 2.1 2.30.082 0.090

Po 3.94.1 0.1530.161

P7.98.1 0.311 0.319

Tape & reel SO-8 mechanical data

Revision history LM2931XX, LM2931AXX33, LM2931AXX50
20/21 Doc ID 6740 Rev 20
8 Revision history
Table 7. Document revision history
Date Revision Changes
21-Jun-2004 12 Document updated.
16-Jun-2006 13 Order codes updated.
27-Jul-2007 14 Added Ta b le 1  in cover page.
21-Aug-2007 15 Added root part number - (see Ta bl e 1 ).
22-Nov-2007 16 Modified: Ta ble 1 .
11-Feb-2008 17 Modified: Table 1 on page 1.
10-Jul-2008 18 Removed package TO-220, modified Table 1 on page 1.
26-May-2010 19 Modified: VI values Table 4 on page 7, Table 5 on page 8 and Table 6 on 
page 9.
02-Nov-2011 20
Modified: Figure 4 on page 6.
Added: (*) ADJ pin on the Adjustable version, Not Connected in the fixed 
output version. on page 4 and Inhibit pin: regulator is enabled when VINH < 1.2 
V , disabled when VINH > 3.25 V on page 6.

LM2931XX, LM2931AXX33, LM2931AXX50

Doc ID 6740 Rev 20 21/21

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