Diodes ZXLD1371 User Manual

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ZX

LD1371

60V HIGH

CCURACY

BUCK/BOO

T/BUCK-B

OST LED

RIVER-CON

ROLLER

Descripti

The ZXLD13 external MOS topology cont through serie to operate in

The 60V cap enables it to in excess of 1

The ZXLD13 patent pendin accuracy in dimming is a PWM control.

The ZXLD137 highlights a f information on

n

1 is an LE

FETs to drive

oller enabling connected L uck, boost an

bility couple

e used in a w

LEDs in seri

1 is a modi

control sch

ll three mo

hieved throu

1 uses two pi

ult, while the

the exact faul

driver cont

high current

it to efficientl

Ds. The mult

buck-boost c

with its mult

de range of a

s.

ied hystereti

me providing

es of operat

h DC control

s for fault dia

multi-level sta

.

oller IC for

LEDs. It is a

control the

-topology ena nfigurations.

i-topology ca

plications an

controller u

high output on. High ac and high freq

nosis. A flag

us pin gives

riving multi-

urrent

les it

ability drive

ing a

urrent

uracy

uency

utput

urther

Pi

Assignm

ADJ

REF

TADJ

SHP

STATUS

SGND PGND

N/C

nts

TSSO

-16EP

16 15 14 13 12 11 10

9

GI PWM

FLAG ISM

VIN VAUX GAT E N/C

Features

• 0.5% typi

• 5 to 60V

• LED driv

• configura

• Wide dyn

o 10:1 o 1000:

• Up to 1M

• High tem

• Available

TS16949

• Available lead Free

ote 1: EU Direc

Typical A

VIN 8V to 22V

C1

10µF

Buck-Boo

ZXLD1371

Document numbe

RoHS ex

RGI2 75k

RGI1

24k

al output curr

perating volta r supports Bu ions

mic range di C dimming

1 dimming ran

z switching

erature contr

in Automoti

certification

in “Green” M

Finish/ RoHS

ive 2002/95/EC (

mptions applied.

plication

VAUX VI

PWM GI

ADJ REF

4

TADJ SHP S

1.

k

T

1

k

t Diagram U

: DS35436 Rev. 1

C2 330pF

nt accuracy

e range

k, Boost and

ming

e at 500Hz

l of LED curre

e Grade w

lding Compo

Compliant (N

oHS) & 2011/65/

Circuit

R1

0R05

ZXL

1371

GNDPGND

NC

tilizing Ther

- 2

ISM

GATE

FLAG

STATUS

uck-boost

t using T

th AEC-Q10

nd (No Br, S

te 1)

U (RoHS 2). All a

ILED = 1A

L1

D1

33µ

PDS3100

Q1 DMN6068LK3

Th

rmally connected

mistor and

ADJ

and

) with

plicable

1 to 6 LEDs

OUT

1

µF

ADJ

w

w.diodes.com

1 of 42

I

ED

0%

1

%

Therma l net

Rth = 1.

Curve S

70°C 85°C

ork response in

k and TH1 =

owing LED

T

LED

Buck co nfigurat i

0k (beta = 39

Ω

Current vs.

Febr

th

H1

n with:

0)

LED

ary 2012

Incorporated

REF

TADJ

A

f

Pin Descriptions

Name

ADJ 1 I

REF 2 O

TADJ 3 I

SHP 4 I/O

STATUS 5 O

SGND 6 P PGND 7 P

N/C 8 N/C 9

GATE 10 O

V

AUX

VIN

11 P

12 P

ISM 13 I

FLAG 14 O

PWM 15 I

GI 16 I

EP PAD P

Notes: 2. Type refers to whether or not pin is an Input, Output, Input/Output or Power supply pin.

Type

(Note 2)

Description

Adjust input (for dc output current control) Connect to REF to set 100% output current.

Drive with dc voltage (125mV<V

< 1.25V) to adjust output current from 10% to 100%

ADJ

of set value. The ADJ pin has an internal clamp that limits the internal node to less than 3V. This provides some failsafe should they get overdriven

Internal 1.25V reference voltage output

Temperature Adjust input for LED thermal current control Connect thermistor/resistor network to this pin to reduce output current above a preset temperature threshold.

Connect to REF to disable thermal compensation function. (See section on thermal

control.) Shaping capacitor for feedback control loop Connect 330pF ±20% capacitor from this pin to ground to provide loop compensation Operation status output (analog output)

Pin is at 4.5V (nominal) during normal operation. Pin switches to a lower voltage to indicate specific operation warnings or fault conditions. (See section on STATUS output.)

Status pin voltage is low during shutdown mode Signal ground (Connect to 0V) Power ground - Connect to 0V and pin 8 to maximize copper area Not Connected internally – recommend connection to pin 7, (PGND), to maximize PCB

copper for thermal dissipation Not Connected internally – recommend connection pin 10 (GATE) to permit wide copper

trace to gate of MOSFET

Gate drive output to external NMOS transistor – connect to pin 9

Auxiliary positive supply to internal switch gate driver

At V

< 8V; a bootstrap circuit is recommended to ensure adequate gate drive voltage

IN

(see Applications section)

At V

> 8V; connect to VIN

IN

>24V; to reduce power dissipation, V

At V

IN

auxiliary power supply (see Applications section). Decouple to ground with capacitor

close to device (see Applications section)

Input supply to device 5V to 60V

Decouple to ground with capacitor close to device (refer to Applications section)

Current monitor input. Connect current sense resistor between this pin and V

The nominal voltage, V

, across the resistor is 218mV fixed in Buck mode and

SENSE

initially 225mV in Boost and Buck-Boost modes, varying with duty cycle.

Flag open drain output

Pin is high impedance during normal operation

Pin switches low to indicate a fault, or warning condition

Digital PWM output current control

Pin driven either by open Drain or push-pull 3.3V or 5V logic levels.

Drive with frequency higher than 100Hz to gate output ‘on’ and ‘off’ during dimming

control.

The device enters standby mode when PWM pin is driven with logic low level for more

than 15ms nominal (Refer to application section for more details)

Gain setting input

Used to set the device in Buck mode or Boost, Buck-boost modes and to control the

sense voltage in Boost and Buck-boost modes

Connect to ADJ pin for Buck mode operation

For Boost and Buck-boost modes, connect to resistive divider from ADJ to SGND. The

GI divider is required to compensate for duty cycle gating in the internal feedback loop

(see Application section). The GI pin has an internal clamp that limits the internal

less than 3V. This provides some failsafe should it become overdriven.

Exposed paddle. Connect to 0V plane for electrical and thermal management

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can be connected to an 8V to 15V

AUX

ZXLD1371

IN

node to

ZXLD1371

Document number: DS35436 Rev. 1 - 2

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Functional Block Diagram

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ZXLD1371

Absolute Maximum Ratings (Voltages to GND Unless Otherwise Stated) (Note 3)

Symbol Parameter Rating Unit

VIN V

AUX

V

ISM

V V I V V

V

Current monitor sense voltage (VIN-V

SENSE GATE

GATE

FLAG

, V

PWM PWM

ADJ

TADJ

, VGI,

TJ TST

Stresses greater than the 'Absolute Maximum Ratings' specified above, may cause permanent damage to the device. These are stress ratings only; functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time. Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when handling and transporting these devices.

ZXLD1371

Document number: DS35436 Rev. 1 - 2

Input supply voltage -0.3 to 65 V Auxiliary supply voltage -0.3 to 65 V Current monitor input relative to GND -0.3 to 65 V

ISM

)

-0.3 to 5 V Gate driver output voltage -0.3 to 20 V Gate driver continuous output current 18 mA Flag output voltage -0.3 to 40 V

Other input pins -0.3 to 5.5 V Maximum junction temperature 150 °C

Storage temperature -55 to 150 °C

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Package Thermal Data

Thermal Resistance Package Typical Unit

Junction-to-Ambient,  Junction-to-Case, JC

(Note 4)

JA

Product Line o

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ZXLD1371

TSSOP-16 EP 50 °C/W TSSOP-16 EP 23 °C/W

Recommended Operating Conditions (-40°C  T

 125°C)

J

Symbol Parameter Performance/Comment Min Max Unit

Normal Operation 8.0 60

VIN

Input supply voltage range

(Note 5) Reduced performance operation

5.0 8.0

V

Normal Operation 8.0 60

V

SENSE

V

I

REF

f

max

V

TADJ

f

PWM

t

PWMH/L

V

PWMH

V

PWML

TJ GI Gain setting ratio for boost and buck-boost modes

Notes: 3. For correct operation SGND and PGND should always be connected together.

4. Measured on “High Effective Thermal Conductivity Test Board" according to JESD51.

5. Device starts up above 5.4V and as such the minimum applied supply voltage has to be above 5.4V (plus any noise margin). The ZXLD1371 will, however, continue to function when the input voltage is reduced from ≥ 8V down to 5.0V. When operating with input voltages below 8V the output current and device parameters may deviate from their normal values; and is dependent on power MOSFET switch, load and ambient temperature conditions. To ensure best operation in Boost and Buck-boost modes with input

voltages, V Performance in Buck mode will be reduced at input voltages (V

6. V not be applied to V V

7. The device contains circuitry to control the switching frequency to approximately 400kHz. The maximum and minimum operating frequency is not tested in production.

Auxiliary supply voltage range (Note 6)

AUX

Differential input voltage External dc control voltage applied to ADJ pin to

ADJ

adjust output current Reference external load current REF sourcing current 1 mA Recommended switching frequency range (Note 7) 300 1000 kHz

Temperature adjustment (T

Recommended PWM dimming frequency range PWM pulse width in dimming mode PWM input high or low 0.002 10 ms

PWM pin high level input voltage 2 5.5 V PWM pin low level input voltage 0 0.4 V

) input voltage range

ADJ

(Note 5) Reduced performance operation

VIN-V

, with 0  V

ISM

ADJ

 2.5 DC brightness control mode from 10% to 100%

0

5.0 8.0 0 450 mV

0.125 1.25 V

V

REF

To achieve 1000:1 resolution 100 500 Hz To achieve 500:1 resolution 100 1000 Hz

Operating Junction Temperature Range -40 125 °C

0.20 0.50

, between 5.0 and 8V a suitable boot-strap network on V

IN

can be driven from a voltage higher than V

AUX

IN

.

in the absence of a voltage at VIN. V

AUX

Ratio= VGI/V

pin is recommended.

AUX

, V

) below 8V. – a boot-strap network cannot be implemented in buck mode.

IN

to provide higher efficiency at low V

IN

AUX

can also be operated at a lower voltage than VIN to increase efficiencies at high

AUX

ADJ

voltages, but to avoid false operation; a voltage should

IN

V

ZXLD1371

Document number: DS35436 Rev. 1 - 2

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Electrical Characteristics (Test conditions: V

IN

= V

= 12V, TA = 25°C, unless otherwise specified.)

AUX

Symbol Parameter Conditions Min Typ Max Units

Supply and reference parameters

V

UV-

V

UV+

I

Quiescent current into VIN

Q-IN

I

Q-AUX

I

Standby current into VIN.

SB-IN

I

SB-AUX

V

REF

ΔV

REF

V

REF_LINE

V

REF-TC

Under-Voltage detection threshold Normal operation to switch disabled Under-Voltage detection threshold Switch disabled to normal operation

Quiescent current into V

Standby current into V

AUX

. Internal reference voltage Change in reference voltage with output

current Reference voltage line regulation

Reference temperature coefficient

VIN or V

or V

V

IN

PWM pin floating. Output not switching

PWM pin grounded for more than 15ms

No load

falling (Note 8)

AUX

rising (Note 8)

AUX

4.5 V

4.9 V

1.5 3 150 300 90 150

0.7 10

1.237 1.25 1.263 V Sourcing 1mA -5 Sinking 25µA 5 VIN = V

, 8.0V<VIN = <60V

AUX

-60 -90 ±50

ppm/°C

DC-DC converter parameters I

ADJ input current (Note 9)

ADJ

VGI

GI Voltage threshold for boost and buck-

boost modes selection (Note 9) IGI GI input current (Note 9) I

PWM

t

PWMoff

T

SDH

T

SDL

PWM input current

PWM pulse width

(to enter shutdown state)

Thermal shutdown upper threshold

(GATE output forced low)

Thermal shutdown lower threshold

(GATE output re-enabled)

 1.25V

ADJ

V

= 5.0V

ADJ

V

= 1.25V

ADJ

V

 1.25V

GI

V

= 5.0V

GI

V

= 5.5V

PWM

PWM input low 10 15 25 ms

Temperature rising. 150 ºC

Temperature falling. 125 ºC

100 nA 5 µA

0.8 V 100 nA

5 µA 36 100 µA

V

High-Side Current Monitor (Pin ISM) I

ISM

V

SENSE_acc

V

SENSE-OC

Notes: 8. UVLO levels are such that all ZXLD1371 will function above 5.4V for rising supply voltages and function down to 5V for falling supply voltages.

9. The ADJ and GI pins have an internal clamp that limits the internal

Input Current

Accuracy of nominal V

voltage

Over-current sense threshold voltage 300 350 375 mV

overdriven.

SENSE

threshold

Measured into ISM pin V

= 1.25V

V

ADJ

node to less than 3V. This provides some failsafe should those pins get

ISM

= 12V

11 20 µA ±0.25 ±2 %

mA µA µA µA

mV

dB

ZXLD1371

Document number: DS35436 Rev. 1 - 2

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Electrical Characteristics (cont.) (Test conditions: V

Symbol Parameter Conditions Min Typ Max Units

Output Parameters

V

FLAGL

I

FLAGOFF

V

STATUS

R

STATUS

Driver output (PIN GATE)

V

GATEH

FLAG pin low level output voltage Output sinking 1mA 0.5 V FLAG pin open-drain leakage current

V

FLAG

Normal operation 4.2 4.5 4.8 Out of regulation (V (Note 11)

STATUS Flag no-load output voltage (Note 10)

VIN under-voltage (V Switch stalled (tON or t Over-temperature (TJ > 125°C) Excess sense resistor current

(V

SENSE

Output impedance of STATUS output Normal operation 10 k

High level output voltage

No load Sourcing 1mA (Note 12)

= 40V

> 0.32V)

IN

= V

= 12V, TA = 25°C, unless otherwise specified.)

AUX

1 µA

out of range)

SHP

< UVLO)

IN

OFF

> 100µs)

3.3 3.6 3.9

1.5 1.8 2.1

0.6 0.9 1.2

10 11 V

V

GATEL

V

GATECL

I

GATE

Low level output voltage

High level GATE CLAMP voltage

Dynamic peak current available during rise or fall of output voltage

Sinking 1mA, (Note 13) V

= V

IN

I

GATE

AU X

= 1mA

ISM

= 18V

Charging or discharging gate of external switch with QG = 10nC and 400kHz

0.5 V

12.8 15 V

±300 mA

Time to assert ‘STALL’ flag and

t

STALL

warning on STATUS output

GATE low or high 100 170 µs

(Note 14)

LED Thermal control circuit (T

V

TADJH

V

TADJL

I

TADJ

Notes: 10. In the event of more than one fault/warning condition occurring, the higher priority condition will take precedence.

For more information see the Application Information section about Flag/Status levels.

11. Flag is asserted if V

12. GATE is switched to the supply voltage V it exceeding 15V.

13. GATE is switched to PGND by an NMOS transistor

14. If t grounded internally and the SHP pin is switched to its nominal operating voltage, before operation is allowed to resume. Restart cycles will be

repeated automatically until the operating conditions are such that normal operation can be sustained. If t remain off until normal operation is possible.

Upper threshold voltage

Lower threshold voltage

T

For example ‘Excessive coil current’ and ‘Out of regulation’ occurring together will produce an output of 0.9V on the STATUS pin. These STATUS pin voltages apply for an input voltage to V therefore may not report the correct status. For 5.4V < V

Buck-boost modes an over-current status may be indicated when operating at high boost ratios – this due to the feedback loop increasing the sense voltage.

pin Input current V

ADJ

SHP

exceeds t

ON

, the device will force GATE low to turn off the external switch and then initiate a restart cycle. During this phase, ADJ is

STALL

) parameters

ADJ

< 1.5V or V

SHP

> 2.5V

AUX

Onset of output current reduction

falling)

(V

TADJ

Output current reduced to <10% of set value (V

= 1.25V

TADJ

of 7.5V < VIN < 60V. Below 7.5V the STATUS pin voltage levels reduce and

IN

< 7.5V the flag pin still reports any error by going low. At low VIN in Boost and

IN

for low values of V

AUX

TADJ

(5V  V

falling)

AUX

 ~12V). For V

560 625 690 mV

380 440 500 mV

1

> 12V, GATE is clamped internally to prevent

AUX

OFF

exceeds t

, the switch will

STALL

µA

ZXLD1371

Document number: DS35436 Rev. 1 - 2

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Typical Characteristics

3

2.5

2

1.5

1

SUPPLY CURRENT (mA)

0.5

0

5 101520253035 4045505560

1.252

SUPPLY VOL TAGE (V)

Supply Voltage vs. Supply Curren t

Product Line o

Diodes Incorporated

ZXLD1371

1.2515

1.251

E (V)

1.2505

LTA

1.25

1.2495

REFERENCE V

1.249

1.2485

1.248

-40 -25 -10 5 20 35 50 65 80 95 110 125

100%

90%

80%

70%

60%

50%

DUTY (%)

40%

30%

JUNCTION TEMPERATURE ( C)

Reference Voltage vs. Junction T emperature

°

T=25°C

A

L=33µH R=146m

S

Buck Mode 2 LEDs

Ω

20%

10%

0%

6121824303642485460

INPUT VOLTAGE (V)

Duty Cycle vs. Input Voltage

ZXLD1371

Document number: DS35436 Rev. 1 - 2

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Typical Characteristics – Linear/DC Dimming

750

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ZXLD1371

750

600

450

300

LED CURRENT (mA)

150

0

0 0.25 0.5 0.75 1 1.25

700

600

500

400

300

LED CURRENT (mA)

200

100

0

0 0.25 0.5 0.75 1 1.25

350

Switching Frequency

Led Current and Swit ch i n g Frequency vs .

Switching Frequency

LED Current an d Swi tching Frequency vs.

ADJ VOLTAGE ( V)

ADJ Voltage in Buck Mode

LED Current

ADJ VOLT AG E ( V)

ADJ Voltage in Buck-Boost M o de

T=25°C

A

V=V=12V

AUX IN

2 LEDs, L=33µH R =300m

S

T= 25°C

A

V= V= 24V

AUX IN

8 LEDs, L = 33µ H GI = 0.23, R = 300m

S

Ω

600

450

300

150

0

1400

1200

1000

800

600

400

200

0

700

SWITCHING FREQUENCY (kHz)

300

Switching Frequency

250

200

150

LED CURRENT (mA)

100

50

0

0 0.25 0.5 0.75 1 1.25

LED Current and Switching Frequency vs.

ZXLD1371

Document number: DS35436 Rev. 1 - 2

ADJ VOLTAGE (V)

ADJ Voltage in Boos t Mode

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LED

T=25°C

A

V=V=12V

AUX IN

12 LEDs, L=33µH GI=0.23, R =300m

S

600

SWITCHING FREQUENCY (kHz)

500

400

300

200

Ω

100

0

February 2012

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0

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0

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(

s

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A

n

r

u

f

Typical

haracteri

1500

1250

1000

750

LED CURRENT (mA)

500

250

tics – PW

T = 25°C

A

V= V =

AUX

IN

L = 33µH, R f= 100H

PWM

/Thermal

24V

=150m

Ω

S

Dimming

Product Li

Di

des Incorpo

e o

ated

ZX

LD1371

I

LED

100%

80%

0

10 2

0

I

v

. Time - P

LED

050 WM DUTY CYCL

LED

urrent vs. PWM

M Pin Tran

60 70 (%)

uty Cyc le

ient Respo

80 90

se

100

60%

40%

LED CURRENT DIMMING FACTOR

20%

0%

0

ZXLD1371

Document numbe

: DS35436 Rev. 1

- 2

25

LED Current

T

w

5

0

PIN VOLT AGE

DJ

Dimming Factor v

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750 mV)

. T Voltage

DJ

1000

1250

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ary 2012

Incorporated

A

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Typical Characteristics – Buck Mode – R

3.2

3.1

3.0

2.9

2.8

LED CURRENT (A)

2.7

2.6 510152025303540

700

T = 25°C, V = V

AAUXIN

L = 15µH, R = 75m

600

C = 100µF, V = 3.8V

IN LED

500

1 LED

400

S

Ω

2 LEDs

= 75m – L = 33µH – I

S

INPUT VOLTAGE (V)

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Diodes Incorporated

= 2.9A

LED

4 LEDs

3 LEDs

ZXLD1371

300

200

SWITCHING FREQUENCY (kHz)

100

0

510152025303540

INPUT VOLTAGE (V)

700

4 LEDs L = 22µH



600

500

400

EFFICIENCY (%)

300

100

0

51015202530 35 40

INPUT VOLTAGE (V)

ZXLD1371

Document number: DS35436 Rev. 1 - 2

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C

URRENT

C

HIN

REQ

UENCY

H

EFFICIENC

Y (%

Typical Characteristics – Buck Mode – R

700

=150m - L = 33µH – I

S

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= 1.45A

LED

ZXLD1371

T = 25°C, V L = 33µH, R = 150m

600

C = 100µF

400

(A)

V=

AAUX,

IN

Ω

S

IN

300

1 ~ 16 LEDs

200

LED

1 LED

100

0

510 15 2025 303540

10 20 25 30

INPUT VOLTAGE (V)

1000

900

800

z)

700

(k

600

500

G F

400

300

SWIT

200

2 LEDs

100

0

510 556015 20 25 30 45 5035 40

4 LEDs

3 LEDs

6 LEDs

5 LEDs

8 LEDs

V (V)

100

95

2 LEDs

3 LEDs

4 LEDs

5 LEDs

6 LEDs

8 LEDs

10 LEDs

IN

10 LEDs 14 LEDs

12 LEDs

14 LEDs

16 LEDs

90

)

85

1 LED

80

75

70

V=

T = 25°C, V

AAUX,

L = 33µH, R = 150m

65

C = 100µF

IN

60

5 1015202530354045505560

ZXLD1371

Document number: DS35436 Rev. 1 - 2

IN

Ω

S

V (V)

IN

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URREN

T

A

SWITCHIN

G FREQUENC

Y

H

E

CIE

C

Y (%

Typical Characteristics – Boost Mode – I

0.45

0.40

)

0.35

(

0.30

L

0.25

0.20

0.15 58 44 5011 17 20 26 38 4129 32

800

14 23 35 47

Diodes Incorporated

= 350mA – RS = 150m – GI

LED

V (V)

IN

Product Line o

= 0.23

RATIO

ZXLD1371

700

z)

600

(k

500

400

300

200

100

0

510 455020 25 4030

100

4 LEDs

15 35

6 LEDs

8 LEDs

90

)

80

N

70

V (V)

IN

10 LEDs

12 LEDs 14 LEDs

16 LEDs

FFI

60

T = 25°C,

V = V

A

AUX IN

S

ΩΩ

IN

Ω

50

L = 33µH, R = 150m , R9 = 120k , R10 = 36k

C = 100µF

40

ZXLD1371

Document number: DS35436 Rev. 1 - 2

12 of 42

www.diodes.com

February 2012

A

f

CUR

RENT

TCHING F

REQ

UENC

Y

H

F

C

Y

Typical Characteristics – Boost Mode – I

0.45

0.43

0.41

0.39

(A)

0.37

0.35

8 LEDs

= 350mA – GI

LED

Product Line o

Diodes Incorporated

= 0.23 – Bootstrap comparison

RATIO

°

T = 25 C, L = 33µH

A

ΩΩ

R = 150m , R9 = 120k

S

Ω

R10 = 36k , C = 100µF

IN

ZXLD1371

LED

0.33

0.31

8 LEDs Bootstrap

0.29

0.27

0.25 6578109 111213141516171819 20

V (V)

IN

500

8 LEDs Bootstrap

z) (k

450 400 350

300

250

8 LEDs

200 150

T = 25 C, L = 33µH

100

SWI

50

°

A

R = 150m , R9 = 120k

ΩΩ

S

R10 = 36k , C = 100µF

Ω

IN

0

65781091112131415 16 17 18 19 20

V (V)

IN

100

90

8 LEDs Bootstrap

80

%

70

IEN I

E

60

50

8 LEDs

°

T = 25 C, L = 33µH

A

ΩΩ

R = 150m , R9 = 120k

S

Ω

R10 = 36k , C = 100µF

IN

40

65781091112131415 16 17 18 19 20

V (V)

IN

ZXLD1371

Document number: DS35436 Rev. 1 - 2

13 of 42

www.diodes.com

February 2012