The category is 'Data Acquisition - Analog to Digital Converters (ADC)'

  • All Manufacturers
  • Moisture Sensitivity Level (MSL)
  • Number of Functions
  • Package / Case
  • RoHS Status
  • JESD-609 Code
  • Number of Bits
  • Number of Terminations
  • Pin Count
  • Sampling Rate
  • Supply Voltage
  • Architecture
  • Base Part Number

Image

Part Number

Manufacturer

Datasheet

Availability

Pricing(USD)

Quantity

RoHS

Factory Lead Time

Lifecycle Status

Contact Plating

Mount

Mounting Type

Package / Case

Surface Mount

Number of Pins

Number of Elements

Operating Temperature

Packaging

Published

Series

JESD-609 Code

Pbfree Code

Part Status

Moisture Sensitivity Level (MSL)

Number of Terminations

ECCN Code

Terminal Finish

Max Power Dissipation

Terminal Position

Terminal Form

Peak Reflow Temperature (Cel)

Number of Functions

Supply Voltage

Terminal Pitch

Reach Compliance Code

Time@Peak Reflow Temperature-Max (s)

Base Part Number

Pin Count

Qualification Status

Operating Supply Voltage

Polarity

Power Supplies

Supply Voltage-Min (Vsup)

Configuration

Number of Channels

Interface

Max Supply Voltage

Min Supply Voltage

Nominal Supply Current

Power Dissipation

Number of Bits

Input Type

Min Input Voltage

Architecture

Number of Inputs

Max Input Voltage

Converter Type

Supply Type

Reference Type

Data Interface

Resolution

Sampling Rate

Voltage - Supply, Analog

Voltage - Supply, Digital

Number of Analog In Channels

Sampling Rate (Per Second)

Max Dual Supply Voltage

Output Bit Code

Power Consumption

Linearity Error-Max (EL)

Integral Nonlinearity (INL)

Min Dual Supply Voltage

Sample and Hold / Track and Hold

Number of A/D Converters

Dual Supply Voltage

Input Capacitance

Number of Converters

Conversion Rate

Ratio - S/H:ADC

Analog Input Voltage-Max

Output Format

Signal to Noise Ratio (SNR)

Negative Supply Voltage-Nom

Max Supply Voltage (DC)

Differential Nonlinearity

Min Supply Voltage (DC)

Analog Input Voltage-Min

Conversion Time-Max

Number of Analog Inputs

Spurious-free dynamic range (SFDR)

Features

Height

Height Seated (Max)

Length

Width

Thickness

Radiation Hardening

REACH SVHC

RoHS Status

Lead Free

TLC0838IPW

Mfr Part No

TLC0838IPW

Texas Instruments Datasheet

64
In Stock

  • 1: $14.759429
  • 10: $13.923990
  • 100: $13.135839
  • 500: $12.392302
  • View all price

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 1 week ago)

Surface Mount

20-TSSOP (0.173, 4.40mm Width)

YES

20

1

-40°C~85°C

Tube

e4

yes

Active

1 (Unlimited)

20

EAR99

Nickel/Palladium/Gold (Ni/Pd/Au)

DUAL

GULL WING

260

1

5V

0.65mm

TLC0838

20

5V

Unipolar

5V

MUX-ADC

5.5V

4.5V

600μA

8

Differential, Pseudo-Differential, Single Ended

SAR

4, 7, 8

ADC, SUCCESSIVE APPROXIMATION

External

SPI

1 B

20 ksps

5V

8

20k

BINARY

3mW

0.3906%

0.4 LSB

SAMPLE

20 ksps

5V

SERIAL

5.5V

4.5V

1.2mm

6.5mm

4.4mm

1mm

No

ROHS3 Compliant

Lead Free

ADS8471IBRGZT

Mfr Part No

ADS8471IBRGZT

Texas Instruments Datasheet

1600
In Stock

  • 1: $56.197110
  • 10: $53.016141
  • 100: $50.015228
  • 500: $47.184178
  • View all price

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 1 week ago)

Gold

Surface Mount

Surface Mount

48-VFQFN Exposed Pad

48

-40°C~85°C

Tape & Reel (TR)

microPOWER™

e4

yes

Active

2 (1 Year)

48

EAR99

240mW

QUAD

NO LEAD

260

1

5V

0.5mm

NOT SPECIFIED

ADS8471

48

Not Qualified

5V

Unipolar

S/H-ADC

1

5.25V

4.75V

44mA

240mW

16

Pseudo-Differential, Single Ended

SAR

ADC, PROPRIETARY METHOD

Analog, Digital, Single

External, Internal

Parallel

2 B

1 Msps

5V

2.7V~5.25V

1

1M

BINARY

150mW

1 LSB

SAMPLE

1 Msps

1:1

4.2V

93 dB

0.75 LSB

1mm

7mm

7mm

900μm

ROHS3 Compliant

Lead Free

LTC2237CUH#PBF

Mfr Part No

LTC2237CUH#PBF

Linear Technology/Analog Devices Datasheet

5
In Stock

  • 1: $11.734662
  • 10: $11.070436
  • 100: $10.443808
  • 500: $9.852649
  • View all price

Min: 1

Mult: 1

18 Weeks

PRODUCTION (Last Updated: 2 weeks ago)

Surface Mount

Surface Mount

32-WFQFN Exposed Pad

32

1

0°C~70°C

Tube

2006

e3

Active

1 (Unlimited)

32

EAR99

Matte Tin (Sn)

144mW

QUAD

NO LEAD

260

1

3V

0.5mm

30

LTC2237

32

Not Qualified

3V

Bipolar

3V

S/H-ADC

3.4V

2.7V

40mA

144mW

10

Differential, Single Ended

Pipelined

ADC, PROPRIETARY METHOD

Single

External, Internal

Parallel

1.25 B

40 Msps

2.7V~3.4V

2.7V~3.4V

1

40M

OFFSET BINARY, 2'S COMPLEMENT BINARY

0.0488%

0.5 LSB

SAMPLE

1:1

1V

0.8mm

5mm

5mm

ROHS3 Compliant

Lead Free

ADC12DL080CIVS/NOPB

Mfr Part No

ADC12DL080CIVS/NOPB

Texas Instruments Datasheet

49
In Stock

  • 1: $36.393684
  • 10: $34.333664
  • 100: $32.390249
  • 500: $30.556838
  • View all price

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 5 days ago)

Tin

Surface Mount

Surface Mount

64-TQFP

64

-40°C~85°C

Tray

e3

yes

Active

3 (168 Hours)

64

EAR99

QUAD

GULL WING

260

1

3.3V

0.5mm

ADC12DL080

64

3.3V

Unipolar

S/H-ADC

2

3.6V

3V

12

Differential

Pipelined

ADC, PROPRIETARY METHOD

Analog, Digital

External, Internal

Parallel

1.5 B

80 Msps

3V~3.6V

2.4V~3.6V

2

80M

447mW

0.0854%

3.5 LSB

SAMPLE

80 Msps

1:1

2V

69.3 dB

1 LSB

Simultaneous Sampling

1.2mm

10mm

10mm

1mm

No

ROHS3 Compliant

Lead Free

ADS7850IRTER

Mfr Part No

ADS7850IRTER

Texas Instruments Datasheet

46
In Stock

  • 1: $14.063928
  • 10: $13.267857
  • 100: $12.516846
  • 500: $11.808345
  • View all price

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 1 day ago)

Gold

Surface Mount

Surface Mount

16-WFQFN Exposed Pad

16

-40°C~125°C

Tape & Reel (TR)

e4

yes

Active

2 (1 Year)

16

EAR99

45mW

QUAD

NO LEAD

260

1

5V

0.5mm

NOT SPECIFIED

ADS7850

16

S/H-ADC

5.5V

40mW

14

Pseudo-Differential

SAR

2

ADC, SUCCESSIVE APPROXIMATION

Analog, Digital

Internal

SPI

1.75 B

750 ksps

5V

1.65V~5.5V

2

750k

BINARY

40mW

1.5 LSB

SAMPLE

1:1

SERIAL

81.5 dB

0.59μs

Simultaneous Sampling

800μm

3mm

3mm

750μm

ROHS3 Compliant

Lead Free

ADS114S06BIPBS

Mfr Part No

ADS114S06BIPBS

Texas Instruments Datasheet

7999
In Stock

  • 1: $19.141508
  • 10: $18.058027
  • 100: $17.035874
  • 500: $16.071580
  • View all price

Min: 1

Mult: 1

8 Weeks

ACTIVE (Last Updated: 1 day ago)

Surface Mount

32-TQFP

YES

32

-40°C~125°C TA

Tray

e4

yes

Active

3 (168 Hours)

32

Nickel/Palladium/Gold (Ni/Pd/Au)

QUAD

GULL WING

260

1

3.3V

NOT SPECIFIED

ADS114

2.7V

MUX-PGA-ADC

16

Differential, Pseudo-Differential, Single Ended

Sigma-Delta

4, 6

ADC, DELTA-SIGMA

External, Internal

SPI

4 msps

±2.5V 2.7V~5.25V

2.7V~3.6V

6

4k

BINARY, 2'S COMPLEMENT BINARY

0.0025%

1

5.2V

SERIAL

-0.5V

0.406μs

PGA, Temperature Sensor

1.2mm

5mm

5mm

1mm

ROHS3 Compliant

AD1671JP

Mfr Part No

AD1671JP

Analog Devices Inc. Datasheet

19
In Stock

-

Min: 1

Mult: 1

OBSOLETE (Last Updated: 4 days ago)

Surface Mount

Surface Mount

28-LCC (J-Lead)

28

0°C~70°C

Tube

e0

no

Obsolete

1 (Unlimited)

28

EAR99

750mW

QUAD

J BEND

225

1

5V

30

AD1671

28

Bipolar, Unipolar

S/H-ADC

1

750mW

12

Single Ended

Pipelined

ADC, FLASH METHOD

External, Internal

Parallel

1.5 B

1.25 Msps

±5V

1

1.25M

5.25V

BINARY, OFFSET BINARY, 2'S COMPLEMENT BINARY

570mW

2.5 LSB

4.75V

SAMPLE

5V

1:1

5V

-5V

0.8μs

4.57mm

No

Non-RoHS Compliant

Contains Lead

AD7721AR

Mfr Part No

AD7721AR

Analog Devices Inc. Datasheet

11
In Stock

-

Min: 1

Mult: 1

Surface Mount

28-SOIC (0.295, 7.50mm Width)

YES

28

-40°C~85°C

Tube

e0

no

Obsolete

1 (Unlimited)

28

EAR99

150mW

DUAL

GULL WING

240

1

5V

not_compliant

30

AD7721

28

Not Qualified

5V

Bipolar, Unipolar

5V

ADC

1

Parallel, SPI, Serial

5.25V

4.75V

150mW

12, 16

Differential

2.4V

Sigma-Delta

2.6V

External

SPI, Parallel

2 B

468.75 ksps

5V

1

312.5k, 468.75k

BINARY

16 LSB

1.6pF

SERIAL, PARALLEL, WORD

8 LSB

2.65mm

7.5mm

Non-RoHS Compliant

Contains Lead

ADS7844N/1KG4

Mfr Part No

ADS7844N/1KG4

Texas Instruments Datasheet

31
In Stock

-

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 3 days ago)

Gold

Surface Mount

Surface Mount

20-SSOP (0.209, 5.30mm Width)

20

1

-40°C~85°C

Tape & Reel (TR)

e4

yes

Active

1 (Unlimited)

20

EAR99

4.5mW

DUAL

GULL WING

260

1

2.7V

0.65mm

ADS7844

20

5V

Unipolar

MUX-S/H-ADC

8

Serial

5.25V

2.7V

550μA

4.5mW

12

Differential, Single Ended

SAR

4, 8

ADC, SUCCESSIVE APPROXIMATION

Single

External

SPI

1.5 B

200 ksps

2.7V~3.6V 5V

2.7V~3.6V 5V

8

200k

BINARY

2 LSB

SAMPLE

200 ksps

1:1

72 dB

0.8 LSB

2mm

7.2mm

5.3mm

1.95mm

No

No SVHC

ROHS3 Compliant

Lead Free

ADS7888SDBVR

Mfr Part No

ADS7888SDBVR

Texas Instruments Datasheet

2400
In Stock

-

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 5 days ago)

Tin

Surface Mount

SOT-23-6

YES

6

-40°C~125°C

Tape & Reel (TR)

microPOWER™

e3

yes

Active

2 (1 Year)

6

EAR99

10mW

DUAL

GULL WING

260

1

3.3V

0.95mm

ADS7888

6

5V

Unipolar

S/H-ADC

1

5.25V

2.35V

2mA

10mW

8

Single Ended

SAR

ADC, SUCCESSIVE APPROXIMATION

Single

Supply

SPI

1 B

1.25 Msps

2.35V~5.25V

2.35V~5.25V

1

1.25M

BINARY

3.8mW

0.3 LSB

SAMPLE

1.25 Msps

1:1

SERIAL

49.5 dB

5.25V

0.3 LSB

2.35V

77 dB

1.45mm

2.9mm

1.6mm

1.2mm

No

No SVHC

Non-RoHS Compliant

Contains Lead

AD7781CRZ

Mfr Part No

AD7781CRZ

Analog Devices Inc. Datasheet

1
In Stock

  • 1: $12.413554
  • 10: $11.710900
  • 100: $11.048018
  • 500: $10.422660
  • View all price

Min: 1

Mult: 1

8 Weeks

PRODUCTION (Last Updated: 1 month ago)

Tin

Surface Mount

14-SOIC (0.154, 3.90mm Width)

YES

14

-40°C~105°C

Tube

e3

no

Active

1 (Unlimited)

14

EAR99

2.1mW

DUAL

GULL WING

260

1

3V

30

AD7781

14

Not Qualified

Bipolar

PGA-ADC

1

5.25V

2.7V

420μA

2.1mW

20

Differential

500mV

Sigma-Delta

5V

ADC, DELTA-SIGMA

Analog, Digital

External

SPI

2.5 B

16.7 sps

2.7V~5.25V

2.7V~5.25V

1

16.7

OFFSET BINARY

0.0006%

SERIAL

PGA

1.5mm

8.75mm

4mm

No SVHC

ROHS3 Compliant

Contains Lead

TLC3548IPWR

Mfr Part No

TLC3548IPWR

Texas Instruments Datasheet

8
In Stock

  • 1: $20.983754
  • 10: $19.795994
  • 100: $18.675467
  • 500: $17.618365
  • View all price

Min: 1

Mult: 1

12 Weeks

ACTIVE (Last Updated: 4 days ago)

Surface Mount

24-TSSOP (0.173, 4.40mm Width)

YES

24

1

-40°C~85°C

Tape & Reel (TR)

e4

yes

Active

2 (1 Year)

24

EAR99

Nickel/Palladium/Gold (Ni/Pd/Au)

DUAL

GULL WING

260

1

5V

0.65mm

NOT SPECIFIED

TLC3548

24

Not Qualified

Unipolar

3/55V

MUX-S/H-ADC

8

5.5V

4.5V

2.8mA

14

Pseudo-Differential, Single Ended

SAR

4, 8

ADC, SUCCESSIVE APPROXIMATION

Analog, Digital

External, Internal

SPI

1.75 B

200 ksps

5V

2.7V~5.5V

8

200k

BINARY, 2'S COMPLEMENT BINARY

20mW

1 LSB

SAMPLE

200 ksps

1:1

4.07V

SERIAL

81 dB

5.5V

2.7V

97 dB

1.2mm

7.8mm

4.4mm

1mm

No SVHC

ROHS3 Compliant

Lead Free

ADC08351CIMTCX

Mfr Part No

ADC08351CIMTCX

Texas Instruments Datasheet

-

-

Min: 1

Mult: 1

Lead, Tin

Surface Mount

Surface Mount

20-TSSOP (0.173, 4.40mm Width)

20

-40°C~85°C

Tape & Reel (TR)

e0

no

Obsolete

1 (Unlimited)

20

EAR99

Tin/Lead (Sn/Pb)

48mW

DUAL

GULL WING

260

1

3V

0.65mm

ADC08351

20

3V

Unipolar

3V

S/H-ADC

1

3.6V

2.7V

8

Single Ended

ADC, RESISTANCE LADDER

Analog, Digital

External

Parallel

1 B

42 Msps

2.7V~3.6V

2.7V~3.6V

1

42M

BINARY

41mW

0.5469%

1.4 LSB

SAMPLE

42 Msps

1:1

3V

45 dB

0.735V

6.5mm

4.4mm

No

Non-RoHS Compliant

Contains Lead

MCP3553T-E/MS

Mfr Part No

MCP3553T-E/MS

Microchip Technology Datasheet

120
In Stock

Min: 1

Mult: 1

14 Weeks

Surface Mount

Surface Mount

8-TSSOP, 8-MSOP (0.118, 3.00mm Width)

8

-40°C~125°C

Tape & Reel (TR)

2009

e3

yes

Active

2 (1 Year)

8

EAR99

Matte Tin (Sn)

DUAL

GULL WING

260

1

2.7V

0.65mm

40

MCP3553

8

Bipolar

2.7/5V

ADC

1

2-Wire, SPI, Serial

5.5V

2.7V

22

Differential

Sigma-Delta

External

SPI

2.575 B

60 sps

2.7V~5.5V

2.7V~5.5V

1

60

2'S COMPLEMENT BINARY

0.006%

60 sps

3mm

3mm

No

Non-RoHS Compliant

Lead Free

ADS8324E/250

Mfr Part No

ADS8324E/250

Texas Instruments Datasheet

1
In Stock

  • 1: $17.195806
  • 10: $16.222459
  • 100: $15.304207
  • 500: $14.437930
  • View all price

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 3 days ago)

Surface Mount

8-TSSOP, 8-MSOP (0.118, 3.00mm Width)

YES

8

-40°C~85°C

Cut Tape (CT)

microPOWER™

e4

yes

Active

2 (1 Year)

8

EAR99

Nickel/Palladium/Gold (Ni/Pd/Au)

3mW

DUAL

GULL WING

260

1

1.8V

0.65mm

ADS8324

8

3.3V

Bipolar

S/H-ADC

1

SPI, Serial

3.6V

1.8V

1.4mA

3mW

14

Differential, Single Ended

SAR

ADC, SUCCESSIVE APPROXIMATION

External

SPI

1.75 B

50 ksps

1.8V~3.6V

1.8V~3.6V

1

50k

2'S COMPLEMENT BINARY

2.5mW

3 LSB

SAMPLE

50 ksps

1:1

0.9V

78 dB

3.6V

2 LSB

1.8V

85 dB

1.07mm

3mm

3mm

970μm

No

No SVHC

ROHS3 Compliant

Lead Free

ADS1174IPAPR

Mfr Part No

ADS1174IPAPR

Texas Instruments Datasheet

1
In Stock

  • 1: $16.916135
  • 10: $15.958619
  • 100: $15.055301
  • 500: $14.203113
  • View all price

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 1 week ago)

Gold

Surface Mount

Surface Mount

64-PowerTQFP

64

-40°C~85°C

Tape & Reel (TR)

e4

yes

Active

3 (168 Hours)

64

EAR99

210mW

QUAD

GULL WING

260

1

5V

0.5mm

NOT SPECIFIED

ADS1174

64

Not Qualified

5V

Bipolar

5V

ADC

5.25V

4.75V

23mA

135mW

16

Differential, Single Ended

Sigma-Delta

Analog, Digital

External

SPI

2 B

52 ksps

5V

1.65V~1.95V

4

52k

2'S COMPLEMENT BINARY

135mW

1 LSB

SAMPLE

1

4

52 ksps

SERIAL

97 dB

1 LSB

8

Simultaneous Sampling

1.2mm

10mm

10mm

1mm

ROHS3 Compliant

Lead Free

ADS8327IBPW

Mfr Part No

ADS8327IBPW

Texas Instruments Datasheet

11472
In Stock

  • 1: $20.244031
  • 10: $19.098143
  • 100: $18.017116
  • 500: $16.997279
  • View all price

Min: 1

Mult: 1

6 Weeks

ACTIVE (Last Updated: 1 week ago)

Gold

Surface Mount

Surface Mount

16-TSSOP (0.173, 4.40mm Width)

-40°C~85°C

Tube

e4

yes

Active

2 (1 Year)

16

EAR99

38.5mW

DUAL

GULL WING

260

1

2.7V

NOT SPECIFIED

ADS8327

16

Not Qualified

5V

Unipolar

S/H-ADC

1

5.5V

2.7V

5mA

30mW

16

Differential, Single Ended

SAR

ADC, SUCCESSIVE APPROXIMATION

Single

External

SPI

2 B

500 ksps

5V

1.65V~5.5V

1

500k

BINARY

15mW

2 LSB

SAMPLE

500 ksps

1:1

SERIAL

91 dB

1 LSB

1.2mm

5mm

4.4mm

1mm

ROHS3 Compliant

Lead Free

ADS7809UB/1K

Mfr Part No

ADS7809UB/1K

Texas Instruments Datasheet

4000
In Stock

  • 1: $21.423805
  • 10: $20.211136
  • 100: $19.067110
  • 500: $17.987839
  • View all price

Min: 1

Mult: 1

16 Weeks

ACTIVE (Last Updated: 1 week ago)

Gold

Surface Mount

Surface Mount

20-SOIC (0.295, 7.50mm Width)

20

-40°C~85°C

Tape & Reel (TR)

e4

yes

Active

3 (168 Hours)

20

EAR99

100mW

DUAL

GULL WING

260

1

5V

ADS7809

20

5V

Bipolar, Unipolar

5V

S/H-ADC

1

Parallel

5.25V

4.75V

100mW

16

Single Ended

SAR

ADC, SUCCESSIVE APPROXIMATION

Analog, Digital

External, Internal

SPI, DSP

2 B

100 ksps

5V

1

100k

BINARY, 2'S COMPLEMENT BINARY

81.5mW

2 LSB

SAMPLE

100 ksps

1:1

SERIAL

88 dB

1 LSB

2.65mm

12.8mm

7.5mm

2.35mm

No

ROHS3 Compliant

Lead Free

LTC2288CUP#PBF

Mfr Part No

LTC2288CUP#PBF

Linear Technology/Analog Devices Datasheet

2000
In Stock

  • 1: $19.974147
  • 10: $18.843535
  • 100: $17.776920
  • 500: $16.770678
  • View all price

Min: 1

Mult: 1

8 Weeks

PRODUCTION (Last Updated: 2 weeks ago)

Surface Mount

Surface Mount

64-WFQFN Exposed Pad

64

0°C~70°C

Tube

2006

e3

Active

1 (Unlimited)

64

EAR99

Matte Tin (Sn)

QUAD

NO LEAD

260

2

3V

0.5mm

30

LTC2288

64

Not Qualified

3V

Bipolar

3V

S/H-ADC

3.4V

2.7V

133mA

450mW

10

Differential, Single Ended

Pipelined

2

ADC, PROPRIETARY METHOD

External, Internal

Parallel

1.25 B

65 Msps

2.7V~3.4V

2.7V~3.4V

1

65M

0.0586%

0.6 LSB

SAMPLE

1:1

1V

-1V

Simultaneous Sampling

0.8mm

9mm

9mm

No SVHC

ROHS3 Compliant

Lead Free

LTC1608IG#PBF

Mfr Part No

LTC1608IG#PBF

Linear Technology/Analog Devices Datasheet

24
In Stock

  • 1: $52.138961
  • 10: $49.187699
  • 100: $46.403489
  • 500: $43.776877
  • View all price

Min: 1

Mult: 1

8 Weeks

PRODUCTION (Last Updated: 3 weeks ago)

Surface Mount

Surface Mount

36-SSOP (0.209, 5.30mm Width)

36

1

-40°C~85°C

Tube

e3

Active

1 (Unlimited)

36

EAR99

Matte Tin (Sn)

420mW

GULL WING

260

1

5V

0.65mm

30

LTC1608

36

Not Qualified

Bipolar

S/H-ADC

420mW

16

Differential, Single Ended

SAR

ADC, SUCCESSIVE APPROXIMATION

Analog, Digital, Dual

External, Internal

Parallel

2 B

500 ksps

±5V

1

500k

5.25V

2'S COMPLEMENT BINARY

4 LSB

4.75V

SAMPLE

5V

1:1

-5V

5.29mm

ROHS3 Compliant

Lead Free