Datasheet LTC6246, LTC6247, LTC6248 Datasheet (Linear)

LTC6246/LTC6247/LTC6248

LTC6246

+

–

624678 TA01a

LTC2366

V

REF

GND

V

DD

3.3V 2.5V

CS

SDO

SCK

OV

DD

3.3V

V

IN

A

IN

499Ω 1%

499Ω

1%

10pF

FREQUENCY (kHz)

0

MAGNITUDE (dB)

0

–10

–30

–50

–70

–20

–40

–60

–80

–90 –100 –110

400 800200 600

624678 TA01b

1000

fIN = 350.195kHz f

SAMP

= 2.2Msps SFDR = 82dB SNR = 70dB 1024 POINT FFT

180MHz, 1mA Power

Efﬁcient Rail-to-Rail

I/O Op Amps

FeaTures

n

Gain Bandwidth Product: 180MHz

n

–3dB Frequency (AV = 1): 120MHz

n

Low Quiescent Current: 1mA Max

n

High Slew Rate: 90V/µs

n

Input Common Mode Range Includes Both Rails

n

Output Swings Rail-to-Rail

n

Low Broadband Voltage Noise: 4.2nV/√Hz

n

Power-Down Mode: 42μA

n

Fast Output Recovery

n

Supply Voltage Range: 2.5V to 5.25V

n

Input Offset Voltage: 0.5mV Max

n

Input Bias Current: 100nA

n

Large Output Current: 50mA

n

CMRR: 110dB

n

Open Loop Gain: 45V/mV

n

Operating Temperature Range: –40°C to 125°C

n

Single in 6-Pin TSOT-23

n

Dual in MS8, 2mm × 2mm Thin DFN,TS0T-23, MS10

n

Quad in MS16

applicaTions

n

Low Voltage, High Frequency Signal Processing

n

Driving A/D Converters

n

Rail-to-Rail Buffer Ampliﬁers

n

Active Filters

n

Video Ampliﬁers

n

Fast Current Sensing Ampliﬁers

n

Battery Powered Equipment

DescripTion

The LTC®6246/LTC6247/LTC6248 are single/dual/quad low power, high speed unity gain stable rail-to-rail input/output operational ampliﬁers. On only 1mA of supply current they feature an impressive 180MHz gain-bandwidth product, 90V/µs slew rate and a low 4.2nV/√Hz of input-referred noise. The combination of high bandwidth, high slew rate, low power consumption and low broadband noise makes these ampliﬁers unique among rail-to-rail input/output op amps with similar supply currents. They are ideal for lower supply voltage high speed signal conditioning systems.

The LTC6246 family maintains high efﬁciency performance from supply voltage levels of 2.5V to 5.25V and is fully speciﬁed at supplies of 2.7V and 5.0V.

For applications that require power-down, the LTC6246 and the LTC6247 in MS10 offer a shutdown pin which disables the ampliﬁer and reduces current consumption to 42µA.

The LTC6246 family can be used as a plug-in replacement for many commercially available op amps to reduce power or to improve input/output range and performance.

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners.

Typical applicaTion

Low Noise Low Distortion Gain = 2 ADC Driver

350kHz FFT Driving ADC

624678fa

1

LTC6246/LTC6247/LTC6248

TOP VIEW

9

KC PACKAGE

8-LEAD PLASTIC UTDFN (2mm s 2mm)

5

6

7

8

4

3

2

1OUT A

–IN A

+IN A

V

–

V

+

OUT B

–IN B

+IN B

+–+

–

1 2 3 4

OUT A

–IN A +IN A

V

–

8 7 6 5

V

+

OUT B –IN B +IN B

TOP VIEW

MS8 PACKAGE

8-LEAD PLASTIC MSOP

+

–

+

–

1 2 3 4 5

OUT A

–IN A +IN A

V

–

SHDNA

10 9 8 7 6

V

+

OUT B –IN B +IN B

SHDNB

TOP VIEW

MS PACKAGE

10-LEAD PLASTIC MSOP

+

–

+

–

1 2 3 4 5 6 7 8

OUT A

–IN A +IN A

V

+

+IN B –IN B

OUT B

16 15 14 13 12 11 10 9

OUT D –IN D +IN D V

–

+IN C –IN C OUT C

TOP VIEW

MS PACKAGE

16-LEAD PLASTIC MSOP

+–+

– +–+

–

OUT 1

V

–

2

+IN 3

6 V

+

5 SHDN 4 –IN

TOP VIEW

S6 PACKAGE

6-LEAD PLASTIC TSOT-23

+

–

OUT A 1

–IN A 2 +IN A 3

V

–

4

8 V

+

7 OUT B 6 –IN B 5 +IN B

TOP VIEW

TS8 PACKAGE

8-LEAD PLASTIC TSOT-23

+

–

+

–

absoluTe MaxiMuM raTings

Total Supply Voltage (V+ to V–) ................................5.5V

Input Current (+IN, –IN, SHDN) (Note 2) ..............±10mA

Output Current (Note 3) ..................................... ±100mA

Operating Temperature Range (Note 4) . –40°C to 125°C

pin conFiguraTion

= 125°C, θJA = 102°C/W (NOTE 9)

T

JMAX

EXPOSED PAD (PIN 9) IS V

–

, MUST BE SOLDERED TO PCB

(Note 1)

Speciﬁed Temperature Range (Note 5) .. –40°C to 125°C

Storage Temperature Range .................. –65°C to 150°C

Junction Temperature ........................................... 150°C

Lead Temperature (Soldering, 10 sec)

(MSOP, TSOT Packages Only) ...............................300°C

= 150°C, θJA = 163°C/W (NOTE 9)

T

JMAX

= 150°C, θJA = 160°C/W (NOTE 9)

T

JMAX

orDer inForMaTion

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE

LTC6246CS6#TRMPBF LTC6246CS6#TRPBF LTDWF 6-Lead Plastic TSOT-23 0°C to 70°C LTC6246IS6#TRMPBF LTC6246IS6#TRPBF LTDWF 6-Lead Plastic TSOT-23 –40°C to 85°C LTC6246HS6#TRMPBF LTC6246HS6#TRPBF LTDWF 6-Lead Plastic TSOT-23 –40°C to 125°C LTC6247CKC#TRMPBF LTC6247CKC#TRPBF DWJT LTC6247IKC#TRMPBF LTC6247IKC#TRPBF DWJT LTC6247CMS8#PBF LTC6247CMS8#TRPBF LTDWH 8-Lead Plastic MSOP 0°C to 70°C LTC6247IMS8#PBF LTC6247IMS8#TRPBF LTDWH 8-Lead Plastic MSOP –40°C to 85°C LTC6247CTS8#TRMPBF LTC6247CTS8#TRPBF LTDWK 8-Lead Plastic TSOT-23 0°C to 70°C LTC6247ITS8#TRMPBF LTC6247ITS8#TRPBF LTDWK 8-Lead Plastic TSOT-23 –40°C to 85°C LTC6247HTS8#TRMPBF LTC6247HTS8#TRPBF LTDWK 8-Lead Plastic TSOT-23 –40°C to 125°C

2

= 150°C, θJA = 125°C/W (NOTE 9)

T

JMAX

= 150°C, θJA = 192°C/W (NOTE 9)

T

JMAX

8-Lead (2mm × 2mm) UTDFN 8-Lead (2mm × 2mm) UTDFN

= 150°C, θJA = 195°C/W (NOTE 9)

T

JMAX

0°C to 70°C –40°C to 85°C

624678fa

LTC6246/LTC6247/LTC6248

orDer inForMaTion

LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE

LTC6247CMS#PBF LTC6247CMS#TRPBF LTDWM 10-Lead Plastic MSOP 0°C to 70°C LTC6247IMS#PBF LTC6247IMS#TRPBF LTDWM 10-Lead Plastic MSOP –40°C to 85°C LTC6248CMS#PBF LTC6248CMS#TRPBF 6248 16-Lead Plastic MSOP 0°C to 70°C LTC6248IMS#PBF LTC6248IMS#TRPBF 6248 16-Lead Plastic MSOP –40°C to 85°C LTC6248HMS#PBF LTC6248HMS#TRPBF 6248 16-Lead Plastic MSOP –40°C to 125°C TRM = 500 pieces. *Temperature grades are identiﬁed by a label on the shipping container.

Consult LTC Marketing for parts speciﬁed with wider operating temperature ranges. Consult LTC Marketing for information on lead based ﬁnish parts.

For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel speciﬁcations, go to: http://www.linear.com/tapeandreel/

(V

elecTrical characTerisTics

speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. For each ampliﬁer VS = 5V, 0V; V

= 5V) The l denotes the speciﬁcations which apply across the

S

= 2V; VCM = V

SHDN

OUT

= 2.5V,

unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

OS

∆V

OS

V

OS TC

I

B

I

OS

e

n

i

n

C

IN

R

IN

A

VOL

CMRR Common Mode Rejection Ratio V

Input Offset Voltage VCM = Half Supply

Input Offset Voltage Match (Channel-to-Channel) (Note 8)

Input Offset Voltage Drift Input Bias Current (Note 7) VCM = Half Supply

Input Offset Current VCM = Half Supply

Input Noise Voltage Density f = 100kHz 4.2 nV/√Hz Input 1/f Noise Voltage f = 0.1Hz to 10Hz 1.6 µV Input Noise Current Density f = 100kHz 2.0 pA/√Hz Input Capacitance Differential Mode

Input Resistance Differential Mode

Large Signal Voltage Gain RL = 1k to Half Supply (Note 10)

= V+ – 0.5V, NPN Mode

V

CM

VCM = Half Supply

= V+ – 0.5V, NPN Mode

V

CM

= V+ – 0.5V, NPN Mode

V

CM

= V+ – 0.5V, NPN Mode

V

CM

Common Mode

= 100Ω to Half Supply (Note 10)

R

L

= 0V to 3.5V

CM

–500

l

–1000

–2.5

l

–3

–600

l

–1000

–3.5

l

–4

l

–350

l

–550

100

l

0

–250

l

–400 –250

l

–400

30

l

14

5

l

2.5 78

l

76

50 500

1000

0.1 2.5 3

50 600

1000

0.1 3.5 4

–2 µV/°C

–30 350

550

400 1000

1500

–10 250

400

–10 250

400

2

0.8

32 14

45 V/mV

15 V/mV

110 dB

µV µV

mV mV

µV µV

mV mV

nA nA

P-P

pF pF

kΩ

MΩ

V/mV

dB

624678fa

3

LTC6246/LTC6247/LTC6248

elecTrical characTerisTics

(V speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. For each ampliﬁer VS = 5V, 0V; V unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

I

CMR

PSRR Power Supply Rejection Ratio V

V

OL

V

OH

I

SC

I

S

I

SD

I

SHDNL

I

SHDNH

V

L

V

H

I

OSD

t

ON

t

OFF

BW –3dB Closed Loop Bandwidth A GBW Gain-Bandwidth Product f = 2MHz, R

, 0.1% Settling Time to 0.1% AV = –1, VO = 2V Step RL = 1k 74 ns

t

S

, 0.01% Settling Time to 0.01% AV = –1, VO = 2V Step RL = 1k 202 ns

t

S

SR Slew Rate A

FPBW Full Power Bandwidth V

Input Common Mode Range

Supply Voltage Range (Note 6) Output Swing Low (V

Output Swing High (V+ – V

– V–) No Load

OUT

) No Load

OUT

Output Short-Circuit Current Sourcing

Supply Current per Ampliﬁer VCM = Half Supply

Disable Supply Current per Ampliﬁer V

SHDN Pin Current Low V

SHDN Pin Current High V

SHDN Pin Input Voltage Low SHDN Pin Input Voltage High

Output Leakage Current Magnitude in Shutdown

Turn-On Time V Turn-Off Time V

= 5V) The l denotes the speciﬁcations which apply across the

S

= 2.5V to 5.25V

S

V

= 1V

CM

= 5mA

I

SINK

= 25mA

I

SINK

= 5mA

I

SOURCE

= 25mA

I

SOURCE

Sinking

= V+ – 0.5V

V

CM

= 0.8V

SHDN

= 0.8V

SHDN

= 2V

SHDN

V

= 0.8V, Output Shorted to Either

SHDN

l

–300

l

–350

l

= 2V; VCM = V

SHDN

0 V

69

73 dB

OUT

S

= 2.5V,

65

2.5 5.25 V 25 40

55

70 110

160

160 250

450

70 100

150

130 175

225

300 500

750

–80 –35

–30

60

100 mA

40

0.95 1

1.4

1.25 1.4

1.8

42 75

200

–3 –4

–1.6 0

0

35 300

350

0.8 V

2 V

100 nA

Supply

= 0.8V to 2V 5 µs

SHDN

= 2V to 0.8V 2 µs

SHDN

= 1, RL = 1k to Half Supply 120 MHz

V

= 1k to Half Supply

L

= –3.33, 4.6V Step (Note 11)

V

= 4V

OUT

(Note 13) 4 MHz

P-P

100

l

70

60

l

50

180 MHz

90 V/µs

dB

mV mV

mA mA

mA

µA µA

nA nA

MHz

V/µs

V

4

624678fa

LTC6246/LTC6247/LTC6248

(V

elecTrical characTerisTics

speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. For each ampliﬁer VS = 5V, 0V; V

= 5V) The l denotes the speciﬁcations which apply across the

S

= 2V; VCM = V

SHDN

OUT

= 2.5V,

unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

= 100kHz, VO = 2V

HD2/HD3 Harmonic Distortion

= 1k to Half Supply

R

L

R

= 100Ω to Half Supply fC = 100kHz, VO = 2V

L

∆G ∆θ

Differential Gain (Note 14) A Differential Phase (Note 14) A Crosstalk A

(V

elecTrical characTerisTics

f

C

fC = 1MHz, VO = 2V fC = 2MHz, VO = 2V

= 1, RL = 1k, VS = ±2.5V 0.2 %

V

= 1, RL = 1k, VS = ±2.5V 0.08 Deg

V

= –1, RL = 1k to Half Supply,

V

= 2V

OUT

P-P

= 2.7V) The l denotes the speciﬁcations which apply across the

S

P-P P-P P-P

, f = 1MHz

speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. For each ampliﬁer VS = 2.7V, 0V; V

110/90

88/80 78/62

90/79 66/60 59/51

–90 dB

= 2V; VCM = V

SHDN

OUT

dBc dBc dBc

=

1.35V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

OS

∆V

V

OS TC

I

B

I

OS

e

n

i

n

C

IN

R

IN

A

VOL

OS

Input Offset Voltage VCM = Half Supply

= V+ – 0.5V, NPN Mode

V

CM

Input Offset Voltage Match

VCM = Half Supply

(Channel-to-Channel) (Note 8)

= V+ – 0.5V, NPN Mode

V

CM

Input Offset Voltage Drift Input Bias Current (Note 7) VCM = Half Supply

= V+ – 0.5V, NPN Mode

V

CM

Input Offset Current VCM = Half Supply

= V+ – 0.5V, NPN Mode

V

CM

Input Noise Voltage Density f = 100kHz 4.6 nV/√Hz Input 1/f Noise Voltage f = 0.1Hz to 10Hz 1.7 µV Input Noise Current Density f = 100kHz 1.8 pA/√Hz Input Capacitance Differential Mode

Common Mode

Input Resistance Differential Mode

Common Mode

Large Signal Voltage Gain RL = 1k to Half Supply

(Note 12)

= 100Ω to Half Supply

R

L

(Note 12)

–100

l

–300

–1.75

l

–2.25

–700

l

–1000

–3.5

l

–4

l

–450

l

–600

50

l

0

–250

l

–350 –250

l

–350

500 1000

1400

0.75 3.25

3.75

–20 700

1000

0.1 3.5 4

2 µV/°C

–100 450

600

350 1000

1500

–10 250

350

–10 250

350

mV mV

nA nA

P-P

2

0.8

32 12

15

l

7.5 2

l

1.3

25 V/mV

7.5 V/mV

kΩ

MΩ

V/mV

µV µV

pF pF

624678fa

5

LTC6246/LTC6247/LTC6248

elecTrical characTerisTics

(V speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. For each ampliﬁer VS = 2.7V, 0V; V

1.35V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

CMRR Common Mode Rejection Ratio V

I

CMR

PSRR Power Supply Rejection Ratio V

V

OL

V

OH

I

SC

I

S

I

SD

I

SHDNL

I

SHDNH

V

L

V

H

I

OSD

t

ON

t

OFF

BW –3dB Closed Loop Bandwidth A GBW Gain-Bandwidth Product f = 2MHz, R

, 0.1 Settling Time to 0.1% AV = –1, VO = 2V Step RL = 1k 119 ns

t

S

, 0.01 Settling Time to 0.01% AV = –1, VO = 2V Step RL = 1k 170 ns

t

S

SR Slew Rate A

Input Common Mode Range

Supply Voltage Range (Note 6) Output Swing Low (V

Output Swing High (V+ – V

– V–) No Load

OUT

) No Load

OUT

Short Circuit Current Sourcing

Supply Current per Ampliﬁer VCM = Half Supply

Disable Supply Current per Ampliﬁer V

SHDN Pin Current Low V

SHDN Pin Current High V

SHDN Pin Input Voltage SHDN Pin Input Voltage

Output Leakage Current Magnitude in Shutdown V

Turn-On Time V Turn-Off Time V

= 2.7V) The l denotes the speciﬁcations which apply across the

S

= 0V to 1.2V

CM

= 2.5V to 5.25V

S

V

= 1V

CM

= 5mA

I

SINK

= 10mA

I

SINK

= 5mA

I

SOURCE

= 10mA

I

SOURCE

Sinking

= V+ – 0.5V

V

CM

= 0.8V

SHDN

= 0.8V

SHDN

= 2V

SHDN

= 0.8V, Output Shorted to Either

SHDN

80

l

78

l

0 V

69

l

65

l

2.5 5.25 V

l

25

l

20

l

–1

l

–1.5

–300

l

–350

l

2.0 V

= 2V; VCM = V

SHDN

100 dB

S

73 dB

20 40

55

80 125

160

110 175

225

60 85

100

135 190

225

180 275

400

–35 –20

–15

50 mA

0.89 1

1.3

1 1.3

1.7

22 50

90

–0.5 0

0

45 300

350

0.8 V

100 nA

OUT

Supply

= 0.8V to 2V 5 µs

SHDN

= 2V to 0.8V 2 µs

SHDN

= 1, RL = 1k to Half Supply 100 MHz

V

= 1k to Half Supply

L

= –1, 2V Step 55 V/µs

V

80

l

50

150 MHz

=

dB

mV mV

mA mA

mA

µA µA

nA nA

V

6

624678fa

LTC6246/LTC6247/LTC6248

INPUT OFFSET VOLTAGE (µV)

PERCENT OF UNITS (%)

22 20

16

12

8

2

18

14

10

6 4

0

–50–150 150

624678 G01

350250–250–375 50

VS = 5V, 0V V

CM

= 2.5V

INPUT OFFSET VOLTAGE (µV)

PERCENT OF UNITS (%)

25

15

5

20

10

0

–125 –25–75

624678 G02

75 12525 175–175

VS = 5V, 0V V

CM

= 2.5V

INPUT OFFSET VOLTAGE (µV)

PERCENT OF UNITS (%)

16

12

8

2

14

10

6

4

0

–1200 400–400

624678 G03

1200 2000–2000

VS = 5V, 0V V

CM

= 4.5V

elecTrical characTerisTics

(V speciﬁed temperature range, otherwise speciﬁcations are at TA = 25°C. For each ampliﬁer VS = 2.7V, 0V; V

1.35V, unless otherwise noted.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

FPBW Full Power Bandwidth V

Crosstalk A

= 2.7V) The l denotes the speciﬁcations which apply across the

S

= 2V

OUT

= –1, RL = 1k to Half Supply,

V

OUT

(Note 13) 3.3 MHz

P-P

= 2V

, f = 1MHz

P-P

= 2V; VCM = V

SHDN

–90 dB

OUT

=

Note 1: Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime.

Note 2: The inputs are protected by back-to-back diodes. If any of the input or shutdown pins goes 300mV beyond either supply or the differential input voltage exceeds 1.4V the input current should be limited to less than 10mA. This parameter is guaranteed to meet speciﬁed performance through design and/or characterization. It is not production tested.

Note 3: A heat sink may be required to keep the junction temperature below the absolute maximum rating when the output current is high.

Note 4: The LTC6246C/LTC6247C/LTC6248C and LTC6246I/LTC6247I/ LTC6248I are guaranteed functional over the temperature range of –40°C to 85°C. The LTC6246H/LTC6247H/LTC6248H are guaranteed functional over the temperature range of –40°C to 125°C.

Note 5: The LTC6246C/LTC6247C/LTC6248C are guaranteed to meet speciﬁed performance from 0°C to 70°C. The LTC6246C/LTC6247C/ LTC6248C are designed, characterized and expected to meet speciﬁed performance from –40°C to 85°C but are not tested or QA sampled at these temperatures. The LTC6246I/LTC6247I/LTC6248I are guaranteed to meet speciﬁed performance from –40°C to 85°C. The LTC6246H/ LTC6247H/LTC6248H are guaranteed to meet speciﬁed performance from –40°C to 125°C.

Note 6: Minimum supply voltage is guaranteed by power supply rejection ratio test.

Note 7: The input bias current is the average of the average of the currents through the positive and negative input pins.

Note 8: Matching parameters are the difference between ampliﬁers A and D and between B and C on the LTC6248; between the two ampliﬁers on the LTC6247.

Note 9: Thermal resistance varies with the amount of PC board metal connected to the package. The speciﬁed values are with short traces connected to the leads with minimal metal area.

Note 10: The output voltage is varied from 0.5V to 4.5V during measurement.

Note 11: Middle 80% of the output waveform is observed. R

= 1k at half

L

supply. Note 12: The output voltage is varied from 0.5V to 2.2V during

measurement. Note 13: FPBW is determined from distortion performance in a gain of +2

conﬁguration with HD2, HD3 < –40dBc as the criteria for a valid output. Note 14: Differential gain and phase are measured using a Tektronix

TSG120YC/NTSC signal generator and a Tektronix 1780R video measurement set.

Typical perForMance characTerisTics

VOS Distribution, VCM = VS/2 (MS, PNP Stage)

VOS Distribution, VCM = VS/2 (TSOT-23, PNP Stage)

VOS Distribution, VCM = V+ – 0.5V (MS, NPN Stage)

624678fa

7

LTC6246/LTC6247/LTC6248

INPUT COMMON MODE VOLTAGE (V)

0

OFFSET VOLTAGE (µV)

500

400

100

200

–300

300

0

–100

–200

–400

–500

1.5 3.51 2.5 4.5

624678 G09

530.5 2 4

–55°C

VS = 5V, 0V

125°C

25°C

OUTPUT CURRENT (mA)

–100

V

OS

(mV)

2.0

1.5

0.5

–1.0

1.0

0

–0.5

–1.5

–2.0

–75 25–25 75

624678 G10

1000–50 50

25°C

125°C

–55°C

VS = ±2.5V

TIME AFTER POWER-UP (s)

0

CHANGE IN OFFSET VOLTAGE (µV)

5

0

–10

–25

–5

–15

–20

–30

–35

20 10060 140

624678 G11

1608040 120

VS = ±2.5V T

A

= 25°C

COMMON MODE VOLTAGE (V)

0

INPUT BIAS CURRENT (nA)

800 600

200

–200

–600

–1200

400

0

–400

–800

–1000

–1400 –1600

1.5 3.51 2.5 4.5

624678 G12

530.5 2 4

25°C

125°C

–55°C

VS = 5V, 0V

INPUT OFFSET VOLTAGE (µV)

PERCENT OF UNITS (%)

18

12

14

10

4

16

8

6

2

0

–1200

624678 G04

400 1200–400 2000–2000

VS = 5V, 0V V

CM

= 4.5V

TEMPERATURE (°C)

VOLTAGE OFFSET (µV)

500

200

300

100

–200

400

0

–100

–300

–400

–15–35

624678 G05

5 25 65 85 105 125–55

VS = 5V, 0V V

CM

= 2.5V

6 DEVICES

45

TEMPERATURE (°C)

VOLTAGE OFFSET (µV)

2500

1000

1500

500

–1000

2000

0

–500

–1500

–2000

–2500

–15–35

624678 G06

5 25 65 85 105 125–55

VS = 5V, 0V V

CM

= 4.5V

6 DEVICES

45

TEMPERATURE (°C)

VOLTAGE OFFSET (µV)

1200

1000

800

600

400

200

0

–15–35

624678 G07

5 25 65 85 105 125–55

VS = 2.7V, 0V V

CM

= 1.35V

6 DEVICES

45

TEMPERATURE (°C)

VOLTAGE OFFSET (µV)

2500

2000

1500

1000

500

0

–1500

–1000

–500

–2000

–15–35

624678 G08

5 25 65 85 105 125–55

VS = 2.7V, 0V V

CM

= 2.2V

6 DEVICES

45

Typical perForMance characTerisTics

Distribution, VCM = V+ – 0.5V

V

OS

(TSOT-23, NPN Stage)

V

vs Temperature

OS

(MS10, PNP Stage)

VOS vs Temperature (MS10, PNP Stage)

VOS vs Temperature (MS10, NPN Stage)

vs Temperature

V

OS

(MS10, NPN Stage)

Offset Voltage vs Input Common Mode Voltage

Offset Voltage vs Output Current

8

Input Bias Current

Warm-Up Drift vs Time

vs Common Mode Voltage

624678fa

LTC6246/LTC6247/LTC6248

TIME (1s/DIV)

0

VOLTAGE NOISE (500nV/DIV)

1.5 VS = ±2.5V

1.0

0.5

0

0.5

–1.0

–1.5

1 73 9

624678 G14

104 5 62 8

TOTAL SUPPLY VOLTAGE (V)

0

SUPPLY CURRENT (mA)

1.20

1.00

0.80

0.60

0.40

0.20

0

1 3

624678 G16

TA = 125°C

TA = 25°C

TA = –55°C

4 52

TEMPERATURE (°C)

–55

INPUT BIAS CURRENT (nA)

700

600

300

–100

400

500

0

200

100

–200

355–25 95

624678 G13

12565

VS = 5V, 0V

VCM = 4.5V

VCM = 2.5V

FREQUENCY (Hz)

1

VOLTAGE NOISE (nV/√Hz)

CURRENT NOISE (pA/√Hz)

1000

en, VCM = 4.5V

en, VCM = 2.5V

in, VCM = 2.5V

in, VCM = 4.5V

100

10

1.0

0.1 10 1k 10M

624678 G15

10k 100k 1M100

SHDN PIN VOLTAGE (V)

0

SUPPLY CURRENT (mA)

1.25

1.00

0.75

0.50

0.25

0

2.521.510.5 3.5

624678 G17

5

125°C

VS = 5V, 0V

25°C

–55°C

4 4.53

SHDN PIN VOLTAGE (V)

0

SHDN PIN CURRENT (µA)

0.25 0

–0.25 –0.50 –0.75 –1.00 –1.25 –1.50 –1.75 –2.00 –2.25 –2.50

2.521.510.5 3.5

624678 G18

5

125°C

VS = 5V, 0V

SHUTDOWN CURRENT

25°C

–55°C

4 4.53

TOTAL SUPPLY VOLTAGE (V)

2

OFFSET VOLTAGE (mV)

12

10

8

6

4

2

0

–2

2.5 3.5

624678 G19

5.5

125°C

25°C

–55°C

4 4.5 53

TOTAL SUPPLY VOLTAGE (V)

2

OFFSET VOLTAGE (mV)

5

4

3

2

1

0

–1

2.5 3.5

624678 G20

5.5

125°C

25°C

–55°C

4 4.5 53

VCM = VCC – 0.5V

LOAD CURRENT (mA)

OUTPUT HIGH SATURATION VOLTAGE (V)

624678 G21

10

1

0.1

0.01

0.01 10 10010.1

VS = ±2.5V

TA = –55°C

TA = 125°C

TA = 25°C

Typical perForMance characTerisTics

Input Bias Current vs Temperature

0.1Hz to 10Hz Voltage Noise

Input Noise Voltage and Noise Current vs Frequency

Supply Current vs Supply Voltage (Per Ampliﬁer)

Minimum Supply Voltage, VCM = VS/2 (PNP Operation)

Supply Current Per Ampliﬁer vs SHDN Pin Voltage

Minimum Supply Voltage, VCM = V+ – 0.5V (NPN Operation)

SHDN Pin Current vs SHDN Pin Voltage

Output Saturation Voltage vs Load Current (Output High)

624678fa

9

LTC6246/LTC6247/LTC6248

LOAD CURRENT (mA)

OUTPUT LOW SATURATION VOLTAGE (V)

624678 G22

10

1

0.1

0.01

0.01 10 10010.1

VS = ±2.5V

TA = –55°C

TA = 125°C

TA = 25°C

OUTPUT VOLTAGE (V)

0

INPUT VOLTAGE (µV)

500

400

300

200

100

0

–100

–200

–300

–400

–500

2.5 3.5

624678 G24

5

RL = 1k TO MID SUPPLY

RL = 1k TO GROUND

RL = 100 TO MID SUPPLY

RL = 100 TO GROUND

TA = 25°C V

S

= 5V, 0V

4 4.521.510.5 3

OUTPUT VOLTAGE (V)

0

INPUT VOLTAGE (µV)

1000

900

500

600

700

800

400 300 200 100

0 –100 –200 –300

2.5

624678 G25

2.7

RL = 1k TO MID SUPPLY

RL = 1k TO GROUND

RL = 100 TO MID SUPPLY

RL = 100 TO GROUND

TA = 25°C V

S

= 2.7V, 0V

21.510.5

POWER SUPPLY VOLTAGE (±V)

1.25

OUTPUT SHORT-CIRCUIT CURRENT (mA)

120 100

80

60

40

20

0 –20 –40 –60 –80

–100

1.651.45 2.05

624678 G23

2.65

TA = 125°C

SINK

SOURCE

TA = 25°C

TA = –55°C

2.25 2.451.85

FREQUENCY (MHz)

GAIN (dB)

624678 G26

6

0

–18

–12

–6

–24

0.01 10 10010.1

VS = ±2.5V T

A

= 25°C

R

L

= 1k

FREQUENCY (MHz)

GAIN (dB)

624678 G27

12

0

6

–12

–6

–18

0.01 10 10010.1

VS = ±2.5V T

A

= 25°C

R

F

= RG = 1k

R

L

= 1k

FREQUENCY (Hz)

GAIN (dB)

PHASE (DEG)

624678 G28

80

10

20

30

40

50

60

70

–10

0

–20

150

0

50

100

–50

–100

100k 100M 300M10M1M

TA = 25°C

R

L

= 1k

VS = ±2.5V

PHASE

GAIN

VS = ±1.35V

VS = ±2.5V

VS = ±1.35V

TOTAL SUPPLY VOLTAGE (V)

2.5

GAIN BANDWIDTH (MHz)

PHASE MARGIN (DEG)

200

180

160

140

120

100

70

60

50

3 3.5 4.5

PHASE MARGIN

GAIN BANDWIDTH PRODUCT

624678 G29

TA = 25°C R

L

= 1k

54

TEMPERATURE (°C)

–55

GAIN BANDWIDTH (MHz)

PHASE MARGIN (DEG)

300

250

200

150

100

60

70

50

40

–35 –15 4525

PHASE MARGIN

GAIN BANDWIDTH PRODUCT

624678 G30

125

TA = 25°C R

L

= 1k

65 85 1055

VS = ±2.5V

VS = ±1.35V

VS = ±2.5V

VS = ±1.35V

Typical perForMance characTerisTics

Output Saturation Voltage vs Load Current (Output Low)

Open Loop Gain

Output Short-Circuit Current vs Power Supply Voltage Open Loop Gain

Gain vs Frequency (A

= 1)

V

Gain vs Frequency (A

= 2)

V

Open Loop Gain and Phase vs Frequency

10

Gain Bandwidth and Phase Margin vs Supply Voltage

Gain Bandwidth and Phase Margin vs Temperature

624678fa

LTC6246/LTC6247/LTC6248

FREQUENCY (Hz)

OUTPUT IMPEDANCE (Ω)

624678 G31

1000

10

100

1

0.1

0.01

0.001 100k 100M 1G10M1M

VS = ±2.5V

AV = 10

AV = 1

AV = 2

FREQUENCY (Hz)

COMMON MODE REJECTION RATIO (dB)

624678 G31

110

90 80 70 60 50 40 30

100

20 10

0

–10

10 100 1k 10k 100k 100M 1G10M1M

TA = 25°C V

S

= ±2.5V

FREQUENCY (Hz)

10

POWER SUPPLY REJECTION RATIO (dB)

50

40

30

20

10

70

80

60

0

–10

100 1k 100k

NEGATIVE SUPPLY

POSITIVE SUPPLY

624678 G33

VS = ±2.5V T

A

= 25°C

100M10M1M10k

TEMPERATURE (°C)

–55

SLEW RATE (V/µs)

140

FALLING, VS = ±2.5V

RISING, VS = ±2.5V

FALLING, VS = ±1.35V

RISING, VS = ±1.35V

120

100

80

60

40

–35 45255–15 85

624678 G34

125

AV = –1, RL = 1k, V

OUT

= 4V

P-P

(±2.5V),

2V

P-P

(±1.35V) SLEW RATE MEASURED

AT MIDDLE 2/3 OF OUTPUT

10565

FREQUENCY (MHz)

0.01

DISTORTION (dBc)

–40

–50

–60

–70

–80

–90

–100

–110

–120

0.1 101

624678 G37

VS = ±2.5V V

OUT

= 2V

P-P

AV = 1

RL = 100Ω, 2ND

RL = 1kΩ, 3RD

RL = 1kΩ, 2ND

RL = 100Ω, 3RD

FREQUENCY (MHz)

0.01

DISTORTION (dBc)

–40

–50

–60

–70

–80

–90

–100

–110

–120

0.1 101

624678 G38

VS = ±1.35V V

OUT

= 1V

P-P

AV = 1

RL = 100Ω, 2ND

RL = 1kΩ, 3RD

RL = 1kΩ, 2ND

RL = 100Ω, 3RD

FREQUENCY (MHz)

0.01

DISTORTION (dBc)

–40

–50

–60

–70

–80

–90

–100

–110

–120

0.1 101

624678 G39

VS = ±2.5V V

OUT

= 2V

P-P

AV = 2

RL = 100Ω, 2ND

RL = 1kΩ, 3RD

RL = 1kΩ, 2ND

RL = 100Ω, 3RD

CAPACITIVE LOAD (pF)

10

OVERSHOOT (%)

80

70

60

50

40

30

20

10

0

100 100001000

624678 G35

VS = ±2.5V V

OUT

= 100mV

P-P

AV = 1

RS = 20Ω

RS = 49.9Ω

RS = 10Ω

+

–

R

S

C

L

V

OUT

V

IN

AV = 1

CAPACITIVE LOAD (pF)

10

OVERSHOOT (%)

80

70

60

50

40

30

20

10

0

100 100001000

624678 G36

VS = ±2.5V V

OUT

= 200mV

P-P

RF = RG = 500Ω, A

V

= 2

RS = 20Ω

RS = 49.9Ω

R

S

500Ω

C

L

V

OUT

V

IN

AV = 2

RS = 10Ω

+

–

Typical perForMance characTerisTics

Output Impedance vs Frequency

Slew Rate vs Temperature

Common Mode Rejection Ratio vs Frequency

Series Output Resistor vs Capacitive Load (A

= 1)

V

Power Supply Rejection Ratio vs Frequency

Series Output Resistor vs Capacitive Load (AV = 2)

Distortion vs Frequency (AV = 1, 5V)

Distortion vs Frequency (AV = 1, 2.7V)

Distortion vs Frequency (AV = 2, 5V)

624678fa

11

LTC6246/LTC6247/LTC6248

OUTPUT STEP (V)

–4

SETTLING TIME (ns)

200

180

160

140

40

60

80

100

120

20

0

–3 –1

624678 G42

4

1mV

10mV 10mV

0 1 32–2

VS = ±2.5V A

V

= 1

T

A

= 25°C

1k

V

OUT

V

IN

+

–

OUTPUT STEP (V)

–4

SETTLING TIME (ns)

200

180

160

140

40

60

80

100

120

20

0

–3 –1

624678 G43

4

10mV

0 1 32–2

1k

V

OUT

V

IN

VS = ±2.5V A

V

= –1

T

A

= 25°C

1mV

10mV

1mV

+

–

V

OUT

1.6V/DIV

A

V

= 1

V

S

= ±2.5V

R

L

= 1k

V

IN

= 1.6V

V

SHDN

2.5V/DIV

0V

624678 G44

10µs/DIV

1V/DIV

0V

A

V

= 1

V

S

= ±2.5V

R

L

= 1k

624678 G45

200ns/DIV

25mV/DIV

0V

A

V

= 1

V

S

= ±2.5V

R

L

= 1k

624678 G46

50ns/DIV

V

OUT

2V/DIV

A

V

= ±2

V

S

= ±2.5V

R

L

= 1k

V

IN

= 3V

P-P

V

IN

1V/DIV

0V

624678 G47

100ns/DIV

FREQUENCY (MHz)

0.01

DISTORTION (dBc)

–40

–50

–60

–70

–80

–90

–100

–110

–120

0.1 101

624678 G40

VS = ±1.35V V

OUT

= 1V

P-P

AV = 2

RL = 100Ω, 2ND

RL = 1kΩ, 3RD

RL = 1kΩ, 2ND

RL = 100Ω, 3RD

FREQUENCY (MHz)

0.01

OUTPUT VOLTAGE SWING (V

P-P

)

5

4

3

2

1

0

0.1 101

624678 G41

VS = ±2.5V T

A

= 25°C

R

L

= 1kΩ

HD2, HD3 < –40dBc

AV = 2 A

V

= –1

Typical perForMance characTerisTics

Distortion vs Frequency

= 2, 2.7V)

A

V

Maximum Undistorted Output Signal vs Frequency

Settling Time vs Output Step (Inverting) SHDN Pin Response Time

Settling Time vs Output Step (Noninverting)

Large Signal Response

12

Small Signal Response Output Overdriven Recovery

624678fa

pin FuncTions

624678 F01

Q15

ESDD5

Q14

C2

C1

BUFFER

AND

OUTPUT BIAS

R5R4

Q13

Q12

I

3

V

–

+

C

Q8

R3

Q11

Q9

Q10

R2R1

Q2Q1Q3Q4

I

1

+

I

2

+

V

BIAS

Q5

Q6Q19

Q7

D8

D7

Q18

Q17

D6

D5

ESDD2

V

–

ESDD1

V

+

ESDD4

V

–

ESDD3

V

+

Q16

V

–

V

+

+IN

–IN

ESDD6

OUT

–IN: Inverting Input of Ampliﬁer. Valid input range from V–

+

.

to V

LTC6246/LTC6247/LTC6248

–

: Negative Supply Voltage. Typically 0V. This can be made

V

a negative voltage as long as 2.5V ≤ (V

+

– V–) ≤ 5.25V.

+IN: Non-Inverting Input of Ampliﬁer. Valid input range

–

from V

V

ranges from 2.5V to 5.25V when V

to V+.

+

: Positive Supply Voltage. Allowed applied voltage

–

= 0V.

applicaTions inForMaTion

Circuit Description

The LTC6246/LTC6247/LTC6248 have an input and output signal range that extends from the negative power supply to the positive power supply. Figure 1 depicts a simpliﬁed schematic of the ampliﬁer. The input stage is comprised of two differential ampliﬁers, a PNP stage, Q1/Q2, and an NPN stage, Q3/Q4 that are active over different common mode input voltages. The PNP stage is active between the negative supply to nominally 1.2V below the positive supply. As the input voltage approaches the positive supply, the transistor Q5 will steer the tail current, I current mirror, Q6/Q7, activating the NPN differential pair

, to the

1

SHDN: Active Low Shutdown. Threshold is typically 1.1V

–

referenced to V

. Floating this pin will turn the part on.

OUT: Ampliﬁer Output. Swings rail-to-rail and can typically source/sink over 50mA of current at a total supply of 5V.

and the PNP pair becomes inactive for the remaining input common mode range. Also, at the input stage, devices Q17 to Q19 act to cancel the bias current of the PNP input pair. When Q1/Q2 are active, the current in Q16 is controlled to be the same as the current in Q1 and Q2. Thus, the base current of Q16 is nominally equal to the base current of the input devices. The base current of Q16 is then mirrored by devices Q17 to Q19 to cancel the base current of the input devices Q1/Q2. A pair of complementary common emitter stages, Q14/Q15, enable the output to swing from rail-to-rail.

624678fa

13

Figure 1. LTC6246/LTC6247/LTC6248 Simpliﬁed Schematic Diagram

LTC6246/LTC6247/LTC6248

applicaTions inForMaTion

Input Offset Voltage

The offset voltage will change depending upon which input stage is active. The PNP input stage is active from the negative supply rail to approximately 1.2V below the positive supply rail, then the NPN input stage is activated for the remaining input range up to the positive supply rail with the PNP stage inactive. The offset voltage magnitude for the PNP input stage is trimmed to less than 500µV with 5V total supply at room temperature, and is typically less than 150μV. The offset voltage for the NPN input stage is typically less than 1.7mV with 5V total supply at room temperature.

Input Bias Current

The LTC6246 family uses a bias current cancellation circuit to compensate for the base current of the PNP input pair. When the input common mode voltage is less than 200mV, the bias cancellation circuit is no longer effective and the input bias current magnitude can reach a value above 1µA. For common mode voltages ranging from

0.2V above the negative supply to 1.2V below the positive supply, the low input bias current of the LTC6246 family allows the ampliﬁers to be used in applications with high source resistances where errors due to voltage drops must be minimized.

Output

The LTC6246 family has excellent output drive capability. The ampliﬁers can typically deliver over 50mA of output drive current at a total supply of 5V. The maximum output current is a function of the total supply voltage. As the supply voltage to the ampliﬁer decreases, the output current capability also decreases. Attention must be paid to keep the junction temperature of the IC below 150°C (refer to the Power Dissipation Section) when the output is in continuous short circuit. The output of the ampliﬁer has reverse-biased diodes connected to each supply. If the output is forced beyond either supply, extremely high current will ﬂow through these diodes which can result in damage to the device. Forcing the output to even 1V beyond either supply could result in several hundred milliamps of current through either diode.

Input Protection

The input stages are protected against a large differential input voltage of 1.4V or higher by 2 pairs of back-to-back diodes to prevent the emitter-base breakdown of the input transistors. In addition, the input and shutdown pins have reverse biased diodes connected to the supplies. The current in these diodes must be limited to less than 10mA. The ampliﬁers should not be used as comparators or in other open loop applications.

ESD

The LTC6246 family has reverse-biased ESD protection diodes on all inputs and outputs as shown in Figure 1.

There is an additional clamp between the positive and negative supplies that further protects the device during ESD strikes. Hot plugging of the device into a powered socket must be avoided since this can trigger the clamp resulting in larger currents ﬂowing between the supply pins.

Capacitive Loads

The LTC6246/LTC6247/LTC6248 are optimized for high bandwidth and low power applications. Consequently they have not been designed to directly drive large capacitive loads. Increased capacitance at the output creates an additional pole in the open loop frequency response, worsening the phase margin. When driving capacitive loads, a resistor of 10Ω to 100Ω should be connected between the ampliﬁer output and the capacitive load to avoid ringing or oscillation. The feedback should be taken directly from the ampliﬁer output. Higher voltage gain conﬁgurations tend to have better capacitive drive capability than lower gain conﬁgurations due to lower closed loop bandwidth and hence higher phase margin. The graphs titled Series Output Resistor vs Capacitive Load demonstrate the transient response of the ampliﬁer when driving capacitive loads with various series resistors.

14

624678fa

applicaTions inForMaTion

624678 F02

C

PAR

5k

–

+

V

OUT

V

IN

5k

5pF

P

D(MAX)

=(VS•I

S(MAX)

)+

V

S

2

 



 



2

/ R

L

LTC6246/LTC6247/LTC6248

Feedback Components

When feedback resistors are used to set up gain, care must be taken to ensure that the pole formed by the feedback resistors and the parasitic capacitance at the inverting input does not degrade stability. For example if the ampliﬁer is set up in a gain of +2 conﬁguration with gain and feedback resistors of 5k, a parasitic capacitance of 5pF (device + PC board) at the ampliﬁer’s inverting input will cause the part to oscillate, due to a pole formed at 12.7MHz. An additional capacitor of 5pF across the feedback resistor as shown in Figure 2 will eliminate any ringing or oscillation. In general, if the resistive feedback network results in a pole whose frequency lies within the closed loop bandwidth of the ampliﬁer, a capacitor can be added in parallel with the feedback resistor to introduce a zero whose frequency is close to the frequency of the pole, improving stability.

Power Dissipation

The LTC6246 and LTC6247 contain one and two ampliﬁers respectively. Hence the maximum on-chip power dissipation for them will be less than the maximum on-chip power dissipation for the LTC6248, which contains four ampliﬁers.

The LTC6248 is housed in a small 16-lead MS package and typically has a thermal resistance (θ

) of 125°C/ W. It is

JA

necessary to ensure that the die’s junction temperature does not exceed 150°C. The junction temperature, T

JA

A

:

, power dis-

calculated from the ambient temperature, T sipation, PD, and thermal resistance, θ

= TA + (PD • θJA)

T

J

, is

The power dissipation in the IC is a function of the supply voltage, output voltage and load resistance. For a given supply voltage with output connected to ground or supply, the worst-case power dissipation P

D(MAX)

occurs when the supply current is maximum and the output voltage at half of either supply voltage for a given load resistance. P

is approximately (since IS actually changes with

D(MAX)

output load current) given by:

Figure 2. 5pF Feedback Cancels Parasitic Pole

Shutdown

The LTC6246 and LTC6247MS have SHDN pins that can shut down the ampliﬁer to 42µA typical supply current. The SHDN pin needs to be taken below 0.8V above the negative supply for the ampliﬁer to shut down. When left ﬂoating, the SHDN pin is internally pulled up to the positive supply and the ampliﬁer remains on.

Example: For an LTC6248 in a 16-lead MS package operating on ±2.5V supplies and driving a 100Ω load to ground, the worst-case power dissipation is approximately given by

P

/Amp = (5 • 1.3mA) + (1.25)2/100 = 22mW

D(MAX)

If all four ampliﬁers are loaded simultaneously then the total power dissipation is 88mW.

At the Absolute Maximum ambient operating temperature, the junction temperature under these conditions will be:

= TA + PD • 125°C/W

T

J

= 125 + (0.088W • 125°C/W) = 136°C which is less than the absolute maximum junction tem-

perature for the LTC6248 (150°C). Refer to the Pin Conﬁguration section for thermal resis-

tances of various packages.

624678fa

15

LTC6246/LTC6247/LTC6248

LTC6246

+

–

624678 F03

LTC2366

V

REF

GND

V

DD

3.3V 2.5V

CS

SDO

SCK

OV

DD

3.3V

V

IN

A

IN

499Ω 1%

499Ω

1%

10pF

FREQUENCY (kHz)

0

MAGNITUDE (dB)

0

–10

–30

–50

–70

–20

–40

–60

–80

–90 –100 –110

400 800200 600

624678 F04

1000

fIN = 350.195kHz f

SAMP

= 2.2Msps SFDR = 82dB SNR = 70dB 1024 POINT FFT

C3

0.1µF

LTC6246

–

+

624678 F05

3V

LT6003

–

+

3V

V

OUT

= VR + IPD • 1M

–3dB BW = 700kHz I

CC

= 2.2mA

OUTPUT NOISE = 160µV

RMS

MEASURED ON A 1MHz BW

V

OUT

IS REFERRED TO V

R

AT ZERO PHOTOCURRENT, V

OUT

= V

R

V

R

R1

1M, 1%

R3 1k

R2 1k

C2

6.8nF FILM OR NPO

Q1 NXP BF862

PD1 OSRAM SFH213

I

PD

R5

20k

R4

10k

R6

10M

C1

0.1pF

R7 1k

C4 1µF

Typical applicaTions

12-Bit ADC Driver

Figure 3 shows the LTC6246 driving an LTC2366 12-bit A/D converter. The low wideband noise of the LTC6246 maintains a 70dB SNR even without the use of an intermediate antialiasing RC ﬁlter. On a single 3.3V supply with a 2.5V reference, a full –1dBFS output can be obtained without the ampliﬁer transitioning between input regions, thus minimizing crossover distortion. Figure 4 shows an FFT obtained with a sampling rate of 2.2Msps and a 350kHz input waveform. Spurious free dynamic range is a quite handsome 82dB.

Low Noise Low Power DC-Accurate Single Supply Photodiode Ampliﬁer

Figure 5 shows the LTC6246 applied as a low power high performance transimpedance ampliﬁer for a photodiode. A low noise JFET Q1 acts as a current buffer, with R2 and R3 imposing a low frequency gain of approximately 1. Transimpedance gain is set by feedback resistor R1 to 1MΩ. R4 and R5 set the LTC6246 inputs at 1V below the 3V rail, with C3 reducing their noise contribution. By feedback this 1V also appears across R2, setting the JFET quiescent current at 1mA completely independent of its pinchoff voltage and I this by placing the JFETs 1mA V

characteristics. It does

DSS

at the gate referenced

GS

to the source, which is sitting 1V above ground. For this JFET, that will typically be about 500mV, and this voltage is imposed as a reverse voltage on the photodiode PD1. At zero I

photocurrent, the output sits at the same volt-

PD

age and rises as photocurrent increases. As mentioned before, R2 and R3 set the JFET gain to 1 at low frequency.

Figure 3. Single Supply 12-Bit ADC Driver

16

Figure 4. 350kHz FFT Showing 82dB SFDR

Figure 5. Low Noise Low Power DC Accurate Single Supply Photodiode Ampliﬁer

624678fa

Typical applicaTions

624678 F06

–

+

1k

2.5V

–2.5V

2.5V

–2.5V

V

IN

1/2LTC6247

50Ω

1.5k

–

+

1/2LTC6247

660nF

V

OUT

30k

FREQUENCY (kHz)

10k

GAIN (dB)

65

60

50

40

30

55

45

35

25

20

1M100k 10M

624678 F07

VS = ±2.5V V

IN

= 4.5mV

P-P

RL = 1kΩ DC GAIN = 30dB (DUE TO 660nF DC BLOCKING CAP) OUTPUT OFFSET = 4mV

624678 F08

56pF

–

+

V

IN

1.1k 2.3k

1/2LTC6247

12pF

2.7k

2.7V

1.2V

910Ω

–

+

1/2LTC6247

120pF

2.7V

V

OUT

5.6pF

1.1k

FREQUENCY (kHz)

10k

GAIN (dB)

10

–10

–30

–50

–70

–20

–40

–60

–80

–90

0

–100

100k 10M1M

624678 F09

100M

VS = 2.7V, 0V V

IN

= 2V

P-P

RL = 1kΩ to 0V

LTC6246/LTC6247/LTC6248

This is not the lowest noise conﬁguration for a transistor, as downstream noise sources appear at the input completely unattenuated. At low frequency, this is not a concern for a transimpedance ampliﬁer because the noise gain is 1 and the output noise is dominated by the 130nV/√Hz of the 1MΩ R1. However, at increasing frequencies the capacitance of the photodiode comes into play and the circuit noise gain rises as the 1MΩ feedback looks back into lower and lower impedance. But capacitor C2 comes to the rescue. In addition to the obvious quenching of noise source R3, capacitor C2 increases the JFET gain to about 30 at high frequency effectively attenuating the downstream noise contributions of R2 and the op amp input noise. Thus the circuit achieves low input voltage noise at high frequency where it is most needed. Ampliﬁer LT6003 is used to buffer the output voltage of the photodiode and R7 and C4 are used to ﬁlter out the voltage noise of the LT6003. Bandwidth to 700kHz was achieved with this circuit, with integrated output noise being 160µV

up to 1MHz. Total

RMS

supply current was a very low 2.2mA.

60dB 5.5MHz Gain Block

Figure 6 shows the LTC6247 conﬁgured as a low power high gain high bandwidth block. Two ampliﬁers each conﬁgured with a gain of 31V/V, are cascaded in series. A 660nF capacitor is used to limit the DC gain of the block to around 30dB to minimize output offset voltage. Figure 7 shows the frequency response of the block. Mid-band voltage gain is approximately 60dB with a –3dB frequency of 5.5MHz, thus resulting in a gain-bandwidth product of

5.5GHz with only 1.9mA of quiescent supply current.

Single 2.7V Supply 4MHz 4th Order Butterworth Filter

Beneﬁtting from low voltage operation and rail-to-rail output, a low power ﬁlter that is suitable for antialiasing can be built as shown in Figure 8. On a 2.7V supply the ﬁlter has a passband of approximately 4MHz with 2V

P-P

input signal and a stopband attenuation that is greater than –75dB at 43MHz as shown in Figure 9. The resistor and capacitor values can be scaled to reduce noise at the cost of large signal power consumption and distortion.

Figure 6. 60dB 5.5MHz Gain Block

Figure 8. Single 2.7V Supply 4MHz 4th Order Butterworth Filter

Figure 7

Figure 9

624678fa

17

LTC6246/LTC6247/LTC6248

2.00 p0.10

NOTE:

1. DRAWING IS NOT A JEDEC PACKAGE OUTLINE

2. DRAWING NOT TO SCALE

3. ALL DIMENSIONS ARE IN MILLIMETERS

4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE

5. EXPOSED PAD SHALL BE SOLDER PLATED

6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE

0.40 p 0.10

BOTTOM VIEW—EXPOSED PAD

0.64 p 0.10

0.55 p0.05

R = 0.115

TYP

R = 0.05

TYP

1.35 REF

1.37 p 0.10

1

4

85

PIN 1 BAR

TOP MARK

(SEE NOTE 6)

0.125 REF

0.00 – 0.05

(KC8) UTDFN 0107 REVØ

0.23 p 0.05

0.45 BSC

0.25 p 0.05

1.35 REF

RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS

APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED

0.64 p0.05

1.37 p0.05

1.15 p0.05

0.70 p0.05

2.55 p0.05

PACKAGE OUTLINE

0.45 BSC

PIN 1 NOTCH R = 0.20 OR

0.25 s 45o CHAMFER

MSOP (MS8) 0307 REV F

0.53 p 0.152

(.021 p .006)

SEATING

PLANE

NOTE:

1. DIMENSIONS IN MILLIMETER/(INCH)

2. DRAWING NOT TO SCALE

3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

0.18

(.007)

0.254

(.010)

1.10

(.043)

MAX

0.22 – 0.38

(.009 – .015)

TYP

0.1016 p 0.0508 (.004 p .002)

0.86

(.034)

REF

0.65

(.0256)

BSC

0o – 6o TYP

DETAIL “A”

GAUGE PLANE

1 2

3

4

4.90 p 0.152

(.193 p .006)

8

7

6

5

3.00 p 0.102

(.118 p .004)

(NOTE 3)

3.00 p 0.102 (.118 p .004)

(NOTE 4)

0.52

(.0205)

REF

5.23

(.206)

MIN

3.20 – 3.45

(.126 – .136)

0.889 p 0.127 (.035 p .005)

RECOMMENDED SOLDER PAD LAYOUT

0.42 p 0.038

(.0165 p .0015)

TYP

0.65

(.0256)

BSC

package DescripTion

8-Lead Plastic UTDFN (2mm × 2mm)

(Reference LTC DWG # 05-08-1749 Rev Ø)

KC Package

18

MS8 Package

8-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1660 Rev F)

624678fa

package DescripTion

MSOP (MS) 0307 REV E

0.53 ± 0.152 (.021 ± .006)

SEATING

PLANE

0.18

(.007)

1.10

(.043)

MAX

0.17 – 0.27

(.007 – .011)

TYP

0.86

(.034)

REF

0.50

(.0197)

BSC

1 2

3

4 5

4.90 ± 0.152 (.193 ± .006)

0.497 ± 0.076

(.0196 ± .003)

REF

8910

7

6

3.00 ± 0.102

(.118 ± .004)

(NOTE 3)

3.00 ± 0.102

(.118 ± .004)

(NOTE 4)

NOTE:

1. DIMENSIONS IN MILLIMETER/(INCH)

2. DRAWING NOT TO SCALE

3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

0.254

(.010)

0° – 6° TYP

DETAIL “A”

GAUGE PLANE

5.23

(.206)

MIN

3.20 – 3.45

(.126 – .136)

0.889 ± 0.127 (.035 ± .005)

RECOMMENDED SOLDER PAD LAYOUT

0.305 ± 0.038

(.0120 ± .0015)

TYP

0.50

(.0197)

BSC

0.1016 ± 0.0508 (.004 ± .002)

LTC6246/LTC6247/LTC6248

MS Package

10-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1661 Rev E)

624678fa

19

LTC6246/LTC6247/LTC6248

MSOP (MS16) 1107 REV Ø

0.53 p 0.152 (.021 p .006)

SEATING

PLANE

0.18

(.007)

1.10

(.043)

MAX

0.17 –0.27

(.007 – .011)

TYP

0.86

(.034)

REF

0.50

(.0197)

BSC

16151413121110

1 2 3 4 5 6 7 8

9

NOTE:

1. DIMENSIONS IN MILLIMETER/(INCH)

2. DRAWING NOT TO SCALE

3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE

5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX

0.254

(.010)

0o – 6o TYP

DETAIL “A”

GAUGE PLANE

5.23

(.206)

MIN

3.20 – 3.45

(.126 – .136)

0.889 p 0.127 (.035 p .005)

RECOMMENDED SOLDER PAD LAYOUT

0.305 p 0.038

(.0120 p .0015)

TYP

0.50

(.0197)

BSC

4.039 p 0.102 (.159 p .004)

(NOTE 3)

0.1016 p 0.0508 (.004 p .002)

3.00 p 0.102

(.118 p .004)

(NOTE 4)

0.280 p 0.076 (.011 p .003)

REF

4.90 p 0.152

(.193 p .006)

package DescripTion

16-Lead Plastic MSOP

(Reference LTC DWG # 05-08-1669 Rev Ø)

MS Package

20

624678fa

package DescripTion

1.50 – 1.75 (NOTE 4)

2.80 BSC

0.30 – 0.45 6 PLCS (NOTE 3)

DATUM ‘A’

0.09 – 0.20 (NOTE 3)

S6 TSOT-23 0302 REV B

2.90 BSC (NOTE 4)

0.95 BSC

1.90 BSC

0.80 – 0.90

1.00 MAX

0.01 – 0.10

0.20 BSC

0.30 – 0.50 REF

PIN ONE ID

NOTE:

1. DIMENSIONS ARE IN MILLIMETERS

2. DRAWING NOT TO SCALE

3. DIMENSIONS ARE INCLUSIVE OF PLATING

4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR

5. MOLD FLASH SHALL NOT EXCEED 0.254mm

6. JEDEC PACKAGE REFERENCE IS MO-193

3.85 MAX

0.62

MAX

0.95 REF

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

1.4 MIN

2.62 REF

1.22 REF

LTC6246/LTC6247/LTC6248

S6 Package

6-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1636)

624678fa

21

LTC6246/LTC6247/LTC6248

1.50 – 1.75 (NOTE 4)

2.80 BSC

0.22 – 0.36 8 PLCS (NOTE 3)

DATUM ‘A’

0.09 – 0.20 (NOTE 3)

TS8 TSOT-23 0802

2.90 BSC (NOTE 4)

0.65 BSC

1.95 BSC

0.80 – 0.90

1.00 MAX

0.01 – 0.10

0.20 BSC

0.30 – 0.50 REF

PIN ONE ID

NOTE:

1. DIMENSIONS ARE IN MILLIMETERS

2. DRAWING NOT TO SCALE

3. DIMENSIONS ARE INCLUSIVE OF PLATING

4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR

5. MOLD FLASH SHALL NOT EXCEED 0.254mm

6. JEDEC PACKAGE REFERENCE IS MO-193

3.85 MAX

0.52 MAX

0.65 REF

RECOMMENDED SOLDER PAD LAYOUT

PER IPC CALCULATOR

1.4 MIN

2.62 REF

1.22 REF

package DescripTion

8-Lead Plastic TSOT-23

(Reference LTC DWG # 05-08-1637)

TS8 Package

22

624678fa

LTC6246/LTC6247/LTC6248

revision hisTory

REV DATE DESCRIPTION PAGE NUMBER

A 2/10 Changes to Graph G15 9

Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

624678fa

23

LTC6246

+

–

624678 TA02a

V

OUT

≈ 0.5V + IPD • 1M

3V

R1

1M, 1%

3V

R2 1k

I

PD

C3

0.1µF

C1

0.1pF

R5

20k

R4

10k

R3 1k

–3dB BW = 700kHz I

CC

= 2.2mA

OUTPUT NOISE = 153µV

RMS

MEASURED ON A 1MHz BW

C2

6.8nF FILM OR NPO

PD1 OSRAM SFH213

Q1 NXP BF862

20nV/√Hz/DIV

200

0

624678 TA02b

100kHz

1MHz

10kHz

0V

5V/DIV

LED DRIVER

VOLTAGE

624678 TA02c

500ns/DIV

500mV/DIV

OUTPUT

WAVEFORM

LTC6246/LTC6247/LTC6248

Typical applicaTion

700kHz, 1MΩ Single Supply Photodiode Ampliﬁer Output Noise Spectrum Transient Response

relaTeD parTs

PART NUMBER DESCRIPTION COMMENTS

Operational Ampliﬁers

LT1818/LT1819 Single/Dual Wide Bandwidth, High Slew Rate Low Noise and

Distortion Op Amps LT1806/LT1807 Single/Dual Low Noise Rail-to-Rail Input and Output Op Amps 325MHz, 13mA, 3.5nV/√Hz, 140V/µs, 550µV, 85mA Output Drive LT6230/LT6231/

Single/Dual/Quad Low Noise Rail-to-Rail Output Op Amps 215MHz, 3.5mA, 1.1nV/√Hz, 70V/µs, 350µV LT6232

LT6200/LT6201 Single/Dual Ultralow Noise Rail-to-Rail Input/Output Op Amps 165MHz, 20mA, 0.95nV/√Hz , 44V/µs, 1mV LT6202/LT6203/

Single/Dual/Quad Ultralow Noise Rail-to-Rail Op Amp 100MHz, 3mA, 1.9nV/√Hz, 25V/µs, 0.5mV LT6204

LT1468 16-Bit Accurate Precision High Speed Op Amp 90MHz, 3.9mA, 5nV/√Hz, 22V/µs, 175µV,

LT1803/LT1804/ LT1805

Single/Dual/Quad Low Power High Speed Rail-to-Rail Input

and Output Op Amps LT1801/LT1802 Dual/Quad Low Power High Speed Rail-to-Rail Input and

Output Op Amps LT6552 Single Supply Rail-to-Rail Output Video Difference Ampliﬁer 75MHz (–3dB), 13.5mA, 55.5nV/√Hz, 350V/µs, 20mV LT1028 Ultralow Noise, Precision High Speed Op Amps 75MHz, 9.5mA, 0.85nV/√Hz, 11V/µs, 40µV LT6233/LT6234/

Single/Dual/Quad Low Noise Rail-to-Rail Output Op Amps 60MHz, 1.2mA, 1.2nV/√Hz, 15V/µs, 0.5mV LT6235

LT6220/LT6221/ LT6222

Single/Dual/Quad Low Power High Speed Rail-to-Rail Input

and Output Op Amps LT6244 Dual High Speed CMOS Op Amp 50MHz, 7.4mA, 8nV/√Hz, 35V/µs, 100µV, Input Bias Current = 1pA LT1632/LT1633 Dual/Quad Rail-to-Rail Input and Output Precision Op Amps 45MHz, 4.3mA, 12nV/√Hz, 45V/µs, 1.35mV LT1630/LT1631 Dual/Quad Rail-to-Rail Input and Output Op Amps 30MHz, 3.5mA, 6nV/√Hz, 10V/µs, 525µV LT1358/LT1359 Dual/Quad Low Power High Speed Op Amps 25MHz, 2.5mA, 8nV/√Hz , 600V/µs, 800µV, Drives All Capacitive Loads

ADC’s

LTC2366 3Msps, 12-Bit ADC Serial I/O 72dB SNR, 7.8mW No Data Latency TSOT-23 Package LTC2365 1Msps, 12-Bit ADC Serial I/O 73dB SNR, 7.8mW No Data Latency TSOT-23 Package LTC1417 Low Power 14-Bit 400ksps ADC Parallel I/O Single 5V or ±5V Supplies, 0V to 4.096V or ±2.048V Input Range LTC1274 Low Power 12-Bit 400ksps ADC Parallel I/O 10mW Single 5V or ±5V Supplies, 0V to 4.096V or ±2.048V Input Range

24

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507

●

www.linear.com

400MHz, 9mA, 6nV/√Hz, 2500V/µs, 1.5mV –85dBc at 5MHz

–96.5dB THD at 10V

, 100kHz

P-P

85MHz, 3mA, 21nV√Hz, 100V/µs, 2mV

80MHz, 2mA, 8.5nV√Hz, 25V/µs, 350µV

60MHz, 1mA, 10nV/√Hz, 20V/µs, 350µV

LT 0210 REV A • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 2009

624678fa

Datasheet LTC6246, LTC6247, LTC6248 Datasheet (Linear) [ru]

FeaTures

applicaTions

DescripTion

Typical applicaTion

absoluTe MaxiMuM raTings

pin conFiguraTion

orDer inForMaTion

elecTrical characTerisTics

Typical perForMance characTerisTics

pin FuncTions

applicaTions inForMaTion

Typical applicaTions

package DescripTion

revision hisTory

Typical applicaTion

relaTeD parTs