ANALOG DEVICES LTC 6900 CS5 Datasheet

LTC6900

Low Power, 1kHz to 20MHz

Resistor Set SOT-23 Oscillator

FEATURES

n

One External Resistor Sets the Frequency

n

1kHz to 20MHz Frequency Range

n

500μA Typical Supply Current, VS = 3V, 3MHz

n

Frequency Error ≤1.5% Max, 5kHz to 10MHz

= 25°C)

(T

A

n

Frequency Error ≤2% Max, 5kHz to 10MHz

= 0°C to 70°C)

(T

A

n

±40ppm/°C Temperature Stability

n

0.04%/V Supply Stability

n

50% ±1% Duty Cycle 1kHz to 2MHz

n

50% ±5% Duty Cycle 2MHz to 10MHz

n

Fast Start-Up Time: 50µs to 1.5ms

n

100 CMOS Output Driver

n

Operates from a Single 2.7V to 5.5V Supply

n

Low Profi le (1mm) ThinSOT™ Package

APPLICATIONS

n

Portable and Battery-Powered Equipment

n

PDAs

n

Cell Phones

n

Low Cost Precision Oscillator

n

Charge Pump Driver

n

Switching Power Supply Clock Reference

n

Clocking Switched Capacitor Filters

n

Fixed Crystal Oscillator Replacement

n

Ceramic Oscillator Replacement

DESCRIPTION

The LTC®6900 is a precision, low power oscillator that is
easy to use and occupies very little PC board space. The
oscillator frequency is programmed by a single external
resistor (R
accuracy operation (≤1.5% frequency error) without the
need for external trim components.

The LTC6900 operates with a single 2.7V to 5.5V power
supply and provides a rail-to-rail, 50% duty cycle square
wave output. The CMOS output driver ensures fast rise/fall
times and rail-to-rail switching. The frequency-setting
resistor can vary from 10k to 2M to select a master
oscillator frequency between 100kHz and 20MHz (5V
supply). The three-state DIV input determines whether the
master clock is divided by 1, 10 or 100 before driving the
output, providing three frequency ranges spanning 1kHz
to 20MHz (5V supply). The LTC6900 features a proprietary
feedback loop that linearizes the relationship between R
and frequency, eliminating the need for tables to calculate
frequency. The oscillator can be easily programmed using
the simple formula outlined below:

f

=10MHz •

OSC

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

). The LTC6900 has been designed for high

SET

100,

DIV Pin = V

⎛
⎜

N•R

⎝

20k

SET

⎞
⎟

⎠

,N=

⎧
⎪

DIV Pin =Open

10,

⎨
⎪

DIV Pin =GND

1,

⎩

+

SET

TYPICAL APPLICATION

Clock Generator

10k ≤ R

SET

≤ 2M

5V

f

OSC

0.1μF

= 10MHz •

1

+

V

OUT

LTC6900

2

GND

3

SET

DIV

6900 TA01a

20k

()

N • R

SET

1kHz ≤ f

5

4

OSC

5V, N = 100

N = 1

≤ 20MHz

OPEN, N = 10

R

vs Desired Output Frequency

SET

10000

1000

(kΩ)

100

SET

R

10

÷100 ÷10 ÷1

1

1k 100k 1M 10M

10k

DESIRED OUTPUT FREQUENCY (Hz)

6900 TA01b

100M

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1

LTC6900

PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS

(Note 1)

Supply Voltage (V+) to GND .........................–0.3V to 6V

+

DIV to GND ....................................–0.3V to (V

SET to GND ....................................– 0.3V to (V

+ 0.3V)

+

+ 0.3V)
Operating Temperature Range (Note 8)

LTC6900C ............................................–40°C to 85°C

LTC6900I .............................................–40°C to 85°C

GND

SET

TOP VIEW

+

V

1
2
3

S5 PACKAGE

5-LEAD PLASTIC TSOT-23

T

= 150°C, θJA = 256°C/W

JMAX

54OUT

DIV

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

Lead Temperature (Soldering, 10 sec)...................300°C

ORDER INFORMATION

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

LTC6900CS5#PBF LTC6900CS5#TRPBF LTZM 5-Lead Plastic TSOT-23 –40°C to 85°C
LTC6900IS5#PBF LTC6900IS5#TRPBF LTZM 5-Lead Plastic TSOT-23 –40°C to 85°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.

Consult LTC Marketing for information on non-standard lead based fi nish parts.
For more information on lead free part marking, go to:

For more information on tape and reel specifi cations, go to:

http://www.linear.com/leadfree/

http://www.linear.com/tapeandreel/

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TA = 25°C. V+ = 2.7V to 5.5V, RL= 5k, CL = 5pF, Pin 4 = V+ unless otherwise noted.
All voltages are with respect to GND.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

∆f Frequency Accuracy (Notes 2, 3) V

R

SET

∆f/∆T Frequency Drift Overtemperature

∆f/∆V Frequency Drift Over Supply (Note 3) V

Frequency-Setting Resistor Range |∆f| < 1.5% V+ = 5V

(Note 3)

Timing Jitter (Note 4) Pin 4 = V

Long-Term Stability of Output
Frequency

Duty Cycle (Note 7) Pin 4 = V

+

= 5V 5kHz ≤ f ≤ 10MHz
5kHz ≤ f ≤ 10MHz, LTC6900C
5kHz ≤ f ≤ 10MHz, LTC6900I
1kHz ≤ f < 5kHz
10MHz < f ≤ 20MHz

+

V

= 3V 5kHz ≤ f ≤ 10MHz
5kHz ≤ f ≤ 10MHz, LTC6900C
5kHz ≤ f ≤ 10MHz, LTC6900I
1kHz ≤ f < 5kHz

SET

+

= 3V

= 63.2k

≤ 400k

SET

≤ 400k

SET

≤ 400k

SET

SET

= 20k to 400k

V

= 63.2k

R

SET

+

= 3V to 5V, R

+

Pin 4 = Open, 20k ≤ R
Pin 4 = 0V, 20k ≤ R

Pin 4 = 0V (DIV by 1), R

, 20k ≤ R

+

or Open (DIV Either by 100 or 10)

±0.5

●

●

±0.5±2±1.5

●

●

20
20

●

●

●

●

±0.004 %/°C

0.04 0.1 %/V

300 ppm/√kHr

49
45

±2
±2

0.1

0.2

0.6

50
50

±1.5
±2.0
±2.5

±2.0
±2.5

400
400

51
55

%
%
%
%
%

%
%
%
%

k
k

%
%
%

%
%

2

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LTC6900

ELECTRICAL CHARACTERISTICS

The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at T
All voltages are with respect to GND.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V
I

V
V
I

V

V

t

t

+

S

IH

IL

DIV

OH

OL

r

f

Operating Supply Range
Power Supply Current R

High Level DIV Input Voltage
Low Level DIV Input Voltage
DIV Input Current (Note 5) Pin 4 = V

High Level Output Voltage (Note 5) V+ = 5V IOH = –1mA

Low Level Output Voltage (Note 5) V+ = 5V IOL = 1mA

OUT Rise Time
(Note 6)

OUT Fall Time
(Note 6)

= 25°C. V+ = 2.7V to 5.5V, RL= 5k, CL = 5pF, Pin 4 = V+ unless otherwise noted.

A

2.7 5.5 V

●

= 400k, Pin 4 = V+, RL = ∞ V+ = 5V

SET

f

= 5kHz V+ = 3V

OSC

= 20k, Pin 4 = 0V, RL = ∞ V+ = 5V

R

SET

f

= 10MHz V+ = 3V

OSC

+

Pin 4 = 0V V

I

+

= 3V IOH = –1mA

V
I

I

+

= 3V IOL = 1mA

V
I

= –4mA

OH

= –4mA

OH

= 4mA

OL

= 4mA

OL

V+ = 5V

+

= 5V

V+ = 5V Pin 4 = V+ or Floating, RL = ∞
Pin 4 = 0V, R

+

= 3V Pin 4 = V+ or Floating, RL = ∞

V
Pin 4 = 0V, R

= ∞

L

= ∞

L

V+ = 5V Pin 4 = V+ or Floating, RL = ∞
Pin 4 = 0V, R

+

= 3V Pin 4 = V+ or Floating, RL = ∞

V
Pin 4 = 0V, R

= ∞

L

= ∞

L

●

●

●

●

V+ – 0.4 V

●

●

●

–4

●

4.8

●

4.5

●

2.7

●

2.2

●

●

●

●

●

0.32

0.29

0.92

0.68

2

–2

4.95

4.8

2.9

2.6

0.05

0.2

0.1

0.4
14

7

19
11

13

6

19
10

0.42

0.38

1.20

0.86

mA
mA

mA
mA

0.5 V
4µA

0.15

0.4

0.3

0.7

µA

V
V

V
V

V
V

V
V

ns
ns

ns
ns

ns
ns

ns
ns

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: Frequencies near 100kHz and 1MHz may be generated using two
different values of R

(see the Selecting the Divider Setting Resistor

SET

paragraph in the Applications Information section). For these frequencies,
the error is specifi ed under the following assumption: 20k < R

SET

≤ 200k.

Note 3: Frequency accuracy is defi ned as the deviation from the
f

equation.

OSC

Note 4: Jitter is the ratio of the peak-to-peak distribution of the period to
the mean of the period. This specifi cation is based on characterization and
is not 100% tested. Also, see the Peak-to-Peak Jitter vs Output Frequency
curve in the Typical Performance Characteristics section.

Note 5: To conform with the Logic IC Standard convention, current out of
a pin is arbitrarily given as a negative value.

Note 6: Output rise and fall times are measured between the 10% and 90%
power supply levels. These specifi cations are based on characterization.

Note 7: Guaranteed by 5V test.
Note 8: The LTC6900C is guaranteed to meet specifi ed performance from

0°C to 70°C. The LTC6900C is designed, characterized and expected to
meet specifi ed performance from –40°C to 85°C but is not tested or
QA sampled at these temperatures. The LTC6900I is guaranteed to meet
specifi ed performance from –40°C to 85°C.

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3

LTC6900

TYPICAL PERFORMANCE CHARACTERISTICS

Frequency Variation vs R

4

TA = 25°C

3

GUARANTEED LIMITS APPLY OVER
20kΩ ≤ R

2

1

0

–1

VARIATION (%)

–2

–3

–4

1k

≤ 400kΩ

SET

10k 100k 1M

2.0

1.5

1.0

SET

TYPICAL HIGH

TYPICAL LOW

R

(Ω)

SET

6900 G01

Supply Current
vs Output Frequency

TA = 25°C

= 5pF

C

L

÷100, 5V

1.00

0.75

0.50

0.25

–0.25

VARIATION (%)

–0.50

–0.75

–1.00

÷1, 5V

÷10, 5V

Frequency Variation Over
Temperature

R

= 63.4k

SET

÷1 OR ÷10 OR ÷100

TYPICAL

HIGH

0

TYPICAL

LOW

–20 0 20 40 60 80

–40

TEMPERATURE (°C)

6900 G02

Output Resistance
vs Supply Voltage

140

120

OUTPUT SOURCING CURRENT

100

80

Peak-to-Peak Jitter
vs Output Frequency

1.0

0.9

0.8

0.7

)

0.6

P-P

0.5

0.4

JITTER (%

0.3

0.2
÷100

0.1

0

1k

OUTPUT FREQUENCY (Hz)

T

= 25°C

A

÷1, VA = 5V

÷1, VA = 3V

÷10

100k 1M10k 10M

6900 G03

SUPPLY CURRENT (mA)

0.5

÷100, 3V ÷10, 3V ÷1, 3V

0

0

1k 10k 100k 1M 10M

OUTPUT FREQUENCY (Hz)

LTC6900 Output Operating at
20MHz, VS = 5V

V+ = 5V, R

1V/DIV

0V

= 10k, CL = 10pF

SET

12.5ns/DIV

6900 G04

6900 G06

OUTPUT RESISTANCE (Ω)

60

OUTPUT SINKING CURRENT

40

2.5 3.0

4.0

3.5
SUPPLY VOLTAGE (V)

LTC6900 Output Operating at
10MHz, VS = 3V

V+ = 3V, R

1V/DIV

0V

= 20k, CL = 10pF

SET

25ns/DIV

4.5

5.0

5.5

6.0

6900 G05

6900 G07

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