LTC6990
TimerBlox: Voltage
Controlled Silicon Oscillator
FEATURES DESCRIPTION
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Fixed-Frequency or Voltage-Controlled Operation The LTC 6990 is a precision silicon oscillator with a pro-
Fixed: Single Resistor Programs Frequency grammable frequency range of 488Hz to 2MHz. It can be
with <1.5% Max Error used as a fixed-frequency or voltage-controlled oscillator
VCO: Two Resistors Set VCO Center (VCO). The LTC6990 is part of the TimerBlox family of
Frequency and Tuning Range versatile silicon timing devices.
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Frequency Range: 488Hz to 2MHz
A single resistor, R , programs the LTC6990s internal
SET
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2.25V to 5.5V Single Supply Operation
master oscillator frequency. The output frequency is deter-
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72A Supply Current at 100kHz
mined by this master oscillator and an internal frequency
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500s Start-Up Time
divider, N , programmable to eight settings from 1 to 128.
DIV
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VCO Bandwidth >300kHz at 1MHz
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CMOS Logic Output Sources/Sinks 20mA 1MHz 50k
f = ,N = 1, 2, 4 128
OUT DIV
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50% Duty Cycle Square Wave Output
N R
DIV SET
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Output Enable (Selectable Low or Hi-Z When Disabled)
Optionally, a second resistor at the SET input provides
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55C to 125C Operating Temperature Range
linear voltage control of the output frequency and can be
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Available in Low Profile (1mm) SOT-23 (ThinSOT)
used for frequency modulation. A narrow or wide VCO
and 2mm 3mm DFN Package
tuning range can be configured by the appropriate selec-
tion of the two resistors.
APPLICATIONS
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Low Cost Precision Programmable Oscillator The LTC6990 includes an enable function that is synchro-
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Voltage-Controlled Oscillator nized with the master oscillator to ensure clean, glitch-free
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High Vibration, High Acceleration Environments output pulses. The disabled output can be configured to
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Replacement for Fixed Crystal and Ceramic Oscillators be high impedance or forced low.
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Portable and Battery-Powered Equipment
For easy configuration of the LTC6990, download the
L, LT, LTC and LTM, Linear Technology, TimerBlox and the Linear logo are registered
TimerBlox Designer tool at www.linear.com/timerblox.
trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks
are the property of their respective owners. Protected by U.S. Patents, including 6342817,
6614313.
TYPICAL APPLICATION
Voltage Controlled Oscillator with 16:1 Frequency Range VCO Transfer Function
1000
MHz
+ f = 1MHz V 0.5
OUT CTRL
V
V
750
OE OUT
LTC6990 +
V
500
+
GND V
C1
R
VCO
0.1F
100k
V 250
CTRL SET DIV
6990 TA01a
R
SET
100k
0
0 0.5 1 1.5 2
V (V)
CTRL
6990 TA01b
6990fc
1
For more information www.linear.com/LTC6990
f (kHz)
OUTLTC6990
ABSOLUTE MAXIMUM RATINGS (Note 1)
+
Supply Voltage (V ) to GND ........................................6V Specified Temperature Range (Note 3)
Maximum Voltage on Any Pin LTC6990C ................................................ 0C to 70C
+
............................. (GND 0.3V) V (V + 0.3V) LTC6990I .............................................40C to 85C
PIN
Operating Temperature Range (Note 2) LTC6990H .......................................... 40C to 125C
LTC6990C ............................................40C to 85C LTC6990MP ....................................... 55C to 125C
LTC6990I .............................................40C to 85C Junction Temperature ........................................... 150C
LTC6990H .......................................... 40C to 125C Storage Temperature Range ..................65C to 150C
LTC6990MP ....................................... 55C to 125C Lead Temperature (Soldering, 10sec)....................300C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
+
6
V 1 OUT
OE 1 6 OUT
7
DIV 2 5 GND
+
GND 2 5 V
SET 3 4 OE
SET 3 4 DIV
DCB PACKAGE S6 PACKAGE
6-LEAD (2mm 3mm) PLASTIC DFN 6-LEAD PLASTIC TSOT-23
T = 150C, = 64C/W, = 10.6C/W T = 150C, = 192C/W, = 51C/W
JMAX JA JC
JMAX JA JC
EXPOSED PAD (PIN 7) CONNECTED TO GND,
PCB CONNECTION OPTIONAL
ORDER INFORMATION
Lead Free Finish
TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE
LTC6990CDCB#TRMPBF LTC6990CDCB#TRPBF LDWX 6-Lead (2mm 3mm) Plastic DFN 0C to 70C
LTC6990IDCB#TRMPBF LTC6990IDCB#TRPBF LDWX 6-Lead (2mm 3mm) Plastic DFN 40C to 85C
LTC6990HDCB#TRMPBF LTC6990HDCB#TRPBF LDWX 6-Lead (2mm 3mm) Plastic DFN 40C to 125C
LTC6990CS6#TRMPBF LTC6990CS6#TRPBF LTDWW 6-Lead Plastic TSOT-23 0C to 70C
LTC6990IS6#TRMPBF LTC6990IS6#TRPBF LTDWW 6-Lead Plastic TSOT-23 40C to 85C
LTC6990HS6#TRMPBF LTC6990HS6#TRPBF LTDWW 6-Lead Plastic TSOT-23 40C to 125C
LTC6990MPS6#TRMPBF LTC6990MPS6#TRPBF LTDWW 6-Lead Plastic TSOT-23 55C to 125C
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: