Linear Technology LTC699X-X TimerBlox: Oscillators, One Shots, PWM, and Delay SC-KIT-TBX SC-KIT-TBX 数据表
产品代码
SC-KIT-TBX
LTC6990
1
6990fc
For more information
www.linear.com/LTC6990
TYPICAL APPLICATION
DESCRIPTION
TimerBlox: Voltage
Controlled Silicon Oscillator
grammable frequency range of 488Hz to 2MHz. It can be
used as a fixed-frequency or voltage-controlled oscillator
(VCO). The LTC6990 is part of the TimerBlox
®
family of
versatile silicon timing devices.
A single resistor, R
A single resistor, R
SET
, programs the LTC6990’s internal
master oscillator frequency. The output frequency is deter-
mined by this master oscillator and an internal frequency
divider, N
DIV
, programmable to eight settings from 1 to 128.
f
OUT
=
1MHz
N
DIV
•
50k
Ω
R
SET
, N
DIV
= 1, 2, 4 …128
Optionally, a second resistor at the SET input provides
linear voltage control of the output frequency and can be
used for frequency modulation. A narrow or wide VCO
tuning range can be configured by the appropriate selec-
tion of the two resistors.
The LTC6990 includes an enable function that is synchro-
The LTC6990 includes an enable function that is synchro-
nized with the master oscillator to ensure clean, glitch-free
output pulses. The disabled output can be configured to
be high impedance or forced low.
For easy configuration of the LTC6990, download the
For easy configuration of the LTC6990, download the
TimerBlox Designer tool at
www.linear.com/timerblox
.
Voltage Controlled Oscillator with 16:1 Frequency Range
L
, LT, LTC and LTM, Linear Technology, TimerBlox and the Linear logo are registered
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.
FEATURES
APPLICATIONS
n
Fixed-Frequency or Voltage-Controlled Operation
– Fixed: Single Resistor Programs Frequency
with <1.5% Max Error
– VCO: Two Resistors Set VCO Center
Frequency and Tuning Range
n
Frequency Range: 488Hz to 2MHz
n
2.25V to 5.5V Single Supply Operation
n
72µA Supply Current at 100kHz
n
500µs Start-Up Time
n
VCO Bandwidth >300kHz at 1MHz
n
CMOS Logic Output Sources/Sinks 20mA
n
50% Duty Cycle Square Wave Output
n
Output Enable (Selectable Low or Hi-Z When Disabled)
n
–55°C to 125°C Operating Temperature Range
n
Available in Low Profile (1mm) SOT-23 (ThinSOT™)
and 2mm × 3mm DFN Package
n
Low Cost Precision Programmable Oscillator
n
Voltage-Controlled Oscillator
n
High Vibration, High Acceleration Environments
n
Replacement for Fixed Crystal and Ceramic Oscillators
n
Portable and Battery-Powered Equipment
VCO Transfer Function
V
CTRL
(V)
0
f
OUT
(kHz)
1000
750
250
500
0
0.5
6990 TA01b
2
1
1.5
6990 TA01a
LTC6990
OE
GND
SET
OUT
V
+
DIV
C1
0.1µF
R
SET
100k
V
+
V
+
V
CTRL
R
VCO
100k
f
OUT
= 1MHz − V
CTRL
• 0.5
MHz
V