LTC6992-1 Datasheet, PDF (1/32 Pages) Linear Technology – TimerBlox Voltage-Controlled Pulse Width Modulator (PWM)

FEATURES
n _{Pulse Width Modulation (PWM) Controlled by}
Simple 0V to 1V Analog Input
n _{Four Available Options Define Duty Cycle Limits}
– Minimum Duty Cycle at 0% or 5%
– Maximum Duty Cycle at 95% or 100%
n _{Frequency Range: 3.81Hz to 1MHz}
n _{Single Resistor Programs Frequency with < 2.4%}
Maximum Error
n _{PWM Duty Cycle Error < 4.5% Maximum}
n _{Frequency Modulation (VCO) Capability}
n _{2.25V to 5.5V Single Supply Operation}
n _{115μA Supply Current at 100kHz}
n _{500μs Start-Up Time}
n _{CMOS Output Driver Sources/Sinks 20mA}
n _{–40°C to 125°C Operating Temperature Range}
n _{Available in Low Profile (1mm) SOT-23 (ThinSOT™)}
and 2mm × 3mm DFN
APPLICATIONS
n _{LED Dimming Control}
n _{PWM Servo Loops}
n _{High Vibration, High Acceleration Environments}
n _{Portable and Battery-Powered Equipment}
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
TimerBlox and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks
are the property of their respective owners.
Electrical Specifications Subject to Change
LTC6992-1/-2/-3/-4
TimerBlox
Voltage-Controlled Pulse
Width Modulator (PWM)
DESCRIPTION
The LTC^®6992 is a silicon oscillator with an easy-to-use
analog voltage-controlled pulse width modulation (PWM)
capability. The LTC6992 is part of the TimerBlox™ family
of versatile silicon timing devices.
A single resistor, R_SET, programs the LTC6992’s inter-
nal master oscillator frequency. The output frequency
is determined by this master oscillator and an internal
frequency divider, N_DIV, programmable to eight settings
from 1 to 16384.
f_OUT
=
1MHz
N_DIV
•
50kΩ
R_SET
,
N_DIV
=
1,4,16
…16384
Applying a voltage between 0V and 1V on the MOD pin sets
the duty cycle, according to the following formula:
Duty
Cycle
=
V_MOD
0.8 • V_SET
−
1
8
≅
V_MOD − 100mV
800mV
The four versions differ in their minimum/maximum duty
cycle. Note that a minimum duty cycle limit of 0% or
maximum duty cycle limit of 100% allows oscillations to
stop at the extreme duty cycle settings.
DEVICE NAME
LTC6992-1
LTC6992-2
LTC6992-3
LTC6992-4
PWM DUTY
CYCLE RANGE
0% to 100%
5% to 95%
0% to 95%
5% to 100%
OUTPUT DUTY CYCLE LIMITS
MIN
MAX
GND
V⁺
GND
V⁺
TYPICAL APPLICATION
1MHz Pulse Width Modulator
ANALOG PWM
DUTY CYCLE
CONTROL
(0V TO 1V)
MOD OUT
LTC6992
GND
V⁺
SET
R_SET
50k
DIV
6992 TA01a
V⁺
C1
0.1μF
MOD
0.5V/DIV
OUT
1V/DIV
2μs/DIV
6992 TA01b
69921234p
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