LTC6992-4 Linear Technology, LTC6992-4 Datasheet - Page 25

• Manufacturer Part Number: LTC6992-4
• Description: TimerBlox Voltage-Controlled Pulse Width Modulator (PWM)
• Manufacturer: Linear Technology

TYPICAL APPLICATIONS
f
MIN
NOTES
WHILE THIS CIRCUIT IS SIMPLER THAN THE CIRCUIT TO THE RIGHT,
ITS FREQUENCY ACCURACY IS WORSE DUE TO THE EFFECT OF
V
+
f
MAX
SUPPLY VARIATION FROM SYSTEM TO SYSTEM AND OVER TEMPERATURE.
DUTY CYCLE CONTROL
‘HC04
V
+
ANALOG PWM
ADJUST FOR 50% DUT CYCLE AT 25°C
(0V TO 1V)
R
VCO
5V
R6
45.3k
D1
1N458
R
SET
16.9k
R7
MOD
GND
SET
LTC6992-X
84.5k
–
+
OUT
R8
DIV
5V
V
+
LT6003
Changing Between Two Frequencies
+10mV/C
R1
130k
R2
50k
R3
130k
Simple Diode Temperature Sensor
MOD
GND
SET
R1
R2
LTC6992-2
N
f = 10kHz
PWM OUTPUT FOR ISOLATED MEASUREMENT
+1% DUTY CYCLE CHANGE PER DEGREE C
–10°C TO 65°C RANGE WITH OPTO-ISOLATOR (DC: 15% TO 95%)
DIV
V
+
6992 TA06
= 16
OUT
DIV
V
f
+
MAX
f
MIN
365Ω
NOTES
3. V
1. WHEN THE NMOSFET IS OFF , THE FREQUENCY IS SET BY R
2. WHEN THE NMOSFET IS ON, THE FREQUENCY IS SET BY R
R9
EITHER FLOATING OR CONNECTED TO GROUND.
R4
1000k
R5
186k
+
SUPPLY VARIATION IS NOT A FACTOR AS THE SWITCHING RESISTOR IS
‘HC04
5V
V
DUTY CYCLE CONTROL
+
LTC6992-1/LTC6992-2/
MOC207M
LTC6992-3/LTC6992-4
ANALOG PWM
D3
(0V TO 1V)
R
2N7002
SET2
5V
Q1
R11
422Ω
R
SET1
MOD
GND
SET
LTC6992-X
C1
1μF
OUT
OUTPUT
DIV
V
+
www.DataSheet4U.com
SET
SET
= R
= R
SET1
SET1
R1
R2
.
|| R
25
6992 TA05
69921234p
SET2
V
+
.