2645L8 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'2645L8' PDF : 20 Pages View PDF
LTC2645
Typical Applications
VLOOP
5.4V TO 80V
LT3010-5
IN
OUT
SHDN SENSE
1µF
GND
+
1µF
PWMINA
PWMINB
500Ω
OPTO-ISOLATORS
PS9851-2
500Ω
0.1µF
ROFFSET1
374k
ROFFSET2
374k
IOVCC
VCC
REF
PD
LTC2645 -12
RGAIN1
76.8k
INA PWM TO
BINARY
DAC A
VOUTA 0.1%
RGAIN2
76.8k
0.1%
0.1%
LTC2055
V+
+
1k
–
1000pF
INB PWM TO
BINARY
DAC B
VOUTB 0.1%
+
1k
INC PWM TO
BINARY
DAC C
VOUTC
VOUTC = ZERO-SCALE
–
V–
1000pF
10k
10k
IND PWM TO
BINARY
DAC D
VOUTD
VOUTD = ZERO-SCALE
REFSEL
GND
IDLSEL
3.01k
IOUTA
10Ω
2N3440
2N3440
10Ω
IOUTB
3.01k
2645 F03
Figure 3. An Opto-Isolated, PWM Regulated 4mA to 20mA Process Controller
ANALOG PWM
DUTY CYCLE
CONTROL
(0V TO 1V)
LTC6992
MOD OUT
GND
V+
SET DIV
2.25V TO 5.5V
C1
0.1µF
RSET
50k
2.7V TO 5.5V
5V
C2
0.1µF
ISOLATION BARRIER
PS9851-1
C3
0.1µF
EXT INPUT: 1V TO VCC
C4
0.1µF
IOVCC VCC IDLSEL REFSEL REF
PD
LTC2645 -12
INA PWM TO
BINARY
DAC A
VOUTA
DAC CONTROL
VOLTAGE OUTPUT
(0V TO VREF)
INB PWM TO
BINARY
DAC B
VOUTB
VOUTB = Hi-Z
INC PWM TO
BINARY
DAC C
VOUTC
VOUTC = Hi-Z
IND PWM TO
BINARY
DAC D
GND
VOUTD VOUTD = Hi-Z
2645 F04
18
Figure 4. Analog Control Voltage with PWM Transmission to DAC Control Voltage Output
For more information www.linear.com/LTC2645
2645f
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