LTC1655I Linear Technology, LTC1655I Datasheet - Page 12

• Manufacturer Part Number: LTC1655I
• Description: 16-Bit Rail-to-Rail Micropower DAC in SO-8 Package
• Manufacturer: Linear Technology

TYPICAL
RELATED PARTS
PART NUMBER DESCRIPTION
LTC1257
LTC1446/
LTC1446L
LTC1448
LTC1450/
LTC1450L
LTC1451
LTC1452
LTC1453
LTC1454/
LTC1454L
LTC1456
LTC1458/
LTC1458L
LTC1650
LTC1658
LTC1659
LTC1655
This circuit shows a digitally programmable current source
from an external voltage source using an external op amp,
an LT1077 and an NPN transistor (2N3440). Any digital
word from 0 to 65535 is loaded into the LTC1655 and its
output correspondingly swings from 0V to 4.096V. In the
configuration shown, R1, R2 resistively divide down the
LTC1655 output voltage. This divided voltage will be
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
[phone] FAX: [phone] www.linear-tech.com
Single 12-Bit V
Reference Can Be Overdriven Up to 12V, i.e., FS
Dual 12-Bit V
Dual 12-Bit V
Single 12-Bit V
Single Rail-to-Rail 12-Bit DAC, Full Scale: 4.095V, V
Internal 2.048V Reference Brought Out to Pin
Single Rail-to-Rail 12-Bit V
Single Rail-to-Rail 12-Bit V
Dual 12-Bit V
Single Rail-to-Rail Output 12-Bit DAC with Clear Pin,
Full Scale: 4.095V, V
Quad 12 Bit Rail-to-Rail Output DACs with Added Functionality
Single 16-Bit V
DAC, Output Swing 4.5V
Single Rail-to-Rail 14-Bit V
V
Single Rail-to-Rail 12-Bit V
V
APPLICATION
CC
CC
= 2.7V to 5.5V
= 2.7V to 5.5V
P
OUT
OUT
OUT
OUT
OUT
OUT
DACs in SO-8 Package
DAC, V
DACs in SO-16 Package with Added Functionality
DAC, Full Scale: 2.048V, V
DACs with Parallel Interface
Industrial DAC in 16-Pin SO, V
CC
: 4.5V to 5.5V
CC
: 2.7V to 5.5V
OUT
OUT
OUT
OUT
U
CLK
D
CS/LD
Multiplying DAC, V
DAC, Full Scale: 2.5V, V
DAC in 8-Pin MSOP,
DAC in 8-Pin MSOP,
IN
Digitally Programmable Current Source
LTC1655
GND
V
5V
CC
CC
: 4.75V to 15.75V,
MAX
V
CC
CC
OUT
CC
: 2.7V to 5.5V
= 12V
= 5V
: 4.5V to 5.5V,
CC
: 2.7V to 5.5V 3V, Low Power, Complete V
R1
100k
1%
R2
100k
1%
0.1 F
forced across the resistor R
the output current will range from 0mA at zero scale to
10mA at full scale. The minimum voltage for V
mined by the load resistor R
With a load resistor of 50 , the voltage source can be as
low as 3.3V.
+
–
LT1077
COMMENTS
5V to 15V Single Supply, Complete V
SO-8 Package
LTC1446: V
LTC1446L: V
Output Swings from GND to REF. REF Input Can Be Tied to V
LTC1450: V
LTC1450L: V
5V, Low Power Complete V
Low Power, Multiplying V
Buffer Amplifier in SO-8 Package
LTC1454: V
LTC1454L: V
Low Power, Complete V
Package with Clear Pin
LTC1458: V
LTC1458L: V
Low Power, Deglitched, 4-Quadrant Mulitplying V
Low Power, Multiplying V
Low Power, Multiplying V
Swings from GND to REF. REF Input Can Be Tied to V
Swings from GND to REF. REF Input Can Be Tied to V
V
S
FOR R
+ 3.3V TO 100V
CC
CC
CC
CC
CC
CC
CC
CC
= 4.5V to 5.5V, V
= 4.5V to 5.5V, V
= 4.5V to 5.5V, V
= 4.5V to 5.5V, V
= 2.7V to 5.5V, V
= 2.7V to 5.5V, V
= 2.7V to 5.5V, V
= 2.7V to 5.5V, V
L
Q1
2N3440
R
205
1%
R
50
A
L
OUT
I
OUT
OUT
OUT
OUT
A
1655 TA04
OUT
. If R
OUT
LINEAR TECHNOLOGY CORPORATION 1998
DAC in SO-8
L
=
DAC with Rail-to-Rail
DAC in MS8 Package. Output
DAC in MS8 Package. Output
(D
(65536)(R
0mA TO 10mA
and Q1’s V
1655f LT/TP 0399 4K • PRINTED IN USA
DAC in SO-8 Package
OUT
OUT
OUT
OUT
IN
DAC in SO-8 Package
OUT
OUT
OUT
OUT
A
)(4.096)
is chosen to be 205 ,
= 0V to 4.095V
= 0V to 4.095V
= 0V to 4.095V
= 0V to 4.095V
OUT
= 0V to 2.5V
= 0V to 2.5V
= 0V to 2.5V
= 0V to 2.5V
A
)
•
DAC in
1
2
CESAT
OUT
S
CC
is deter-
voltage.
CC
CC