LTC1595AIS8 Linear Technology, LTC1595AIS8 Datasheet - Page 9

• Manufacturer Part Number: LTC1595AIS8
• Description: IC D/A CONV 16BIT MULTPLYNG8SOIC
• Manufacturer: Linear Technology

Specifications of LTC1595AIS8

• Settling Time: 1µs
• Number Of Bits: 16
• Data Interface: Serial
• Number Of Converters: 1
• Voltage Supply Source: Single Supply
• Power Dissipation (max): 55µW
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIONS
Description
The LTC1595/LTC1596 are 16-bit multiplying DACs which
have serial inputs and current outputs. They use precision
R/2R technology to provide exceptional linearity and
stability. The devices operate from a single 5V supply and
provide 10V reference input and voltage output ranges
when used with an external op amp. These devices have
a proprietary deglitcher that reduces glitch impulse to
1nV-s over a 0V to 10V output range.
Serial I/O
The LTC1595/LTC1596 have SPI/MICROWIRE compat-
ible serial ports that accept 16-bit serial words. Data is
accepted MSB first and loaded with a load pin.
The 8-pin LTC1595 has a 3-wire interface. Data is shifted
into the SRI data input on the rising edge of the CLK pin.
At the end of the data transfer, data is loaded into the DAC
register by pulling the LD pin low (see LTC1595 Timing
Diagram).
P
0.1 F
7
6
5
CLK
SRI
LD
V
5V
DD
8
V
LTC1595
REF
1
U
GND
V
–10V TO 10V
R
REF
FB
2
4
P
FOR DAISY-CHAINING
OUT1
INFORMATION
Figure 1. Unipolar Operation (2-Quadrant Multiplication) V
U
TO NEXT DAC
–10V TO 10V
(b)
3
V
0.1 F
33pF
–
+
REF
LT1001
W
5V
1595/96 F01b
10
11
4
7
5
6
9
8
STB3
STB1
SRI
LD1
SRO
LD2
STB2
STB4
CLR
V
0V TO –V
13
OUT
U
DGND
V
DD
LTC1596
12
14
REF
V
REF
15
AGND
R
FB
(a)
16
3
The 16-pin LTC1596 can operate in identical fashion to the
LTC1595 but offers additional pins for flexibility. Four
clock pins are available STB1, STB2, STB3 and STB4.
STB1, STB2 and STB4 operate like the CLK pin of the
LTC1595, capturing data on their rising edges. STB3
captures data on its falling edge (see Truth Table 1).
The LTC1596 has two load pins, LD1 and LD2. To load
data, both pins must be taken low. If one of the pins is
grounded, the other pin will operate identically to LTC1595’s
LD pin. An asynchronous clear input (CLR) resets the
LTC1596 to zero scale (and the LTC1596-1 to midscale)
when pulled low (see Truth Table 2).
The LTC1596 also has a data output pin SRO that can be
connected to the SRI input of another DAC to daisy-chain
multiple DACs on one 3-wire interface (see LTC1596
Timing Diagram).
Unipolar (2-Quadrant Multiplying) Mode
(V
The LTC1595/LTC1596 can be used with a single op amp
to provide 2-quadrant multiplying operation as shown in
Figure 1. With a fixed –10V reference, the circuits shown
give a precision unipolar 0V to 10V output swing.
OUT1
OUT2
Table 1. Unipolar Binary Code Table
OUT
LTC1595/LTC1596/LTC1596-1
1111
1000
0000
0000
MSB
2
1
IN DAC REGISTER
BINARY NUMBER
= 0V to –V
DIGITAL INPUT
1111 1111 1111
0000 0000 0000
0000 0000 0001
0000 0000 0000
1595/96 F01a
33pF
–
+
LT1001
OUT
REF
LSB
= 0V to – V
)
–V
–V
–V
0V
V
0V TO –V
REF
REF
REF
REF
OUT
ANALOG OUTPUT
(65,535/65,536)
(32,768/65,536) = –V
(1/65,536)
REF
V
OUT
REF
/2
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