LTC1657 LINER [Linear Technology], LTC1657 Datasheet - Page 5

• Manufacturer Part Number: LTC1657
• Description: Parallel 16-Bit Rail-to-Rail Micropower DAC
• Manufacturer: LINER [Linear Technology]

PIN
WR (Pin 1): Write Input (Active Low). Used with CSMSB
and/or CSLSB to control the input registers. While WR and
CSMSB and/or CSLSB are held low, data writes into the
input register.
CSLSB (Pin 2): Chip Select Least Significant Byte (Active
Low). Used with WR to control the LSB 8-bit input regis-
ters. While WR and CSLSB are held low, the LSB byte
writes into the LSB input register. Can be connected to
CSMSB for simultaneous loading of both sets of input
latches on a 16-bit bus.
CSMSB (Pin 3): Chip Select Most Significant Byte (Active
Low). Used with WR to control the MSB 8-bit input
registers. While WR and CSMSB are held low, the MSB
byte writes into the MSB input register. Can be connected
to CSLSB for simultaneous loading of both sets of input
latches on a 16-bit bus.
D0 to D7 (Pins 4 to 11): Input data for the Least Significant
Byte. Written into LSB input register when WR = 0 and
CSLSB = 0.
D8 to D15 (Pins 12 to 19): Input data for the Most Signifi-
cant Byte. Written into MSB input register when WR = 0
and CSMSB = 0.
GND (Pin 20): Ground.
REFLO (Pin 21): Lower input terminal of the DAC’s inter-
nal resistor ladder. Typically connected to Analog Ground.
An input code of (0000)
U
FUNCTIONS
U
U
H
will connect the positive input of
the output buffer to this end of the ladder. Can be used to
offset the zero scale above ground.
REFHI (Pin 22): Upper input terminal of the DAC’s internal
resistor ladder. Typically connected to REFOUT. An input
code of (FFFF)
output buffer to 1LSB below this voltage.
REFOUT (Pin 23): Output of the internal 2.048V reference.
Typically connected to REFHI to drive internal DAC resistor
ladder.
V
5.5V. Requires a 0.1 F bypass capacitor to ground.
V
X1/X2 (Pin 26): Gain Setting Resistor Pin. Connect to GND
for G = 2 or to V
tied to a low impedance source, such as ground or V
to ensure stability of the output buffer when driving
capacitive loads.
CLR (Pin 27): Clear Input (Asynchronous Active Low). A
low on this pin asynchronously resets all input and DAC
registers to 0s.
LDAC (Pin 28): Load DAC (Asynchronous Active Low).
Used to asynchronously transfer the contents of the input
registers to the DAC register which updates the output
voltage. If held low, the DAC register loads data from the
input registers which will immediately update V
CC
OUT
(Pin 24): Positive Power Supply Input. 4.5V V
(Pin 25): Buffered DAC Output.
H
OUT
will connect the positive input of the
for G = 1. This pin should always be
LTC1657
OUT
.
CC
OUT
5
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