Datasheet

4
LTC1657/LTC1657L
The ● denotes specifications which apply over the full operating
temperature range T
A
= T
MIN
to T
MAX
. V
CC
= 5V (LTC1657), V
CC
= 3V (LTC1657L), unless otherwise noted.
ELECTRICAL CHARACTERISTICS
LTC1657 LTC1657L
SYMBOL PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
Digital I/O
V
IH
Digital Input High Voltage ● 2.4 2.0 V
V
IL
Digital Input Low Voltage ● 0.8 0.6 V
I
LEAK
Digital Input Leakage V
IN
= GND to V
CC
● ±10 ±10 µA
C
IN
Digital Input Capacitance (Note 7) ● 10 10 pF
Switching Characteristics
t
CS
CS (MSB or LSB) Pulse Width ● 40 60 ns
t
WR
WR Pulse Width ● 40 60 ns
t
CWS
CS to WR Setup ● 00ns
t
CWH
CS to WR Hold ● 00ns
t
DWS
Data Valid to WR Setup ● 40 60 ns
t
DWH
Data Valid to WR Hold ● 00ns
t
LDAC
LDAC Pulse Width ● 40 60 ns
t
CLR
CLR Pulse Width ● 40 60 ns
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: External reference REFHI = 2.2V. V
CC
= 5V (LTC1657).
External reference REFHI = 1.3V. V
CC
= 3V (LTC1657L).
Note 3: Nonlinearity is defined from code 128 to code 65535 (full scale).
See Applications Information.
Note 4: Digital inputs at 0V or V
CC
.
Note 5: DAC switched between all 1s and all 0s. V
FS
= 4.096V.
Note 6: D0 to D15 toggle between all 0s and all 1s with REFHI = 0V,
CSMSB = CSLSB = WR = LDAC = High
Note 7: Guaranteed by design. Not subject to test.
Note 8: DAC inputs all 1s.
Note 9: X1/X2 tied to GND, the voltage noise will be a factor of 2 greater.
Note 10: Using 2.048V (1.25V) external reference with 3nV/√Hz noise at
1kHz for LTC1657/(LTC1657L).