9
For more information www.linear.com/LTC2640
electrical characteristics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 4.5V to 5.5V, V
OUT
unloaded unless otherwise specified.
LTC2640-HM12/-HM10/-HM8/-HZ12/-HZ10/-HZ8, LTC2640A-HM12/-HZ12 (V
FS
= 4.096V)
timing characteristics
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
CC
= 4.5V to 5.5V. (See Figure 1) (Note 8).
LTC2640-HM12/-HM10/-HM8/-HZ12/-HZ10/-HZ8, LTC2640A-HM12/-HZ12 (V
FS
= 4.096V)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
t
1
SDI Valid to SCK Setup
l
4 ns
t
2
SDI Valid to SCK Hold
l
4 ns
t
3
SCK High Time
l
9 ns
t
4
SCK Low Time
l
9 ns
t
5
CS/LD Pulse Width
l
10 ns
t
6
LSB SCK High to CS/LD High
l
7 ns
t
7
CS/LD Low to SCK High
l
7 ns
t
9
CLR Pulse Width
l
20 ns
t
10
CS/LD High to SCK Pos. Edge
l
7 ns
SCK Frequency 50% Duty Cycle
l
50 MHz
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: All voltages are with respect to GND.
Note 3: High temperatures degrade operating lifetimes. Operating lifetime
is derated at temperatures greater than 105°C.
Note 4: Linearity and monotonicity are defined from code k
L
to code
2
N
– 1, where N is the resolution and k
L
is given by k
L
= 0.016 • (2
N
/ V
FS
),
rounded to the nearest whole code. For V
FS
= 2.5V and N = 12, k
L
= 26
and linearity is defined from code 26 to code 4,095. For V
FS
= 4.096V
and N = 12, k
L
= 16 and linearity is defined from code 16 to code 4,095.
Note 5: Inferred from measurement at code 16 (LTC2640-12), code 4
(
LTC2640-10) or code 1 (LTC2640-8), and at full-scale.
Note 6: This IC includes current limiting that is intended to protect the
device during momentar
y overload conditions. Junction temperature can
exceed the rated maximum during current limiting. Continuous operation
above the specified maximum operating junction temperature may impair
device reliability.
Note 7: Digital inputs at 0V or V
CC
.
Note 8: Guaranteed by design and not production tested.
Note 9: Internal Reference mode. DAC is stepped 1/4 scale to 3/4 scale
and 3/4 scale to 1/4 scale. Load is 2k in parallel with 100pF to GND.
Note 10: Temperature coefficient is calculated by dividing the maximum
change in output voltage by the specified temperature range.
Note 11: Full-scale error is determined using the reference voltage
measured at the REF pin.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
e
n
Output Voltage Noise Density At f = 1kHz, External Reference
At f = 10kHz, External Reference
At f = 1kHz, Internal Reference
At f = 10kHz, Internal Reference
140
130
210
200
nV√Hz
nV√
Hz
nV√Hz
nV√Hz
Output Voltage Noise 0.1Hz to 10Hz, External Reference
0.1Hz to 10Hz, Internal Reference
0.1Hz to 200kHz, External Reference
0.1Hz to 200kHz, Internal Reference,
C
REF
= 0.33µF
20
20
650
670
µV
P-P
µV
P-P
µV
P-P
µV
P-P
