Datasheet
5
21576512f
LTC2157-12/
LTC2156-12/LTC2155-12
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
DIGITAL DATA OUTPUTS
V
OD
Differential Output Voltage 100Ω Differential Load, 3.5mA Mode
100Ω Differential Load, 1.75mA Mode
l
l
247
125
350
175
454
250
mV
mV
V
OS
Common Mode Output Voltage 100Ω Differential Load, 3.5mA Mode
100Ω Differential Load, 1.75mA Mode
l
l
1.125
1.125
1.250
1.250
1.375
1.375
V
V
R
TERM
On-Chip Termination Resistance Termination Enabled, OV
DD
= 1.8V 100 Ω
DIGITAL INPUTS AND OUTPUTS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 5)
TIMING CHARACTERISTICS
The l denotes the specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. (Note 5)
SYMBOL PARAMETER CONDITIONS
LTC2157-12 LTC2156-12 LTC2155-12
UNITSMIN TYP MAX MIN TYP MAX MIN TYP MAX
f
S
Sampling Frequency (Note 9)
l
10 250 10 210 10 170 MHz
t
L
ENC Low Time (Note 8) Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On
l
l
1.9
1.5
2
2
50
50
2.26
1.5
2.38
2.38
50
50
2.79
1.5
2.94
2.94
50
50
ns
ns
t
H
ENC High Time (Note 8) Duty Cycle Stabilizer Off
Duty Cycle Stabilizer On
l
l
1.9
1.5
2
2
50
50
2.26
1.5
2.38
2.38
50
50
2.79
1.5
2.94
2.94
50
50
ns
ns
DIGITAL DATA OUTPUTS
SYMBOL PARAMETER CONDITIONS
LTC215X-12
MIN TYP MAX UNITS
t
D
ENC to Data Delay C
L
= 5pF (Note 8)
l
1.7 2 2.3 ns
t
C
ENC to CLKOUT Delay C
L
= 5pF (Note 8)
l
1.3 1.6 2 ns
t
SKEW
DATA to CLKOUT Skew t
D
– t
C
(Note 8)
l
0.3 0.4 0.55 ns
Pipeline Latency 5 5 Cycles
SPI Port Timing (Note 8)
t
SCK
SCK Period Write Mode
Readback Mode C
SDO
= 20pF, R
PULLUP
= 2k
l
l
40
250
ns
ns
t
S
CS to SCK Set-Up Time
l
5 ns
t
H
SCK to CS Hold Time
l
5 ns
t
DS
SDI Set-Up Time
l
5 ns
t
DH
SDI Hold Time
l
5 ns
t
DO
SCK Falling to SDO Valid Readback Mode, C
SDO
= 20pF, R
PULLUP
= 2k
l
125 ns
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 voltage values are with respect to GND with GND and OGND
shorted (unless otherwise noted).
Note 3: When these pin voltages are taken below GND or above V
DD
, they
will be clamped by internal diodes. This product can handle input currents
of greater than 100mA below GND or above V
DD
without latchup.
Note 4: When these pin voltages are taken below GND they will be
clamped by internal diodes. When these pin voltages are taken above V
DD
they will not be clamped by internal diodes. This product can handle input
currents of greater than 100mA below GND without latchup.
Note 5: V
DD
= OV
DD
= 1.8V, f
SAMPLE
= 250MHz (LTC2157),
210MHz (LTC2156), or 170MHz (LTC2155), differential ENC
+
/ENC
–
= 2V
P-P
sine wave, input range = 1.5V
P-P
with differential drive, unless otherwise noted.
Note 6: Integral nonlinearity is defined as the deviation of a code from a
best fit straight line to the transfer curve. The deviation is measured from
the center of the quantization band.
Note 7: Offset error is the offset voltage measured from –0.5LSB when the
output code flickers between 0000 0000 0000 and 1111 1111 1111 in 2’s
complement output mode.
Note 8: Guaranteed by design, not subject to test.
Note 9: Recommended operating conditions.