LT1720 Datasheet, PDF (3/28 Pages) Linear Technology – Dual/Quad, 4.5ns, Single Supply 3V/5V Comparators with Rail-to-Rail Outputs

LT1720/LT1721
ELECTRICAL CHARACTERISTICS The q denotes specifications that apply over the full operating temperature
range, otherwise specifications are at T_A = 25°C. V_CC = 5V, V_CM = 1V, C_OUT = 10pF, V_OVERDRIVE = 20mV, unless otherwise specified.
SYMBOL
I_B
I_OS
CMRR
PSRR
A_V
V_OH
V_OL
I_CC
t_PD20
t_PD5
∆t_PD
t_SKEW
t_r
t_f
t_JITTER
f_MAX
PARAMETER
Input Bias Current
Input Offset Current
Common Mode Rejection Ratio
Power Supply Rejection Ratio
Voltage Gain
Output High Voltage
Output Low Voltage
Supply Current (Per Comparator)
Propagation Delay
Propagation Delay
Differential Propagation Delay
Propagation Delay Skew
Output Rise Time
Output Fall Time
Output Timing Jitter
Maximum Toggle Frequency
CONDITIONS
MIN TYP MAX
q –6
0
q
0.6
(Note 4)
q 55
70
(Note 5)
q 65
80
(Note 6)
∞
I_SOURCE = 4mA, V_IN = V_TRIP+ + 10mV
q V_CC – 0.4
I_SINK = 10mA, V_IN = V_TRIP– – 10mV
q
0.4
V_CC = 5V
V_CC = 3V
q
4
7
q
3.5
6
V_OVERDRIVE = 20mV (Note 7)
4.5
6.5
q
8.0
V_OVERDRIVE = 5mV (Notes 7, 8)
q
7
10
13
(Note 9) Between Channels
(Note 10) Between t_PD+/t_PD–
10% to 90%
0.3
1.0
0.5
1.5
2.5
90% to 10%
2.2
V_IN = 1.2V_P-P (6dBm), Z_IN = 50Ω t_PD+
15
V_CM = 2V, f = 20MHz
t_PD–
11
V_OVERDRIVE = 50mV, V_CC = 3V
70.0
V_OVERDRIVE = 50mV, V_CC = 5V
62.5
UNITS
µA
µA
dB
dB
V
V
mA
mA
ns
ns
ns
ns
ns
ns
ns
ns
ps_RMS
ps_RMS
MHz
MHz
Note 1: Absolute Maximum Ratings are those values beyond which the
life of a device may be impaired.
Note 2: If one input is within these common mode limits, the other
input can go outside the common mode limits and the output will be
valid.
Note 3: The LT1720/LT1721 comparators include internal hysteresis.
The trip points are the input voltage needed to change the output state
in each direction. The offset voltage is defined as the average of V_TRIP+
and V_TRIP–, while the hysteresis voltage is the difference of these two.
Note 4: The common mode rejection ratio is measured with V_CC = 5V
and is defined as the change in offset voltage measured from V_CM =
– 0.1V to V_CM = 3.8V, divided by 3.9V.
Note 5: The power supply rejection ratio is measured with V_CM = 1V
and is defined as the change in offset voltage measured from V_CC =
2.7V to V_CC = 6V, divided by 3.3V.
Note 6: Because of internal hysteresis, there is no small-signal region
in which to measure gain. Proper operation of internal circuity is
ensured by measuring V_OH and V_OL with only 10mV of overdrive.
Note 7: Propagation delay measurements made with 100mV steps.
Overdrive is measured relative to V_TRIP^±.
Note 8: t_PD cannot be measured in automatic handling equipment with
low values of overdrive. The LT1720/LT1721 are 100% tested with a
100mV step and 20mV overdrive. Correlation tests have shown that
t_PD limits can be guaranteed with this test, if additional DC tests are
performed to guarantee that all internal bias conditions are correct.
Note 9: Differential propagation delay is defined as the larger of the
two:
∆t_PDLH = t_PDLH(MAX) – t_PDLH(MIN)
∆t_PDHL = t_PDHL(MAX) – t_PDHL(MIN)
where (MAX) and (MIN) denote the maximum and minimum values of
a given measurement across the different comparator channels.
Note 10: Propagation Delay Skew is defined as:
t_SKEW = |t_PDLH – t_PDHL|
3