LTC1403AIMSE-1-PBF 查看數據表（PDF） - Linear Technology

零件编号

产品描述 (功能)

生产厂家

LTC1403AIMSE-1-PBF

Serial 12-Bit/14-Bit, 2.8Msps Sampling ADCs with Shutdown

Linear Technology 

LTC1407-1/LTC1407A-1

APPLICATIO S I FOR ATIO

LT1818/LT1819: 400MHz, 2500V/µs, 9mA, Single/Dual

Voltage Mode Operational Amplifier.

LT6200: 165MHz GBWP, –85dBc distortion at 1MHz,

unity gain stable, rail-to-rail in and out, 15mA/amplifier,

0.95nV/√Hz.

LT6203: 100MHz GBWP, –80dBc distortion at 1MHz,

unity gain stable, rail-to-rail in and out, 3mA/amplifier,

1.9nV/√Hz.

LT6600: Amplifier/Filter Differential In/Out with 10MHz

Cutoff.

can add distortion. NPO and silvermica type dielectric

capacitors have excellent linearity. Carbon surface mount

resistors can generate distortion from self heating and

from damage that may occur during soldering. Metal film

surface mount resistors are much less susceptible to both

problems. When high amplitude unwanted signals are close

in frequency to the desired signal frequency a multiple

pole filter is required.

High external source resistance, combined with 13pF of

input capacitance, will reduce the rated 50MHz input band-

width and increase acquisition time beyond 39ns.

INPUT FILTERING AND SOURCE IMPEDANCE

The noise and the distortion of the input amplifier and

other circuitry must be considered since they will add to

the LTC1407-1/LTC1407A-1 noise and distortion. The

small-signal bandwidth of the sample-and-hold circuit is

50MHz. Any noise or distortion products that are present

at the analog inputs will be summed over this entire band-

width. Noisy input circuitry should be filtered prior to the

analog inputs to minimize noise. A simple 1-pole RC filter

is sufficient for many applications. For example, Figure 1

shows a 47pF capacitor from CHO+ to ground and a 51Ω

source resistor to limit the net input bandwidth to 30MHz.

The 47pF capacitor also acts as a charge reservoir for the

input sample-and-hold and isolates the ADC input from

sampling-glitch sensitive circuitry. High quality capaci-

tors and resistors should be used since these components

ANALOG 51Ω*

INPUT

1 CH0+

47pF*

VCM

1.5V DC

ANALOG 51Ω*

INPUT

2

3

10µF

11

CH0–

LTC1407-1/

LTC1407A-1

VREF

GND

4 CH1+

47pF*

VCM

1.5V DC

5 CH1–

14071 F01

*TIGHT TOLERANCE REQUIRED TO AVOID

APERTURE SKEW DEGRADATION

Figure 1. RC Input Filter

INPUT RANGE

The analog inputs of the LTC1407-1/LTC1407A-1 may be

driven fully differentially with a single supply. Either input

may swing up to 3V, provided the differential swing is no

greater than 1.25V. In the valid input range, each input of

each channel is always up to ±1.25V away from the other

input of each channel. The –1.25V to 1.25V range is also

ideally suited for AC-coupled signals in single supply

applications. Figure 2 shows how to AC couple signals in

a single supply system without needing a mid-supply 1.5V

DC external reference. The DC common mode level is

supplied by the previous stage that is already bounded by

single supply voltage of the system. The common mode

range of the inputs extends from ground to the supply

voltage VDD. If the difference between the CH0+ and CH0–

inputs or the CH1+ and CH1– inputs exceeds 1.25V, the

output code will stay fixed at zero and all ones, and if this

difference goes below –1.25V, the ouput code will stay

fixed at one and all zeros.

C2

1µF

R3

51Ω

VIN

C3

56pF

R2

LTC1407-1/

1.6k

LTC1407A-1

1 CHO+

2 CHO–

R1

1.6k

C1

4.09V 3

C4

VREF

1µF 10µF

14071 F02

C1, C2: FILM TYPE

C3: COG TYPE

C4: CERAMIC BYPASS

Figure 2. AC Coupling of AC Signals with 1kHz Low Cut

14071f

13

Share Link: