Datasheet LTC1403, LTC1403A (Analog Devices) - 10

LTC1403/LTC1403A
applications inFormation DRIVING THE ANALOG INPUT
available in the Linear Technology Databooks and on the The differential analog inputs of the LTC1403/LTC1403A LinearViewTM CD-ROM.) are easy to drive. The inputs may be driven differentially or
LTC
®
1566-1:
Low Noise 2.3MHz Continuous Time Low- as a single-ended input (i.e., the A – IN input is grounded). Pass Filter. Both differential analog inputs, A + – IN with AIN , are sampled
LT1630:
Dual 30MHz Rail-to-Rail Voltage FB Amplifier. at the same instant. Any unwanted signal that is common 2.7V to ±15V supplies. Very high A to both inputs of each input pair will be reduced by the VOL, 500µV offset and 520ns settling to 0.5LSB for a 4V swing. THD and noise common mode rejection of the sample-and-hold circuit. are –93dB to 40kHz and below 1LSB to 320kHz (A The inputs draw only one small current spike while charging V = 1, 2V the sample-and-hold capacitors at the end of conversion. P-P into 1kΩ, VS = 5V), making the part excellent for AC applications (to 1/3 Nyquist) where rail-to-rail performance During conversion, the analog inputs draw only a small is desired. Quad version is available as LT1631. leakage current. If the source impedance of the driving circuit is low, then the LTC1403/LTC1403A inputs can be
LT1632:
Dual 45MHz Rail-to-Rail Voltage FB Amplifier. driven directly. As source impedance increases, so will 2.7V to ±15V supplies. Very high AVOL, 1.5mV offset and acquisition time. For minimum acquisition time with high 400ns settling to 0.5LSB for a 4V swing. It is suitable source impedance, a buffer amplifier must be used. The for applications with a single 5V supply. THD and noise main requirement is that the amplifier driving the analog are –93dB to 40kHz and below 1LSB to 800kHz (AV = 1, input(s) must settle after the small current spike before 2VP-P into 1kΩ, VS = 5V), making the part excellent for the next conversion starts (settling time must be 39ns AC applications where rail-to-rail performance is desired. for full throughput rate). Also keep in mind while choos- Quad version is available as LT1633. ing an input amplifier, the amount of noise and harmonic
LT1813:
Dual 100MHz 750V/µs 3mA Voltage Feedback distortion added by the amplifier. Amplifier. 5V to ±5V supplies. Distortion is –86dB to 100kHz and –77dB to 1MHz with ±5V supplies (2VP-P into 500Ω).
CHOOSING AN INPUT AMPLIFIER
Excellent part for fast AC applications with ±5V supplies. Choosing an input amplifier is easy if a few requirements
LT1801:
80MHz GBWP, –75dBc at 500kHz, 2mA/Amplifier, are taken into consideration. First, to limit the magnitude 8.5nV/√Hz. of the voltage spike seen by the amplifier from charging
LT1806/LT1807:
325MHz GBWP, –80dBc Distortion at the sampling capacitor, choose an amplifier that has a low 5MHz, Unity-Gain Stable, R-R In and Out, 10mA/Ampli- output impedance (<100Ω) at the closed-loop bandwidth fier, 3.5nV/√Hz. frequency. For example, if an amplifier is used in a gain of 1 and has a unity-gain bandwidth of 50MHz, then the
LT1810:
180MHz GBWP, –90dBc Distortion at 5MHz, Unity- output impedance at 50MHz must be less than 100Ω. The Gain Stable, R-R In and Out, 15mA/Amplifier, 16nV/√Hz. second requirement is that the closed-loop bandwidth must
LT1818/LT1819:
400MHz, 2500V/µs,9mA, Single/Dual be greater than 40MHz to ensure adequate small-signal Voltage Mode Operational Amplifier. settling for full throughput rate. If slower op amps are used, more time for settling can be provided by increasing
LT6200:
165MHz GBWP, –85dBc Distortion at 1MHz, the time between conversions. The best choice for an op Unity-Gain Stable, R-R In and Out, 15mA/Amplifier, amp to drive the LTC1403/LTC1403A will depend on the 0.95nV/√Hz. application. Generally, applications fall into two categories:
LT6203:
100MHz GBWP, –80dBc Distortion at 1MHz, Unity- AC applications where dynamic specifications are most Gain Stable, R-R In and Out, 3mA/Amplifier, 1.9nV/√Hz. critical and time domain applications where DC accuracy and settling time are most critical. The following list is
LT6600-10:
Amplifier/Filter Differential In/Out with 10MHz a summary of the op amps that are suitable for driving Cutoff. the LTC1403/LTC1403A. (More detailed information is 1403fc 10 For more information www.linear.com/LTC1403 Document Outline Features Applications Block Diagram Description Absolute Maximum Ratings Order Information Pin Configuration Converter Characteristics Analog Input Dynamic Accuracy Internal Reference Characteristics Digital Inputs and Digital Outputs Power Requirements Timing Characteristics Typical Performance Characteristics Pin Functions Block Diagram Timing Diagram Applications Information Package Description Revision History Related Parts