Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

LTC1405IGN Datasheet(PDF) 7 Page - Linear Technology

Part # LTC1405IGN
Description  12-Bit, 5Msps, Sampling ADC
Download  16 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  LINER [Linear Technology]
Direct Link  http://www.linear.com
Logo LINER - Linear Technology

LTC1405IGN Datasheet(HTML) 7 Page - Linear Technology

Back Button LTC1405IGN Datasheet HTML 3Page - Linear Technology LTC1405IGN Datasheet HTML 4Page - Linear Technology LTC1405IGN Datasheet HTML 5Page - Linear Technology LTC1405IGN Datasheet HTML 6Page - Linear Technology LTC1405IGN Datasheet HTML 7Page - Linear Technology LTC1405IGN Datasheet HTML 8Page - Linear Technology LTC1405IGN Datasheet HTML 9Page - Linear Technology LTC1405IGN Datasheet HTML 10Page - Linear Technology LTC1405IGN Datasheet HTML 11Page - Linear Technology Next Button
Zoom Inzoom in Zoom Outzoom out
 7 / 16 page
background image
7
LTC1405
Conversion Details
The LTC1405 is a high performance 12-bit A/D converter
that operates up to 5Msps. It is a complete solution with
an on-chip sample-and-hold, a 12-bit pipelined CMOS
ADC, a low drift programmable reference and an input
programmable gain amplifier. The digital output is paral-
lel, with a 12-bit two’s complement output and an out-of-
range (overflow) bit.
The rising edge of the CLK begins a conversion. The
differential analog inputs are simultaneously sampled and
passed on to the pipelined A/D. After two more conversion
starts (plus a 150ns conversion time) the digital outputs
are updated with the conversion result and will be ready for
capture on the third rising clock edge. Thus even though
a new conversion is begun every time CLK goes high, each
result takes three clock cycles to reach the output.
The analog signals that are passed from stage to stage in
the pipelined A/D are stored on capacitors. The signals on
these capacitors will be lost if the delay between conver-
sions is too long. For accurate conversion results, the part
should be clocked faster than 20kHz.
In some pipelined A/D converters if there is no clock
present, dynamic logic on the chip will droop and the
power consumption sharply increases. The LTC1405
doesn’t have this problem. If the part is not clocked for
1ms, an internal timer will refresh the dynamic logic. Thus
the clock can be turned off for long periods of time to save
power.
Power Supplies
The LTC1405 will operate from either a single 5V or dual
±5V supply, making it easy to interface the analog input to
single or dual supply systems. The digital output drivers
have their own power supply pin (OVDD) which can be set
from 3V to 5V, allowing direct connection to either 3V or
5V digital systems. For single supply operation, VSS should
be connected to analog ground. For dual supply operation,
VSS should be connected to – 5V. Both VDD pins should be
connected to a clean 5V analog supply. (Don’t connect VDD
to a noisy system digital supply.)
APPLICATIO S I FOR ATIO
Analog Input Ranges
The LTC1405 has a flexible analog input with a wide
selection of input ranges. The input range is always
differential and is set by the voltages at the VREF and the
GAIN pins (Figure 1). The input range of the A/D core is
fixed at
±VREF/2. The reference voltage, VREF, is either set
by the on-chip voltage reference or directly driven by an
external voltage. The GAIN pin is a digital input that
controls the gain of a preamplifier in the sample-and-hold
circuit. The gain of this PGA can be set to 1x or 2x. Table 1
gives the input range in terms of VREF and GAIN.
Table 1
INPUT RANGE
GAIN PIN
PGA GAIN
(VIN = AIN+ – AIN–)
5V (Logic H)
1x
– VREF/2 < VIN < VREF/2
OV (Logic L)
2x
– VREF/4 < VIN < VREF/4
VREF
–AIN
+AIN
GAIN
1405 F01
1x/2x
VIN
+
±VREF/2
PGA
S/H
ADC
CORE
Internal Reference
Figure 2 shows a simplified schematic of the LTC1405
reference circuitry. An on-chip temperature compensated
bandgap reference (VCM) is factory trimmed to 2.500V.
The voltage at the VREF pin sets the input span of the ADC
to
±VREF/2. An internal voltage divider converts VCM to
2.048V, which is connected to a reference amplifier. The
reference programming pin, SENSE, controls how the
reference amplifier drives the VREF pin. If SENSE is tied to
ground, the reference amplifier feedback is connected to
the R1/R2 voltage divider, thus making VREF = 4.096V. If
SENSE is tied to VREF, the reference amplifier feedback is
connected to SENSE thus making VREF = 2.048V. If SENSE
is tied to VDD, the reference amplifier is disconnected from
VREF and VREF can be driven by an external voltage. With
two additional resistors, VREF can be set to any voltage
between 2.048V and 4.5V.
Figure 1. Analog Input Circuit


Similar Part No. - LTC1405IGN

ManufacturerPart #DatasheetDescription
logo
Linear Technology
LTC1405IGN LINER-LTC1405IGN Datasheet
328Kb / 20P
   12-Bit, 5Msps, Sampling ADC
More results

Similar Description - LTC1405IGN

ManufacturerPart #DatasheetDescription
logo
Linear Technology
LTC1405 LINER-LTC1405_1 Datasheet
328Kb / 20P
   12-Bit, 5Msps, Sampling ADC
LTC1405 LINER-LTC1405_15 Datasheet
334Kb / 20P
   12-Bit, 5Msps, Sampling ADC
LTC2315-12 LINER-LTC2315-12_15 Datasheet
695Kb / 22P
   12-Bit, 5Msps Serial Sampling ADC in TSOT
LTC2315-12 LINER-LTC2315-12 Datasheet
911Kb / 20P
   12-Bit, 5Msps Serial Sampling ADC in TSOT
LTC2325-16 LINER-LTC2325-16 Datasheet
1Mb / 30P
   Quad, 16-Bit, 5Msps/Ch Simultaneous Sampling ADC
LTC1420 LINER-LTC1420 Datasheet
267Kb / 20P
   12-Bit, 10Msps, Sampling ADC
logo
Analog Devices
AD1678 AD-AD1678_15 Datasheet
4Mb / 12P
   12 BIT 200KSPS SAMPLING ADC
logo
Linear Technology
LTC1420 LINER-LTC1420_15 Datasheet
256Kb / 20P
   12-Bit, 10Msps, Sampling ADC
LTC2385-18 LINER-LTC2385-18 Datasheet
1Mb / 22P
   18-Bit, 5Msps SAR ADC
logo
Maxim Integrated Produc...
MAX1211 MAXIM-MAX1211 Datasheet
534Kb / 30P
   65Msps, 12-Bit, IF Sampling ADC
2004
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.NET
Does ALLDATASHEET help your business so far?  [ DONATE ] 

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   Link Exchange   |   Manufacturer List
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com