LTC1418AIG

Features:

 Single Supply 5V or ±5V Operation
 Sample Rate: 200ksps
 ±1.25LSB INL and ±1LSB DNL Max
 Power Dissipation: 15mW (Typ)
 Parallel or Serial Data Output
 No Missing Codes Over Temperature
 Power Shutdown: Nap and Sleep
 External or Internal Reference
 Differential High Impedance Analog Input
 Input Range: 0V to 4.096V or ±2.048V
 81.5dB S/(N + D) and 94dB THD at Nyquist
 28-Pin Narrow PDIP and SSOP Packages

Application

The LTC1418 uses a successive approximation algorithm and an internal sample-and-hold circuit to convert an analog signal to a 14-bit parallel or serial output. The ADC is complete with a precision reference and an internal clock. The control logic provides easy interface to microprocessors and DSPs (please refer to Digital Interface section for the data format).

Conversion start is controlled by the CS  and CONVST  inputs. At the start of the conversion the successive approximation register (SAR) is reset. Once a conversion cycle has begun it cannot be restarted.

During the conversion, the internal differential 14-bit capacitive DAC output is sequenced by the SAR from the most significant bit (MSB) to the least significant bit (LSB).

Referring to Figure 1, the A_IN⁺ and A_IN inputs are connected to the sample-and-hold capacitors (CSAMPLE) during the acquire phase and the comparator offset is nulled by the zeroing switches. In this acquire phase, a minimum delay of 1ms will provide enough time for the sample-andhold capacitors to acquire the analog signal. During the convert phase the comparator zeroing switches open, putting the comparator into compare mode. The input switches the CSAMPLE capacitors to ground, transferring the differential analog input charge onto the summing junction. This input charge is successively compared with the binary weighted charges supplied by the differential capacitive DAC. Bit decisions are made by the high speed comparator. At the end of a conversion, the differential DAC output balances the A_IN + and A_IN input charges.

The SAR contents (a 14-bit data word) which represent the difference of A_IN ⁺ and A_IN are loaded into the 14-bit output latches.


Pinout




Specifications

Supply Voltage (V_DD) ................................................. 6V
Negative Supply Voltage (V_SS)
    Bipolar Operation Only ........................... 6V to GND
Total Supply Voltage (V_DD to V_SS)
    Bipolar Operation Only ....................................... ..12V
Analog Input Voltage (Note 3)
    Unipolar Operation .................. 0.3V to (V_DD + 0.3V)
    Bipolar Operation........... (VSS 0.3V) to (V_DD + 0.3V)
Digital Input Voltage (Note 4)
    Unipolar Operation ................................0.3V to 10V
    Bipolar Operation.........................(VSS 0.3V) to 10V
Digital Output Voltage
Unipolar Operation .................. ....0.3V to (VDD + 0.3V)
Bipolar Operation........... ....(VSS 0.3V) to (VDD + 0.3V)
Power Dissipation................................................ 500mW
Operation Temperature Range
    LTC1418C................................................ 0°C to 70°C
    LTC1418I............................................ 40°C to 85°C
Storage Temperature Range ................65°C to 150°C
Lead Temperature (Soldering, 10 sec)................... 300°C

Description

The LTC^®1418 is a low power, 200ksps, 14-bit A/D converter. Data output is selectable for 14-bit parallel or serial format. This versatile device can operate from a single 5V or ±5V supply. An onboard high performance sample-and-hold, a precision reference and internal timing minimize external circuitry requirements. The low 15mW power dissipation is made even more attractive with two user selectable power shutdown modes.

The LTC1418 converts 0V to 4.096V unipolar inputs from a single 5V supply and ±2.048V bipolar inputs from ±5V supplies. DC specs include ±1.25LSB INL, ±1LSB DNL and no missing codes over temperature. Outstanding AC performance includes 82dB S/(N + D) and 94dB THD at the Nyquist input frequency of 100kHz.

The flexible output format of LTC1418 allows either parallel or serial I/O. The SPI/MICROWIRETM compatible serial I/O port can operate as either master or slave and can support clock frequencies from DC to 10MHz. A separate convert start input and a data ready signal (BUSY ) allow easy control of conversion start and data transfer.


Parameters:

Technical/Catalog Information	LTC1418AIG
Vendor	Linear Technology
Category	Integrated Circuits (ICs)
Number of Bits	14
Package / Case	28-SSOP
Data Interface	Serial/Parallel
Packaging	Tube
Sampling Rate (Per Second)	200k
Operating Temperature	-40°C ~ 85°C
Voltage Supply Source	Dual ±
Number of Inputs and Type	2 Single-Ended, Unipolar; 2 Single-Ended, Bipolar; 1 Differential, Unipolar; 1 Differential, Bipolar
Number of Converters	1
Power Dissipation (Max)	21.5mW Unipolar; 31.5mW Bipolar
Drawing Number	161; 05-08-1640; G; 16
Lead Free Status	Contains Lead
RoHS Status	RoHS Non-Compliant
Other Names	LTC1418AIG LTC1418AIG