The LTC1745 is a 25Msps sampling 12-bit a /D converter designed for digitized high frequency, wide dynamic range signals. Ideal for demanding communications applications, its AC performance includes 72.5dB signal-to-noise ratio and 91dB spurious free dynamic range. Pin selectable input ranges of ±1V and ±1.6V and resistance programmable modes allow the LTC1745's input range to be optimized for a variety of applications.
Functional block diagram
The converter's 0.3psRMS ultra low jitter gives undersampling excellent noise performance. Dc specifications include ±1LSB INL maximum and ±0.75LSB DNL overtemperature. Digital interface compatible with 5V, 3V and 2V logic systems. ENC and ENC inputs may be driven differently from PECL, GTL, and other low-wave logic families, or from single-ended TTL or CMOS.
Timing diagram
Low noise, high gain ENC and ENC inputs can also be driven by sinusoidal signals without degrading performance. A separate digital output power supply can operate from 0.5V to 5V, making it easy to connect directly to a low-voltage dsp or fifo. A TSSOP package with flow-through pins simplifies board layout.
Features
● Sample Rate: 25Msps
● 72.5dB SNR and 91dB SFDR (3.2V Range)
● 71dB SNR and 96dB SFDR (2V Range)
● No Missing Codes
● Single 5V Supply
● Low Power Dissipation: 380mW
● Selectable Input Ranges: ±1V or ±1.6V
● 240MHz Full Power Bandwidth S/H
● Pin Compatible Family
- 25 Msps: LTC1746 (14-Bit), LTC1745 (12-Bit)
- 50 Msps: LTC1744 (14-Bit), LTC1743 (12-Bit)
- 65 Msps: LTC1742 (14-Bit), LTC1741 (12-Bit)
- 80 Msps: LTC1748 (14-Bit), LTC1747 (12-Bit)
Applications
● Telecom
● Medical imaging
● Receiver
● Base station
● Spectrum analysis
● Imaging system
