Converter offers direct IF sampling up to 500 MHz.
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Press Release Summary:
Housed in 48-Pin TSSOP package, LTC1750 analog to digital converter (ADC) simplifies basestation design by eliminating second intermediate frequency (IF) down-conversion stage. This 80 Msps, 14-bit ADC undersamples up to 500 MHz input frequencies and delivers 84 dB spurious free dynamic range with 140 MHz inputs and 74 dB SFDR with 350 MHz inputs. Features include configurable I/O, on-chip PGA, and selectable input ranges: 1.35-2.25 Vp-p.
Original Press Release:
80Msps, 14-Bit ADC Offers Direct IF Sampling up to 500MHz
Simplifies Basestation Design by Eliminating Second IF Stage
MILPITAS, CA - March 29, 2004 - A new 80 Msps, 14-bit analog to digital converter (ADC) from Linear Technology provides designers of cellular base stations with a dramatic improvement in dynamic performance. The LTC1750 greatly simplifies the design and reduces the cost of cellular basestations by eliminating the second intermediate frequency (IF) down-conversion stage. The device provides wide input bandwidth and excellent dynamic performance for direct IF digitizing applications. The LTC1750 undersamples up to 500MHz input frequencies and delivers 84dB spurious free dynamic range (SFDR) with 140MHz inputs and 74dB SFDR with 350MHz inputs. The device's wide bandwidth and excellent AC performance are ideal for use in cellular basestations and broadband software radios, where it can directly digitize the first IF and eliminate the second IF down-conversion stage.
The LTC1750 offers the flexibility to configure the input and the output specifically for the application. An on-chip programmable gain amplifier (PGA) allows multiple input ranges to optimize the performance. The larger input range offers industry-leading low noise, and the smaller range lowers the gain requirements on the drive circuitry, making it easier to meet the IP3 requirements. If the input ever goes out of range there is automatic indicator on the overflow pin. A separate digital output supply pin allows connection to low voltage DSPs, FIFOs or logic as low as 0.5V.
The LTC1750 is one device in a family of pin compatible high speed ADCs. The LTC1749 is a pin compatible 12-bit version of the LTC1750 allowing multiple price/performance products with one design. For other high-speed applications this pin compatible family extends from 25Msps to 80Msps and from 12-bits to 14-bits. Each device is available in the 48-pin TSSOP package for both the commercial and the industrial temperature ranges.
Pricing for 1,000-piece quantities begins at $32.30 each for the LTC1750, $19.55 each for the LTC1749.
Summary of Features: LTC1749/LTC1750
LTC1750: 14-Bit 80Msps Wide Bandwidth ADC
LTC1749: 12-Bit 80Msps Wide Bandwidth ADC
500MHz Full Power Bandwidth S/H
Excellent Dynamic Performance
LTC1750 - 71.7dB SNR & 84dB SFDR @ 140MHz
Selectable Input Ranges: 1.35Vp-p to 2.25Vp-p
Output Supply Pin: 0.5V to 5V Range
Single 5V Supply
Power Dissipation: 1.45W
48-Pin TSSOP Package
Company Background
Linear Technology Corporation was founded in 1981 as a manufacturer of high performance linear integrated circuits. Linear Technology products include operational, instrumentation and audio amplifiers; voltage regulators,power management devices, DC-DC converters and voltage references; comparators; monolithic filters; communications interface circuits; one-chip data acquisition sub-systems; pulse-width modulators and sample-and-hold devices; and high frequencydevices. Applications for Linear Technology's high performance circuits include wireless and broadband telecommunications infrastructure, cellular telephones, networking products and satellite systems, notebook and desk top computers, computer peripherals, video/multimedia, industrial and medical instrumentation, automotive electronics, factory automation, process control, military and space systems, and high-end consumer products including digital cameras, MP3 players and other electronic products.
Note: LT, AND LTC are registered trademarks of Linear Technology Corp.
