Linear Technology has pushed sampling rates for its 12-bit analog-to-digital converter (ADC) family for high-IF applications to 250 Msamples/s while holding the chip's power consumption to a modest 740 mW at 2.5 V. Analog input bandwidth for the LTC2242-12 is 1.2 GHz.
By running the part at 2.5 V, it can be driven with either a full 2-V or a 1-V p-p signal (see the figure). Yet even with 2.5 V running the analog side, the converter lets circuit designers choose any voltage between 0.5 and 2.6 for the digital supply. This facilitates direct connection to any digital downconverter, regardless of whether its interface is low-voltage differential signalling, fullrate CMOS, or demultiplexed CMOS.
The LTC2242-12 is part of a pin-compatible family of 10- and 12-bit 2.5-V ADCs. Lower-power, lower-cost family members sample at 210 and 170 Msamples/s. The new chips also are pin-compatible with Linear's 3.3-V LTC2220 family.
Helping to minimize board-space requirements, the chip family's 9- by 9-mm quad flat no-lead (QFN) packages integrate the necessary bypass capacitance.
The LTC2242-12 costs $59 each in 1000-piece quantities. The 210- and 170- Msample/s versions cost $42 and $35. The 10-bit versions cost $39, $32, and $25.