DATA SHEET SKY12349-362LF: 0.7-4.0 GHz Five-Bit Digital Attenuator with Serial-to-Parallel Driver (0.5 dB LSB) Applications Base stations Wireless and RF data Wireless local loop gain control circuits Features Broadband operation: 0.7 to 4.0 GHz Attenuation: 15.5 dB LSB attenuation: 0.5 dB Low insertion loss: 1 dB 900 MHz Positive voltage operation: 5 V Integrated silicon serial-to-parallel driver Small, QFN (24-pin, 4 x 4 mm) package (MSL1, 260 C per JEDEC J-STD-020) Figure 1. SKY12349-362LF Block Diagram Description The SKY12349-362LF is a GaAs FET five-bit digital attenuator I/C with a serial-to-parallel driver. The device is provided in a 4 x 4 mm, 24-pin Quad Flat No-Lead (QFN) package. The SKY12349-362LF is particularly suited for applications in which high attenuation accuracy, low insertion loss, and low intermodulation products are required. A functional block diagram is shown in Figure 1. The pin configuration and package are shown in Figure 2. Signal pin assignments and functional pin descriptions are provided in Table 1. Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 201399A Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice January 6, 2011 1 DATA SHEET SKY12349-362LF FIVE-BIT DIGITAL ATTENUATOR Figure 2. SKY12349-362LF Pinout 24-Pin QFN (Top View) Table 1. SKY12349-362LF Signal Descriptions Pin Name Description Pin Name Description 1 GND or N/C Ground or no connection 13 GND or N/C Ground or no connection 2 RF1 RF input/output. Must be DC blocked. 14 VCC Fixed bias for SPI 3 GND or N/C Ground or no connection 15 GND or N/C Ground or no connection 4 GND or N/C Ground or no connection 16 GND or N/C Ground or no connection 5 SERIAL OUTPUT Data output delayed by eight clock cycles 17 RF2 RF input/output. Must be DC blocked. 6 GND or N/C Ground or no connection 18 GND or N/C Ground or no connection 7 RESET Reset. Clears shift registers. 19 GND Ground 8 CLOCK Serial clock input 20 GND Ground 9 LATCH ENABLE On rising edge of pulse, shifts five most 21 GND Ground recent clocked-in bits to set attenuation state 10 GND or N/C Ground or no connection 22 GND Ground 11 SERIAL INPUT Data input 23 GND Ground 12 GND or N/C Ground or no connection 24 GND Ground Note: Exposed pad must be grounded. Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 January 6, 2011 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice 201399A