DATA SHEET SKY12339-350LF: 0.4-3.0 GHz 5-Bit Digital Attenuator (1 dB LSB) Applications WiMAX, GSM, CDMA, WCDMA, WLAN, Bluetooth , Zigbee , and mobile radio base stations or terminal equipment Telecommunications and instrumentation Features Broadband operation: 0.4 to 3.0 GHz Attenuation: 31 dB LSB attenuation: 1 dB Low insertion loss: 1.2 dB 900 MHz Positive voltage operation: 4.5 to 5.5 V Low current consumption: 1.5 mA typical 5 V Small, QFN (16-pin, 3 x 3 mm) package (MSL1, 260 C per JEDEC J-STD-020) Figure 1. SKY12339-350LF Block Diagram Description The SKY12339-350LF is a monolithic, GaAs binary-weighted five- bit single positive control voltage digital attenuator. The device operates from 0.4 to 3.0 GHz. DC power consumption is very low, typically 1.5 mA, with a supply voltage of 5 V. The SKY12339-350LF has an LSB of 1 dB and total attenuation of 31 dB. The two RF ports are bilateral each can be used as the RF input or the RF output. An external supply voltage of 4.5 to 5.5 V is required. The SKY12339-350LF is comprised of five cascaded fixed attenuators, each of which has a shunt bypass switch. Beginning at the 1 dB LSB, each succeeding fixed attenuator produces twice the attenuation of the preceding stage. The state of each bypass switch is controlled by the logic level voltage applied to the associated control voltage input. A logic high voltage closes the associated switch, which bypasses that fixed attenuator stage a logic low opens the switch to force the input signal to that stage through the associated attenuator. 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 201143C Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice January 17, 2011 1 DATA SHEET SKY12339-350LF 5-BIT DIGITAL ATTENUATOR Figure 2. SKY12339-350LF Pinout 16-Pin QFN (Top View) Table 1. SKY12339-350LF Signal Descriptions Pin Name Description Pin Name Description 1 VS Supply voltage 9 GND Ground 2 RF1 RF input/output. A DC block is required. 10 N/C No connection 3 N/C No connection 11 RF2 RF input/output. A DC block is required. 4 GND Ground 12 V5 Control voltage input for 16 dB weighted bit 5 GND Ground 13 V4 Control voltage input for 8 dB weighted bit 6 GND Ground 14 V3 Control voltage input for 4 dB weighted bit 7 GND Ground 15 V2 Control voltage input for 2 dB weighted bit 8 GND Ground 16 V1 Control voltage input for 1 dB weighted bit Note: Exposed paddle must be grounded. The state of the SKY12339-350LF is determined by the logic Electrical and Mechanical Specifications provided in Table 4. The absolute maximum ratings of the SKY12339-350LF are provided in Table 2. Electrical specifications are provided in Table 3. Typical performance characteristics of the SKY12339-350LF are illustrated in Figures 3 through 9. Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 January 17, 2011 Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice 201143C