6-Bit, 75 Digital Step Attenuator F1978 5MHz to 3GHz Datasheet Description Features The F1978 Digital Step Attenuator (DSA) is a product in IDTs Frequency: 5MHz to 3000MHz TM Glitch-Free DSA Family, which is optimized for the demanding Serial and 6-bit parallel interface requirements of CATV and satellite systems. It operates in the 31.5dB control range frequency range of 5MHz to 3000MHz. This device is offered in a 0.5dB step compact 4mm 4mm, 20-pin Thin QFN package with a 75 TM Glitch-Free technology, low transient overshoot impedance for ease of integration. 3.0V to 5.25V supply The F1978 DSA has RF performance identical to the F1975 1.8V or 3.3V control logic Digital Step Attenuator. The difference between the F1978 and F1975 is that the F1978 has an additional programming mode Attenuator step error: 0.1dB at 1GHz called Direct Serial Programming. Consult the Programming Low insertion loss: 1.2dB at 1GHz section of this datasheet or the application note AN-945 Ultra-linear IIP3: +64dBm Comparison of F1975 and F1978 Digital Step Attenuator IIP2: +125dBm typical Serial Programming Methods. Stable integral non-linearity over temperature Low current consumption: 550A typical Bi-directional Advantages Operating temperature: -40C to +105C Digital step attenuators are used in receivers and transmitters to 4mm 4mm, 20-TQFN package provide gain control. The F1978 is a 6-bit step attenuator optimized for these demanding applications. The silicon design has very low insertion loss and low distortion (+64dBm IIP3). The device has pinpoint attenuation accuracy. Most importantly, the F1978 TM Block Diagram includes IDTs Glitch-Free technology, which results in low over- shoot and ringing during most significant bit (MSB) transitions. Figure 1. Block Diagram TM Glitch-Free technology protects the power amplifier or analog-to-digital converter (ADC) from damage during transitions between attenuation states TM Glitch-Free Extremely accurate attenuation levels Ultra-low distortion Low insertion loss for best signal-to-noise ratio (SNR) RF2 RF1 Allows direct serial programming of attenuation SPI Decoder Bias Typical Applications CATV infrastructure CATV set-top boxes CATV satellite modems Data network equipment Fiber networks 2017 Integrated Device Technology, Inc. 1 Rev O August 28, 2017 V DD V MODE D 5:0 DATA CLK LEF1978 Datasheet Pin Assignments Figure 2. Pin Assignments for 4mm 4mm 0.75mm, 20-TQFN Package Top View (Through Package) 20 19 18 17 16 15 D5 1 D4 RF1 2 14 RF2 3 13 DATA Exposed Pad V MODE 4 12 CLK NC 5 11 LE GND 6 7 8 9 10 2017 Integrated Device Technology, Inc. 2 Rev O August 28, 2017 V DD D0 D1 NC NC NC NC D2 GND D3