SP4308 Datasheet, PDF (1/10 Pages) SIPAT Co,Ltd – 75 Ω RF Digital Attenuator

Product Description
The SP4308 is a high linearity, 5-bit RF Digital Step Attenuator
(DSA) covering 31 dB attenuation range in 1dB steps, and is
pin compatible with the SP430x series. This 75-ohm RF DSA
provides both parallel (latched or direct mode) and serial
CMOS control interface, operates on a single 3-volt supply and
maintains high attenuation accuracy over frequency and
temperature. It also has a unique control interface that allows
the user to select an initial attenuation state at power-up. The
SP4308 exhibits very low insertion loss and low power
consumption. This functionality is delivered in a 4x4 mm QFN
footprint.
The SP4308 is manufactured on SIPAT’s CMOS
process, a patented variation of silicon-on-insulator (SOI)
technology on a sapphire substrate, offering the performance
of GaAs with the economy and integration of conventional
CMOS.
Figure 1. Functional Schematic Diagram
RF Input
Switched Attenuator Array
RF Output
Product Specification
SP4308
75 Ω RF Digital Attenuator
5-bit, 31 dB, DC – 4.0 GHz
Features
• Attenuation: 1 dB steps to 31 dB
• Flexible parallel and serial programming
interfaces
• Latched or direct mode
• Unique power-up state selection
• Positive CMOS control logic
• High attenuation accuracy and linearity
over temperature and frequency
• Very low power consumption
• Single-supply operation
• 75 Ω impedance
• Pin compatible with SP430x series
• Packaged in a 20 Lead 4x4 mm QFN
Figure 2. Package Type
20 Lead 4x4 mm QFN
Parallel Control 5
Serial Control ³
Power-Up Control ²
Control Logic Interface
Table 1. Electrical Specifications @ +25°C, V_DD = 3.0 V
Parameter
Test Conditions
Frequency
Minimum
Operation Frequency
DC
Insertion Loss²
DC ≤ 1.2 GHz
-
Attenuation Accuracy
Any Bit or Bit
Combination
DC ≤ 1.2 GHz
-
1 dB Compression3,4
Input IP3^1,2,4
Return Loss
1 MHz ≤ 1.2 GHz
30
Two-tone inputs up to
+18 dBm
1 MHz ≤ 1.2 GHz
-
DC ≤ 1.2 GHz
10
Switching Speed
50% control to 0.5 dB
of final value
-
Notes: 1. Device Linearity will begin to degrade below 1 MHz
2. See figures on Pages 4 to 6 for data across frequency.
3. Note Absolute Maximum in Table 3.
4. Measured in a 50 Ω system.
Typical
1.4
-
34
52
13
-
Maximum
2000
1.95
±(0.2 + 4% of atten setting)
Not to Exceed +0.4 dB
-
-
-
1
Units
MHz
dB
dB
dB
dBm
dBm
dB
µs
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