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Document No. 70-0162-03 │ www.psemi.com ©2005 Peregrine Semiconductor Corp. All rights reserved.
20 Lead 4x4 mm QFN
The PE4308 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 PE430x 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
PE4308 exhibits very low insertion loss and low power
consumption. This functionality is delivered in a 4x4 mm QFN
footprint.

The PE4308 is manufactured on Peregrine’s UltraCMOS™
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.
Product Specification
75 Ω RF Digital Attenuator
5-bit, 31 dB, DC – 4.0 GHz
Product Description
Figure 1. Functional Schematic Diagram
PE4308
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 PE430x series
• Packaged in a 20 Lead 4x4 mm QFN
Table 1. Electrical Specifications @ +25°C, V
DD
= 3.0 V
Notes: 1. Device Linearity will begin to degrade below 1 MHz
2. Figures on Pages 2 to 4 for data across frequency.
3. Note Absolute Maximum in Table 3.
4. Measured in a 50 Ω system.
Control Logic Interface
Parallel Control
Power-Up Control
Serial Control
RF Input RF Output
Switched Attenuator Array
5
3
2
Parameter Test Conditions Frequency Minimum Typical Maximum Units
Operation Frequency DC 2000 MHz
Insertion Loss
2
DC ≤ 1.2 GHz - 1.4 1.95 dB
Attenuation Accuracy
Any Bit or Bit
Combination
DC ≤ 1.2 GHz - -
±(0.2 + 4% of atten setting)
Not to Exceed +0.4 dB
dB
dB
1 dB Compression3,4 1 MHz ≤ 1.2 GHz 30 34 - dBm
Input IP3
1,2,4

Two-tone inputs up to
+18 dBm
1 MHz ≤ 1.2 GHz - 52 - dBm
Return Loss DC ≤ 1.2 GHz 10 13 - dB
Switching Speed
50% control to 0.5 dB
of final value
- - 1 µs
Figure 2. Package Type