PE4308-02 - Peregrine Semiconductor Corp.

Document No. 70-0162-04 www.psemi.com

Page 1 of 11

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

prov ides both par al lel (l atc hed or dir ec t mod e) an d seri al

CMOS control interface, operates on a single 3-volt supply and

mai ntains hig h atte nu ati o n acc uracy over fr eq ue n c y 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™

pro c ess, a patented variation of silicon-o n-insulator (SOI )

technology on a sapphire substrate, offering the performance

of GaAs with the econom y and i nte gr ation of conventi on al

CMOS.

Pro duct Specificat ion

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

• Hi gh att en uation acc urac y and li n ear i ty

over temperature and frequency

• Very low power consumption

• Single-sup pl y op er ation

• 75  impedance

• Pin compatible with PE430x series

• Packaged in a 20 Lead 4x4 mm QFN

Table 1. Electrical Specifications @ +25°C, VDD = 3.0 V

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  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

Inser t io n Los s2 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 sett ing)

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- t on e in put s up to

+18 dBm 1 MHz  1.2 GHz - 52 - dBm

Return Loss DC  1.2 GHz 10 13 - dB

Switching Speed 50% co nt r ol t o 0. 5 dB

of final value - - 1 µs

Fig ur e 2. Pa ck ag e Typ e

Product Specification

PE4308

Page 2 of 11

Table 2 . Pin Descriptions

Electrostatic Discharge (ESD) Precautions

When handling this UltraCMOS™ device, observe

the same precautions that you would use with other

ESD-sensitive devices. Although this device

contains circuitry to protect it from damage due to

ESD, precautions should be taken to avoid

exceeding the rate specified in Table 3.

Expose d Solder Pad Connection

The exposed solder pad on the bottom of the

package must be grounded for proper device

operation.

Notes: 1: B o th R F ports mus t be he ld at 0 VDC or DC blocked with an

external series capacitor.

2: Latc h E na bl e ( LE) has an interna l 10 0 k resistor to VDD.

3: Connect pin 12 to GND to enable internal negative voltage

generator. Connect pin 12 to VSS (-VDD) to bypass and

disable internal negative voltage generator.

4. Place a 10 k resistor in series, as close to pin as possible

to avoid frequency resonance. See “Resistor on Pin 1 & 3”

paragraph

Figure 14. Pin Configurati on (Top View)

Latc h-Up Avoidance

Unlike conv entio na l CMOS de v ic es, UltraCMOS™

devices are immune to latch-up.

Swi tc hing Frequency

The PE4308 has a maximum 25 kHz switching rate.

Resi st o r on Pin 1 & 3

A 10 k resistor on the inputs to Pin 1 & 3 (see

Figure 5) will eliminate pack age resonan c e be tween

the RF input pin and the two digital inputs. Specified

attenuation error versus frequency performance is

dependent upon this condition.

VDD

PUP1

PUP2

VDD

GND

1

20

19

18

17

16

15

14

13

12

11

6

7

8

9

10

2

3

4

5

C16

RF1

Data

Clock

LE GND

Vss/GND

P/S

RF2

C8

C4

C2

GND

C1

N/C

20-lead

QFN

4x4mm

Exposed Solder Pad

No. Pin

Name Description

1 C16 Attenuation control bit, 16dB (Note 4).

2 RF1 RF port (Note 1).

3 Data Serial interface data input (Note 4).

4 Clock Serial interface clock input.

5 LE Latch Enable input (Note 2).

6 VDD Power supply pin.

7 PUP1 Power-up selection bit.

8 PUP2 Power-up selection bit.

9 VDD Power supply pin.

10 GND Ground connection.

11 GND Ground connection.

12 Vss/GND Negative supply voltage or GND

conn ecti on ( Note 3)

13 P/S Parallel/Serial mode select.

14 RF2 RF port (Note 1).

15 C8 Attenuation control bit, 8 dB.

16 C4 Attenuation control bit, 4 dB.

17 C2 Attenuation control bit, 2 dB.

18 GND Ground connection.

19 C1 Attenuation control bit, 1 dB.

20 N/C No connect

Pad dl e G N D Ground for proper op er a tion

Table 3. Absolute Maximum Ratings

Table 4. Operating Ranges

Symbol Parameter/Conditions Min Max Units

VDD Power supply voltage -0.3 4.0 V

VI Voltage on any input -0.3 VDD+

0.3 V

TST Storage temperature range -65 150 °C

PIN Input po wer (5 0) +30 dBm

VESD ESD voltage (Human Body

Model) 500 V

Parameter Min Typ Max Units

VDD Power Supply

Voltage 2.7 3.0 3.3 V

IDD Power Supply

Current 100 µA

Digital Input High 0.7xVDD V

Digital Input Low 0.3xVDD V

Digital Input Leakage 1 µA

Input Pow er +24 dB m

Temperature range -40 85 °C

Product Specification

PE4308

Document No. 70-0162-04 www.psemi.com

Page 3 of 11

Evaluation Kit

The Digital Attenuator Evaluation Kit was designed to

ease customer ev aluation of the PE 4308 DS A.

J9 is used in c onjunction with t he supplied DC cable to

supply VDD, GND, and –VDD. If use of the internal

negative voltage generator is desired, then connect

–VDD (black banana plug) t o ground. I f an ex ternal –V DD

is desir ed, then apply - 3 V.

J1 should be connected to the LPT1 port of a PC with

the supplied control cable. The evaluation software is

written to operate the DSA in serial mode, so switch 7

(P/S) on the DIP switch SW1 should be ON with all

other switches off. Using the software, enable or

disable each attenuation setting to the desired

combined attenuation. The software automatically

programs the DSA each time an attenuation state is

enabled or disabled. Note: Jumper J6 supplies power

to t he ev aluation board suppor t circ uits.

To evaluate the power up options, first disconnect the

control cable from the evaluation board. The control

cable must be removed to prevent the PC port from

biasing the c ontrol pins.

During power up wit h P/ S=1 high and LE= 1, the default

power-up signal attenuation is set to the value present

on the five control bits on the five parallel data inputs

(C1 to C16). This allows any one of the 32 attenuation

settings t o be specif ied as the power-up state.

During power up wit h P/ S=0 high and LE= 0, the control

bits ar e automatically set to one of four possible values

presented through the PUP interface. These four

values are selected by the two power-up control bits,

PUP1 and PU P 2, as s hown in the Table 6.

Pin 20 is open and c an be c onnec ted to any bias.

Note: Res i s tors on pins 1 and 3 are

required and s hould be plac ed as close

to t he part as possible t o avoid pack age

resonanc e and m eet error s pec ifications

over frequency.

Figure 4. Evaluation Board Layout

Figure 5. Evaluation Board Schematic

Peregr ine S pec ification 101/0112

Peregr ine S pec ification 102/0142

Product Specification

PE4308

Page 4 of 11

-50

-40

-30

-20

-10

0

0 500 1000 1500 2000

Output Return Loss (dB)

RF Frequency (MHz)

-50

-40

-30

-20

-10

0

0 500 1000 1500 2000

Input Return Loss (dB)

RF Frequency (MHz)

31dB

16dB

8dB

0

5

10

15

20

25

30

35

0 500 1000 1500 2000

Attenuation (dB)

RF Frequency (MHz)

31dB

16dB

8dB

4dB

2dB 1dB

-5

-4

-3

-2

-1

0

0 500 1000 1500 2000

Insertion Loss (dB)

RF Frequency (MHz)

Typical Pe rformance Data (25°C, VDD = 3.0 V unless otherwise noted)

Fig ure 7. At t enu at ion at Majo r st ep s

Figure 9. Output Return Loss at Majo r

Attenuation S teps (Zo=75 ohms)

Figure 8. Input Return Loss at Major

Attenuation S teps (Zo=75 ohms)

Figure 6. Insertion Loss (Zo=75 ohms)

Product Specification

PE4308

Document No. 70-0162-04 www.psemi.com

Page 5 of 11

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 5 10 15 20 25 30 35

Attenuation Error (dB)

Attenuation Setting (dB)

500MHz, -40C

500MHz, 85C

500MHz, 25C

-2

-1.5

-1

-0.5

0

0.5

0 500 1000 1500 2000

Attenuation Error (dB)

RF Frequency (MHz)

31dB

16dB

8dB

2dB

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 5 10 15 20 25 30 35

Attenuation Error (dB)

Attenuation Setting (dB)

1GHz, -40C

1GHz, 85C

1GHz, 25C

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 5 10 15 20 25 30 35

Attenuation Error (dB)

Attenuation Setting (dB)

10MHz, -40C

10MHz, 85C

10MHz, 25C

Figure 11. Attenuation Error Vs. Attenuation

Setting

Figure 13. Attenuation Error Vs. Attenuation

Setting

Figure 12. Attenuation Error Vs. Attenuation

Setting

Figure 10. Attenuation Error Vs. Frequency

Typical Pe rformance Data (25°C, VDD = 3.0 V unless otherwise noted)

Note: Positive att enuation error indicates higher attenuation than target value

Product Specification

PE4308

Page 6 of 11

20

25

30

35

40

45

50

55

60

0 500 1000 1500 2000

IIP3 (dBm)

RF Frequency (MHz)

0

5

10

15

20

25

30

35

40

0 500 1000 1500 2000

1dB Compression (dBm)

RF Frequency (MHz)

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 5 10 15 20 25 30 35

Attenuation Error (dB)

Attenuation Setting (dB)

1.2GHz, -40C

1.2GHz, 85C

1.2GHz, 25C

Figure 15. Input 1 dB Compression (Zo=50 ohms)

Figure 16. Input IP3 (Zo=50 ohms)

Figure 14. Attenuation Error vs. Attenuation

Setting

Typical Pe rformance Data (25°C, VDD = 3.0 V unless otherwise noted)

Note: Positive att enuation error indicates higher attenuation than target value

Product Specification

PE4308

Document No. 70-0162-04 www.psemi.com

Page 7 of 11

Programming Options

Parallel/Serial Sele c tion

Either a parallel or serial interface can be used to

control the PE4308. The P/S bit provides this

selection , with P/S=LOW selecting the pa rallel

interface and P/S=HIGH selecting the serial

interface.

Parallel Mode Interface

The parallel interface consists of five CMOS-

compatible control lines that select the desired

attenuation state, as shown in Table 5.

The parallel interface timing requirements are

defined by Figure 19 (Parallel Interface Timing

Diagram), Table 9 (Parallel Interface AC

Characteristics), and switching speed (Table 1).

For latched parallel programming the Latch Enable

(LE) should be held LOW while changing attenuation

state control values, then pulse LE HIGH to LOW

(per Figure 19) to latch new attenuation state into

device.

For direct parallel programming, the Latch Enable

(LE) line should be pulled HIGH. Changing

at tenu ation state control value s will c hange device

state to new attenuation. Direct Mode is ideal for

manual control of the device (using hardwire,

switches, or jumpers).

Table 5. Truth Table

Serial Interface

The PE4308’s serial interface is a 6-bit serial-in,

parallel-out shift register buffered by a transparent

latch. The latch is controlled by three CMOS-

compatible signals: Data, Clock, and Latch Enable

(LE). The Data and Clock inputs allow data to be

serially entered into the shift register, a process that

is independent of the state of the LE input.

The LE input controls the latch. When LE is HIGH,

the latch is transparent and the contents of the serial

shift register control the attenuator. When LE is

brought LOW, data in the shift register is latched.

The shift register should be loaded while LE is held

LOW to prevent the attenuator value from changing

as data is entered. The LE input should then be

toggled HIGH and brought LOW again, latching the

new data. The stop bit (B0) of the data should

always be low to prevent an unknown state in the

device. The timing for this operation is defined by

Figure 17 (Serial Interface Timing Diagram) and

Table 8 (Serial Interface AC Characteristics).

Power-up Control Settings

The PE4308 always assumes a specifiable

attenuation setting on power-up. This feature exists

for both the Serial and Parallel modes of operation,

and allows a known attenuation state to be

established before an initial serial or parallel control

word is provided.

When the attenuator powers up in Serial mode (P/

S=1), the five control bits and a stop bit are set to

whatever data is present on the five parallel data

inputs (C1 to C16). This allows any one of the 32

attenuation settings to be specified as the power-up

state.

When the attenuator powers up in Parallel mode (P/

S=0) with LE=0, the control bits are automatically set

to one of four possible values. These four values

are selected by the two power-up control bits, PUP1

and PUP2, as shown in Table 6 (Power-Up Truth

Table, Parallel Mode).

Table 6. Power-Up Truth Table, Parallel

Interface Mode

Note: Power up with LE=1 provides normal parallel operation

with C1-C16, and PUP1 and PUP2 are not active.

P/S LE PUP2 PUP1 Attenuation State

0 0 0 0 Reference Loss

0 0 0 1 8 dB

0 0 1 0 16 dB

0 0 1 1 31 dB

0 1 X X Defi ned by C1-C16

P/S C16 C8 C4 C2 C1 Attenuation State

0 0 0 0 0 0 Reference Loss

0 0 0 0 0 1 1 dB

0 0 0 0 1 0 2 dB

0 0 0 1 0 0 4 dB

0 0 1 0 0 0 8 dB

0 1 0 0 0 0 16 dB

0 1 1 1 1 1 31 dB

Note: Not all 32 possible combinations of C1-C16 are shown.

Product Specification

PE4308

Page 8 of 11

B5 B4 B3 B2 B1 B0

C16C8C4C2C1 0

↑↑

LSB (last in)MSB (first in)

Table 7. 5-Bit Attenuator Serial Programming

Regi ster Map

Table 9. Pa rallel Interface AC Characteristics

Figure 18. Parallel Interface Timing Diagram

Table 8. Serial Interface AC Characteristics

Figure 17. Serial Interface Timing Diagram

VDD = 3.0 V, -40° C < TA < 85° C, un le ss othe rw is e spe cified VDD = 3.0 V, -40° C < TA < 85° C, un le ss othe rw is e spe cified

Note: The stop bit (B0) must always be low to prevent the attenuator

from entering an un known state.

Note: fClk is verified during the functional pattern test. Serial

programming sections of the functional pattern are clocked

at 10 MHz to verify fclk specification.

t

PDSUP

t

PDHLD

LE

t

LEPW

Parallel Data

C16:C1

LE

Clock

Data MSB LSB

t

LESU P

t

SDSUP

t

SDHL D

t

LEPW

Symbol Parameter Min Max Unit

fClk Serial data clock

frequency (Note 1) 10 MHz

tClkH Serial clock HIGH time 30 ns

tClkL Serial clock LOW time 30 ns

tLESUP LE se t-up time after last

clock fa lling edge 10 ns

tLEPW LE mi ni mum p uls e w id th 30 ns

tSDSUP Seri al d ata set- up ti me

before clock rising edge 10 ns

tSDHLD S erial data hold time

after clock falling edge 10 ns

Symbol Parameter Min Max Unit

tLEPW LE mi ni mum p uls e w id th 10 ns

tPDSUP Data set-up time before

ris in g ed ge of LE 10 ns

tPDHLD D ata hold time after

falling edge of LE 10 ns

Product Specification

PE4308

Document No. 70-0162-04 www.psemi.com

Page 9 of 11

Figure 19. Package Drawing

1.00

2.00

0.23

0.10 C A B

EXPOSED PAD

4.00

DETAIL A

16

15

115

1

6

20

10

0.50 TYP

2.00 TYP

0.55

2

1

DETAIL A

0.18

0.435

SEATING

PLANE

0.08 C

0.10 C

0.020

0.20 REF

EXPOSED PAD &

TERMINAL PADS

0.80

- C -

2.00 X 2.00

2.00

4.00

- B -

- A -

INDEX AREA

0.25 C

1. Dimension applies to metallized terminal and is measured

between 0.25 and 0.30 from terminal tip.

2. Coplanarity applies to the exposed heat sink slug as well as the

terminals.

3. Dimensions are in millimeters.

Product Specification

PE4308

Page 10 of 11

Figure 20. Marking Specifications

Figure 21. Tape and Reel Drawing

4308

YYWW

ZZZZZ

YYWW = Dat e Code

ZZZZZ = Last five digits of PSC Lot Number

Table 10. Ordering Information

Or der Code Part Marking Description Package Shipping Method

4308-01 4308 PE4308-20MLP 4x4mm-75A 20-lead 4x4 mm QFN 75 units / Tube

4308-02 4308 PE4308-20MLP 4x4mm-3000C 20-lead 4x4 mm QFN 3000 units / T&R

4308-00 PE4308-EK PE4308-20MLP 4x4mm-EK Evaluation Kit 1 / Box

4308-51 4308 PE4 308G -2 0M LP 4x 4 m m-75A Gr ee n 20-l ead 4x 4 m m QFN 75 unit s / Tube

4308-52 4308 PE430 8G -20M LP 4x 4m m-300 0C Gr ee n 20-l ead 4x 4 m m QFN 30 00 units / T&R

Product Specification

PE4308

Document No. 70-0162-04 www.psemi.com

Page 11 of 11

Sales Offices

The Americas

Peregrine Semiconductor Corporation

9450 Carroll Park Drive

San Diego, CA 92121

Tel: 858-731-9400

Fax: 858-731-9499

North Asia Pacific

Peregrine Semiconductor K.K.

Teiko k u Hote l Tower 10B-6

1- 1-1 Uchisa iwai-c ho, Ch iy oda- k u

Tokyo 100-0011 Japan

Tel: +81-3-3502-5211

Fax: +81-3-3502-5213

Peregrine Semiconductor, Korea

#B-2402, Kolon Tripolis, #210

Geumgok-dong, Bundang- gu, Seongnam-si

Gyeonggi-do, 463-480 S. Korea

Tel: +82-31-728-4300

Fax: +82-31-728-4305

Europe

Peregrine Semiconductor Europe

Bâtiment Maine

13-15 rue des Quatre Vents

F-92380 Garches , France

Tel: +33-1-4741-9173

Fax : +33-1 -4741 -917 3

For a list of represent atives in your ar ea, please r efer to our Web sit e at: www.psemi.com

Data Sheet Identification

Advance Information

The product is in a formative or design st age. The data

sheet contains design target specifications f or product

development. Specif ications and features may change in

any manner without notice.

Preliminary Specification

The data sheet contains preliminary data. Additional data

may be added at a later date. Peregrine reserves t he right

to change specifications at any time without notice in order

to supply t he best possible product.

Product Specification

The data sheet contains final data . In the event Peregrine

dec ide s to cha nge the spe c ific a tions, Peregrine will notify

cust omers of the intended changes by is s u ing a DCN

(Document Change Not ice).

The information in t his data sheet is believed to be reliable.

Howeve r, Peregrine assume s no liabilit y for the use of this

information. Use shall be entir ely at the user’s own r isk.

No patent rights or licenses t o any circuits described in this

data sheet are implied or granted to any third party.

Peregrine’s pr oducts are not designed or int ended for use in

devices or systems intended f or surgical implant, or in other

applications intended t o support or sustain life, or in any

application in which the failure of t he Per egrine product could

create a situat ion in which personal injury or death might occur.

Peregr ine assumes no liability for damages, including

consequential or incidental damages, arising out of the use of

its products in such applications.

The Peregrine name, logo, and UTSi are r egistered tr ademarks

and UltraCMOS and HaRP are tr ademarks of Per egrine

Semiconductor Cor p.

South As ia Pa cific

Peregrine Semiconductor, China

Shanghai, 200040, P.R. China

Tel: +86-21-5836-8276

Fax: +86-21-5836-7652

Spa ce and Defense Products

Americas :

Tel: 858-731-9453

Europe, Asia Pacific:

180 Rue Jean de G uiramand

13852 Aix- En- Provence Cedex 3, France

Tel: +33-4-4239-3361

Fax: +33-4-4239-7227