RFSA2524
RFSA2524
Serial Controlled Digital
Step Attenuator 50MHz to
4000MHz, 5Bit, 1dB LSB
SERIAL CONTROLLED DIGITAL STEP ATTENUATOR
50MHz TO 4000MHz, 5-BIT, 1dB LSB
Features
GND
1
Frequency Range 50MHz to
4000MHz
VDD
2

5-Bits, 31dB Range, 1dB Step
GND

High Linearity, IIP3 >48dBm

DATA
NC
LE
CLK
PUP
NC
Package: MCM, 24-Pin, 4.2mm x 4.2mm
24
23
22
21
20
19
18
GND
17
GND
3
16
GND
RF1
4
15
RF2
3V and 5V Logic Compatible
GND
5
14
GND

Serial-to-Parallel Controller
GND
6
13
GND

Serial Programming Interface

Power-up Programming Modes


On-chip ESD Protection Class 1C
HBM
Single Supply, 3V to 5V Operation
Functional Block Diagram



Transceiver RF and IF
Applications
Cellular, PCS, GSM, UMTS, LTE,
WiMax/WiFi
12
GND
9
Applications
11
GND
8
Footprint Compatible with Most
24-Pin, 4mm x 4mm, QFNs
10
GND
7
GND

5-Bit DSA
GND

SPI
GND

Product Description
RFMD's RFSA2524 is a 5-bit digital step attenuator (DSA) that features high linearity over the entire 31dB gain control range with excellent step accuracy in 1dB
steps. The RFSA2524 is programmed via a serial mode control interface that is
both 3V and 5V compatible. The RFSA2524 also offers a rugged Class 1C HBM ESD
rating via on-chip ESD circuitry. The MCM package is footprint compatible with most
24-pin, 4mm x 4mm, QFN packages.
Wireless Data, Satellite
Terminals
Test Equipment
Ordering Information
RFSA2524SR
RFSA2524SQ
RFSA2524TR7
RFSA2524TR13
RFSA2524PCK-410
7” reel with 100 pieces
Sample bag with 25 pieces
7” reel with 750 pieces
13” reel with 2500 pieces
50MHz to 4000MHz PCBA with 5-piece sample bag
Optimum Technology Matching® Applied
GaAs HBT
GaAs MESFET
InGaP HBT
SiGe BiCMOS
Si BiCMOS
SiGe HBT
GaAs pHEMT
Si CMOS
GaN HEMT
BiFET HBT
Si BJT
RF MICRO DEVICES®, RFMD®, Optimum Technology Matching®, Enabling Wireless Connectivity™, PowerStar®, POLARIS™ TOTAL RADIO™ and UltimateBlue™ are trademarks of RFMD, LLC. BLUETOOTH is a trademark owned by Bluetooth SIG, Inc., U.S.A. and licensed for use by RFMD. All other trade names, trademarks and registered trademarks are the property of their respective owners. ©2012, RF Micro Devices, Inc.
DS120510
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
1 of 12
RFSA2524
Absolute Maximum Ratings
Parameter
Supply Voltage
Rating
Unit
+5.5
V
DC Supply Current
15
mA
Power Dissipation
83
mW
28.3
dBm
Operating Temperature (TCASE)
-40 to +85
°C
Storage Temperature
-40 to +150
°C
Junction Temperature
150
°C
Max RF Input Power
ESD Rating (HBM)
Frequency Range
The information in this publication is believed to be accurate and reliable. However, no
responsibility is assumed by RF Micro Devices, Inc. ("RFMD") for its use, nor for any
infringement of patents, or other rights of third parties, resulting from its use. No
license is granted by implication or otherwise under any patent or patent rights of
RFMD. RFMD reserves the right to change component circuitry, recommended application circuitry and specifications at any time without prior notice.
RFMD Green: RoHS compliant per EU Directive 2002/95/EC, halogen free
per IEC 61249-2-21, < 1000ppm each of antimony trioxide in polymeric
materials and red phosphorus as a flame retardant, and <2% antimony in
solder.
Class 1C
Moisture Sensitivity Level
Parameter
Caution! ESD sensitive device.
Exceeding any one or a combination of the Absolute Maximum Rating conditions may
cause permanent damage to the device. Extended application of Absolute Maximum
Rating conditions to the device may reduce device reliability. Specified typical performance or functional operation of the device under Absolute Maximum Rating conditions is not implied.
MSL3
Min.
Specification
Typ.
50
Insertion Loss
Gain Control Range
Max.
4000
Unit
MHz
0.68
dB
50MHz, 0dB attenuation
0.79
dB
500MHz, 0dB attenuation
0.89
dB
850MHz, 0dB attenuation
1.26
dB
2100MHz, 0dB attenuation
1.42
dB
2700MHz, 0dB attenuation
2.11
dB
4000MHz, 0dB attenuation
1dB step size
31
dB
Step Accuracy
±(0.1 + 5.0% attenuation setting)
dB
Input IP3
48
Input P0.5dB
Condition
50
dBm
50MHz to 3000MHz, Min. 48dBm 8dB Bit
26
dBm
50MHz to 100MHz, all states
28
dBm
Input Return Loss
29
dB
50MHz to 2700MHz, all states
17
dB
2700MHz to 4000MHz, all states
Output Return Loss
28
dB
50MHz to 2700MHz, all states
22
dB
2700MHz to 4000MHz, all states
5-bit, Serial
bit
Serial interface
200
ns
tRISE, tFALL (10%/90% RF)
ns
tON, tOFF (50% CTL to 10%/90% RF)
V
Typical performance based on 5V operation.
Control Interface
Settling Time
Switching Speed
Supply Voltage (VDD)
Supply Current
Control Voltage (VCTL)
200
4.75
5.0
5.5
5.25
150MHz to 2500MHz, all states
mA
Low, VCTL = 0V to 0.8V
V
High, VCTL = 2.0V to VDD
V
Notes:
1. VDD = 5V, VCTL = 5V, T = 25°C
2. IIP3 measured with PIN = +12dBm/tone, 1MHz spacing
2 of 12
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
DS120510
RFSA2524
Parameter
Frequency Range
Min.
Specification
Typ.
50
Insertion Loss
Gain Control Range
Max.
4000
Unit
Condition
MHz
0.75
dB
50MHz, 0dB attenuation
0.87
dB
500MHz, 0dB attenuation
0.97
dB
850MHz, 0dB attenuation
1.35
dB
2100MHz, 0dB attenuation
1.52
dB
2700MHz, 0dB attenuation
2.23
dB
4000MHz, 0dB attenuation
1dB step size
31
dB
±(0.1 + 5.0% attenuation setting)
dB
35
dBm
50MHz to 100MHz
50
dBm
100MHz to 3000MHz, Min. 46dBm 8dB Bit
and 16dB Bit
19
dBm
50MHz to 100MHz, all states
21
dBm
Input Return Loss
28
dB
50MHz to 2700MHz, all states
17
dB
2700MHz to 4000MHz, all states
Output Return Loss
27
dB
50MHz to 2700MHz, all states
22
dB
2700MHz to 4000MHz, all states
Serial interface
Step Accuracy
Input IP3
46
Input P0.5dB
Control Interface
150MHz to 2500MHz, all states
5-bit, Serial
bit
Settling Time
200
ns
tRISE, tFALL (10%/90% RF)
Switching Speed
200
ns
tON, tOFF (50% CTL to 10%/90% RF)
V
Typical performance based on 3V operation.
Supply Voltage (VDD)
Supply Current
Control Voltage (VCTL)
2.8
3.0
3.3
5.2
mA
Low, VCTL = 0V to 0.8V
V
High, VCTL = 2.0V to VDD
V
Notes:
1. VDD = 3V, VCTL = 3V, T = 25°C
2. IIP3 measured with PIN = +12dBm/tone, 1MHz spacing
DS120510
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
3 of 12
RFSA2524
Typical Performance at 5V VDD - Broadband Application Circuit
Insertion Loss versus Frequency
Normalized Attenuation versus Frequency
2.5
0
-5
-10
Attenuation (dB)
Insertion Loss (dB)
2.0
1.5
1.0
-20
-25
-40°C
0.5
-15
8dB
16dB
31dB
-30
0.0
-35
0
1,000
2,000
Frequency (MHz)
3,000
4,000
0
Input Return Loss versus Frequency
1000
2000
Frequency (MHz)
3000
4000
Output Return Loss versus Frequency
45
50
40
35
1dB
4dB
16dB
40
Output Return Loss (dB)
0dB
2dB
8dB
31dB
45
Input Return Loss (dB)
2dB
4dB
25°C
85°C
30
25
20
15
35
30
25
20
15
10
10
5
5
0
0dB
2dB
8dB
31dB
1dB
4dB
16dB
0
0
1000
2000
Frequency (MHz)
3000
0
4000
1000
Relative Phase versus Frequency
1dB
2dB
4dB
8dB
16dB
31dB
3000
4000
1.00
0.75
Worst Case Step Error (dB)
40
2000
Frequency (MHz)
Worst Case Step Error Between
Successive States
50
Relative Phase (Deg)
1dB
30
20
10
0
0.50
0.25
0.00
-0.25
-0.50
-0.75
-10
-1.00
0
4 of 12
1000
2000
Frequency (MHz)
3000
4000
0
1000
2000
Frequency (MHz)
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
3000
4000
DS120510
RFSA2524
Typical Performance at 5V VDD - Broadband Application Circuit
Major Step Error versus Frequency
Step Error versus Attenuation
1.00
1.0
0.8
0.75
0.6
0.50
50MHz
400MHz
1000MHz
2000MHz
3000MHz
4000MHz
Step Error (dB)
Step Error (dB)
0.4
0.25
0.00
-0.25
-0.50
-0.75
0.2
0.0
-0.2
-0.4
1dB
2dB
4dB
8dB
-0.6
16dB
31dB
-0.8
-1.00
-1.0
0
1000
2000
Frequency (MHz)
4000
3000
0
Input IP3 versus Frequency
4
8
12
16
20
Attenuation (dB)
24
32
28
Input P0.5dB versus Frequency
35
60
55
Input P0.5dB (dB)
Input IP3 (dBm)
30
50
45
40
35
0dB
1dB
2dB
4dB
8dB
16dB
25
0dB
1dB
2dB
4dB
8dB
16dB
20
31dB
30
15
0
DS120510
500
1000
1500
2000
Frequency (MHz)
2500
3000
0
500
1000
1500
Frequency (MHz)
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
2000
2500
5 of 12
RFSA2524
Typical Performance at 3V VDD - Broadband Application Circuit
Insertion Loss versus Frequency
Normalized Attenuation versus Frequency
2.5
0
-5
-10
Attenuation(dB)
Insertion Loss (dB)
2.0
1.5
1.0
-20
-25
-40°C
0.5
-15
8dB
16dB
31dB
-30
0.0
-35
0
1,000
2,000
Frequency (MHz)
3,000
4,000
0
Input Return Loss versus Frequency
45
40
40
35
35
30
25
20
15
10
5
0dB
1dB
2dB
4dB
8dB
16dB
1000
2000
Frequency (MHz)
3000
4000
Output Return Loss versus Frequency
45
Output Return Loss (dB)
Input Return Loss (dB)
2dB
4dB
25°C
85°C
30
25
20
15
0dB
2dB
8dB
31dB
10
5
31dB
0
1dB
4dB
16dB
0
0
1000
2000
Frequency (MHz)
3000
0
4000
1000
Relative Phase versus Frequency
1dB
2dB
4dB
8dB
16dB
31dB
3000
4000
1.00
0.75
Worst Case Step Error (dB)
40
2000
Frequency (MHz)
Worst Case Step Error Between
Successive States
50
Relative Phase (Deg)
1dB
30
20
10
0
0.50
0.25
0.00
-0.25
-0.50
-0.75
-10
-1.00
0
6 of 12
1000
2000
Frequency (MHz)
3000
4000
0
1000
2000
Frequency (MHz)
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
3000
4000
DS120510
RFSA2524
Typical Performance at 3V VDD - Broadband Application Circuit
Major Step Error versus Frequency
Step Error versus Attenuation
1.00
1.0
0.8
0.75
0.6
0.50
Step Error (dB)
Step Error (dB)
0.4
0.25
0.00
-0.25
-0.50
-0.75
0.2
0.0
-0.2
1dB
2dB
-0.4
50MHz
400MHz
4dB
8dB
-0.6
1000MHz
2000MHz
16dB
31dB
-0.8
3000MHz
4000MHz
-1.00
-1.0
0
1000
2000
Frequency (MHz)
4000
3000
0
Input IP3 versus Frequency
4
8
12
16
20
Attenuation (dB)
24
28
32
Input P0.5dB versus Frequency
35
60
55
Input P0.5dB (dB)
Input IP3 (dBm)
30
50
45
40
35
0dB
1dB
2dB
4dB
8dB
16dB
25
0dB
1dB
2dB
4dB
8dB
16dB
20
31dB
30
15
0
DS120510
500
1000
1500
2000
Frequency (MHz)
2500
3000
0
500
1000
1500
Frequency (MHz)
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
2000
2500
7 of 12
RFSA2524
Serial Port Interface
SPI Timing Diagram
Programming Example - 5-Bit
t6
t1
t2
t3
t4
t8
t5
CLK
CLK
DATA
DATA
MSB
D4
D3
D2
LSB
D0
D1
t7
LE
LE
t9
DOUT
t10
Truth Table
Control Bits
C16
C8
C4
C2
C1
Relative Gain
Setting
1
1
1
1
1
Max gain
1
1
1
1
0
-1dB
1
1
1
0
1
-2dB
1
1
0
1
1
-4dB
1
0
1
1
1
-8dB
0
1
1
1
1
-16dB
0
0
0
0
0
-31dB
SPI Timing Diagram Specifications
Parameter
Limit
Unit
Comment
t1
25
MHz max
CLK Frequency
State
Logic
t2
20
ns min
CLK High
Low
0V to 0.8V
t3
20
ns min
CLK Low
High
2.0V to 5.0V
t4
5
ns min
DATA to CLK Setup Time
t5
5
ns min
DATA to CLK Hold Time
t6
30
ns min
Data Valid
PUP
Attenuator Setting
t7
5
ns min
LE to CLK Setup Time
Low
Attenuation at max, 31dB
t8
5
ns min
CLK to LE Setup Time
High
Attenuation at min, 0dB
t9
10
ns min
LE Pulse Width
t10
20
ns max
Output Set
8 of 12
Logic Voltage Levels
Power-up Programming Truth Table
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
DS120510
RFSA2524
Evaluation Board Schematic
Evaluation Board Bill of Materials (BOM)
Description
Reference
Designator
Manufacturer
RFSA2524
U1
RFMD
RFSA2524
CAP, 1nF, 10%, 10V, X5R, 0402
C7
Taiyo Yuden (USA), Inc.
RM UMK105BJ102KV-F
C11-C12
Murata Electronics
GRM155R71E103KA01D
R1-R2, R4-R5, R8
Kamaya, Inc
RMC1/16SJPTH
Millimeter Wave Technologies,
LLC
MW-846-F-DD-75
Evaluation Board
Manufacturer’s P/N
SA2714410(A)
CAP, 10000pF, 10%, 25V, X7R, 0402
RES, 0Ω, 5%, 1/16W, 0402
DNP
R3, R6-R7, R9
DNP
C1-C6, C8-C9, C13-C20
CONN, F FEM EDGE MOUNT, 75Ω, 0.035"
DNP
J1-J2
J99-J100
CONN, HDR, ST, PLRZD, 9-PIN
P1
ITW Pancon
MPSS100-9-C
CONN, SKT, 24-PIN DIP, .600", T/H
P2
Aries Electronics Inc.
24-6518-10
DS120510
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
9 of 12
RFSA2524
Evaluation Board Assembly Drawing
10 of 12
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
DS120510
RFSA2524
Pin Names and Descriptions
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Name
GND
VDD
GND
RF1
GND
GND
GND
GND
GND
GND
GND
GND
GND
GND
RF2
GND
GND
GND
NC
PUP
21
22
23
24
EPAD
CLK
LE
NC
DATA
GND
DS120510
Description
Connect to Low Inductance Path to Ground
Power Supply
Connect to Low Inductance Path to Ground
RF port. External DC block required
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
RF port. External DC block required.
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
Connect to Low Inductance Path to Ground
No internal connection. EVB can be ground or no connect
Power-up Programming pin
Low = max attenuation (31dB) at power-up
High = min attenuation (0dB) at power-up
Serial Clock
Latch Enable
No internal connection; EVB can be ground or no connect
Serial Data
DC and RF Ground; Must be soldered to EVB ground plane over a bed of vias for thermal and RF performance.
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
11 of 12
RFSA2524
Package Drawing
Branding Diagram
12 of 12
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at (+1) 336-678-5570 or customerservice@rfmd.com.
DS120510