RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
RF MICRO DEVICES® and RFMD® 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. ©2013, RF Micro Devices, Inc.
1 of 9
RF3931D
30W GaN on SiC Power Amplifier Die
The RF3931D is a 48V, 30W, GaN on SiC high power discrete
amplifier die designed for commercial wireless infrastructure, cellular
and WiMAX infrastructure, industrial/scientific/medical and general
purpose broadband amplifier applications. Using an advanced high
power density Gallium Nitride (GaN) semiconductor process, the
RF3931D is able to achieve high efficiency and flat gain over a broad
frequency range in a single amplifier design with proper packaging and
assembly. The RF3931D is an unmatched 0.5m gate, GaN transistor
die suitable for many applications with > 46.5dBm saturated power,
> 63% drain efficiency, and >14dB small signal gain at 2GHz.
Functional Block Diagram
Ordering Information
RF3931D 30W GaN on SiC Power Amplifier Die
Package: Die
Features
■ Broadband Operation DC to 4GHz
■ Advanced GaN HEMT Technology
■ Packaged Small Signal
Gain = 14dB at 2GHz
■ 48V Typical Packaged
Performance
Output Power: 50W at P3dB
Drain Efficiency: 65% at P3dB
■ Large Signal Models Available
■ Chip Dimensions:
0.96mm x 1.33mm x 0.10mm
■ Active Area Periphery: 6.6mm
Applications
■ Commercial Wireless
Infrastructure
■ Cellular and WiMAX
Infrastructure
■ Civilian and Military Radar
■ General Purpose Broadband
Amplifiers
■ Public Mobile Radios
■ Industrial, Scientific, and
Medical
RF IN
VG
RF OUT
VD
GND
RF3931D
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Absolute Maximum Ratings
Parameter
Rating
Unit
Drain Voltage (VD)
150
V
Gate Voltage (VG)
-8 to +2
V
Gate Current (IG)
23
mA
Operational Voltage
50
V
Storage Temperature Range
-55 to +125
°C
Operating Junction Temperature (TJ)
200
°C
Human Body Model (based on packaged device)
Class 1A
MTTF (TJ < 200°C, 95% Confidence Limits)*
3E + 06
Hours
Thermal Resistance, RTH (junction to case)** measured at TC = 85°C, DC
bias only
3.6
°C/W
Caution! ESD sensitive device.
RFMD Green: RoHS compliant per EU
Directive 2011/65/EU, 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 solder.
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.
Nominal Operating Parameters
Parameter
Specification
Unit
Condition
Min
Typ
Max
Recommended Operating
Conditions
Drain Voltage (VDSQ)
24
48
V
Gate Voltage (VGSQ)
-4.5
-3.5
-2.5
V
Drain Bias Current
130
mA
Frequency of Operation
DC
4000
MHz
Die Capacitance from Packaged
Capacitance Measurements
Package capacitance removed during calibration.
CRSS
4
pF
VG = -8V, VD = 0V
CISS
17
pF
COSS
12
pF
DC Functional Test
IG (ON) - Forward Bias Diode Gate Current
3
mA
VG = 1.1V, VD = 0V
IG (OFF) - Gate Leakage
0.2
mA
VG = -8V, VD = 0V
ID (OFF) - Drain Leakage
0.2
mA
ID (OFF) - 48V Drain Leakage
2.0
mA
VG = -8V, VD = 48V
ID (OFF) - 150V Drain Leakage
4.0
mA
VG = -8V, VD = 150V
VGS (TH) - Threshold Voltage
-4.8
-3.4
-2.5
V
VD = 48V, ID = 6mA
VDS (ON) - Drain Voltage at High Current
0.84
V
VG = 0V, ID = 1.0A
Operation of this device beyond any one of these limits may cause permanent damage. For reliable continuous operation, the device voltage and
current must not exceed the maximum operating values specified above.
*MTTF - Median time to failure as determined by the process technology wear-out failure mode. Refer to product qualification report for FIT (random)
failure rate.
**Thermal resistance assumes AuSn die attach on 1.5mm thick CPC carrier similar to Kyocera A1933. User will need to define this specification in
the final application and ensure bias conditions satisfy the following expression: PDISS < (TJ - TC) / RTH J-C and TC = TCASE to maintain maximum
operating junction temperature and MTTF
Bias Conditions should also satisfy the following expression: PDISS < (TJ – TC) / RTH J-C and TC = TCASE
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Parameter
Specification
Unit
Condition
Min
Typ
Max
RF Typical Performance of
Packaged Die
Test Conditions: CW operation, VDSQ = 48V, IDQ = 130mA,
T = 25°C, in a tuned test circuit.
VGS (Q)
-3.5
V
Small Signal Gain
20
dB
f = 900MHz
14
dB
f = 2140MHz
Output Power at P3dB
47
dBm
f = 900MHz
46.5
dBm
f = 2140MHz
Drain Efficiency at P3dB
65
%
f = 900MHz
63
%
f = 2140MHz
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Typical Performance of (non-internally matched) packaged die in tuned circuit
(T = 25°C, unless noted)
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Typical Performance of (non-internally matched) packaged die in tuned circuit
(T = 25°C, unless noted) (continued)
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Typical Performance of (non-internally matched) packaged die in tuned circuit
(T = 25°C, unless noted) (continued)
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Die Drawing (all dimensions in mm)
Bias Instruction for RF3931D Die
ESD Sensitive Material. Please use proper ESD precautions when handling devices die.
Die must be mounted with minimal die attach voids for proper thermal dissipation.
This device is a depletion mode HEMT and must have gate voltage applied for pinch off prior to applying drain voltage.
1. Mount device on carrier or package with minimal die attach voiding and applying proper heat removal techniques.
2. Connect ground to the ground supply terminal, and ensure that both the VG and VD grounds are also c onnected to this
ground terminal.
3. Apply -8V to VG.
4. Apply 48V to VD.
5. Increase VG until drain current reaches desired bias point.
6. Apply RF input.
External dimension tolerance due to dicing process development.
Detail of Unit Cell
Bond Pad Key
G = Gate
S = Source
D = Drain
Die thickness = 0.101mm
Die backside metal = Au
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Assembly Notes
Die Storage
Individual bare die should be held in appropriately sized ESD waffle trays or ESD GEL packs.
Die should be stored in CDA/N2 cabinets and in a controlled temperature and humidity environment.
Die Handling
Die should only be picked using an auto or semi-automated pick system and an appropriate pick tool.
Pick parameters will need to be carefully defined so not to cause damage to either the top or bottom die surface.
GaN HEMT devices are ESD sensitive materials. Please use proper ESD precautions when handling devices or evaluation
boards.
RFMD does not recommend operating this device with typical drain voltage applied and the gate pinched off in a high
humidity, high temperature environment.
Caution: The use of inappropriate or worn-out ejector needle and improper ejection parameter settings can cause die backside
tool marks or micro-cracks that can eventually lead to die cracking.
Die Attach
There are two commonly applied die attach processes: adhesive die attach and eutectic die attach. Both processes use special
equipment and tooling to mount the die.
EUTECTIC ATTACH
80/20 AuSn preform, 0.5 - 1mil thickness, made from virgin melt gold.
Pulsed heat or die scrub attach process using auto / semi-automatic equipment.
Attach process carried out in an inert atmosphere.
Custom die pick collets are required that match the outline of the die and the specific process employed using either
pulsed, fixed heat, or scrub.
Maximum temperature during die attach should be no greater than 320°C and for less than 30 seconds.
Key parameters that need to be considered include: die placement force, die scrub profile and heat profile.
Minimal amount of voiding is desired to ensure maximum heat transfer to the carrier and no voids should be present
under the active area of the die.
Voiding can be measured using X-ray or Acoustic microscopy.
The acceptable level of voiding should be determined using thermal modeling analysis.
ADHESIVE ATTACH
High thermal silver filled epoxy is dispensed in a controlled manner and die is placed using an appropriate collet.
Assembled parts are cured at temperatures between 150°C and 180°C.
Always refer to epoxy manufacturer's data sheet.
Industry recognized standards for epoxy die attach are clearly defined within MIL-883.
Early Life Screen Conditions
RFMD recommends an Early Life Screen test that subjects this die to TJ = 250°C (junction temperature) for at least 1 hour prior to
field deployment.
RF Micro Devices Inc. 7628 Thorndike Road, Greensboro, NC 27409-9421 DS130906
For sales or technical support, contact RFMD at +1.336.678.5570 or customerservice@rfmd.com.
The information in this publication is believed to be accurate. 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.
RF3931D
Mounting and Thermal Considerations
The thermal resistance provided as RTH (junction to case) represents only the packaged device thermal characteristics. This is
measured using IR microscopy capturing the device under test temperature at the hottest spot of the die. At the same time, the
package temperature is measured using a thermocouple touching the backside of the die embedded in the device heat-sink but
sized to prevent the measurement system from impacting the results. Knowing the dissipated power at the time of the
measurement, the thermal resistance is calculated.
In order to achieve the advertised MTTF, proper heat removal must be considered to maintain the junction at or below the
maximum of 200°C. Proper thermal design includes consideration of ambient temperature and the thermal resistance from
ambient to the back of the package including heat-sinking systems and air flow mechanisms. Incorporating the dissipated DC
power, it is possible to calculate the junction temperature of the device.
DC Bias
The GaN HEMT device is a depletion mode high electron mobility transistor (HEMT). At zero volts VGS the drain of the device is
saturated and uncontrolled drain current will destroy the transistor. The gate voltage must be taken to a potential lower than the
source voltage to pinch off the device prior to applying the drain voltage, taking care not to exceed the gate voltage maximum
limits. RFMD recommends applying VGS = -5V before applying any VDS.
RF Power transistor performance capabilities are determined by the applied quiescent drain current. This drain current can be
adjusted to trade off power, linearity, and efficiency characteristics of the device. The recommended quiescent drain current (IDQ)
shown in the RF typical performance table is chosen to best represent the operational characteristics for this device, considering
manufacturing variations and expected performance. The user may choose alternate conditions for biasing this device based on
performance trade-offs.
GaN HEMT Capacitances
The physical structure of the GaN HEMT results in three terminal capacitors similar to other FET technologies. These
capacitances exist across all three terminals of the device. The physical manufactured characteristics of the device determine the
value of the CDS (drain to source), CGS (gate to source) and CGD (gate to drain). These capacitances change value as the terminal
voltages are varied. RFMD presents the three terminal capacitances measured with the gate pinched off (VGS = -8V) and zero volts
applied to the drain. During the measurement process, the parasitic capacitances of the package that holds the amplifier is
removed through a calibration step. Any internal matching is included in the terminal capacitance measurements. The capacitance
values presented in the typical characteristics table of the device represent the measured input (CISS), output (COSS), and reverse
(CRSS) capacitance at the stated bias voltages. The relationship to three terminal capacitances is as follows:
CISS = CGD + CGS
COSS = CGD + CDS
CRSS = CGD