Maxim MAX2601-MAX2602 3.6v, 1w rf power transistors for 900mhz application Datasheet

19-1185; Rev 2; 5/97
KIT
ATION
EVALU
E
L
B
AVAILA
3.6V, 1W RF Power Transistors
for 900MHz Applications
________________________Applications
____________________________Features
♦ Low Voltage: Operates from 1 Li-Ion or
3 NiCd/NiMH Batteries
♦ DC-to-Microwave Operating Range
♦ 1W Output Power at 900MHz
♦ On-Chip Diode for Accurate Biasing (MAX2602)
♦ Low-Cost Silicon Bipolar Technology
♦ Does Not Require Negative Bias or Supply Switch
♦ High Efficiency: 58%
______________Ordering Information
TEMP. RANGE
PIN-PACKAGE
MAX2601ESA
-40°C to +85°C
8 PSOPII
MAX2602ESA
MAX2602E/D
-40°C to +85°C
-40°C to +85°C
8 PSOPII
Dice*
PART
*Dice are specified at TA = +25°C, DC parameters only.
_________________Pin Configurations
Narrow-Band PCS (NPCS)
915MHz ISM Transmitters
TOP VIEW
Microcellular GSM (Power Class 5)
AMPS Cellular Phones
C
1
8
C
C
1
8
C
E
2
7
E
E
2
7
E
Two-Way Paging
E
3
6
E
BIAS
3
6
E
CDPD Modems
B
4
5
B
B
4
5
B
Digital Cellular Phones
Land Mobile Radios
MAX2601
MAX2602
PSOPII
PSOPII
Typical Application Circuit appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
MAX2601/MAX2602
_______________General Description
The MAX2601/MAX2602 are RF power transistors optimized for use in portable cellular and wireless equipment
that operates from three NiCd/NiMH cells or one Li-Ion
cell. These transistors deliver 1W of RF power from a
3.6V supply with efficiency of 58% when biased for constant-envelope applications (e.g., FM or FSK). For NADC
(IS-54) operation, they deliver 29dBm with -28dBc ACPR
from a 4.8V supply.
The MAX2601 is a high-performance silicon bipolar RF
power transistor. The MAX2602 includes a highperformance silicon bipolar RF power transistor, and a
biasing diode that matches the thermal and process
characteristics of the power transistor. This diode is
used to create a bias network that accurately controls
the power transistor’s collector current as the temperature changes.
The MAX2601/MAX2602 can be used as the final stage
in a discrete or module power amplifier. Silicon bipolar
technology eliminates the need for voltage inverters
and sequencing circuitry, as required by GaAsFET
power amplifiers. Furthermore, a drain switch is not
required to turn off the MAX2601/MAX2602. This
increases operating time in two ways: it allows lower
system end-of-life battery voltage, and it eliminates the
wasted power from a drain-switch device.
The MAX2601/MAX2602 are available in thermally
enhanced, 8-pin SO packages, which are screened to
the extended temperature range (-40°C to +85°C). The
MAX2602 is also available in die form.
MAX2601/MAX2602
3.6V, 1W RF Power Transistors
for 900MHz Applications
ABSOLUTE MAXIMUM RATINGS
Collector-Emitter Voltage, Shorted Base (VCES) ....................17V
Emitter Base Reverse Voltage (VEBO)...................................2.3V
BIAS Diode Reverse Breakdown Voltage (MAX2602) ..........2.3V
Average Collector Current (IC)........................................1200mA
Continuous Power Dissipation (TA = +70°C)
PSOPII (derate 80mW/°C above +70°C) (Note 1) ..........6.4W
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +165°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1: Backside slug must be properly soldered to ground plane (see Slug Layout Techniques section).
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
DC ELECTRICAL CHARACTERISTICS
(TA = TMIN to TMAX, unless otherwise noted.)
PARAMETER
Collector-Emitter Breakdown
Voltage
SYMBOL
BVCEO
BVCES
CONDITIONS
IC < 100µA
MIN
Open base
15
Shorted base
15
TYP
MAX
UNITS
V
Collector-Emitter Sustaining
Voltage
LVCEO
IC = 200mA
5.0
V
Collector-Base Breakdown
Voltage
BVCBO
IC < 100µA, emitter open
15
V
100
DC Current Gain
hFE
IC = 250mA, VCE = 3V
Collector Cutoff Current
ICES
VCE = 6V, VBE = 0V
0.05
Output Capacitance
COB
VCB = 3V, IE = 0mA, f = 1MHz
9.6
1.5
µA
pF
AC ELECTRICAL CHARACTERISTICS
(Test Circuit of Figure 1, VCC = 3.6V, VBB = 0.750V, ZLOAD = ZSOURCE = 50Ω, POUT = 30dBm, f = 836MHz, TA = +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
Frequency Range
f
Base Current
IB
Harmonics
2fo, 3fo
Stability under Continuous
Load Mismatch Conditions
Two-Tone IMR
Noise Figure
VCC = 3.6V, POUT = 30dBm
MIN
TYP
DC
MAX
UNITS
1
GHz
4.2
mA
-43
dBc
dBc
VCC = 3.0V, POUT = 29dBm
-42
POUT = 30dBm
11.6
dB
No modulation
58
%
VCC = 5.5V, all angles (Note 3)
8:1
POUT = +30dBm total power, f1 = 835MHz,
f2 = 836MHz
-16
IM5
NF
VBB = 0.9V
3.3
Power Gain
Collector Efficiency
CONDITIONS
(Note 2)
η
VSWR
IM3
-25
dBc
dB
Note 2: Guaranteed by design.
Note 3: Under these conditions: a) no spurious oscillations shall be observed at collector greater than -60dBc; b) no parametric
degradation is observable when mismatch is removed; and c) no current draw in excess of the package dissipation
capability is observed.
2
_______________________________________________________________________________________
3.6V, 1W RF Power Transistors
for 900MHz Applications
VBB = 1.00V
30
VBB = 0.95V
0.6
VBB = 0.90V
0.4
POUT
29
IM3
25
POUT
IM3
15
IM5
5
28
0.2
POUT, IM3, AND IM5
ARE RMS COMPOSITE
TWO-TONE POWER
LEVELS
MAX2601-03
MAX2601-02
35
POUT, IM3, IM5 (dBm)
POUT, IM3, AND IM5
ARE RMS COMPOSITE
TWO-TONE POWER LEVELS
POUT (dBm)
ICC (A)
31
MAX2601-01
1.0
0.8
TWO-TONE OUTPUT POWER, IM3, IM5
vs. INPUT POWER
TWO-TONE OUTPUT POWER AND IM3
vs. COLLECTOR CURRENT
COLLECTOR CURRENT
VBB = 0.85V
VBB = 0.80V
0
1
2
3
4
5
6
0.5
0.4
0.6
0.7
10
5
0.8
15
20
25
VCE (V)
ICC (A)
INPUT POWER (dBm)
TWO-TONE OUTPUT POWER, IM3, IM5
vs. INPUT POWER (f = 433MHz)
ACPR vs. OUTPUT POWER
(IS-54 π/4 DQPSK MODULATION, VBB = 0.85V)
COLLECTOR EFFICIENCY vs. OUTPUT POWER
(IS-54 π/4 DQPSK MODULATION, VBB = 0.85V)
3.0V
-22
60
ACPR (dBc)
15
IM3
IM5
EFFICIENCY (%)
-26
POUT, IM3, AND IM5
ARE RMS COMPOSITE
TWO-TONE
POWER LEVELS
3.6V
-28
-30
4.2V
-32
-34
5
POUT, IM3, AND IM5
ARE RMS COMPOSITE
TWO-TONE POWER
LEVELS
3.0V
50
-24
25
MAX2601-06
POUT
MAX2601-05
-20
MAX2601-04
35
POUT, IM3, IM5 (dBm)
-5
27
0
40
3.6V
30
4.2V
20
4.8V
4.8V
-36
10
-38
-40
-5
10
5
15
20
25
0
10
15
20
25
30
35
10
OUTPUT POWER (dBm)
INPUT POWER (dBm)
15
20
25
30
35
OUTPUT POWER (dBm)
______________________________________________________________Pin Description
PIN
FUNCTION
NAME
MAX2601
MAX2602
1, 8
1, 8
C
Transistor Collector
2, 3, 6, 7, Slug
2, 6, 7, Slug
E
Transistor Emitter
—
3
BIAS
4, 5
4, 5
B
Anode of the Biasing Diode that matches the thermal and process characteristics of the power transistor. Requires a high-RF-impedance, lowDC-impedance (e.g., inductor) connection to the transistor base (Pin 4).
Current through the biasing diode (into Pin 3) is proportional to 1/15 the
collector current in the transistor.
Transistor Base
_______________________________________________________________________________________
3
MAX2601/MAX2602
__________________________________________Typical Operating Characteristics
(Test Circuit of Figure 1, input/output matching networks optimized for specific measurement frequency, VCC = 3.6V, VBB = 0.750V,
POUT = 30dBm, ZLOAD = ZSOURCE = 50Ω, f = 836MHz, TA = +25°C, unless otherwise noted.)
MAX2601/MAX2602
3.6V, 1W RF Power Transistors
for 900MHz Applications
VCC
VBB
5Ω
1000pF
0.1µF
100nH
24Ω
1000pF
1
4
8
1000pF
RFIN
0.1µF
L1
1000pF
T2
10pF
2pF
5
2pF
T1
12pF
2, 6, 7
BACKSIDE
SLUG
L1 = COILCRAFT A05T INDUCTOR, 18.5nH
T1, T2 = 1", 50Ω TRANSMISSION LINE ON FR-4
Figure 1. Test Circuit
_______________Detailed Description
MAX2601/MAX2602
The MAX2601/MAX2602 are high-performance silicon
bipolar transistors in power-enhanced, 8-pin SO packages. The base and collector connections use two pins
each to reduce series inductance. The emitter connects to three (MAX2602) or four (MAX2601) pins in
addition to a back-side heat slug, which solders directly to the PC board ground to reduce emitter inductance
and improve thermal dissipation. The transistors are
intended to be used in the common-emitter configuration for maximum power gain and power-added
efficiency.
Current Mirror Bias
(MAX2602 only)
The MAX2602 includes a high-performance silicon
bipolar RF power transistor and a thermally matched
biasing diode that matches the power transistor’s thermal and process characteristics. This diode is used to
create a bias network that accurately controls the
power transistor’s collector current as the temperature
changes (Figure 2).
The biasing diode is a scaled version of the power transistor’s base-emitter junction, in such a way that the
current through the biasing diode is 1/15 the quiescent
collector current of the RF power transistor. Supplying
the biasing diode with a constant current source and
connecting the diode’s anode to the RF power transistor’s base ensures that the RF power transistor’s quiescent collector current remains constant through
4
VCC
VCC
RBIAS
RFC
RFOUT
COUT
RFC
Q1
Q2
CBIAS
CIN
RFIN
Figure 2. Bias Diode Application
temperature variations. Simply tying the biasing diode
to the supply through a resistor is adequate in most situations. If large supply variations are anticipated, connect the biasing diode to a reference voltage through a
resistor, or use a stable current source. Connect the
biasing diode to the base of the RF power transistor
through a large RF impedance, such as an RF choke
(inductor), and decouple to ground through a surfacemount chip capacitor larger than 1000pF.
_______________________________________________________________________________________
3.6V, 1W RF Power Transistors
for 900MHz Applications
Optimum Port Impedance
The source and load impedances presented to the
MAX2601/MAX2602 have a direct impact upon its gain,
output power, and linearity. Proper source- and loadterminating impedances (ZS and ZL) presented to the
power transistor base and collector will ensure optimum
performance.
For a power transistor, simply applying the conjugate of
the transistor’s input and output impedances calculated
from small-signal S-parameters will yield less than optimum device performance.
For maximum efficiency at VBB = 0.75V and VCC =
3.6V, the optimum power-transistor source and load
impedances (as defined in Figure 3) are:
At 836MHz: ZS = 5.5 + j2.0
ZL = 6.5 + j1.5
At 433MHz: ZS = 9.5 - j2.5
ZL = 8.5 - j1.5
ZS and ZL reflect the impedances that should be presented to the transistor’s base and collector. The package parasitics are dominated by inductance (as shown
in Figure 3), and need to be accounted for when calculating ZS and ZL.
The internal bond and package inductances shown
in Figure 3 should be included as part of the endapplication matching network, depending upon exact
layout topology.
Slug Layout Techniques
The most important connection to make to the
MAX2601/MAX2602 is the back side. It should connect
directly to the PC board ground plane if it is on the top
side, or through numerous plated through-holes if the
ground plane is buried. For maximum gain, this connection should have very little self-inductance. Since it
is also the thermal path for heat dissipation, it must
have low thermal impedance, and the ground plane
should be large.
4
3
2
1
MAX2601
MAX2602
2.8nH
2.8nH
2.8nH
ZS
5
2.8nH
ZL
6
7
8
Figure 3. Optimum Port Impedance
_______________________________________________________________________________________
5
MAX2601/MAX2602
__________Applications Information
MAX2601/MAX2602
3.6V, 1W RF Power Transistors
for 900MHz Applications
________________________________________________________Package Information
DIM
D
0°-8°
A
0.101mm
0.004in.
e
B
A1
C
L
8-Pin PSOPII
E
6
H
A
A1
B
C
E
e
H
L
INCHES
MAX
MIN
0.069
0.053
0.010
0.004
0.019
0.014
0.010
0.007
0.157
0.150
0.050
0.244
0.228
0.050
0.016
DIM PINS
D
8
MILLIMETERS
MIN
MAX
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
3.80
4.00
1.27
5.80
6.20
0.40
1.27
INCHES
MILLIMETERS
MIN MAX
MIN
MAX
0.189 0.197 4.80
5.00
_______________________________________________________________________________________
21-0041A
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