19-1234; Rev 5; 8/03
IT
TION K
VALUA
E
BLE
AVAILA
900MHz Image-Reject Transceivers
General Description
Features
o
Receive/Transmit Mixers with 35dB Image Rejection
o
Adjustable-Gain LNA
o
Up to +2dBm Combined Receiver Input IP3
o
4dB Combined Receiver Noise Figure
o
>35dB of Transmit Power Control Range
o
PA Predriver Provides up to +2dBm
o
Low Current Consumption: 23mA Receive
26mA Transmit
9.5mA Oscillator
o
0.5µA Shutdown Mode
o
Operates from Single +2.7V to +4.8V Supply
MAX2420/MAX2421/MAX2422/MAX2460/MAX2463
The MAX2420/MAX2421/MAX2422/MAX2460/MAX2463
are highly integrated front-end ICs that provide the lowest
cost solution for cordless phones and ISM-band radios
operating in the 900MHz band. All devices incorporate
transmit and receive image-reject mixers to reduce filter
cost. They operate with a +2.7V to +4.8V power supply,
allowing direct connection to a three-cell battery stack.
The receive path incorporates an adjustable-gain LNA
and an image-reject downconverter with 35dB image
suppression. These features yield excellent combined
downconverter noise figure (4dB) and high linearity with
an input third-order intercept point (IP3) of up to +2dBm.
The transmitter consists of a variable-gain IF amplifier
with more than 35dB control range, an image-reject
upconverter with 35dB image rejection, and a power-
amplifier (PA) predriver that produces up to +2dBm (in
some applications serving as the final power stage).
All devices include an on-chip local oscillator (LO),
requiring only an external varactor-tuned LC tank for
operation. The integrated divide-by-64/65 dual-modulus
prescaler can also be set to a direct mode, in which it
acts as an LO buffer amplifier. Four separate power-
down inputs can be used for system power manage-
ment, including a 0.5µA shutdown mode. These parts
are compatible with commonly used modulation
schemes such as FSK, BPSK, and QPSK, as well as fre-
quency hopping and direct sequence spread-spectrum
systems. All devices come in a 28-pin SSOP package.
For applications using direct VCO or BPSK transmit mod-
ulation, as well as receive image rejection, consult the
MAX2424/MAX2426 data sheet. For receive-only devices,
refer to the MAX2440/MAX2441/MAX2442 data sheet.
_______________Ordering Information
PART
MAX2420EAI
MAX2421EAI
MAX2422EAI
MAX2460EAI
MAX2463EAI
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
28 SSOP
28 SSOP
28 SSOP
28 SSOP
28 SSOP
Functional Diagram appears on last page.
___________________Pin Configuration
TOP VIEW
V
CC
1
CAP1 2
RXOUT 3
TXGAIN 4
RXIN 5
V
CC
6
GND 7
GND 8
TXOUT 9
LNAGAIN 10
V
CC
11
TXIN 12
N.C. 13
CAP2 14
28 GND
27 GND
26 GND
25 TANK
________________________Applications
Cordless Phones
Wireless Telemetry
Wireless Networks
Spread-Spectrum Communications
Two-Way Paging
______________________Selector Guide
PART
MAX2420
MAX2421
MAX2422
MAX2460
MAX2463
IF FREQ
(MHz)
10.7
46
70
10.7
110
INJECTION
TYPE
High side
High side
High side
Low side
Low side
LO FREQ
(MHz)
f
RF
+ 10.7
f
RF
+ 46
f
RF
+ 70
f
RF
- 10.7
f
RF
- 110
MAX2420
MAX2421
MAX2422
MAX2460
MAX2463
24 TANK
23 V
CC
22 V
CC
21 PREOUT
20 PREGND
19 MOD
18 DIV1
17 VCOON
16 RXON
15 TXON
SSOP
1
________________________________________________________________
Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
900MHz Image-Reject Transceivers
MAX2420/MAX2421/MAX2422/MAX2460/MAX2463
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ...........................................................-0.3V to +5.5V
TXIN Input Power (330Ω system) ......................................-8dBm
Voltage on TXOUT......................................-0.3V to (V
CC
+ 1.0V)
Voltage on TXGAIN, LNAGAIN, TXON,
RXON, VCOON, DIV1, MOD ....................-0.3V to (V
CC
+ 0.3V)
RXIN Input Power..............................................................10dBm
TANK,
TANK
Input Power ...................................................2dBm
Continuous Power Dissipation (T
A
= +70°C)
SSOP (derate 9.50mW/°C above +70°C) ......................762mW
Operating Temperature Range
MAX242_EAI/MAX246_EAI ................................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +165°C
Lead Temperature (soldering, 10s) .................................+300°C
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.
CAUTION!
ESD SENSITIVE DEVICE
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +4.8V, no RF signals applied, LNAGAIN = TXGAIN = open, VCOON = 2.4V, RXON = TXON = MOD = DIV1 = 0.45V,
PREGND = GND, T
A
= T
MIN
to T
MAX
. Typical values are at T
A
= +25°C, V
CC
= +3.3V, unless otherwise noted.) (Note 1)
PARAMETER
Supply-Voltage Range
Oscillator Supply Current
Prescaler Supply Current
(divide-by-64/65 mode) (Note 2)
Prescaler Supply Current
(buffer mode) (Note 3)
Receive Supply Current (Note 4)
Transmitter Supply Current (Note 5)
Shutdown Supply Current
Digital Input Voltage High
Digital Input Voltage Low
Digital Input Current
Note 1:
Note 2:
Note 3:
Note 4:
DIV1 = 2.4V
RXON = 2.4V, PREGND = floating
RXON = 0.45V, TXON = 2.4V, PREGND = floating
VCOON = RXON = TXON =
MOD = DIV1 = GND
T
A
= +25°C
T
A
= T
MIN
to T
MAX
2.4
0.45
±1
±10
PREGND = floating
CONDITIONS
MIN
2.7
9.5
4.2
5.4
23
26
0.5
10
TYP
MAX
4.8
14
6
8.5
36
42
UNITS
V
mA
mA
mA
mA
mA
µA
µA
V
V
µA
RXON, TXON, DIV1, VCOON, MOD
RXON, TXON, DIV1, VCOON, MOD
Voltage on any one digital input = V
CC
or GND
≥25°C
guaranteed by production test, <25°C guaranteed through correlation to worst-case temperature testing.
Calculated by measuring the combined oscillator and prescaler supply current and subtracting the oscillator supply current.
Calculated by measuring the combined oscillator and LO buffer supply current and subtracting the oscillator supply current.
Calculated by measuring the combined receive and oscillator supply current and subtracting the oscillator supply current.
With LNAGAIN = GND, the supply current drops by 4.5mA.
Note 5:
Calculated by measuring the combined transmit and oscillator supply current and subtracting the oscillator supply current.
2
_______________________________________________________________________________________
900MHz Image-Reject Transceivers
MAX2420/MAX2421/MAX2422/MAX2460/MAX2463
AC ELECTRICAL CHARACTERISTICS
(MAX242X/246X EV kit, V
CC
= +3.3V; f
LO
= 925.7MHz (MAX2420), f
LO
= 961MHz (MAX2421), f
LO
= 985MHz (MAX2422),
f
LO
= 904.3MHz (MAX2460); f
LO
= 805MHz (MAX2463); f
RXIN
= 915MHz; P
RXIN
= -35dBm; P
TXIN
= -15dBm (330Ω); LNAGAIN = 2V;
TXGAIN = V
CC
; VCOON = 2.4V; RXON = TXON = MOD = DIV1 = PREGND = GND; T
A
= +25°C; unless otherwise noted.)
PARAMETER
RECEIVER
(RXON = 2.4V)
Input Frequency Range
(Notes 6, 7)
MAX2420/MAX2460
IF Frequency Range
(Notes 6, 7)
Image Frequency Rejection
MAX2420/MAX2421/MAX2460
LNAGAIN = V
CC
,
T
A
= +25°C
Conversion Power Gain (Note 8)
MAX2422
MAX2463
MAX2421
MAX2422
MAX2463
800
8.5
36
55
86
26
20
19
18
19.5
18
17
12
-16
LNAGAIN = V
CC
LNAGAIN = 1V
-19
4
12
-17
-8
-26
-18
-60
500
5
dB
dBm
dBm
dBm
ns
10.7
46
70
110
35
22
21
20
24.5
23.5
22.5
25
24
23
dB
1000
12.5
55
85
132
dB
MHz
MHz
CONDITIONS
MIN
TYP
MAX
UNITS
LNAGAIN = V
CC
, MAX2420/MAX2421/MAX2460
T
A
= T
MIN
to T
MAX
MAX2422
(Note 6)
MAX2463
LNAGAIN = 1V
LNAGAIN = GND
Noise Figure (Notes 6, 8)
Input Third-Order Intercept
(Notes 6, 9)
Input 1dB Compression
LO to RXIN Leakage
Receiver Turn-On Time
TRANSMITTER
(TXON = 2.4V)
Output Frequency Range
(Notes 6, 7)
DIV1 = V
CC
LNAGAIN = 1V
LNAGAIN = V
CC
LNAGAIN = 1V
LNAGAIN = V
CC
LNAGAIN = 1V
Receiver on or off
(Note 10)
800
MAX2420/MAX2460
8.5
36
55
86
26
MAX2420/2460
T
A
= +25°C
MAX2421
MAX2422
MAX2463
MAX2420/2460
T
A
= T
MIN
to T
MAX
MAX2421
(Note 6)
MAX2422
MAX2463
11
10
9
8
10.5
10
9
8
10.7
46
70
110
35
13.5
12.5
12
11
1000
12.5
55
85
132
MHz
IF Frequency Range
MAX2421
MAX2422
MAX2463
MHz
Image Frequency Rejection
dB
16
15
14.5
13.5
16.5
15.5
15
14
3
dB
Conversion Gain
_______________________________________________________________________________________
900MHz Image-Reject Transceivers
MAX2420/MAX2421/MAX2422/MAX2460/MAX2463
AC ELECTRICAL CHARACTERISTICS (continued)
(MAX242X/246X EV kit, V
CC
= +3.3V; f
LO
= 925.7MHz (MAX2420), f
LO
= 961MHz (MAX2421), f
LO
= 985MHz (MAX2422),
f
LO
= 904.3MHz (MAX2460); f
LO
= 805MHz (MAX2463); f
RXIN
= 915MHz; P
RXIN
= -35dBm; P
TXIN
= -15dBm (330Ω); LNAGAIN = 2V;
TXGAIN = V
CC
; VCOON = 2.4V; RXON = TXON = MOD = DIV1 = PREGND = GND; T
A
= +25°C; unless otherwise noted.)
PARAMETER
Output 1dB Compression
Output Third-Order Intercept
(Note 11)
LO to TXOUT Suppression
(Note 12)
Noise Figure
TXGAIN Control Slope (Note 13)
Gain Control Range (Note 13)
Transmitter Turn-On Time (Note 14)
OSCILLATOR AND PRESCALER
Oscillator Frequency Range
(Notes 6, 15)
Oscillator Phase Noise
Oscillator Pulling
Prescaler Output Level
Oscillator Buffer Output Level
(Note 6)
Required Modulus Setup Time
(Note 6)
Required Modulus Hold Time
(Note 6)
10kHz offset (Note 16)
Standby to TX, or standby to RX
RX to TX with P
RXIN
= -45dBm (RX mode) to
P
RXIN
= 0dBm (TX mode) (Note 17)
Z
L
= 100kΩ
| |
10pF
DIV1 = 2.4V, Z
L
= 50Ω, T
A
= +25°C
DIV1 = 2.4V, Z
L
= 50Ω, T
A
= T
MIN
to T
MAX
Divide-by-64/65 mode (Note 18)
Divide-by-64/65 mode (Note 18)
-11
-12
10
0
690
82
8
70
500
-8
kHz
mV
P-P
dBm
ns
ns
1100
MHz
dBc/Hz
1V
≤
TXGAIN
≤
2V
CONDITIONS
MIN
TYP
2
11
34
23
33
36
400
MAX
UNITS
dBm
dBm
dBc
dB
dB/V
dB
ns
Note 6:
Guaranteed by design and characterization.
Note 7:
Image rejection typically falls to 30dBc at the frequency extremes.
Note 8:
Refer to the
Typical Operating Characteristics
for plots showing receiver gain vs. LNAGAIN voltage, input IP3 vs.
LNAGAIN voltage, and noise figure vs. LNAGAIN voltage.
Note 9:
Two tones at P
RXIN
= -45dBm each, f1 = 915.0MHz and f2 = 915.2MHz.
Note 10:
Time delay from RXON = 0.45V to RXON = 2.4V transition to the time the output envelope reaches 90% of its final value.
Note 11:
Two tones at P
TXIN
= -21dBm each (330Ω), f1 = 10.6MHz, f2 = 10.8MHz (MAX2420/MAX2460), f1 = 45.9MHz,
f2 = 46.1MHz (MAX2421), f1 = 69.9MHz, f2 = 70.1MHz (MAX2422).
Note 12:
Refer to the
Typical Operating Characteristics
for statistical data.
Note 13:
Refer to the
Typical Operating Characteristics
for a plot showing transmitter gain vs. TXGAIN voltage.
Note 14:
Time delay from TXON = 0.45V to TXON = 2.4V transition to the time the output envelope reaches 90% of its final value.
Note 15:
Refers to useable operating range. Tuning range of any given tank circuit design is typically much narrower (refer to Figure 2).
Note 16:
Using tank components L3 = 5.0nH (Coilcraft A02T), C2 = C3 = C26 = 3.3pF, R6 = R7 = 10Ω.
Note 17:
This approximates a typical application in which TXOUT is followed by an external PA and a T/R switch with finite isolation.
Note 18:
Relative to the rising edge of PREOUT.
4
_______________________________________________________________________________________
900MHz Image-Reject Transceivers
Typical Operating Characteristics
(MAX242X/246X EV kit, V
CC
= +3.3V; f
LO
= 925.7MHz (MAX2420), f
LO
= 961MHz (MAX2421), f
LO
= 985MHz (MAX2422), f
LO
= 904.3MHz
(MAX2460); f
LO
= 805MHz (MAX2463); f
RXIN
= 915MHz; P
RXIN
= -35dBm; P
TXIN
= -15dBm (330Ω); LNAGAIN = 2V; TXGAIN = V
CC
;
VCOON = 2.4V; RXON = TXON = MOD = DIV1 = PREGND = GND; T
A
= +25°C; unless otherwise noted.)
RECEIVER SUPPLY CURRENT
vs. TEMPERATURE
MAX2420-01
MAX2420/MAX2421/MAX2422/MAX2460/MAX2463
TRANSMITTER SUPPLY CURRENT
vs. TEMPERATURE
MAX2420-02
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
4.0
3.5
VCOON = GND
MAX2420-03
42
40
38
36
I
CC
(mA)
34
32
30
28
26
24
-40
-20
0
20
40
60
80
RXON = V
CC
PREGND = FLOATING
INCLUDES OSCILLATOR
CURRENT
V
CC
= 4.8V
46
44
42
40
I
CC
(mA)
38
36
34
32
30
28
26
-40
-20
0
20
V
CC
= 3.3V
V
CC
= 2.7V
TXON = V
CC
PREGND = FLOATING
INCLUDES OSCILLATOR
CURRENT
40
60
80
V
CC
= 4.8V
4.5
3.0
I
CC
(µA)
2.5
2.0
1.5
1.0
0.5
0
100
-40
-20
0
20
40
60
80
100
V
CC
= 2.7V
V
CC
= 4.8V
V
CC
= 3.3V
V
CC
= 3.3V
V
CC
= 2.7V
100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
RECEIVER GAIN vs. LNAGAIN
MAX2420-04
RECEIVER INPUT IP3 vs. V
LNAGAIN
MAX2420-05
RECEIVER NOISE FIGURE
vs. LNAGAIN
35
30
NOISE FIGURE (dB)
25
20
15
10
5
AVOID
THIS
REGION
0
0.5
1.0
DIV1 = V
CC
RXON = V
CC
LNA
ADJUSTABLE MAX
PARTIALLY
GAIN
GAIN
BIASED
MAX2420-06
25
20
15
RECEIVER GAIN (dB)
10
5
0
-5
-10
-15
-20
0
LNA
OFF
LNA
PARTIALLY
BIASED
5
LNA
OFF
LNA
ADJUSTABLE MAX
PARTIALLY
GAIN
GAIN
BIASED
AVOID
THIS
REGION
40
LNA
OFF
0
ADJUSTABLE
GAIN
MAX
GAIN
IIP3 (dBm)
-5
-10
AVOID
THIS
REGION
RXON = V
CC
-15
RXON = V
CC
-20
0.5
1.0
1.5
2.0
0
0.5
1.0
LNAGAIN VOLTAGE (V)
0
1.5
2.0
1.5
2.0
LNAGAIN VOLTAGE (V)
LNAGAIN VOLTAGE (V)
MAX2420
RECEIVER GAIN vs. TEMPERATURE
MAX2420-07
RECEIVER NOISE FIGURE vs.
TEMPERATURE AND SUPPLY VOLTAGE
MAX2420-08
RECEIVER INPUT IP3
vs. TEMPERATURE
MAX2420-09
26
RECEIVER GAIN (dB)
LNAGAIN = V
CC
RXON = V
CC
V
CC
= 2.7V
V
CC
= 4.8V
5.5
LNAGAIN = V
CC
RXON = V
CC
DIV1 = V
CC
V
CC
= 4.8V
V
CC
= 3.3V
4.0
V
CC
= 2.7V
3.5
-6
-8
-10
IIP3 (dBm)
LNAGAIN = 1V
5.0
NOISE FIGURE (dB)
24
22
V
CC
= 3.3V
4.5
-12
-14
-16
-18
RXON = V
CC
20
LNAGAIN = 2V
18
3.0
-40
-20
0
20
40
60
80
100
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
-20
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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