U2741B-MFBG3Y [ATMEL]
Telecom Circuit, 1-Func, PDSO16, 0.150 INCH, 0.635 INCH PITCH, SSO-16;
| 型号： | U2741B-MFBG3Y |
| 厂家： | 
ATMEL |
| 描述： | Telecom Circuit, 1-Func, PDSO16, 0.150 INCH, 0.635 INCH PITCH, SSO-16 电信 光电二极管 电信集成电路 |
| 文件： | 总7页 (文件大小：60K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
U2741B
UHF ASK/FSK Transmitter
Description
The U2741B is a PLL transmitter IC which has been 450 MHz. It can be used in both FSK and ASK systems.
specially developed for the demands of RF low-cost data
transmission systems at data rates up to 20 kBaud.
Electrostatic sensitive device.
The transmitting frequency range is 300 MHz to Observe precautions for handling.
FD eOanteu-crheisp solution with minimum external circuitry
D XTO output for clocking the ꢀ C, thereby together
with M44C090 or M44C890 the optimum system
D Lower cost than the usual discrete solutions using
cost-effectiveness
SAW and transistors
D Very small SSO16 package, pitch 0.635, 150 mil
D Very large FSK frequency deviation achievable by
±100 ppm pulling of the reference crystal
D Supply voltage 2.0 V to 5.5 V
in the temperature range –20°C to 70°C
Supply voltage 2.2 V to 5.5 V
D Very high transmitting frequency accuracy compared
to SAW solutions. This enables receivers at lower
bandwidth than is possible with SAW resonators.
in the temperature range –40°C to 85°C
D “Single-Ended Open-Collector” output (same anten-
nas can be used as in discrete solutions, simpler D ESD protection according to MIL-STD.883
adaptation of magnetic loop antennas)
(4KV HBM) except Pins XTO1/ 2, ANT and LF
System Block Diagram
UHF ASK/FSK
Remote control transmitter
UHF ASK/FSK
Remote control receiver
1 Li cell
U3741BM
U2741B
1...3
Demod.
IF Amp
Control
XTO
mC
Encoder
PLL
M44Cx9x
Keys
Antenna Antenna
XTO
VCO
PLL
Power
amp.
LNA
VCO
Figure 1. System block diagram
Order Information
Extended Type Number
U2741B-MFB
Package
Remarks
SSO16
SSO16
SSO16
Tube
Taped and reeled
Tube, optimized power-supply rejection,
U2741B-MFBG3
U2741B-NFB
value of C differs from M-version, en-
4
hanced XTO stability
U2741B-NFBG3
SSO16
Taped and reeled, see above
Rev. A2, 22-Dec-00
1 (7)
U2741B
Pin Description
ASK 1
Pin
1
Symbol
ASK
Function
Modulation input ASK
Modulation input FSK
Supply voltage
DIVIC
16
15
14
13
12
11
10
9
2
FSK
PWRSET
PWRVCC
ANT
FSK
VCC
CLK
2
3
VCC
4
CLK
Clock output
3
5
GND
LFVCC
LFGND
LF
Ground
6
Supply voltage VCO
VCO ground
4
U2741B
7
PWRGND1
8
Circuit PLL loop
FM modulation output
Connection for crystal
GND
LFVCC
LFGND
LF
5
9
XTO2
XTO1
PWRGND2
XTO1
6
7
10
11
12
13
14
PWRGND2 Power GND2
PWRGND1 Power GND1
ANT
RF output
XTO2
8
PWRVCC Supply voltage power
amplifier
15
16
PWRSET Applied to VCC
DIVIC
Pitch factor setting for crystal
L: high crystal frequency;
H: low crystal frequency
Figure 2. Pinning SSO16
Block Diagram
ASK
FSK
VCC
DIVC
OR
PWRSET
PWRVCC
ANT
Power
up
PA
VCO
f
CLK
GND
PWRGND1
64
PWRGND2
LFVCC
LFGND
LF
f
XTO
n
XTO1
XTO2
U2741B
Figure 3. Block diagram
2 (7)
Rev. A2, 22-Dec-00
U2741B
General Description
Application Circuit
The fully integrated VCO and the “single-ended open-
collector” output allow particularly simple, low-cost RF
miniature transmitters to be assembled. The single-ended
output enables a considerably simplified adaptation of
both a magnetic loop antenna of any form or a ꢁ /4
antenna. This is because the load impedance must not be
balanced as would be the case with a differential output.
The following component values are recommendations
for a typical application. C5, C6, C7 are block capacitors.
The values of these capacitors depend on the board
layout. C5 = 1 nF, C6 = 1 nF, C7 = 22 nF are typically used
here. For C5, the impedance between f = 100 MHz and
f = 1 GHz should be as low as possible.
C3 is not needed in ASK transmitter applications. In the
case of FSK, C3 is selected in such a way that the desired
transmission frequency deviation is achieved (typ.
± 30 kHz). The capacitance here depends upon the
crystal’s load capacity (C4) recommended by the
manufacturer of the crystal. C2 = 3.9 nF, C1 = 15 nF,
The XTO’s frequency can be selected at either 13.56 MHz
(USA 9.844 MHz) or 6.78 MHz (USA 4.9219 MHz).
Thus, it is possible to use not only exceptionally small SMD
crystals at 13.56 MHz but also very low-cost 6.78-MHz
crystals in a wired metal package (e.g. in the HC49S
housing). The frequency is selected by connecting PIN16
(DIVC) to either GND or VS.
R4 = 220
ꢂꢃ
CLoop1, CLoop2 are selected so that the antenna
oscillates in resonance and the adaptation to the
appropriate impedance transformation is possible.
At high frequencies, crystals have a very fast start-up time
(< 1.5 ms at 13.56 MHz, < 3 ms at 6.78 MHz), whereby
a wait time of 5 to 10 ms is required until the transmitter
IC is locked. This means that the processor does not need
to poll a lock detect output.
LFeed is an inductor for the antenna’s DC current supply.
A typical value is LFeed = 220 nH. LFeed can be either
printed on the PC_Board or be a discrete component.
Functional Description
Further information regarding the application is provided
in the description of the “RKE Design Kit (U2741B,
U3741B)” in chapter 2.2.2. This chapter labeled
“Application Hints U2741B” also describes the antenna
design in more detail.
The IC can be switched on at both the FSK and the ASK
input. The IC’s ChipSelect is performed by the logical OR
operation of ASK and FSK input. In the case of
V
FSK , VASK ≤ 0.3 V, the power-down supply current is
ISoff < 0.35 µA. The ASK input activates the power
amplifier and the PLL. The FSK input only activates the
PLL and, if capacitor C3 is installed, pulls the crystal to the
lower frequency, whereby the transmitter is FSK
modulated. After switching on at FSK, the VCO locks onto
the 32 or 64 times higher frequency of the crystal oscillator.
Output Power Measurement
The following output network (see figure 4) can be used
for output power evaluation, the exact values of L10, C10
are dependent on the layout.
L10, C10 is the transformation network to adopt the
output impedance of the IC to 50
shows the values for an output power of 2 mW and an
ꢂꢃ The following table
FSK Transmission
The U2741B is switched on by V
= V . 5 ms later, V
S S
FSK
R
= 1.2 kꢂꢃ
PWRSET
is applied to V . The output can then be modulated by
ASK
means of Pin FSK. This is done by connecting capacitor
C3 in parallel to the load capacitor C4.
f/ MHz
315
C10/ pF
2.7
L10/ nH
56
Z
/ ꢂ
Load_opt
260 + j330
185 + j268
ASK Transmission
433.92
1.8
33
The U2741B is activated by V
= V . V
remains
VS
FSK
S
ASK
0 V for 5 ms, then the output power can be modulated by
means of Pin ASK. In this case, V remains = V during
the message, the capacitor C3 is not mounted.
PWRVCC
FSK
S
L10
Take-Over of the Clock Pulse in the µC
ANT
Z
Load-opt
C10
The clock of the crystal oscillator can be used for clocking
the µC. The M44C090 and M44C890 have the special
feature of starting with an integrated RC oscillator to
50 ꢂ
switch on the U2741B with V
= V . 5 ms later, the
FSK
S
15009
3.39-MHz clock frequency is present, so that the message
can be sent with crystal accuracy.
Figure 4. Measurement output network
Rev. A2, 22-Dec-00
3 (7)
U2741B
+VS= 2.0...5.5V
ASK
1
DIVC
16
PWRSET
15
PWRVCC
14
ANT
13
PWRGND1
12
PWRGND2
11
XTO1
10
ASK
FSK
OR
FSK
2
CLoop2
RPWRSET
Power
up
VCC
3
C7
LFeed
C5
CLK
4
VCO
f
PA
CLK
3.39MHz
CLoop1
GND
5
64
LFVCC
6
C6
f
13.56MHz
XTO
LFGND
7
n
C4
LF
8
XTO2
9
C1
R4
U2741B
C3
Antenna
C2
Figure 5. Application circuit
Absolute Maximum Ratings
Parameters
Supply voltage
Symbol
Min.
Typ.
Max.
6
Unit
V
V
S
Power dissipation
P
250
150
125
105
mW
°C
tot
Junction temperature
Storage temperature
Ambient temperature
T
j
T
stg
–55
–40
°C
T
amb
°C
Thermal Resistance
Parameters
Symbol
Value
180
Unit
K/W
Junction ambient
R
thJA
4 (7)
Rev. A2, 22-Dec-00
U2741B
Electrical Characteristics
All parameters are refered to GND (Pin 5).
The possible operating ranges refer to different circuit conditions:
V = 2.0 V to 5.5 V @ T
= –20°C to +70°C, V = 2.2 V to 5.5 V @ T = –40°C to +85°C (Typ. 25°C, 3 V)
S
amb
S
amb
Parameters
Test Conditions / Pins
Symbol
ISoff
Min.
Typ.
4.7
Max.
0.35
6.2
Unit
µA
Supply current (power down) VASK, VFSK v 0.3 V, VS < 3.6 V
Supply current
VASK = GND, VFSK = VS, Vs = 3 V
ISon
mA
(power up, output OFF)
Supply current
VASK = VS, VS = 3 V
IStransmit
mA
(power up, output ON)
RPWRSET = 1.2 kꢂ
10
12.5
Output power
VS = 3 V, Tamb = 25°C,
f = 433.92 MHz
RPWRSET = 1.2 kꢂ
RPWRSET = 1.8 kꢂ
PRef
PRef
1.5
–0.5
3
1
5
3
dBm
dBm
Output power variation for
the full temperature range
T
= –40°C to +85°C,
amb
ꢄPRef
ꢄPRef
–1.5
–4.0
dB
dB
f = 433.92 MHz, V = 3.0 V
S
V = 2.4 V
S
T
= –20°C to +85°C,
amb
ꢄPRef
ꢄPRef
–5.5
dB
dB
f = 433.92 MHz, V = 2.0 V
S
P
out
= P + ꢄPRef
Ref
Output power variation for
f = 315 MHz compared to
f = 433.92 MHz
f = 315 MHz
1.5
P
out
= P + ꢄPRef
Ref
Maximum peak output
antenna voltage
Voutmax
VS – 0.7 V
V(peak)
@Pout = 2.0 mW,
The load impedance must be selected
to meet the V maximum requirement.
out
The supply current is not dependent on
the load impedance tolerance.
Spurious emission
@ Tamb = 25°C
fo ± n × fPC (fPC = 6.78 MHz)
Load capacitance at CLK ≤ 3 pF
f = 230 MHz to 470 MHz
f < 230 MHz, f > 470 MHz
Em
Em
–40
–58
dBC
dBC
Oscillator frequency XTO
M-version: @ Tamb = 25°C
N-version: full temperature range
(monitoring)
Crystal frequency = 13.56 MHz
fXTO
13.56
– 30 ppm
13.56
6.78
13.56
+30 ppm
MHz
MHz
6.78 MHz
load capacity of the crystal must be
selected accordingly
fXTO
6.78
–30 ppm
6.78
+30 ppm
Loop bandwidth
For best LO noise
BLoop
100
kHz
Loop filter components:
C2 = 3.9 nF, C1 = 15 nF, R4 = 220 ꢂ
Phase noise PLL
Referring to the phase comparator
PNPLL
–111
–105
dBC/Hz
dBC/Hz
fPC = 6.78 MHz
Phase noise VCO
@ 1 MHz
@ 36 MHz
PNVCO
PNVCO
–91
–123
–87
–119
Frequency range of the VCO
fVCO
300
450
MHz
MHz
Clock output
Clkout
fout/128
(CMOS µC compatible)
Rev. A2, 22-Dec-00
5 (7)
U2741B
Electrical Characteristics (continued)
All parameters are refered to GND (Pin 5).
The possible operating ranges refer to different circuit conditions:
V = 2.0 V to 5.5 V @ T
= –20°C to +70°C, V = 2.2 V to 5.5 V @ T
= –40°C to +85°C (Typ. 25°C, 3 V)
S
amb
S
amb
Parameters
Test Conditions / Pins
Symbol
CCLK
Min.
Typ.
Max.
10
Unit
pF
Load capacitance at CLK
Series resonance R of the
crystal
fXTO = 13.56 MHz
XTO = 9.84 MHz
fXTO = 6.78 MHz
fXTO = 4.90 MHz
Rs
Rs
Rs
Rs
80
ꢂ
f
100
150
225
FSK modulation frequency
rate
Duty cycle of the
modulation signal = 50%
fmodFSK
0
0
20
kHz
kHz
ASK modulation frequency
rate
Duty cycle of the
modulation signal = 50%
fmodASK
20
CLK output
– Output current Low
– Output current Low
– Output current High
– Output current High
VCLK = 0.2 × VS
VCLK = 0.3 × VS
VCLK = 0.8 × VS
VCLK = 0.7 × VS
Iol
Iol
Ioh
Ioh
150
200
–150
–200
ꢀA
ꢀA
ꢀA
ꢀA
100
ASK input
– Low level input voltage
– High level input voltage
– Input current High
VASKl
VASKh
IASKh
0.3
V
V
ꢀA
1.7
1.7
140
FSK input
– Low level input voltage
– High level input voltage
– Input current High
VFSKl
VFSKh
IFSKh
0.3
V
V
ꢀA
140
Package Information
Package SSO16
Dimensions in mm
5.00 max
6.2
5.8
5.00
4.80
1.40
0.2
0.25
3.95 max
0.25
0.10
0.635
4.45
5.2
4.8
16
9
technical drawings
according to DIN
specifications
13045
1
8
6 (7)
Rev. A2, 22-Dec-00
U2741B
Ozone Depleting Substances Policy Statement
It is the policy of Atmel Germany GmbH to
1. Meet all present and future national and international statutory requirements.
2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems
with respect to their impact on the health and safety of our employees and the public, as well as their impact on
the environment.
It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as
ozone depleting substances (ODSs).
The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs and forbid
their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these
substances.
Atmel Germany GmbH has been able to use its policy of continuous improvements to eliminate the use of ODSs listed
in the following documents.
1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively
2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental
Protection Agency (EPA) in the USA
3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C (transitional substances) respectively.
Atmel Germany GmbH can certify that our semiconductors are not manufactured with ozone depleting substances
and do not contain such substances.
8.
We reserve the right to make changes to improve technical design and may do so without further notice.
Parameters can vary in different applications. All operating parameters must be validated for each customer
application by the customer. Should the buyer use Atmel Wireless & Microcontrollers products for any unintended
or unauthorized application, the buyer shall indemnify Atmel Wireless & Microcontrollers against all claims,
costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death
associated with such unintended or unauthorized use.
Data sheets can also be retrieved from the Internet:
http://www.atmel–wm.com
Atmel Germany GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany
Telephone: 49 (0)7131 67 2594, Fax number: 49 (0)7131 67 2423
Rev. A2, 22-Dec-00
7 (7)
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