U2793B
300–MHz Quadrature Modulator
Description
The IC U2793B is a 300-MHz quadrature modulator that
uses Atmel Wireless & Microcontrollers’ advanced UHF
process. It features low current consumption, single-
ended RF ports and adjustment-free application, which
makes the device suitable for all digital radio systems,
e.g., GSM, PCN, JDC and WLAN. As an option, output
level and spurious products are adjustable at Pins 19
and 20. In conjunction with Atmel Wireless &
Microcontrollers’ U2795B mixer, an up converter up to
2 GHz can be realized.
Electrostatic sensitive device.
Observe precautions for handling.
Features
D
Supply voltage: 5 V (typical)
D
Low power consumption: 15 mA / 5 V (typical at
0 dBm output level
D
Output level and spurious products adjustable
(optional)
D
Excellent sideband suppression by means of duty
cycle regeneration of the LO input signal
D
Phase-control loop for precise 90° phase shifting
D
Power-down mode
D
Low LO input level: –15 dBm (typical)
D
50-W single-ended LO and RF port
D
LO frequency range of 30 MHz to 300 MHz
Benefits
D
Extended talk time due to increased battery life
D
Few external components results in cost and board
space saving
D
Adjustment free hence saves time
D
Modular system for different applications by adding
U2795B reduces the costs
Block Diagram
S
PD
BB
Ai
BB
Ai
LO
i
LO
i
10
9
8
PD
1
V
Power 6,7
S
down
V
13
Ref
19
LP2
LP1
20
RF
o
4
AC
GND
AC
GND
14
Duty cycle
15 regenerator
Frequency
doubler
0
°
90
°
90
°
control
loop
S
BB
Bi
BB
Bi
11
12
93 7672 e
2
3,16,17,18
GND
Figure 1. Block diagram
5
Ordering Information
Extended Type Number
U2793B-MFS
U2793B-MFSG3
Package
SSO20
SSO20
Tube
Taped and reeled
Remarks
Rev. A4, 09-Oct-00
1 (9)
U2793B
Pin Description
Pin
PD
AC
GND
GND
RF
o
AC
GND
V
S
V
S
S
PD
B
BAi
BB
Ai
1
2
3
4
5
U2793B
6
7
8
9
10
94 7862 e
Symbol
PD
GND
RF
o
V
S
V
S
S
PD
BB
Ai
BB
Ai
BB
Bi
BB
Bi
V
Ref
LO
i
LO
i
GND
GND
GND
LP2
LP1
AC
GND
AC ground
Ground
RF output
Function
Power down port
20
19
18
17
16
15
14
13
12
11
LP1
LP2
GND
GND
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
AC
GND
AC ground
Supply voltage
Supply voltage
Settling time power down
Baseband input A
Baseband input A inverse
Baseband input B
Baseband input B inverse
Reference voltage (2.5 V)
Input LO
Input LO inverse, typically grounded
Ground
Ground
Ground
Output low pass and power control
Output low pass and power control
GND
LO
i
LO
i
V
Ref
BB
Bi
BB
Bi
Figure 2. Pinning SSO20
Absolute Maximum Ratings
Parameters
Supply voltage
Input voltage
Junction temperature
Storage temperature range
Pins 6 and 7
Pins 9, 10, 11, 12, 14 and 15
Symbol
V
S
V
i
T
j
T
stg
Value
6
0 to V
S
125
–40 to +125
Unit
V
V
°C
°C
Operating Range
Parameters
Supply voltage
Ambient temperature range
Pins 6 and 7
Symbol
V
S
T
amb
Value
4.5 to 5.5
–40 to +85
Unit
V
°C
Thermal Resistance
Parameters
Junction ambient
SSO20
Symbol
R
thja
Value
140
Unit
K/W
2 (9)
Rev. A4, 09-Oct-00
U2793B
Electrical Characteristics
Test conditions (unless otherwise specified); V
S
= 5 V, T
amb
= 25°C, referred to test circuit.
System impedance Zo = 50
W,
f
LO
= 150 MHz, P
LO
= –15 dBm, V
BBi
= 1.0 V
pp
, differential
Parameters
Supply-voltage range
Supply current
Baseband inputs
Input-voltage range (diff.)
Input impedance
Input-frequency range
LO input
Frequency range
Input level
1
Test conditions / Pin
Pins 6 and 7
Pins 6 and 7
Pin 9–10, 11–12
Symbol
V
S
I
S
V
BBi
Z
BBi
f
BBi
Min.
4.5
Typ.
5
15
1000
30
Max.
5.5
Unit
V
mA
1500
50
300
mVpp
kW
MHz
MHz
dBm
W
0
30
–15
2)
Pins 14 and 15
f
LOi
P
LOi
Z
iLO
VSWR
LO
DCR
LO
Pin 4
f
LO
= 150 MHz,
V
BBi
= 1 V
pp
, differential
f
LO
= 50 MHz,
V
BBi
= 0.3 V
pp
, differential
P
LO
= –20 dBm
3
–5
Input impedance
Voltage standing wave ratio
Duty-cycle range
RF output
Output level
3.5
0.4
–3
–1
0
0.6
dBm
P
RFo
LO suppression
Voltage standing wave ratio
Sideband suppression
Phase error
4
Amplitude error
Noise floor
Power-down mode
Supply current
Settling time
Switching voltage
Power on
Power down
Reference voltage
Voltage range
Output impedance
Note:
1
Note:
2
Note:
3
LO
RFo
VSWR
RF
SBS
RFo
Pe
Ae
32
35
45
1.4
45
<1
<"0.25
–137
–143
1
10
10
2
dB
dB
deg
dB
dBm/Hz
V
BBi
= 2 V, V
BBi
= 3 V
V
BBi
= V
BBi
= 2.5 V
V
PD
v
0.5 V,
Pins 6, 7,
V
PD
= 1 V
Pins 1 to 4 C
SPD
= 100 pF
C
LO =
100 pF, C
RFo
= 1 nF
Pin 1
N
FL
I
PD
t
SPD
mA
ms
V
PDon
V
PDdown
Pin 13
V
Ref
Zo
Ref
4
1
2.5
"5%
30
V
V
V
W
Required LO level is a function of the LO frequency.
The LO input impedance is consisting of a 50
W
resistor in series with a 15 pF capacitor
With the Pins 19 and 20 spurious performance especially for low frequency application can be improved
by adding a chip capacitor between LP1 and LP2. In conjunction with a parallel resistor the output level
can be adjusted to the following mixer stage without degration of LO suppression and noise performance
Rev. A4, 09-Oct-00
3 (9)
U2793B
Note: 4
2.57
2.56
2.55
V (V)
ref
2.54
2.53
2.52
2.51
2.5
–40
95 9655
which would decrease if the I/Q input level is reduced.
For T
amb
= –40 to +85°C and V
S
= 4.5 to 5.5 V
20
Supply current ( mA )
16
12
8
4
0
–40
0
40
Temperature (
°C
)
80
120
95 9657
0
40
Temperature (
°C
)
80
120
Figure 3. Reference voltage versus T
amb
Figure 5. Supply current versus T
amb
8
0
4
P
LO
( dBm )
120
IP3 ( dBm )
6
–10
–20
2
–30
0
–40
95 9656
–40
0
40
Temperature (
°C
)
80
0
95 9658
50
100
150
200
250
300
f
LO
( MHz )
Figure 4. OIP3 versus T
amb
, LO = 150 MHz, level –10 dBm
Figure 6. Recommended LO power range versus LO frequency
at T
amb
= 25°C
4 (9)
Rev. A4, 09-Oct-00
U2793B
0
1200
1000
P
O
=0dBm
V
BBi
( mV
pp
)
800
600
400
200
0
0
40
Temperature (
°C
)
80
120
95 9661
P
O
=–1dBm
Output power ( dBm )
–0.4
–0.8
–1.2
–1.6
–2
–40
P
O
=–3dBm
0
50
100
150
200
250
300
95 9659
f
LO
( MHz )
Figure 7. Output power versus T
amb
Figure 9. Typical required V
BBi
input signal (differential)
versus LO frequency for P
O
= 1 dBm and P
O
= –3 dBm
0
–4
P
O
( dBm )
–8
–12
–16
0
95 9660
50
100
150
200
250
300
f
LO
( MHz )
Figure 8. Typical output power vs. LO frequency at
T
amb
= 25°C, V
BBi
= 250 mV (differential)
Rev. A4, 09-Oct-00
5 (9)
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