DATA SHEET
BIPOLAR ANALOG INTEGRATED CIRCUIT
µ
PC2794GS
FREQUENCY DOWN CONVERTER FOR
VHF TO UHF BAND TV/VCR TUNER
DESCRIPTION
The
µ
PC2794GS is a Silicon monolithic IC designed for TV/VCR tuner applications. This IC consists of a double
balanced mixer (DBM), local oscillator, preamplifier for precscaler operation, IF amplifier, regulator, UHF/VHF
switching circuit, and so on. This one-chip IC covers a wide frequency band from VHF to UHF bands. This IC is
packaged in 20-pin SOP (Small Outline Package) suitable for surface mounting.
FEATURES
• VHF to UHF bands operation.
• Low distortion
• Supply voltage
CM: VHF (@f
RF
= 470 MHz) 96 dB
µ
UHF (@f
RF
= 890 MHz) 92 dB
µ
: 9V
• Packaged in 20-pin SOP suitable for surface mounting
ORDERING INFORMATION
Part Number
Package
20-pin plastic SOP (300 mil)
Package Style
Embossed tape 24 mm wide. 2.5 k/REEL.
Pin 1 indicates pull-out direction of tape
µ
PC2794GS-E1
For evaluation sample order, please contact your local NEC office. (Part number for sample order:
µ
PC2794GS)
Caution electro-static sensitive device
The information in this document is subject to change without notice. Before using this document, please
confirm that this is the latest version.
Not all devices/types available in every country. Please check with local NEC representative for availability
and additional information.
Document No. P11888EJ3V0DS00 (3rd edition)
Date Published October 1999 N CP(K)
Printed in Japan
The mark
shows major revised points.
©
1996,1999
µ
PC2794GS
PIN CONFIGURATION (Top View)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
UHF OSC Collector
UHF OSC Base
UHF OSC Base
UHF OSC Collector
UB
OSC OUTPUT
GND
VHF OSC Base
VHF OSC Base
VHF OSC Collector
REG
IF OUTPUT
V
CC
MIX OUTPUT
MIX OUTPUT
VHF RF INPUT
VHF RF INPUT
GND
UHF RF INPUT
UHF RF INPUT
(Tr. 1)
(Tr. 2)
(Tr. 1)
(Tr. 2)
1
20
(Tr. 1)
(Tr. 2)
(Tr. 1)
10
11
INTERNAL BLOCK DIAGRAM
20
19
18
17
16
15
14
13
IF
Amp
12
11
REG.
U OSC
V OSC
1
2
3
4
5
6
7
8
9
10
2
Data Sheet P11888EJ3V0DS00
µ
PC2794GS
PIN EXPLANATION
Pin Voltage TYP.
Pin No.
Symbol
above: VHF mode
below: UHF mode
6.90
6.25
6.00
3.90
3
UOSC
base (Tr. 1)
6.00
3.90
4
UOSC
collector
(Tr. 2)
6.90
Function and Explanation
Equivalent Circuit
1
UOSC
collector
(Tr. 1)
Collector pin of UHF oscillator.
Assemble LC resonator with 2
pin through capacitor ~ 1 pF to
oscillate with active feedback loop.
Base pin of UHF oscillator
with balance amplifier. Connected
to LC resonator through feedback
capacitor ~ 300 pF.
Base pin of UHF oscillator
with balance amplifier.
Connected to LC resonator
through feedback capacitor ~ 300 pF.
Collector pin of UHF oscillator
with balance amplifier. Assemble
LC resonator with 3 pin through
capacitor ~ 1 pF to oscillate with
active feedback loop.
Double balanced oscillator with
transistor 1 and transistor 2.
Switching pin for VHF or UHF
operation.
VHF operation = open
UHF operation = 9.0 V
3
5
1
4
2
2
UOSC
base (Tr. 2)
6.25
5
UB
—
9.0
6
OSC
output
5.40
UHF and VHF oscillator output
pin. In case of F/S tuner
application, connected PLL
symthesizer IC’s input pin.
REG
5.40
6
from
½
OSC
7
GND
0.0
0.0
GND pin of VHF and UHF
oscillator.
Base pin of VHF oscillator.
Grounded through capacitor ~
10 pF.
Base pin of VHF oscillator.
Assemble LC resonator with
10 pin to oscillate with active
feedback loop.
8
VOSC
base
(Tr. 1)
3.50
5.90
3.50
5.90
6.20
6.90
8
10
9
REG
9
VOSC
base
(Tr. 2)
10
VOSC
collector
(Tr. 1)
Collector pin of VHF oscillator.
Connected to LC resonator
through feedback capacitor ~
3 pF.
Data Sheet P11888EJ3V0DS00
3
µ
PC2794GS
Pin Voltage TYP.
Pin No.
Symbol
above: VHF mode
below: UHF mode
6.90
6.90
12
IF output
2.60
Function and Explanation
Equivalent Circuit
11
REG
Monitor pin of regulator output
voltage.
IF output pin of VHF-UHF
band functions.
13
2.60
12
13
V
CC
9.0
9.0
Power supply pin for VHF-
UHF band functions.
VHF and UHF MIX output pins.
These pins should be
equipped with tank circuit to
adjust intermediate frequency.
Bypass pin for VHF MIX input.
Grounded through capacitor.
14
MIX
output1
7.10
7.00
7.10
7.00
2.75
13
14 15
15
MIX
output2
16
VRF input
(bypass)
½
from
VHF
OSC
2.80
17
16
17
VRF input
2.75
VRF signal input pin from
antenna.
2.80
18
GND
0.0
GND pin of MIX, IF amplifier
and regulator.
14
15
13
0.0
from
UHF
OSC
19
URF input
(bypass)
–
Bypass pin for UHF MIX input.
Grounded through capacitor.
19
20
½
2.65
20
URF input
–
URF signal input pin from
antenna.
2.65
4
Data Sheet P11888EJ3V0DS00
µ
PC2794GS
ABSOLUTE MAXIMUM RATINGS (T
A
= 25
°
C unless otherwise specified)
Parameter
Supply Voltage 1
Supply Voltage 2
Power dissipation
Operating ambient temperature
Storage temperature
Symbol
V
CC
UB
P
D
T
A
T
stg
T
A
= 80
°C*
1
Condition
Rating
11.0
11.0
700
–40 to +80
–60 to +150
Unit
V
V
mW
°C
°C
*1
Mounted on 50
×
50
×
1.6 mm double copper epoxy glass board.
RECOMMENDED OPERATING RANGE
Parameter
Supply voltage 1
Supply voltage 2
Operating ambient temperature
Symbol
V
CC
UB
T
A
MIN.
8.0
8.0
–20
TYP.
9.0
9.0
+25
MAX.
10.0
10.0
+80
Unit
V
V
°C
ELECTRICAL CHARACTERISTICS (T
A
= 25
°
C, V
CC
= 9 V, f
IF
= 45 MHz, P
osc
= –10 dBm)
Parameter
Circuit Current 1
Circuit Current 2
Conversion Gain 1
Conversion Gain 2
Conversion Gain 3
Conversion Gain 4
Conversion Gain 5
Noise Figure 1
Noise Figure 2
Noise Figure 3
Noise Figure 4
Noise Figure 5
Maximum Output Power 1
Maximum Output Power 2
Maximum Output Power 3
Maximum Output Power 4
Maximum Output Power 5
Symbol
I
CC
1
I
CC
2
CG1
CG2
CG3
CG4
CG5
NF1
NF2
NF3
NF4
NF5
P
O (sat)
1
P
O (sat)
2
P
O (sat)
3
P
O (sat)
4
P
O (sat)
5
Test Conditions
@VHF, no input signal
@UHF, no input signal
f
RF
= 55 MHz, P
RF
= –30 dBm
f
RF
= 200 MHz, P
RF
= –30 dBm
f
RF
= 470 MHz, P
RF
= –30 dBm
f
RF
= 470 MHz, P
RF
= –30 dBm
f
RF
= 890 MHz, P
RF
= –30 dBm
f
RF
= 55 MHz
f
RF
= 200 MHz
f
RF
= 470 MHz
f
RF
= 470 MHz
f
RF
= 890 MHz
f
RF
= 55 MHz, P
RF
= 0 dBm
f
RF
= 200 MHz, P
RF
= 0 dBm
f
RF
= 470 MHz, P
RF
= 0 dBm
f
RF
= 470 MHz, P
RF
= 0 dBm
f
RF
= 890 MHz, P
RF
= 0 dBm
*1
*1
*2
*2
*2
*2
*2
*3
*3
*3
*3
*3
*2
*2
*2
*2
*2
MIN.
36.0
37.0
19.5
19.5
20.5
28.5
28.5
—
—
—
—
—
10.0
10.0
10.0
10.0
10.0
TYP.
48.0
50.0
23.0
23.0
24.0
32.0
32.0
11.0
11.0
11.0
9.0
10.0
13.0
13.0
13.0
13.0
13.0
MAX.
56.0
60.0
26.5
26.5
27.5
35.5
35.5
14.0
14.0
14.0
12.0
13.0
—
—
—
—
—
Unit
mA
mA
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
dBm
dBm
dBm
dBm
dBm
*1
By measurement circuit 1
*2
By measurement circuit 2
*3
By measurement circuit 3
Data Sheet P11888EJ3V0DS00
5
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