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CXA3556N
IF Down Converter for Digital Broadcast
Description The CXA3556N is a one-chip integrated IC that processes IF signals of a digital broadcast tuner and includes an AGC amplifier circuit, a mixer circuit, a local oscillator circuit and an output amplifier circuit. The package utilizes a 24-pin SSOP suitable for surface mounting. Features * AGC control width that has a 56dB variable range * Low noise characteristics * Low distortion characteristics (in particular, during AGC gain reduction) * Includes switching function between down converter mode and linear amplifier mode * Variable output amplifier gain by changing external resistance * Includes RF AGC output pin * Variable RF AGC settings * AGC control curve characteristics with excellent linearity Applications Digital broadcast tuners Structure Bipolar silicon monolithic IC 24 pin SSOP (Plastic)
Absolute Maximum Rating (Ta = 25C) * Supply voltage Vcc -0.3 to +12 * Operating temperature Topr -55 to +150 Operating Conditions * Supply voltage Vcc * Operating temperature Topr
V C
4.75 to 5.25 -25 to +75
V C
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
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E02426-PS
CXA3556N
Block Diagram and Pin Configuration
IFIN1
1
24 AGCIN
IFIN2
2
23 MODESEL
RFAGC
3
Comparator
22 AGCGND
IREG
4
REG
21 AO2
VREG
5
AGC Amp. Output Amp.
20 AO1
LOB1
6
19 GND
LOC1
7
18 AGCREF
LOC2
8
OSC
Mixer
17 E2
LOB2
9
16 E1
VCC1 10
15 AIN2
MO1 11
14 AIN1
MO2 12
13 VCC2
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CXA3556N
Pin Description and Equivalent Circuit Pin No. Symbol Pin voltage Equivalent circuit Pin description
1
IFIN1
1.4V
10
VCC1
1 2 5k 5k
IF inputs.
2
IFIN2
1.4V
22 AGCGND
3
3
RFAGC
--
22 AGCGND
RF AGC voltage output. Comparator output. Low level: 0.4V or less High level: 8V or more
VCC1 10
4
IREG
2.6V
4
Connects external resistance 27k.
22 AGCGND
10
VCC1
5
VREG
3.3V
5
Connects external capacitance 1F.
22 AGCGND
6
LOB1
2.9V
10
6
8
7
9 VCC1
7
LOC1
3.7V Connects external capacitance and crystal oscillator.
8
LOC2
3.7V
19 GND
9
LOB2
2.9V
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CXA3556N
Pin No. 10
Symbol VCC1
Pin voltage 5V
10
Equivalent circuit
Pin description Power supply.
VCC1
11
MO1
2.3V
11 12
Mixer output pin.
12
MO2
2.3V
19 GND
13 14
VCC2 AIN1
5V 1.3V
10 200 VCC1
Power supply.
15
AIN2
1.3V
14 200 15
16
E1
0.6V
19
10k
10k
Output amplifier circuit inputs. Gain of output amplifier circuit can be changed by connecting external resistance between Pins 16 and 17.
GND
17
E2
0.6V
17
16
10
VCC1 90A 18
18
AGCREF
--
RF AGC setting voltage adjustment pin. Connect external resistance between Pin 18 and GND and change the value to change RF AGC output voltage.
22
AGCGND
19
GND
0V
VCC1
GND
20
AO1
2.7V
10
20 21
Output amplifier output.
21
AO2
2.7V
19
GND
-4-
CXA3556N
Pin No. 22
Symbol AGCGND
Pin voltage 0V
Equivalent circuit
Pin description AGC circuit GND. Selects either IF down converter mode or linear amplifier mode. When the voltage applied to this pin is 0.3V or less, the mode is down converter mode. When the voltage is 4.75 to 5.25V, the mode is linear amplifier mode.
20k
23
MODESEL
--
23
22
GND
10
VCC1
24
AGCIN
--
24 22
AGC control. Input voltage range is 0 to 2.2V.
AGCGND
-5-
CXA3556N
Electrical Characteristics (VCC = 5V, Ta = 25C) (1) IF down converter mode (fvco = 49.38MHz) Item Symbol Measurement conditions Input signal = no signal AGC_IN voltage = 0V Input signal = 1 wave (43.5MHz), AGC_IN voltage = 2.2V Output signal = 1Vp-p Input signal = 1 wave (43.5MHz), AGC_IN voltage = 0V Output signal = 1Vp-p G3 = G1 - G2 Input signal = 2 waves (43.5MHz, 43.6MHz)/-26dBm Output signal = 1Vp-p Input signal = 2 waves (43.5MHz, 43.6MHz)/-21dBm Output signal = 1Vp-p Input signal = -60dBm (43.5MHz) Output signal = 1Vp-p Input signal = -20dBm (43.5MHz) Output signal = 1Vp-p Min. 44 65 10 54 -44 -42 -- -- Typ. Max. Unit 63 68.5 12.2 56 -51 -51 77 73 15 58 -- -- mA dB dB dB dBc dBc
Current ICCA consumption A Gain 1 Gain 2 Gain width IM3_1 IM3_2 G1 G2 G3 DIS1 DIS2
Output noise 1 NF1 Output noise 2 NF2
-100 -96 dBc/Hz -120 -111 dBc/Hz
(2) Linear amplifier mode Item Symbol Measurement conditions Input signal = no signal AGC_IN voltage = 0V Input signal = 1 wave (43.5MHz), AGC_IN voltage = 2.2V Output signal = 1Vp-p Input signal = 1 wave (43.5MHz), AGC_IN voltage = 0V Output signal = 1Vp-p G6 = G4 - G5 Input signal = 2 waves (43.5MHz, 43.6MHz)/-26dBm Output signal = 1Vp-p Input signal = 2 waves (43.5MHz, 43.6MHz)/-21dBm Output signal = 1Vp-p Input signal = -60dBm (43.5MHz) Output signal = 1Vp-p Input signal = -20dBm (43.5MHz) Output signal = 1Vp-p Min. 44 65 10 54 -44 -42 -- -- Typ. Max. Unit 63 68.5 12.7 56 -51 -51 77 73 15 58 -- -- mA dB dB dB dBc dBc
Current ICCB consumption B Gain 4 Gain 5 Gain width IM3_3 IM3_4 G4 G5 G6 DIS3 DIS4
Output noise 3 NF3 Output noise 4 NF4
-100 -96 dBc/Hz -120 -111 dBc/Hz
(3) Output amplifier characteristics Item F characteristics Symbol F Measurement conditions Input signal = 60MHz Short between Pins 16 and 17 Min. -3 Typ. Max. Unit -1.5 0 dB
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CXA3556N
Measurement circuit 1 IF down converter mode
AGCIN 0 to 2.2V 3 5V (ICC2)
Output
1
51
51
470
470 R
1n
10n
10n
1k
680
51p 24
AGCIN
51p
23
MODESEL
22
AGCGND
21
AO2
20
AO1
19
GND
18
AGCREF
17
E2
16
E1
15
AIN2
14
AIN1
13
VCC2
6.8H 51p 51p
6.8H
RFAGC
VREG
LOC1
LOC2
LOB1
LOB2
IFIN1
IFIN2
IREG
VCC1
MO1
MO2
1 1n 200
2 1n 1n
3
4 27k 1n
5
6
7
8
9
10
11 100p
12
300
300
1
2p
10p
2p
10n
10n
47k
1H 49.38MHz 2 100p 27p 1 Toko 617DB-1018 2 3rd overtone crystal oscillator (49.381MHz) 3 ICCA = ICC1 + ICC2
1
1
27p
SG input
9V
5V (ICC1) 3
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CXA3556N
Measurement circuit 2 Linear mode
AGCIN 0 to 2.2V 5V (ICC1) 4 5V (ICC2)
Output
1
51
51
470
470 R
1n
1n
1n
680
24
AGCIN
23
MODESEL
22
AGCGND
21
AO2
20
AO1
19
GND
18
AGCREF
17
E2
16
E1
15
AIN2
14
AIN1 MO1
13
VCC2 MO2
RFAGC
VREG
LOC1
LOC2
LOB1
LOB2
IFIN1
IFIN2
IREG
VCC1
1 1n 200
2 1n 1n
3
4 27k 1n
5
6
7
8
9
10
11 100p
12
300
300
1 1k 2k 2k
1n
1n
47k
5V 1
100p 4 ICCB = ICC1 + ICC2
SG input
9V
5V (ICC1) 4
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CXA3556N
Measurement circuit 3 Output amplifier F characteristics
AGCIN 0 to 2.2V 5V (ICC2)
Output
IF input 5V (ICC2)
1
51
51
1
470
470
50k 200 1n 1n 15
AIN2
1n
1n
1n
24
AGCIN
23
MODESEL
22
AGCGND
21
AO2
20
AO1
19
GND
18
AGCREF
17
E2
16
E1
14
AIN1 MO1
13
VCC2
RFAGC
VREG
LOC1
LOC2
LOB1
LOB2
IFIN1
IFIN2
IREG
VCC1
1
2
3
4 27k
5
6
7
8
9
10
11 100p
12
1n
1n 1n
1n 47k
1 1k 2k 2k
5V 1
100p
9V
5V (ICC1)
-9-
MO2
CXA3556N
Application circuit IF down converter mode
AGCIN 0 to 2.2V Output 1 27k 1k VCC
10k 10n 10n
1k 1
680
47p 24 AGCIN 23 MODESEL 22 AGCGND 21 AO2 20 AO1 19 GND 18 AGCREF 17 E2 16 E1 15 AIN2 14 AIN1 13 VCC2 6.8H 47p LOC2
47p
6.8H 47p
RFAGC
VREG
LOC1
LOB1
LOB2
IREG
IFIN1
IFIN2
VCC1
MO1
MO2
1
2
3
4 27k
5
6
7
8
9
10
11
12
330
330
1n
1n
1n 1n
1
2p
10p
2p
10n
10n
1H IF input 47k 1 27p 49.38MHz 2 1 27p
RFAGC 9V
VCC
Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.
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CXA3556N
Description of Functions The CXA3556N is an IF down converter IC for digital broadcasts. This IC contains a mixer circuit, a local oscillator circuit and an AGC circuit that standardizes IF signals in response to levels of input signals. It can also operate in a mode other than down converter (linear amplifier mode) and making possible use in a wide variety of digital broadcast tuners. (Control using Pin 23 bias voltage.) 1. AGC Circuit This is a variable gain amplifier circuit that standardizes output in response to levels of input signals. This circuit has especially excellent low distortion and noise characteristics even when the input level is large. It also has a variable width of 56dB as the gain control range with excellent linearity of the gain control curve. 2. Local Oscillator Circuit This circuit has a structure that uses a crystal oscillator and oscillates at 3rd overtone frequency. The circuit sets the parallel frequency of the parallel LC resonator between Pins 7 and 8 close to a tertiary overtone frequency (FVCO). This oscillator circuit can also use an LC resonance circuit in place of the crystal oscillator to form an oscillator circuit. 3. Output Amplifier Circuit Adding a resistor between Pins 16 and 17 allows the gain to be changed in proportion to that resistance. (Refer to characteristic graph Fig. 5 Gain vs. resistance between E1 and E2.) The output stage of this amplifier is also designed to be 500 load/1Vp-p. 4. Mixer Circuit This circuit outputs the frequency difference between the signal input to IF IN and the local oscillator signal. 5. RF AGC Circuit This circuit has high image quality in both strong and weak electric fields. In particular, it controls the RF IC gain existing in the first stage of the CXA3556N to delay the characteristics related to S/N to the maximum limits. The circuit controls the RF IC gain using RF AGC voltage (Pin 3) in order that signals input to IF IN (Pins 1, 2) grow larger in weak electric fields. The RF AGC voltage at Pin 3 is obtained from results of a comparison between the AGC control voltage (Pin 24 input voltage) that detects output signals and the voltage at Pin 18 that can be freely set using the resistance value. When the control voltage is low, the RF IC gain decreases and when the control voltage is high, the RF IC gain increases.
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CXA3556N
IF down converter mode characteristics Fig. 1. Gain vs. AGCIN voltage
80 70 60 50
Gain [dB]
Fig. 2. Output noise vs. input level
-60 -70
Output noise [dBc/Hz]
-80 -90 -100 -110 -120 -130 -70
40 30 20 10 0 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 AGCIN voltage [V]
-60
-50
-40
-30
-20
-10
0
Input level [dBm]
Fig. 3. IM3 vs. input level
0 -10 -20
IM3 [dBc]
Fig. 4. REFAGC voltage vs. AGCIN voltage
10 9 8
REFAGC voltage [V]
7 6 5 4 3 2 R = 30k
-30 -40 -50 -60
1 -70 -70 0 -60 -50 -40 -30 -20 -10 0 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 AGCIN voltage [V] Input level [dBm]
Fig. 5. Gain vs. resistance between E1 and E2
16 14 12 10
Gain [dB]
Fig. 6. Input characteristics
70MHz 109 -625 3.6pF 30MHz 488.44 -1.3237k 4.0079pF j50 j25 j100
8 6 4 2 0 -2 -4 1 10 100 1000 10000 100000 1E+06 -j25 Start 30MHz -j50 Resistance between E1 and E2 [] -j100 Stop 70MHz 0 50 70MHz 30MHz
Gain when 1k is connected between E1 and E2 is 0dB.
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CXA3556N
Package Outline
Unit: mm
24PIN SSOP (PLASTIC)
+ 0.2 1.25 - 0.1 7.8 0.1 0.1 13
24
A
5.6 0.1 7.6 0.2
1 b
12
0.13 M B 0.65
b=0.22 0.03 0.1 0.1
0.5 0.2
DETAIL B : PALLADIUM
0 to 10 NOTE: Dimension "" does not include mold protrusion. DETAIL A
PACKAGE STRUCTURE
PACKAGE MATERIAL EPOXY RESIN PALLADIUM PLATING COPPER ALLOY 0.1g LEAD TREATMENT LEAD MATERIAL PACKAGE MASS
SONY CODE EIAJ CODE JEDEC CODE
SSOP-24P-L01 P-SSOP24-7.8x5.6-0.65
+ 0.03 0.15 - 0.01
- 13 -
Sony Corporation

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