Document
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 = 25°C) • 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
–2–
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 27kΩ.
22 AGCGND
10
VCC1
5
VREG
3.3V
5
Connects external capacitance 1µF.
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
–3–
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 90µA 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 = 25°C) (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 1.