SANYO LA7790M Datasheet

Overview
The LA7790M is a QPSK data transmitter for digital cable TV applications. By integrating the I/Q quadrature modulator, RF amplifier, electronic volume control, mute control, and other functions onto a single chip, parts count is reduced and set size is miniaturized.
Features
terminator), suitable for directly driving the cable.
• RF output frequency range of 5 to 70 MHz. Frequency range selection function permits broadband designs.
• Electronic volume control for direct-current control of RF output level.
• Muting ensures ample attenuation during periods with no transmission.
• Support for both internal and external bias for I/Q modulation inputs.
• Support for I/Q modulation frequencies up to 10 MHz. (typ: 500 mVp-p)
Functions
• I/Q quadrature modulator
• I/Q input bias power supply
• RF amplifier
• Varactor diode-based VCO
• Muting
• Electronic volume control
• Power-saving modes
• Switchable output frequency range
• Power supply voltage of 5 V (4.5 to 5.5 V)
Package Dimensions
unit: mm
3108-MFP24D
Monolithic Linear IC
5061998RM (OT) No. 5689-1/14
SANYO: MFP24D
[LA7790M]
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
QPSK Transmitter for Cable TV
LA7790M
Ordering number : EN5689A
Ambient temperature, Ta (°C)
Allowable power dissipation, Pd
max
(mW)
No. 5689-2/14
LA7790M
Parameter Symbol Conditions Ratings Unit
Maximum power supply voltage V
CC
max Pins 1, 10, and 24 7 V
Circuit voltage Vmax Pins 1, 12, 17, 20, 21, and 23 V
CC
V
Circuit current
I
11
Output lead-in current
1 mA
I
19
2 mA Allowable power dissipation Pd max Ta 54°C 650 mW Operating ambient temperature Topr –20 to +70 °C Storage temperature Tstg –55 to +150 °C
Specifications
Maximum Ratings at Ta = 25°C
Parameter Symbol Conditions
Ratings
Unit
min typ max
Current drain
Circuit current 1 I
1
With no signal, pin 1 26 33 44 mA
Circuit current 2 I
24
+ I10With no signal, pins 24 and 10 44 55 73 mA
Modulator fo: f(V19) = 25 MHz
Output frequency range f
(V19)
5 70 MHz
Output signal level V
19(DSB)
Note 1: V20= V23= GND,
–7 –4 –2 dBm
V
12
= V17= V21= VCC, S1 = A
Output harmonic distortion
V
19(HD2)
Note 2: V20= V23= GND, 40 dB
V
19(HD3)V12
= V17= V21= VCC, S1 = A 35 dB
Output secondary harmonic distortion V
19(2fo)
Note 3: V20= V23= GND,
20 dB
V
12
= V17= V21= VCC, S1 = A
Output tertiary harmonic distortion V
19(3fo)
Note 3: V20= V23= GND,
8 dB
V
12
= V17= V21= VCC, S1 = A
Carrier suppression ratio V
19(fo)
Note 4: V20= V23= GND,
30 dB
V
12
= V17= V21= VCC, S1 = A
Sideband suppression ratio V
19(SSB)
Note 5: V20= V23= GND,
30 dB
V
12
= V17= V21= VCC, S1 = A
I input level V
4.5
V
4.5
= |V4— V5| 500 mVp-p
Q input level V
8.9
V
8.9
= |V8— V9| 500 mVp-p
I input DC voltage V
4, 5
External DC bias voltage 1.9 2.1 2.3 V
Q input DC voltage V
8, 9
External DC bias voltage 1.9 2.1 2.3 V
Reference voltage V
6
Internal DC bias voltage 1.9 2.1 2.3 V
Variable attenuator
Minimum gain control voltage V
21
V12= V17= VCC, V20= V23= GND, S1 = A 0 0.5 V
Gain range V
19(GR)
Note 6: V20= V23= GND, V12= V17= VCC,
45 dB
S1 = A, V
21
= VCC→ 0.5 V
Modulator output impedance R
19
V12= V17= V21= VCC,
80 120 160
V
20
= V23= GND, S1 = A
VCO
Oscillator frequency range f
(osc)
V12= V17= V21= VCC,
20 280 MHz
V
20
= V23= GND, S1 = A
VCO output level
V
11(fo)
V12= V17= V21= VCC,
500 700 900 mVp-p
V
20
= V23= GND, S1 = A
VCO output impedance
R
11
V12= V17= V21= VCC,
200 300 400
V
20
= V23= GND, S1 = A
Band switch
Band switch 1 “H” level
V
17H
Note 7: V12= V21= VCC,
4 V
f(V19) = 25 MHz V
20
= V23= GND, S1 = A
Band switch 1 “L” level
V
17L
Note 7: V12= V21= VCC,
1 V
f(V19) = 12.5 MHz V
20
= V23= GND, S1 = A
Operating Characteristics at Ta = 25°C, VCC= 5.0 V
Parameter Symbol Conditions Ratings Unit
Operating power supply voltage V
CC
op Pins 1, 10, and 24 4.5 to 5.5 V
Recommended Conditions at Ta = 25°C
Continued on next page.
No. 5689-3/14
LA7790M
Parameter Symbol Conditions
Ratings
Unit
min typ max
Band switch 2 “H” level
V
12H
Note 7: V17= V21= VCC,
4 V
f(V
11
) = 25 MHz V20= V23= GND, S1 = A
Band switch 2 “L” level
V
12L
Note 7: V17= V21= VCC,
1 V
f(V
11
) = 12.5 MHz V20= V23= GND, S1 = A
RF output amplifier
Maximum output level V
1
max
Note 8: V
12
= V17= V21= VCC,
7 10 13 dBm
V
20
= V23= GND, SG3 = –6 dBm, S1 = A
V
1(HD2)
Note 8: V12= V17= V21= VCC,
40 dBc
Maximum output distortion
V
20
= V23= GND, SG3 = –6 dBm, S1 = A
V
1(HD3)
40 dBc
Muting
Muting on voltage V
23H
V12= V17= V21= VCC,
4 V
V
20
= GND, S1 = B
Muting off voltage V
23L
V12= V17= V21= VCC,
1 V
V
20
= GND, S1 = B
Muting attenuation V
1(mute)
Note 9: V23= 1 V 4 V
70 dB
V
12
= V17= V21= VCC, V20= GND, S1 = B
Power save function
Power save on voltage V
20H
4 V
Power save off voltage V
20L
1 V
Power save current I
1
Note 10: V20= 4 V 0 0.1 mA
Continued from preceding page.
Pin Assignment
Note 1 Input: SG1 =1 MHz CW, 500 mVp-p, SG2 = No Signal or
SG2 = 1 MHz CW, 500 mVp-p, SG1 = No Signal
Output:
Note 2 Input: Same as Note 1 Output:
No. 5689-4/14
LA7790M
Note 4 Input: SG1 =SG2 = 1 MHz CW, 500 mVp-p Output:
Note 6 Input: SG1 =1 MHz CW, 500 mVp-p Output:
Note 5 Input: SG1 = 1 MHz CW, 500 mVp-p, 0deg
SG1 = 1 MHz CW, 500 mVp-p, 90deg
Output:
Note 3 Input: Same as Note 1 Output:
No. 5689-5/14
LA7790M
Note 7 Input: SG1 =1 MHz CW, 500 mVp-p Output:
Note 8 Input: SG3 =25 MHz CW, –6 dBm Output:
Note 9 Input: SG1 =1 MHz CW, 500 mVp-p Output:
Note 10 I1= pin 1 current when V20 = 4 V (power save on).
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