Technical Data
MC44BS373CA
Rev. 2.6, 6/2004
MC44BS373CA
Data Sheet
PLL-Tuned UHF and VHF
Audio/Video High-Integration
Modulator
MC44BS373CA
SO16NB Package
QFN20 Package
Ordering Information
Device
MC44BS373CAD,R2
MC44BS373CAFC,R2
MC44BS373CAEF,R2
Temp Range
–20 to +85°C
–20 to +85°C
–20 to +85°C
Package
SO16NB
QFN20
Lead Free
SO16NB
Lead Free
NOTE: For tape and reel, add R2 suffix.
Contents
1 Features . . . . . . . . . . . . . . . . . . . . . . 2
2 Comparing the MC44BS373CA to the
MC44BC373/4C. . . . . . . . . . . . . . . . . 2
3 Pin Descriptions. . . . . . . . . . . . . . . . . 3
4 MC44BS373CA Functional Overview 5
5 Maximum Ratings . . . . . . . . . . . . . . . 6
6 Thermal Ratings . . . . . . . . . . . . . . . . 6
7 Electrostatic Discharge . . . . . . . . . . . 7
8 Electrical Characteristics . . . . . . . . . . 7
9 I2C Bit Mapping . . . . . . . . . . . . . . . . . 8
10 I2C Programming . . . . . . . . . . . . . . 10
11 Modulator High-Frequency
Characteristics . . . . . . . . . . . . . . . . . 13
12 Video Characteristics. . . . . . . . . . . . 14
13 Audio Characteristics. . . . . . . . . . . . 16
14 Characterization Measurement
Conditions . . . . . . . . . . . . . . . . . . . . 17
15 MC44BS373CA Modes of Operation 22
16 High Speed I2C Compatible Bus. . . 27
17 Pin Circuit Schematics. . . . . . . . . . . 31
18 Application Diagrams. . . . . . . . . . . . 32
19 MC44BS373CA Evaluation Board
Schematic and Layout . . . . . . . . . . . 36
20 Packaging Instructions . . . . . . . . . . 41
21 Marking Instructions . . . . . . . . . . . . 42
22 Case Outlines . . . . . . . . . . . . . . . . . 43
23 Document Revision History . . . . . . . 48
The MC44BS373CA audio and video modulator is for use in VCRs, set-top boxes, and
similar devices.
•
•
•
Supports multiple standards
TV output level 82 dBµV typical
5- and 3.3-V compatible I
2
C bus
Figure 1 shows the pin connections for both package options.
PLLFLT
GNDD
18
SCL
SDA
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
GNDD
VCCD
PLLFLT
TVOVCC
TVOUT
GND
VCCA
VIDEO
LOP
CAS
XTAL
GND
PREEM
1
2
3
4
5
20
19
VCCD
SDA
SCL
17 16
15
14
13
12
11
TVOVCC
TVOUT
NC
GND
NC
LOP
XTAL
GND
PREEM
AUDIO
SPLLFLT
6
7
8
9
10
AUDIO
SPLLFLT
AUXIN
VIDEO
SO16NB Package
QFN20 Package
Figure 1. MC44BS373CA Pin Connections
VCCA
Features
1 Features
The MC44BS373CA is a multi-standard, PAL/SECAM/NTSC modulator.
The channel is set by an on-chip high-speed I
2
C-compatible bus receiver. A phase-locked loop (PLL) tunes
the modulator over the full UHF range.
The modulator incorporates a sound subcarrier oscillator and uses a second PLL to derive 4.5-, 5.5-, 6.0-,
and 6.5-MHz subcarrier frequencies. These frequencies are selectable by bus.
The modulation standard can be chosen using a control bit that selects between positive and negative
modulation.
The picture-to-sound ratio may be adjusted using the bus. In addition, an on-chip video test pattern generator
can be switched on with a 1-kHz audio test signal.
The MC44BS373CA also has the following features:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Integrated on-chip programmable UHF oscillator
No external varicaps diodes/inductor or tuned components
Extremely low external component count
Channel 21–69 UHF operation
VHF range possible by internal dividers (30–450 MHz)
Boosted TVOUT level (82 dBµV typical)
High-speed read and write I
2
C bus compatible (800 kHz)
I
2
C address selectable by pin (four choices) using external resistor (available only in QFN20
package)
I
2
C bus 5- and 3.3-V compatible
Fixed video modulation depth (93% typical in system L and 82% typical in the other standards)
Peak white clip disabled by bus
Programmable picture/sound carrier ratio (12 and 16 dB)
Integrated on-chip programmable sound subcarrier oscillator (4.5, 5.5, 6.0 and 6.5 MHz)—no
external varicaps
Programmable sound reference frequency (31.25 and 62.5 kHz)
Direct RF sound modulator input (FM and AM modulator bypassed) for NICAM or stereo sound
applications (available only in QFN20 package)
On-chip video test pattern generator with sound test signal (1 kHz)
Low-power programmable modulator standby mode
Transient output inhibit during PLL lock-up at power-on
Logical output port controlled by bus
ESD protection, minimum 4 KV
2 Comparing the MC44BS373CA to the MC44BC373/4C
Compared to the MC44BC373/4C devices, the MC44BS373CA has the following improvements:
•
•
Higher output level (82 versus 74.5 dBµV)
Higher video signal to noise (+3 dB)
MC44BS373CA Data Sheet
Pin Descriptions
•
•
•
•
•
•
•
•
•
I
2
C bus 3.3-V compatible
Lower power consumption in normal and standby modes (–2 mA)
Can be powered down without holding down I
2
C lines
TB1 bit no longer available (limited compatibility with MC44355 devices no longer available)
New SREF bit to program sound reference frequency (31.25 and 62.5 kHz)
Four different I
2
C addresses selectable by single pin with external resistor (available only in QFN20
package)
Direct sound RF modulator (FM and AM sound modulators bypassed) for NICAM or stereo sound
applications (available only in QFN20 package)
Switch between two integrated VCOs controlled directly by frequency divider (at 700 MHz)
Lower RF second harmonic spurious but higher third harmonic spurious. In applications it is easier
to filter UHF third harmonics spurious than second harmonics, as these frequencies are always out
of the UHF band. Unfortunately, the second harmonic can fall back into the same UHF band (for
instance channel 21 second harmonic). For this reason, it is almost impossible to have a good
rejection of low UHF second harmonic with an external low-pass filter. This is why the design has
been optimized for maximum second harmonic rejection in spite of an increase in the third
harmonic level.
3 Pin Descriptions
This section describes the pins of the MC44BS373CA. First the 16-pin package will be considered, then the
20-pin package.
3.1 SO16 Package Pin Descriptions
The pins of the 16-pin package are listed in Table 1, along with a description of each.
Table 1. SO16 Package Pin Descriptions
Pin
1
2
3
4
5
6
7
8
Name
SCL
SDA
LOP
XTAL
GND
PREEM
AUDIO
I
2
C clock
I
2
C data
Logical output port controlled by I
2
C bus
Crystal
Ground
Pre-emphasis capacitor
Audio input
Description
Pin
9
10
11
12
Name
VIDEO
VCCA
GND
TVOUT
Video input
Main analog supply voltage
Analog ground
TV output signal
Description
13 TVOVCC TV output stage supply voltage
14
15
16
PLLFLT
VCCD
GNDD
RF PLL loop filter
Digital supply voltage
Digital ground
SPLLFLT Sound PLL loop filter
MC44BS373CA Data Sheet
Pin Descriptions
3.2 QFN20 Package Pin Descriptions
The pins of the 20-pin package are listed in Table 2, along with a description of each.
Table 2. QFN20 Package Pin Descriptions
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Name
LOP
CAS
XTAL
GND
PREEM
AUDIO
SPLLFLT
AUXIN
VIDEO
VCCA
NC
GND
NC
TVOUT
TVOVCC
PLLFLT
VCCD
GNDD
SCL
SDA
Description
Logical output port controlled by I
2
C bus
Chip address selection (external pull-down resistor or open)
Crystal
Ground
Pre-emphasis capacitor
Audio input
Sound PLL loop filter
Sound auxiliary input (sound FM and AM modulators bypassed)
Video input
Main analog supply voltage
Not connected
Analog ground
Not connected
TV output signal
TV output stage supply voltage
RF PLL loop filter
Digital supply voltage
Digital ground
I
2
C clock
I
2
C data
MC44BS373CA Data Sheet
MC44BS373CA Functional Overview
4 MC44BS373CA Functional Overview
Figure 2 shows a simplified block diagram of the MC44BS373CA.
LOP
Peak
White
Clip
L /BG
VIDEO
SPLLFLT
MODULATOR
SECTION
I
2
C
BUS
Video
Modulator
Clamp
31.25/62.5
kHz
Sound
PFD
Sound
Oscillator
and FM
Modulator
Audio
Amplifier
AUDIO
PREEM
L/BG
TVOVCC
TVOUT
75
Ω
LPF
Prog
Divider
VCCA
LPF
ALC
GND
GND
I
2
C BUS
I
2
C BUS
FM
AM
LPF
L/BG
AM Modulator
AUXIN
(only in QFN 20)
RF Sound
Modulator
BUS SECTION
CAS
(only in QFN 20)
SCL
SDA
VHF Dividers
VCO and PLL SECTION
PLL
I
2
C BUS
High Speed
I
2
C Bus
Receiver
UHF OSC
Prescaler/8
I
2
C BUS
Prog
Divider
Phase
Comp
Ref Divider
/128
4-MHz
XCO
31.25 kHz
PLLFLT
XTAL
VCCD
GNDD
Figure 2. MC44BS373CA Simplified Block Diagram
The MC44BS373CA device has three main sections:
•
•
•
A high-speed I
2
C-compatible bus section
A PLL section to synthesize the UHF/VHF output channel frequency (from an integrated UHF
oscillator, divided for VHF output)
A modulator section, which accepts audio and video inputs, then uses them to modulate the
UHF/VHF carrier
An on-chip video test pattern generator with an audio test signal is included.
The MC44BS373CA operates as a multi-standard modulator and can handle the following systems using
the same external circuit components: B/G, I, D/K, L, M/N.
High-frequency BiCMOS technology allows integration of the UHF tank circuit and certain filtering
functions.
MC44BS373CA Data Sheet
TI Technology Forum
京公网安备 11010802033920号
EEWORLD
