mc44bc373c Freescale Semiconductor, Inc, mc44bc373c Datasheet - Page 17

• Manufacturer Part Number: mc44bc373c
• Description: Pll Tuned Uhf And Vhf Audio/video High Integration Modulator
• Manufacturer: Freescale Semiconductor, Inc

13 Modulator Description
13.1 Power ON Settings
At power-ON, the MC44BC373C/4C configuration is as follows:
These settings can be customized in special masked version.
13.2 Power Supply
The three device Vccs (pins 10, 13, 15) must be applied at the same time to ensure all internal blocks are
correctly biased. All other pins must not be biased before Vcc is applied to device.
13.3 Standby modes
During standby mode, the modulator is switched to low power consumption: the sound oscillator, UHF
oscillator, video and sound modulator sections bias are internally turned OFF.
The IIC bus section remains active.
Modulator can be programmed in standby mode with combination of 3 bits:OSC=1, SO=1 and ATT=1
13.4 System L or B / G Selection
SYSL bit internally switches the following functions:
C1—High Order Bits
C0—Low Order Bits
FM—High Order Bits
FL—Low Order Bits
Note:
Note:
Note:
Note:
Note:
•
•
N0 to N11 are set to have UHF oscillator on channel 36 (591.25MHz).
Peak White Clip is ON.
Sound frequency is 5.5MHz.
Logic Output Port is low voltage.
Picture to sound ratio is 12dB.
SYSL = 0 enables B/G system
— Video modulation polarityNegative
— Video modulation depth80% Typical (See “Video Characteristics” on page 10.)
— Sound modulation typeFM
SYSL = 1 enables L system
— Video modulation polarityPositive
— Video modulation depth90% Typical (See “Video Characteristics” on page 10.)
— Sound modulation typeAM
WRITE MODE
Freescale Semiconductor, Inc.
For More Information On This Product,
MC44BC373C/374C Technical Data
Bit 7
N5
1
0
0
Go to: www.freescale.com
Bit 6
N4
0
0
0
Bit 5
N11
N3
0
0
Bit 4
N10
N2
0
0
Bit 3
N9
N1
0
1
Bit 2
N8
N0
0
0
Modulator Description
Bit 1
N7
0
0
0
Bit 0
N6
0
0
0
ACK
ACK
ACK
ACK
ACK