MC44BS374CAEF Freescale Semiconductor, MC44BS374CAEF Datasheet - Page 20

• Manufacturer Part Number: MC44BS374CAEF
• Description: IC AUDIO/VIDEO MODULATOR 16-SOIC
• Manufacturer: Freescale Semiconductor

Specifications of MC44BS374CAEF

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

MC44BS374CA Modes of Operation
15 MC44BS374CA Modes of Operation
15.1 Power ON Settings
At power-ON, the MC44BS374CA is configured as follows:
15.2 Power Supply
The three device Vccs (pins 10, 13 and 15) must be applied at the same time to ensure all internal blocks
are correctly biased. Do not bias any other pin before Vcc is applied to the MC44BS374CA.
When all Vccs are switched to 0V, SDA and SCL pins are high impedance.
15.3 Standby modes
During standby mode, the modulator is switched to low power consumption. That is, the sound oscillator,
UHF oscillator, and the video and sound modulator section’s bias are internally turned OFF.
The I
The MC44BS374CA can be set to standby mode with a combination of 3 bits: OSC=1, SO=1 and ATT=1
15.4 Transient Output Inhibit
To minimize the risk of interference to other channels while the UHF PLL is acquiring a lock on the
desired frequency, the Sound and Video modulators are turned OFF during a time out period for each of
the following two cases:
There is a time-out of 263ms until the output is enabled. This lets the UHF PLL settle to its programmed
frequency. During the 263ms time-out, the sound PLL current source is set to 10 µA typical to speed up the
locking time. After the 263ms time-out, the current source is switched to 1 µA. Use care when selecting
loop filter components, to ensure the loop transient does not exceed this delay.
C1-High Order Bits
C0-Low Order Bits
FM-High Order Bits
FL-Low Order Bits
Note: N0 to N11 are set to have UHF oscillator on channel E36 ( 591.25 MHz ).
Note: Peak White Clip is ON.
Note: Sound frequency is 5.5 MHz.
Note: Logic Output Port is low voltage.
Note: Picture to sound ratio is 12 dB.
• Power-ON from zero ( i.e., all Vcc is switched from 0 V to 5 V ).
• UHF oscillator power-ON from OFF state ( i.e., OSC bit is switched from 1 to 0 )
2
C bus section remains active.
WRITE MODE
Freescale Semiconductor, Inc.
For More Information On This Product,
Bit 7
N5
1
0
0
MC44BS374CA Technical data
Table 7. Power ON Settings
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
Bit 1
N7
0
0
0
Bit 0
N6
0
0
0
ACK
ACK
ACK
ACK
ACK