MC44BC374CDTB 데이터 시트보기 (PDF) - Freescale Semiconductor
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MC44BC374CDTB Datasheet PDF : 30 Pages
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Modulator Description Freescale Semiconductor, Inc.
13.5 Test Bit TB1
This test bit allows a different bus format.
• TB1=0 — All MC44BC373C/4C Functions Available—Normal Mode.
• TB1=1 — Limited Software Compatibility with MC443533. MC44BC373C/4C Functions Not
Available. TB1=1, allows a first evaluation of MC44BC373C/4C using software developed for
MC44353 devices.
WRITE MODE†
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 ACK
CA—CHIP ADDRESS
1
1
0
0
1
0
1
0
ACK
C1—High Order Bits
1
*
*
*
PS
*
* SYSL ACK
C0—Low Order Bits
*
*
* SFD1 SFD0 1
0
0
ACK
FM—High Order Bits
0 TPEN N11 N10 N9
N8
N7
N6 ACK
FL—Low Order Bits
N5
N4
N3
N2
N1
N0
*
*
ACK
† Case TB1=1 compatible with MC44353
• All “∗” are don’t care bits.
• PS bit replaces PSD2 bit in MC44353 bus format:
• PS = 0 is for Picture-to-Sound ratio = 12dB
• PS = 1 is for Picture-to-Sound ratio = 16dB
• SFD1 and SFD0 bits have the same definition for both bus formats (MC44353 and MC44BC373C/4C) and
allows a select sound frequency between 4.5MHz, 5MHz, 5.5MHz, and 6.5MHz.
• SYSL bit is the same definition for both bus formats (MC44353 and MC44BC373C/4C) and allows a select
system L or BG.
• All MC44BC373C/4C functions are set to their default values.
13.6 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:
• Power-ON from zero (i.e., all Vcc is switched from 0V to 5V).
• UHF oscillator power-ON from OFF state (i.e., OSC bit is switched from 1 to 0)
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 10µA typical to speed up the
locking time. After the 263ms time-out, the current source is switched to 1µA. Use care when selecting
loop filter components, to ensure the loop transient does not exceed this delay.
For test purposes, it is possible to disable the 263ms delay using Test Mode1–State1.h (this is called speed
up mode).
13.7 UHF Oscillator—VHF range
The UHF oscillator is fully integrated and does not require any external components.
For low frequency testing or VHF range operation (test mode 1, states 1.b to 1.c), the UHF oscillator can
be internally divided by: 2, 4, 8, or 16.
MC44BC373C/374C Technical Data
For More Information On This Product,
Go to: www.freescale.com
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