- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄379898 > CLC5902VLA (NATIONAL SEMICONDUCTOR CORP) Dual Digital Tuner/AGC PDF資料下載
參數(shù)資料
| 型號： | CLC5902VLA |
| 廠商： | NATIONAL SEMICONDUCTOR CORP |
| 元件分類： | 調(diào)諧器 |
| 英文描述： | Dual Digital Tuner/AGC |
| 中文描述： | 1-BAND, AUDIO TUNER, PQFP128 |
| 封裝： | PLASTIC, QFP-128 |
| 文件頁數(shù)： | 20/28頁 |
| 文件大?。?/td> | 783K |
| 代理商： | CLC5902VLA |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁當(dāng)前第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁
Rev. 3.05 May 27, 1999
20
1999 National Semiconductor Corporation
AGC
The CLC5902 AGC processor monitors the output level of
the ADC and servos it to the desired setpoint. The ADC
input is controlled by the DVGA to maintain the proper
setpoint level. DVGA operation results in a compression
of the signal through the ADC. The DVGA signal com-
pression is reversed in the CLC5902 to provide > 120dB
of linear dynamic range. This is illustrated in Figure 30.
In order to use the AGC the DRCS Control Panel software
should be used to calculate the programmable parameters.
To generate these parameters only the desired setpoint,
deadband+hysteresis, and loop time constant need to be
supplied. All subsequent calculations are performed by the
software. Complete details of the AGC operation are pro-
vided in an appendix but are not required reading.
AGC setpoint and deadband+hysteresis are illustrated in
Figure 31. The loop time constant is a measure of how fast
the loop will track a changing signal. Values down to
approximately 1.0 microsecond will be stable with the sec-
ond order LC noise filter. Since the DVGA operates with
6dB steps the deadband should always be greater than 6dB
to prevent oscillation. An increased deadband value will
reduce the amount of AGC operation. A decreased dead-
band value will increase the amount of AGC operation but
will hold the ADC output closer to the setpoint. The
threshold should be set so that transients do not cause sus-
tained overrange at the ADC inputs. The threshold setting
can also be used to set the ADC input near its optimal per-
formance level.
The AGC may be configured to free run, operate for a pro-
grammable period of time (burst mode), or stop running.
If
a burst start pulse is applied to the
AGC_EN
pin in burst
mode, the AGC will free run for AGC_HOLD_COUNT
CK
periods then freeze. At the beginning of the next burst
either the freeze value is maintained or an initial condition
is set from AGC_IC_A|B based on
AGC_RESET_EN.
Allowing the AGC to free run should be appropriate for
most applications. Table 4 shows the AGC mode control
bits.
Power Management
The CLC5902 can be placed in a low power (static) state
by stopping the input clock. To prevent this from placing
the CLC5902 into unexpected states, the
SI
pin of the
CLC5902 should be asserted prior to disabling the input
clock and held asserted until the input clock has returned
to a stable condition.
Figure 30
Output Gain Scaling vs. Input Signal
Input Power
ADC Output
ADC Full Scale
AGC Threshold
Deadband+Hysteresis
O
DDCOupu
Diversity Receiver
Chipset Full Scale
OvrThsRng
Figure 31
AGC Setup.
DVGA Input Power
D
Deadband
Hysteresis=Deadband-6dB
Reference
Setpoint
6
6dB
AGC Mode
AgcHldIC
AgcRstEn
AgcForce
Free Run
0
0
1
Burst, hold previous value
0
0
0
Burst, use initial conditions
0
1
0
Manual
1
0
0
Table 4
AGC Operating Modes
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| CLC5903 | Dual Digital Tuner / AGC |
| CLC5903SM | Dual Digital Tuner / AGC |
| CLC5903VLA | Dual Digital Tuner / AGC |
| CLC5955 | 11-bit, 55MSPS Broadband Monolithic A/D Converter |
| CLC5955MTDX | 11-bit, 55MSPS Broadband Monolithic A/D Converter |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| CLC5903 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Dual Digital Tuner / AGC |
| CLC5903CISM/NOPB | 功能描述:上下轉(zhuǎn)換器 RoHS:否 制造商:Texas Instruments 產(chǎn)品:Down Converters 射頻:52 MHz to 78 MHz 中頻:300 MHz LO頻率: 功率增益: P1dB: 工作電源電壓:1.8 V, 3.3 V 工作電源電流:120 mA 最大功率耗散:1 W 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFP-128 |
| CLC5903SM | 功能描述:上下轉(zhuǎn)換器 RoHS:否 制造商:Texas Instruments 產(chǎn)品:Down Converters 射頻:52 MHz to 78 MHz 中頻:300 MHz LO頻率: 功率增益: P1dB: 工作電源電壓:1.8 V, 3.3 V 工作電源電流:120 mA 最大功率耗散:1 W 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFP-128 |
| CLC5903SM/NOPB | 功能描述:上下轉(zhuǎn)換器 RoHS:否 制造商:Texas Instruments 產(chǎn)品:Down Converters 射頻:52 MHz to 78 MHz 中頻:300 MHz LO頻率: 功率增益: P1dB: 工作電源電壓:1.8 V, 3.3 V 工作電源電流:120 mA 最大功率耗散:1 W 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFP-128 |
| CLC5903VLA | 功能描述:上下轉(zhuǎn)換器 RoHS:否 制造商:Texas Instruments 產(chǎn)品:Down Converters 射頻:52 MHz to 78 MHz 中頻:300 MHz LO頻率: 功率增益: P1dB: 工作電源電壓:1.8 V, 3.3 V 工作電源電流:120 mA 最大功率耗散:1 W 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PQFP-128 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。