參數資料
型號: MAX3580ETJ+T
廠商: Maxim Integrated Products
文件頁數: 11/20頁
文件大?。?/td> 0K
描述: IC TV TUNER DIRECT-CONV 32TQFN
產品培訓模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標準包裝: 2,500
類型: 直接轉換電視調諧器
應用: 機頂盒
安裝類型: 表面貼裝
封裝/外殼: 32-WFQFN 裸露焊盤
供應商設備封裝: 32-TQFN-EP(5x5)
包裝: 帶卷 (TR)
MAX3580
Direct-Conversion TV Tuner
______________________________________________________________________________________
19
RF Tracking Filter
The MAX3580 utilizes two narrowband RF tracking filters,
one for VHF and one for UHF. Each filter is comprised of
a fixed inductor and three digitally controlled variable
capacitors named series, shunt, and parallel capacitors.
The integrated RF tracking filters uses an external induc-
tor between IND1 and IND2 pins to set the filter’s center
frequency. The inductor value must be 68nH ±2% in
order to achieve the corner frequency response. The vari-
able capacitors are factory calibrated to this particular
inductor value. The value of each capacitor is also set to
compensate for process variation of each individual part
and to receive the desired RF channel.
The process variation is factory calibrated by determin-
ing the best capacitor values for three discrete frequen-
cies, which are stored in the on-chip ROM table. Upon
power-up these values (6 bytes total) have to be read
out of the MAX3580 ROM table and stored in the micro-
processor local memory.
When tuning the MAX3580 to a given Rx frequency, the
correct capacitor value has to be calculated using the
following linear formulas and written to the appropriate
registers. This is in addition to programming the PLL
with the desired frequency.
The formulas differ for VHF and UHF bands but are the
same for all three capacitor values. Since the factory
calibration coefficients stored on the MAX3580 can dif-
fer for each capacitor, the calculations have to be exe-
cuted for all three capacitor values separately.
VHF: Capacitor = ROM_value_VHF -
(RX_frequency_in_MHz - 200MHz ) / 10MHz
In other words, the capacitor values to be written to the
MAX3580 decrease 1 count per 10MHz above 200MHz
and increase accordingly below 200MHz.
UHF: Capacitor = ROM_value_UHF_lo -
(ROM_value_UHF_lo - ROM_value_UHF_hi)
x (RX_frequency_in_MHz - 470MHz ) / 390MHz
This means the capacitor values stored in the UHF_lo
entries of the MAX3580 ROM table are the correct values
for 470MHz reception and the UHF_hi values for 860MHz
reception. For any frequency in between, the capacitor
values are obtained by a simple linear interpolation.
Note: When tuning to frequencies above 860MHz
channel center frequency, do not use the formula
above, but rather keep programming the tracking filter
with the coefficients obtained for 860MHz.
Examples: Assuming the MAX3580 ROM table entries
are CSERIES VHF = 8, CSERIES UHF_lo = 15, CSERIES
UHF_hi = 3
208MHz:
CSERIES = 8 - round ( ( 208-200 ) / 10 ) = 7
(floating point division, round to nearest
integer after division)
8 - floor ( ( 208 - 200 + 5) / 10 ) = 7
(all calculations using signed integer values,
truncate result of division)
677MHz:
CSERIES = 15 - round ( (15-3) x (677 - 470) /
390 ) = 9 (floating point division, round to
nearest integer after division) 15 - floor
( ( ( 15-3) x (677-470) + 195 ) / 390 ) = 9
(all calculations using signed integer values,
truncate result of division)
Power-Supply Layout
To minimize coupling between different sections of the
IC, the ideal power-supply layout is a star configuration,
which has a large decoupling capacitor at the central
VCC node. The VCC traces branch out from this node,
with each trace going to separate VCC pins of the
MAX3580. Next to each VCC pin is a bypass capacitor
with a low impedance to ground at the frequency of
interest. Use at least one via per bypass capacitor for a
low-inductance ground connection.
The three ground pins (GND_PLL, GND_CP,
GND_TUNE) must be connected to the ground plane
by separate via holes and must not be directly connect-
ed to the exposed paddle.
Chip Information
PROCESS: BiCMOS
Package Information
For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in
the package code indicates RoHS status only. Package draw-
ings may show a different suffix character, but the drawing per-
tains to the package regardless of RoHS status.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
32 TQFN-EP
T3255-5
相關PDF資料
PDF描述
MAX3624AETJ+T IC CLOCK GENERATOR PREC 32TQFN
MAX3625ACUG+T IC CLOCK GENERATOR PREC 24-TSSOP
MAX3625BEUG+T IC CLOCK GENERATOR PREC 24TSSOP
MAX3645EEE+T IC AMP LIMITING 16-QSOP
MAX3654ETE+T IC AMP TRANSIMPEDANCE 16-TQFN
相關代理商/技術參數
參數描述
MAX3580EVKIT+ 功能描述:射頻開發(fā)工具 MAX3580 Eval Kit RoHS:否 制造商:Taiyo Yuden 產品:Wireless Modules 類型:Wireless Audio 工具用于評估:WYSAAVDX7 頻率: 工作電源電壓:3.4 V to 5.5 V
MAX358C/D 功能描述:多路器開關 IC RoHS:否 制造商:Texas Instruments 通道數量:1 開關數量:4 開啟電阻(最大值):7 Ohms 開啟時間(最大值): 關閉時間(最大值): 傳播延遲時間:0.25 ns 工作電源電壓:2.3 V to 3.6 V 工作電源電流: 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UQFN-16
MAX358C/D DIE 制造商:Maxim Integrated Products 功能描述:
MAX358CJE 功能描述:多路器開關 IC RoHS:否 制造商:Texas Instruments 通道數量:1 開關數量:4 開啟電阻(最大值):7 Ohms 開啟時間(最大值): 關閉時間(最大值): 傳播延遲時間:0.25 ns 工作電源電壓:2.3 V to 3.6 V 工作電源電流: 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UQFN-16
MAX358CPE 功能描述:多路器開關 IC 8:1 Fault-Protected Analog MUX RoHS:否 制造商:Texas Instruments 通道數量:1 開關數量:4 開啟電阻(最大值):7 Ohms 開啟時間(最大值): 關閉時間(最大值): 傳播延遲時間:0.25 ns 工作電源電壓:2.3 V to 3.6 V 工作電源電流: 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UQFN-16