- 您現在的位置：買賣IC網 > PDF目錄98266 > TMDS261BPAGR (TEXAS INSTRUMENTS INC) SPECIALTY CONSUMER CIRCUIT, PQFP64 PDF資料下載
參數資料
| 型號： | TMDS261BPAGR |
| 廠商： | TEXAS INSTRUMENTS INC |
| 元件分類： | 消費家電 |
| 英文描述： | SPECIALTY CONSUMER CIRCUIT, PQFP64 |
| 封裝： | GREEN, PLASTIC, TQFP-64 |
| 文件頁數： | 25/49頁 |
| 文件大小： | 11321K |
| 代理商： | TMDS261BPAGR |
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頁第20頁第21頁第22頁第23頁第24頁當前第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁
up(min)
DD
R
V
/ Isink
=
(1)
t
k
RC
=
(2)
(
)
t/RC
DD
V(t)
V
1 e
-
=
-
(3)
www.ti.com .......................................................................................................................................................................................... SLLS987 – SEPTEMBER 2009
2. The maximum transition time on the bus:
The maximum transition time, T, of an I2C bus is set by an RC time constant, where R is the pullup resistor
value and C is the total load capacitance. The parameter, k, can be calculated from Equation 3 by solving for
t, the times at which certain voltage thresholds are reached. Different input threshold combinations introduce
different values of t. Table 4 summarizes the possible values of k under different threshold combinations.
Table 4. Value of k for Different Input Threshold Voltages
Vth–\Vth+
0.7 VDD
0.65 VDD
0.6 VDD
0.55 VDD
0.5 VDD
0.45 VDD
0.4 VDD
0.35 VDD
0.3 VDD
0.1 VDD
1.0986
0.9445
0.8109
0.6931
0.5878
0.4925
0.4055
0.3254
0.2513
0.15 VDD
1.0415
0.8873
0.7538
0.6360
0.5306
0.4353
0.3483
0.2683
0.1942
0.2 VDD
0.9808
0.8267
0.6931
0.5754
0.4700
0.3747
0.2877
0.2076
0.1335
0.25 VDD
0.9163
0.7621
0.6286
0.5108
0.4055
0.3102
0.2231
0.1431
0.0690
0.3 VDD
0.8473
0.6931
0.5596
0.4418
0.3365
0.2412
0.1542
0.0741
—
From Equation 1, Rup(min) = 5.5 V/3 mA = 1.83 k to operate the bus under a 5-V pullup voltage and provide less
than 3 mA when the I2C device is driving the bus to a low state. If a higher sink current, for example 4 mA, is
allowed, Rup(min) can be as low as 1.375 k.
Given a 5-V I2C device with input low and high threshold voltages at 0.3 VDD and 0.7 Vdd, respectively, the value
of k is 0.8473 from Table 4. Taking into account the 1.83-k
pullup resistor, the maximum total load capacitance
is C(total-5V) = 645 pF. Ccable(max) should be restricted to be less than 545 pF if Csource and Ci can be as high as 50
pF. Here the Ci is treated as Csink, the load capacitance of a sink device.
Fixing the maximum transition time from Table 4, T = 1
s, and using the k values from Table 4, the
recommended maximum total resistance of the pullup resistors on an I2C bus can be calculated for different
system setups.
To support the maximum load capacitance specified in the HDMI specification, Ccable(max) = 700 pF/Csource = 50
Table 5. Pullup Resistors for Different Threshold Voltages and 800-pF Load
Vth–\Vth+
0.7 VDD
0.65 VDD
0.6 VDD
0.55 VDD
0.5 VDD
0.45 VDD
0.4 VDD
0.35 VDD
0.3 VDD
UNIT
0.1 VDD
1.14
1.32
1.54
1.80
2.13
2.54
3.08
3.84
4.97
k
0.15 VDD
1.20
1.41
1.66
1.97
2.36
2.87
3.59
4.66
6.44
k
0.2 VDD
1.27
1.51
1.80
2.17
2.66
3.34
4.35
6.02
9.36
k
0.25 VDD
1.36
1.64
1.99
2.45
3.08
4.03
5.60
8.74
18.12
k
0.3 VDD
1.48
1.80
2.23
2.83
3.72
5.18
8.11
16.87
—
k
Or, limiting the maximum load capacitance of each cable to 400 pF to accommodate with I2C specification
version 2.1, Ccable(max) = 400 pF/Csource = 50 pF/Ci = 50 pF; the maximum values of R(max) are calculated as
shown in Table 6.
Table 6. Pullup Resistor Upon Different Threshold Voltages and 500-pF Loads
Vth–\Vth+
0.7 VDD
0.65 VDD
0.6 VDD
0.55 VDD
0.5 VDD
0.45 VDD
0.4 VDD
0.35 VDD
0.3 VDD
UNIT
0.1 VDD
1.82
2.12
2.47
2.89
3.40
4.06
4.93
6.15
7.96
k
0.15 VDD
1.92
2.25
2.65
3.14
3.77
4.59
5.74
7.46
10.30
k
0.2 VDD
2.04
2.42
2.89
3.48
4.26
5.34
6.95
9.63
14.98
k
0.25 VDD
2.18
2.62
3.18
3.92
4.93
6.45
8.96
13.98
28.99
k
0.3 VDD
2.36
2.89
3.57
4.53
5.94
8.29
12.97
26.99
—
k
Copyright 2009, Texas Instruments Incorporated
31
Product Folder Link(s) :TMDS261B
相關PDF資料 |
PDF描述 |
|---|---|
| TMDS261BPAG | SPECIALTY CONSUMER CIRCUIT, PQFP64 |
| TMDS261PAGR | SPECIALTY CONSUMER CIRCUIT, PQFP64 |
| TMDS261PAG | SPECIALTY CONSUMER CIRCUIT, PQFP64 |
| TMDS341APFCR | 3-CHANNEL, AUDIO/VIDEO SWITCH, PQFP80 |
| TMDS351PAGR | 3-CHANNEL, AUDIO/VIDEO SWITCH, PQFP64 |
相關代理商/技術參數 |
參數描述 |
|---|---|
| TMDS261PAG | 功能描述:視頻開關 IC 2 to 1 HDMI Switch RoHS:否 制造商:Texas Instruments 開關數量:4 開啟電阻（最大值）:12 Ohms 傳播延遲時間: 開啟時間（最大值）: 關閉時間（最大值）: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:WQFN-42 封裝:Reel |
| TMDS261PAGR | 功能描述:視頻開關 IC 2 to 1 HDMI Switch RoHS:否 制造商:Texas Instruments 開關數量:4 開啟電阻（最大值）:12 Ohms 傳播延遲時間: 開啟時間（最大值）: 關閉時間（最大值）: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝 / 箱體:WQFN-42 封裝:Reel |
| TMDS28027USB | 功能描述:仿真器/模擬器 TMX320F28027 Piccolo controlSTICK RoHS:否 制造商:Blackhawk 產品:System Trace Emulators 工具用于評估:C6000, C5000, C2000, OMAP, DAVINCI, SITARA, TMS470, TMS570, ARM 7/9, ARM Cortex A8/R4/M3 用于:XDS560v2 |
| TMDS2MTRPFCKIT | 功能描述:電源管理IC開發工具 Dual Motor Control and PFC Dev Kit RoHS:否 制造商:Maxim Integrated 產品:Evaluation Kits 類型:Battery Management 工具用于評估:MAX17710GB 輸入電壓: 輸出電壓:1.8 V |
| TMDS3080005 | 功能描述:EMULATOR CABLE RoHS:是 類別:編程器，開發系統 >> 配件 系列:- 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program RoHS指令信息:IButton RoHS Compliance Plan 標準包裝:1 系列:- 附件類型:USB 至 1-Wire? RJ11 適配器 適用于相關產品:1-Wire? 設備 產品目錄頁面:1429 (CN2011-ZH PDF) |
發布緊急采購，3分鐘左右您將得到回復。