參數(shù)資料
型號(hào): TSC2302IRGZRG4
廠商: TEXAS INSTRUMENTS INC
元件分類: 消費(fèi)家電
英文描述: SPECIALTY CONSUMER CIRCUIT, PQCC48
封裝: GREEN, PLASTIC, VQFN-48
文件頁(yè)數(shù): 52/85頁(yè)
文件大小: 1483K
代理商: TSC2302IRGZRG4
www.ti.com
1
300
200
100
0
10 k
100 k
1 M
10 M
100 M
DAC
Fullscale
Output
Current
A
400
500
RRNG Resistor Value
DAC FULLSCALE OUTPUT CURRENT
vs
RRNG RESISTOR VALUE
600
1000
900
800
700
1100
TSC2302
SLAS394 – JULY 2003
Figure 66. DAC Output Current Range vs RRNG Resistor Value
For example, consider an LCD that has a contrast control voltage VBIAS that can range from 2 V to 4 V, that
draws 400 A when used, and has an available 5-V supply. This is higher than the TSC2302 supply voltage, but
it is within the absolute maximum ratings.
The maximum VBIAS voltage is 4 V, and this occurs when the D/A converter current is 0, so only the 400-A
load current ILOAD is flowing from 5 V to VBIAS. This means 1 V is dropped across R1, so R1 = 1 V/400 A =
2.5 k
.
The minimum VBIAS is 2 V, which occurs when the D/A converter current is at its full scale value, IMAX. In this
case, 5 V - 2 V = 3 V is dropped across R1, so the current through R1 is 3 V/2.5 k
= 1.2 mA. This current is
IMAX + ILOAD = IMAX + 400 uA, so IMAX must be set to 800 A. This means that RRNG should be around 1
M
.
Since the voltage at the AOUT pin must not go below 1.5 V, this limits the voltage at the bottom of R2 to be
1.5-V minimum; this occurs when the D/A converter is providing its maximum current, IMAX. In this case, IMAX
+ILOAD flows through R1, and IMAX flows through R2. Thus,
R2 x IMAX + R1(IMAX + ILOAD) = 5 V - 1.5 V = 3.5 V
(12)
W R1 = 2.5 k
IMAX = 800A, ILOAD = 400A, thus allowing R2 to be solved as 625 .
In the previous example, when the DAC current is zero, the voltage on the AOUT pin rises above the TSC2302
supply voltage. This is not a problem, however, since V+ was within the absolute maximum ratings of the
TSC2302, so no special precautions are necessary. Many LCD displays require voltages much higher than the
absolute maximum ratings of the TSC2302. In this case, the addition of an NPN transistor, as shown in Figure
67, protects the AOUT pin from damage.
56
相關(guān)PDF資料
PDF描述
TSDC4872IJT 1 W, 1 CHANNEL, AUDIO AMPLIFIER, PBGA8
TS4872IJT 1 W, 1 CHANNEL, AUDIO AMPLIFIER, PBGA8
TSH103ID 3 CHANNEL, VIDEO AMPLIFIER, PDSO8
TSH103IDT 3 CHANNEL, VIDEO AMPLIFIER, PDSO8
TSH120ICT SPECIALTY CONSUMER CIRCUIT, PDSO6
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TSC2303IZQZ 制造商:Texas Instruments 功能描述:
TSC2303IZQZR 制造商:Texas Instruments 功能描述:
TSC236 制造商:TSC 制造商全稱:Taiwan Semiconductor Company, Ltd 功能描述:High Voltage NPN Transistor
TSC236CIC0 制造商:TSC 制造商全稱:Taiwan Semiconductor Company, Ltd 功能描述:High Voltage NPN Transistor
TSC236CZ C0 功能描述:兩極晶體管 - BJT High voltage NPN Transistor RoHS:否 制造商:STMicroelectronics 配置: 晶體管極性:PNP 集電極—基極電壓 VCBO: 集電極—發(fā)射極最大電壓 VCEO:- 40 V 發(fā)射極 - 基極電壓 VEBO:- 6 V 集電極—射極飽和電壓: 最大直流電集電極電流: 增益帶寬產(chǎn)品fT: 直流集電極/Base Gain hfe Min:100 A 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:PowerFLAT 2 x 2