欢迎访问ic37.com |
会员登录 免费注册
发布采购

TC1054-2.7VCT 参数 Datasheet PDF下载

TC1054-2.7VCT图片预览
型号: TC1054-2.7VCT
PDF下载: 下载PDF文件 查看货源
内容描述: 具有关断功能和错误输出50毫安CMOS LDO [50mA CMOS LDO WITH SHUTDOWN AND ERROR OUTPUT]
分类和应用: 调节器光电二极管输出元件
文件页数/大小: 12 页 / 125 K
品牌: TELCOM [ TELCOM SEMICONDUCTOR, INC ]
 浏览型号TC1054-2.7VCT的Datasheet PDF文件第1页浏览型号TC1054-2.7VCT的Datasheet PDF文件第2页浏览型号TC1054-2.7VCT的Datasheet PDF文件第3页浏览型号TC1054-2.7VCT的Datasheet PDF文件第5页浏览型号TC1054-2.7VCT的Datasheet PDF文件第6页浏览型号TC1054-2.7VCT的Datasheet PDF文件第7页浏览型号TC1054-2.7VCT的Datasheet PDF文件第8页浏览型号TC1054-2.7VCT的Datasheet PDF文件第9页  
PRELIMINARY INFORMATION  
50mA CMOS LDO WITH SHUTDOWN  
AND ERROR OUTPUT  
TC1054  
Pull-up resistor R1 can be tied to VOUT, VIN or any other  
voltage less than (VIN = 0.3V).  
DETAILED DESCRIPTION  
The TC1054 is a precision fixed output voltage regula-  
tor. (If an adjustable version is desired, please see the  
TC1070 or TC1071 data sheets.) Unlike the bipolar regula-  
tors, the TC1054 supply current does not increase with load  
current. In addition, VOUT remains stable and within regula-  
tion at very low load currents (an important consideration in  
RTC and CMOS RAM battery back-up applications).  
Figure 1 shows a typical application circuit. The regula-  
tor is enabled any time the shutdown input (SHDN) is at or  
above VIH, and shutdown (disabled) when SHDN is at or  
below VIL. SHDN may be controlled by a CMOS logic gate,  
or I/O port of a microcontroller. If the SHDN input is not  
required, it should be connected directly to the input supply.  
While in shutdown, supply current decreases to 0.05µA  
(typical) and VOUT falls to zero volts and ERROR is open  
circuited.  
VOUT  
HYSTERESIS (VHYS  
)
VTH  
ERROR  
VIH  
VOL  
Figure 2. ERROR Output Operation  
Output Capacitor  
A 1µF(min) capacitor from VOUT to ground is recom-  
mended. The output capacitor should have an effective  
series resistance of 5or less, and a resonant frequency  
above 1MHz. A 1µF capacitor should be connected from  
VIN to GND if there is more than 10 inches of wire between  
the regulator and the AC filter capacitor, or if a battery is  
used as the power source. Aluminum electrolytic or tanta-  
lum capacitor types can be used. (Since many aluminum  
electrolytic capacitors freeze at approximately – 30°C, solid  
tantalums are recommended for applications operating  
below – 25°C.) When operating from sources other than  
batteries, supply-noise rejection and transient response  
can be improved by increasing the value of the input and  
output capacitors and employing passive filtering tech-  
niques.  
V
V
V
OUT  
OUT  
IN  
1µF  
1µF  
C1  
BATTERY  
GND  
TC1054VCT  
+
V
SHDN  
ERROR  
R1  
1M  
Shutdown Control  
(to CMOS Logic or Tie  
C2 Requires Only  
if ERROR is used as a  
Processor RESET Signal  
(See Text)  
BATTLOW  
or RESET  
to V if unused)  
IN  
0.2µF  
C2  
Figure 1. Typical Application Circuit  
Thermal Considerations  
ERROR Open Drain Output  
Thermal Shutdown  
ERROR is driven low whenever VOUT falls out of regu-  
lation by more than – 5% (typical). This condition may be  
caused by low input voltage, output current limiting, or  
thermal limiting. The ERROR threshold is 5% below rated  
VOUT regardless of the programmed output voltage value  
(e.g. ERROR = VOL at 4.75 (typ.) for a 5.0V regulator and  
2.85V (typ.) for a 3.0V regulator). ERROR output operation  
is shown in Figure 2.  
Integrated thermal protection circuitry shuts the regula-  
tor off when die temperature exceeds 160°C. The regulator  
remains off until the die temperature drops to approximately  
150°C.  
Power Dissipation  
The amount of power the regulator dissipates is prima-  
rilyafunctionofinputandoutputvoltage,andoutputcurrent.  
The following equation is used to calculate worst case  
actual power dissipation:  
Note that ERROR is active when VOUT falls to VTH, and  
inactive when VOUT rises above VTH = VHYS  
.
As shown in Figure 1, ERROR can be used as a battery  
low flag, or as a processor RESET signal (with the addition  
of timing capacitor C2). R1 x C2 should be chosen to  
maintain ERROR below VIH of the processor RESET input  
for at least 200msec to allow time for the system to stabilize.  
TC1054-01 6/12/97  
4