- 您现在的位置：买卖IC网 > PDF目录383880 > TC1043CEQR (Microchip Technology Inc.) Linear Building Block . Low Power Voltage Reference with Dual Op Amp, Dual Comparator, and Shutdown Mode PDF资料下载
参数资料
| 型号： | TC1043CEQR |
| 厂商： | Microchip Technology Inc. |
| 英文描述： | Linear Building Block . Low Power Voltage Reference with Dual Op Amp, Dual Comparator, and Shutdown Mode |
| 中文描述： | 线性积木。低功耗电压参考与双路运算放大器，双比较，和关断模式 |
| 文件页数： | 6/20页 |
| 文件大小： | 508K |
| 代理商： | TC1043CEQR |
TC1043
DS21347B-page 6
2002 Microchip Technology Inc.
4.0
TYPICAL APPLICATIONS
The TC1043 lends itself to a wide variety of applica-
tions, particularly in battery powered systems. It typi-
cally
finds
application
processor supervisory, and interface circuitry.
in
power
management,
4.1
Wake-Up Timer
Many microcontrollers have a low power “sleep” mode
that significantly reduces their supply current. Typically,
the microcontroller is placed in this mode via a software
instruction, and returns to a fully enabled state upon
reception of an external signal (“wake-up”). The wake-
up signal is usually supplied by a hardware timer. Most
system applications demand that this timer have a long
duration (typically seconds or minutes), and consume
as little supply current as possible.
The circuit shown in Figure 4-1 is a wake-up timer
made from comparator CMPTR2. (CMPTR2 is used
because the wake-up timer must operate when SHDN
is active.) Capacitor C1 charges through R1 until a volt-
age equal to V
R
is reached, at which point the WAKE-
UP is driven active. Upon wake-up, the microcontroller
resets the timer by forcing a logic low on a dedicated,
open drain I/O port pin. This discharges C1 through R4
(the value of R4 is chosen to limit the maximum current
sunk by the I/O port pin). With a 3V supply, the circuit
as shown consumes typically 6
μ
A and furnishes a
nominal timer duration of 25 seconds.
4.2
Precision Battery Monitor
Figure 4-2 is a precision battery low/battery dead mon-
itoring circuit. Typically, the battery low output warns
the user that a battery dead condition is imminent. Bat-
tery dead typically initiates a forced shutdown to pre-
vent operation at low internal supply voltages (which
can cause unstable system operation).
The circuit of Figure 4-2 uses a single TC1043 (one op
amp is unused) and only six external resistors. AMP 1
is a simple buffer, while CMPTR1 and CMPTR2 provide
precision voltage detection using V
R
as a reference.
Resistors R2 and R4 set the detection threshold for
BATTLOW, while resistors R1 and R3 set the detection
threshold for BATTFAIL. The component values shown
assert BATTLOW at 2.2V (typical) and BATTFAIL at
2.0V (typical). Total current consumed by this circuit is
typically 22
μ
A at 3V. Resistors R5 and R6 provide hys-
teresis
for
comparators
respectively.
CMPTR1
and
CMPTR2
4.3
Dual LDO with Shutdown
Figure 4-3 shows a portion of a TC1043 configured as
a dual low dropout regulator with shutdown. AMP1 and
AMP2 are independent error amplifiers that use V
R
as
a reference. Resistors RA
1
, RB
1
, RA
2
and RB
2
set the
feedback around the amplifiers and therefore deter-
mine the output voltage settings (please see equation
in the figure). RA
1
, RB
1
, RA
2
and RB
2
can have large
ohmic values (i.e. 100’s of k
) to minimize supply cur-
rent.
Using the 2N2222 output transistors as shown, these
regulators exhibit low dropout operation. For example,
with V
OUT
= 3.0V, the typical dropout voltage is only
50mV at an output current of 50mA. The unused com-
parators can be used in conjunction with this circuit as
power-on reset or low voltage detectors for a complete
LDO solution at a very low installed cost.
4.4
External Hysteresis
Hysteresis can be set externally with two resistors
using positive feedback techniques (see Figure 4-3).
The design procedure for setting external comparator
hysteresis is as follows:
1.
Choose the feedback resistor R
C
. Since the
input bias current of the comparator is at most
100pA, the current through R
C
can be set to
100nA (i.e. 1000 times the input bias current)
and retain excellent accuracy. The current
through R
C
at the comparator’s trip point is V
R
/
R
C
where V
R
is a stable reference voltage.
FIGURE 4-1:
WAKE-UP TIMER
2.
Determine the hysteresis voltage (V
HY
) between
the upper and lower thresholds.
Calculate R
A
as follows:
3.
WAKE-UP
R1
5M
R4
C1
10μF
V
DD
V
DD
V
R
I/O
*
*
Open Drain Port Pin
Microcontroller
CMPTR2
TC1043
+
–
相关PDF资料 |
PDF描述 |
|---|---|
| TC1046 | High Precision Temperature-to-Voltage Converter |
| TC1046VNB | High Precision Temperature-to-Voltage Converter |
| TC1047 | Precision Temperature-to-Voltage Converter |
| TC1047VNB | Precision Temperature-to-Voltage Converter |
| TC1047A | Precision Temperature-to-Voltage Converter |
相关代理商/技术参数 |
参数描述 |
|---|---|
| TC1043CEQRTR | 功能描述:校验器 IC VR/Op-Amp/Shtdwn RoHS:否 制造商:STMicroelectronics 产品: 比较器类型: 通道数量: 输出类型:Push-Pull 电源电压-最大:5.5 V 电源电压-最小:1.1 V 补偿电压（最大值）:6 mV 电源电流（最大值）:1350 nA 响应时间: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SC-70-5 封装:Reel |
| TC1044 | 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:Charge Pump DC-TO-DC Voltage Converter |
| TC1044S | 制造商:MICROCHIP 制造商全称:Microchip Technology 功能描述:Charge Pump DC-TO-DC Voltage Converter |
| TC1044SCOA | 功能描述:电荷泵 High Voltage RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube |
| TC1044SCOA713 | 功能描述:电荷泵 High Voltage RoHS:否 制造商:Maxim Integrated 功能:Inverting, Step Up 输出电压:- 1.5 V to - 5.5 V, 3 V to 11 V 输出电流:100 mA 电源电流:1 mA 最大工作温度:+ 70 C 封装 / 箱体:SOIC-8 Narrow 封装:Tube |
发布紧急采购，3分钟左右您将得到回复。