參數資料
型號: LM3723IM5X-4.63/NOPB
廠商: NATIONAL SEMICONDUCTOR CORP
元件分類: 電源管理
英文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
封裝: SOT-23, 5 PIN
文件頁數: 11/12頁
文件大?。?/td> 290K
代理商: LM3723IM5X-4.63/NOPB
TABLE 1. Monitored Tolerance Table
Reset
Threshold
Supply Voltage
2.5V
3.3V
5.0V
4.63 ± %
90.8-94.4
%
3.08 ± %
91.8-95.2
%
2.32 ± %
90.8-94.8
%
ENSURING A VALID RESET OUTPUT DOWN TO V
CC = 0V
When V
CC falls below 1V, the LM3722 RESET output is un-
able to sink the rated current. A high-impedance CMOS logic
input connected to RESET can therefore drift to undetermined
voltages. To prevent this situation, a 100k
Ω resistor should
be connected from the RESET output to ground, as shown in
A 100k
Ω pull-up resistor to V
CC is also recommended for the
LM3723, if RESET is required to remain valid for V
CC < 1V.
20014410
FIGURE 1. Circuit for RESET Valid from V
CC = 0V
OPEN DRAIN OUTPUT (LM3724)
An open drain output allows easy paralleling of multiple mi-
croprocessor reset circuits without requiring additional logic
gates. Open drain outputs also allow interfacing devices of
differing logic levels or families, since the output pull-up re-
sistor may be connected to any supply voltage up to 5.5V,
regardless of LM3724 V
CC.
The pull up resistor is calculated so that maximum current flow
into RESET is less than 10 mA when activated. The resistor
must be small enough so that the leakage current of all con-
nected devices does not create an excessive voltage drop
when the output is not activated. A resistor value of 100 k
will generally suffice.
NEGATIVE-GOING V
CC TRANSIENTS
The LM3722/LM3723/LM3724 are relatively immune to short
negative-going transients or glitches on V
CC. Figure 2 shows
the maximum pulse width a negative-going V
CC transient can
have without causing a reset pulse. In general, as the mag-
nitude of the transient increases, going further below the
threshold, the maximum allowable pulse width decreases.
Typically, a V
CC transient that goes 125 mV below the reset
threshold and lasts 40 s or less will not cause a reset pulse.
A 0.1 F bypass capacitor mounted as close as possible to
the V
CC pin will provide additional transient rejection.
20014414
FIGURE 2. Maximum Transient Duration without Causing
a Reset Pulse vs. Reset Comparator Overdrive
INTERFACING TO PS WITH BIDIRECTIONAL RESET
PINS
Microprocessors with bidirectional reset pins, such as the
Motorola 68HC11 series, can be connected to the LM3722
RESET output. To ensure a correct output on the LM3722
even when the microprocessor reset pin is in the opposite
state, connect a 4.7k
Ω resistor between the LM3722 RE-
SET output and the P reset pin, as shown in Figure 3. Buffer
the LM3722 RESET output to other system components.
www.national.com
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LM3722/LM3723/LM3724
相關PDF資料
PDF描述
LM3723IM5-2.32/NOPB 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
LM3722EM5X-2.32/NOPB 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO5
LM3723I2.32MWC 1-CHANNEL POWER SUPPLY SUPPORT CKT, UUC
LM3723E2.32MWC 1-CHANNEL POWER SUPPLY SUPPORT CKT, UUC
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相關代理商/技術參數
參數描述
LM3724EM5-2.32 制造商:Texas Instruments 功能描述:RESET CIRCUIT SMD SOT23-5 3724
LM3724EM5-2.32/NOPB 功能描述:IC MPU SUPERVISR 2.32V SOT23-5 RoHS:是 類別:集成電路 (IC) >> PMIC - 監(jiān)控器 系列:- 標準包裝:1 系列:- 類型:簡單復位/加電復位 監(jiān)視電壓數目:1 輸出:開路漏極或開路集電極 復位:低有效 復位超時:標準傳輸延遲為 60 µs 電壓 - 閥值:3V 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:SC-74A,SOT-753 供應商設備封裝:SOT-23-5 包裝:Digi-Reel® 其它名稱:LM8364BALMF30DKR
LM3724EM5-3.08 制造商:Texas Instruments 功能描述:Processor Supervisor 3.08V 2.5V/3.3V/5V 5-Pin SOT-23 T/R 制造商:Texas Instruments 功能描述:RESET CIRCUIT, SMD, SOT23-5, 3724 制造商:National Semiconductor Corporation 功能描述:Supervisory Circuit,Temp.,LM3724EM5-3.08 制造商:Texas Instruments 功能描述:Supervisory Circuit,Temp.,LM3724EM5-3.08
LM3724EM5-3.08/NOPB 功能描述:監(jiān)控電路 5-PIN MICROPROCESSOR RESET CIRCUITS RoHS:否 制造商:STMicroelectronics 監(jiān)測電壓數: 監(jiān)測電壓: 欠電壓閾值: 過電壓閾值: 輸出類型:Active Low, Open Drain 人工復位:Resettable 監(jiān)視器:No Watchdog 電池備用開關:No Backup 上電復位延遲(典型值):10 s 電源電壓-最大:5.5 V 最大工作溫度:+ 85 C 安裝風格:SMD/SMT 封裝 / 箱體:UDFN-6 封裝:Reel
LM3724EM5-4.63 制造商:Texas Instruments 功能描述:RESET CIRCUIT, SMD, SOT23-5, 3724 制造商:Texas Instruments 功能描述:RESET CIRCUIT, SMD, SOT23-5, 3724; Threshold Voltage:4.63V; No. of Supervisors / Monitors:1; Supply Voltage Min:1V; Supply Voltage Max:5.5V; Reset Type:Active-Low; Digital IC Case Style:SOT-23; No. of Pins:5; Supply Current:8A; ;RoHS Compliant: Yes 制造商:Texas Instruments 功能描述:Supervisory Circuit,Temp.,LM3724EM5-4.63