參數(shù)資料
型號: LTC692CS8
廠商: LINEAR TECHNOLOGY CORP
元件分類: 電源管理
英文描述: Microprocessor Supervisory Circuits
中文描述: 1-CHANNEL POWER SUPPLY SUPPORT CKT, PDSO8
封裝: PLASTIC, SOIC-8
文件頁數(shù): 8/16頁
文件大?。?/td> 308K
代理商: LTC692CS8
8
LTC692/LTC693
Microprocessor Reset
The LTC692/LTC693 use a bandgap voltage reference and
a precision voltage comparator C1 to monitor the 5V
supply input on V
CC
(see BLOCK DIAGRAM). When V
CC
falls below the reset voltage threshold, the RESET output
is forced to active low state. The reset voltage threshold
accounts for a 10% variation on V
CC
, so the RESET output
becomes active low when V
CC
falls below 4.50V (4.40V
typical). On power-up, the RESET signal is held active low
for a minimum of 140ms after reset voltage threshold is
reached to allow the power supply and microprocessor to
stabilize. The reset active time is adjustable on the LTC693.
On power-down, the RESET signal remains active low
even with V
CC
as low as 1V. This capability helps hold the
microprocessor in stable shutdown condition. Figure 1
shows the timing diagram of the RESET signal.
The precision voltage comparator, C1, typically has 40mV
of hysteresis which ensures that glitches at the V
CC
pin do
not activate the RESET output. Response time is typically
10
μ
s. To help prevent mistriggering due to transient loads,
V
CC
pin should be bypassed with a 0.1
μ
F capacitor with the
leads trimmed as short as possible.
The LTC693 has two additional outputs: RESET and LOW
LINE. RESET is an active high output and is the inverse of
RESET. LOW LINE is the output of the precision voltage
comparator C1. When V
CC
falls below the reset voltage
threshold, LOW LINE goes low. LOW LINE returns high as
soon as V
CC
rises above the reset voltage threshold.
Battery Switchover
The battery switchover circuit compares V
CC
to the
V
BATT
input, and connects V
OUT
to whichever is higher.
When V
CC
rises to 70mV above V
BATT
, the battery
switchover comparator, C2, connects V
OUT
to V
CC
through
a charge pumped NMOS power switch, M1. When V
CC
falls to 50mV above V
BATT
, C2 connects V
OUT
to V
BATT
through a PMOS switch, M2. C2 has typically 20mV of
hysteresis to prevent spurious switching when V
CC
remains nearly equal to V
BATT
. The response time of C2
is approximately 20
μ
s.
During normal operation, the LTC692/LTC693 use a charge
pumped NMOS power switch to achieve low dropout and
low supply current. This power switch can deliver up to
50mA to V
OUT
from V
CC
and has a typical “on” resistance
of 5
. The V
OUT
pin should be bypassed with a capacitor
of 0.1
μ
F or greater to ensure stability. Use of a larger
bypass capacitor is advantageous for supplying current to
heavy transient loads.
When operating currents larger than 50mA are required
from V
OUT
, or a lower dropout (V
CC
– V
OUT
voltage differ-
ential) is desired, the LTC693 should be used. This prod-
uct provides BATT ON output to drive the base of the
external PNP transistor (Figure 2). If higher currents are
needed with the LTC692, a high current Schottky diode
can be connected from the V
CC
pin to the V
OUT
pin to
supply the extra current.
U
S
A
O
PPLICATI
U
U
V
CC
t1
t1 = RESET ACTIVE TIME
V1 = RESET VOLTAGE THRESHOLD
V2 = RESET VOLTAGE THRESHOLD +
RESET THRESHOLD HYSTERESIS
t1
V2
V2
V1
V1
LTC692/3 F01
RESET
LOW LINE
Figure 1. Reset Active Time
相關PDF資料
PDF描述
LTC692I Microprocessor Supervisory Circuits
LTC692IS8 Microprocessor Supervisory Circuits
LTC693C Microprocessor Supervisory Circuits
LTC693CN Microprocessor Supervisory Circuits
LTC693CS Microprocessor Supervisory Circuits
相關代理商/技術參數(shù)
參數(shù)描述
LTC692CS8#PBF 功能描述:IC MPU SUPERVISORY CIRCUIT 8SOIC RoHS:是 類別:集成電路 (IC) >> PMIC - 監(jiān)控器 系列:- 其它有關文件:STM6717 View All Specifications 標準包裝:1 系列:- 類型:多壓監(jiān)控器 監(jiān)視電壓數(shù)目:2 輸出:開路漏極或開路集電極 復位:低有效 復位超時:最小為 600 ms 電壓 - 閥值:1.11V,3.075V 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® 產(chǎn)品目錄頁面:1194 (CN2011-ZH PDF) 其它名稱:497-7019-6
LTC692CS8#TR 功能描述:IC SUPERVISORY CIRCUIT MPU 8SOIC RoHS:否 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(shù)目:1 輸出:開路漏極或開路集電極 復位:高有效 復位超時:- 電壓 - 閥值:1.8V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:6-TSOP(0.059",1.50mm 寬)5 引線 供應商設備封裝:5-TSOP 包裝:剪切帶 (CT) 其它名稱:NCP301HSN18T1GOSCT
LTC692CS8#TRPBF 功能描述:IC MPU SUPERVISORY CIRCUIT 8SOIC 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(shù)目:1 輸出:開路漏極或開路集電極 復位:高有效 復位超時:- 電壓 - 閥值:1.8V 工作溫度:-40°C ~ 125°C 安裝類型:表面貼裝 封裝/外殼:6-TSOP(0.059",1.50mm 寬)5 引線 供應商設備封裝:5-TSOP 包裝:剪切帶 (CT) 其它名稱:NCP301HSN18T1GOSCT
LTC692CS8-PBF 制造商:LINER 制造商全稱:Linear Technology 功能描述:Microprocessor Supervisory Circuits
LTC692CS8-TRPBF 制造商:LINER 制造商全稱:Linear Technology 功能描述:Microprocessor Supervisory Circuits