參數資料
型號: L7556
英文描述: Low-Power SLICs with Battery Switch
中文描述: 低功耗SLIC組件的電池開關
文件頁數: 1/28頁
文件大?。?/td> 700K
代理商: L7556
Data Sheet
January 2000
L7556, L7557 Low-Power SLICs
with Battery Switch
Features
I
Auxiliary input for second battery, and internal
switch to enable its use to save power
I
Low active power (typical 125 mW during on-hook
transmission)
I
Supports meter pulse injection
I
Spare op amp for meter pulse filtering
I
–16 V to –60 V power supply operation
I
Distortion-free on-hook transmission
I
Convenient operating states:
— Forward powerup
— Disconnect (high impedance)
— 2-wire wink (zero loop voltage)
I
Adjustable supervision functions:
— Off-hook detector with longitudinal rejection
— Ground key detector
— Ring trip detector
I
Independent, adjustable, dc and ac parameters:
— dc feed resistance
— Loop current limit
— Termination impedance
I
Thermal protection
Description
These electronic subscriber loop interface circuits
(SLICs) are optimized for low power consumption
while providing an extensive set of features.
The SLICs include an auxiliary battery input and a
built-in switch. In short-loop applications, they can be
used in high battery to present a high on-hook volt-
age, and then switched to low battery to reduce off-
hook power.
The SLICs also include a summing node for meter
pulse injection to 2.2 Vrms. A spare, uncommitted op
amp is included for meter pulse filtering.
The switched battery is applied to the power amplifi-
ers of the device. There are two versions. The L7556
has the battery switch completely under processor
control. The L7557 can automatically switch to lower
battery when appropriate and includes hysteresis to
avoid frequent switching. To make the switch silent,
an external capacitor can be added to slow the tran-
sition.
The L7556 is suited for applications serving only
short loops, where a high on-hook voltage is required
for compatibility with preexisting standards.
The L7557 is suited for applications where a full loop
range is needed, but low short-loop power is desired.
It is a much lower-cost solution than a switching reg-
ulator, and also occupies much less PCB area, need-
ing only a battery filter capacitor and a diode for
implementation.
The device is available in a 32-pin PLCC package. It
is built by using a 90 V complementary bipolar inte-
grated circuit (CBIC) process.
相關PDF資料
PDF描述
L7582 CAP CER .75PF 50V C0G 0603
L7583A Line Card Access Switch
L7583BAJ Telecomm/Datacomm
L7583BF Telecomm/Datacomm
L7583CAJ Telecomm/Datacomm
相關代理商/技術參數
參數描述
L7558 制造商:HAMAMATSU 制造商全稱:Hamamatsu Corporation 功能描述:High-speed, high-power infrared LED for spatial light transmission
L7558-01 制造商:HAMAMATSU 制造商全稱:Hamamatsu Corporation 功能描述:High-speed, high-power infrared LED for spatial light transmission
L755AC 制造商:MCM 功能描述:AC ADAPTER L755-S5355 制造商:PREMIER FARNELL 功能描述:AC ADAPTER L755-S5355
L755KEYBOARD 制造商:MCM 功能描述:KEYBOARD L755-S5355 制造商:PREMIER FARNELL 功能描述:KEYBOARD L755-S5355
L7560 制造商:HAMAMATSU 制造商全稱:Hamamatsu Corporation 功能描述:High-speed, high output power LED with mini-lens