datasheetbank_Logo
Integrated circuits, Transistor, Semiconductors Search and Datasheet PDF Download Site

L4945 View Datasheet(PDF) - STMicroelectronics

Part Name
Description
View to exact match
L4945
ST-Microelectronics
STMicroelectronics ST-Microelectronics
L4945 Datasheet PDF : 6 Pages
1 2 3 4 5 6
TEST CIRCUIT
L4945
ELECTRICAL CHARACTERISTICS (refer to the test circuit, Vi = 14. 4V, Co = 47µF, ESR < 10,
Rp = 1K, RL = 1K, –40°C TJ 125°C, unless otherwise specified)
Symbol
Vo
Parameter
Output Voltage
Vi
Vo
Vo
Vi –Vo
Iq
Operating Input Voltage
Line Regulation
Load Regulation
Dropout Voltage
Quiescent Current
Vo
T
SVR
Temperature Output Voltage
Drift
Supply Volt. Rej.
Isc
Output Short Circuit Current
Test Conditions
Io = 0mA to 500mA
Over Full T Range
Tj = 25°C
Io = 0mA to (*) 500mA
Vi = 6V to 26V ;
Io = 5mA
Io = 5mA to 500mA
Io = 500mA, TJ = 25°C
Over Full T Range
Io = 0mA, TJ = 25°C
Io = 0mA Over Full T
Io = 500mA Over Full T
Io = 350mA ; f = 120Hz
Co = 100µF ;
Vi = 12V ± 5Vpp
Min. Typ. Max. Unit
4.80 5.00 5.20
V
4.90 5.00 5.10
V
6
26
V
2
10
mV
15
0.40
5
6.5
110
– 0.5
60
mV
0.55
V
0.75
V
10
mA
13
mA
180 mA
mV/°C
50
60
dB
0.50 0.80 1.50
A
(*) For a DC voltage 26 < Vi < 37V the device is not operating
FUNCTIONAL DESCRIPTION
The block diagram shows the basic structure of
the devices : the reference, the error amplifier, the
driver, the power PNP, the protection and reset
functions.
The power stage is a Lateral PNP transistor
which allows a very low dropout voltage (typ.
400mV at TJ = 25°C, max. 750mV over the full
temperature range @ IO = 500mA). The typical
curve of the dropout voltage as a function of the
junction temperature is shown in Fig. 1 : that is
the worst case, where IO = 500mA.
The current consumption of the devices (quies-
cent current) are maximum 10mA - over full T -
when no load current is required.
The internal antisaturation circuit allows a drastic
reduction in the current peak which takes place
during the start up.
The three gain stages (operational amplifier,
driver and power PNP) require the external ca-
pacitor (Comin = 20µF) to guarantee the global
stability of the system.
Load dump and field decay protections (± 80V, t =
300ms), reverse voltage (– 18V) and short circuit
protection, thermal shutdown are the main fea-
tures that make the devices specially suitable for
applications in the automotive enviroment.
3/6
 

Share Link: 

datasheetbank.com [ Privacy Policy ] [ Request Datasheet ] [ Contact Us ]