|
|
PDF LT1579CGN-3 Data sheet ( Hoja de datos )
| Número de pieza | LT1579CGN-3 | |
| Descripción | 300mA Dual Input Smart Battery Backup Regulator | |
| Fabricantes | Linear Technology | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LT1579CGN-3 (archivo pdf) en la parte inferior de esta página. Total 20 Páginas | ||
|
No Preview Available !
FEATURES
s Maintains Output Regulation with Dual Inputs
s Dropout Voltage: 0.4V
s Output Current: 300mA
s 50µA Quiescent Current
s No Protection Diodes Needed
s Two Low-Battery Comparators
s Status Flags Aid Power Management
s Adjustable Output from 1.5V to 20V
s Fixed Output Voltages: 3V, 3.3V and 5V
s 7µA Quiescent Current in Shutdown
s Reverse-Battery Protection
s Reverse Current Protection
s Remove, Recharge and Replace Batteries Without
Loss of RegulationDaisy-Chained Control Outputs
U
APPLICATIONS
s Dual Battery Systems
s Battery Backup Systems
s Automatic Power Management for
Battery-Operated Systems
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATION
5V Dual Battery Supply
IN1
+
1µF 2.7M
LBI1
OUT
1M LT1579-5
+ IN2
1µF 2.7M
LBI2
1M
SS
SHDN
LBO1
LB02
BACKUP
DROPOUT
BIASCOMP
GND
5V
+ 300mA
4.7µF
TO
POWER
MANAGEMENT
0.01µF
1579 TA01
LT1579
300mA Dual Input Smart
Battery Backup Regulator
DESCRIPTION
The LT®1579 is a dual input, single output, low dropout
regulator. This device is designed to provide an
uninterruptible output voltage from two independent input
voltage sources on a priority basis. All of the circuitry
needed to switch smoothly and automatically between
inputs is incorporated.
The LT1579 can supply 300mA of output current from
either input at a dropout voltage of 0.4V. Quiescent current
is 50µA, dropping to 7µA in shutdown. Two comparators
are included to monitor input voltage status. Two addi-
tional status flags indicate which input is supplying power
and provide an early warning against loss of output
regulation when both inputs are low. A secondary select
pin is provided so that the user can force the device to
switch from the primary input to the secondary input.
Internal protection circuitry includes reverse-battery pro-
tection, current limiting, thermal limiting and reverse-
current protection.
The device is available in fixed output voltages of 3V, 3.3V
and 5V, and as an adjustable device with a 1.5V reference
voltage. The LT1579 regulators are available in narrow
16-lead SO and 16-lead SSOP packages with all features,
and in SO-8 with limited features.
Automatic Input Switching
12
10 VIN1 SWITCHOVER
8 POINT
VIN2 = 10V
ILOAD = 50mA
80
6 IIN1
IIN2 60
4 40
2 20
00
5.05
5.00
4.95
0 2 4 6 8 10 12 14 16 18 20
TIME (ms)
1578 TA02
1
1 page  
TYPICAL PERFORMANCE CHARACTERISTICS
Guaranteed Dropout Voltage
0.8
= TEST POINTS
0.7
TJ ≤ 125°C
0.6
0.5
TJ = 25°C
0.4
0.3
0.2
0.1
0
0 50 100 150 200 250 300
OUTPUT CURRENT (mA)
1579 G35
Quiescent Current in Shutdown
7
VIN1 = 20V
6
VIN2 = 6V
VSHDN = 0V
5
4
IVIN1
3
2 IVIN2
1
0
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
1579 G36
LT1579-5 Output Voltage
5.12
ILOAD = 1mA
5.09
5.06
5.03
5.00
4.97
4.94
4.91
4.88
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
1579 G05
Dropout Voltage
0.7
A: ILOAD = 300mA
0.6
B: ILOAD = 150mA
C: ILOAD = 100mA
D: ILOAD = 50mA
0.5 E: ILOAD = 10mA
F: ILOAD = 1mA
0.4
A
B
C
0.3 D
0.2 E
0.1
0
– 50 – 25
F
0 25 50 75
TEMPERATURE (°C)
100 125
1579 G01
LT1579-3 Output Voltage
3.08
ILOAD = 1mA
3.06
3.04
3.02
3.00
2.98
2.96
2.94
2.92
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
1579 G03
Adjust Pin Voltage
1.54
ILOAD = 1mA
1.53
1.52
1.51
1.50
1.49
1.48
1.47
1.46
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
1579 G05
LT1579
Quiescent Current
100
90
VIN = 6V
RL = ∞ (FIXED)
80 RL = 500k (ADJUSTABLE)
70
60 OPERATING
QUIESCENT
50 CURRENT
40
30
20 STANDBY
QUIESCENT
10 CURRENT
0
– 50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
1579 G02
LT1579-3.3 Output Voltage
3.38
ILOAD = 1mA
3.36
3.34
3.32
3.30
2.28
2.26
2.24
2.22
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
1579 G04
Input Current
60 IIN2
50
IIN1
40
VOUT = 5V
VIN2 = 6V
ILOAD = 0
30
20
10
0
–0.2 –0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
VIN1 – VOUT (V)
1579 G07
5
5 Page 
LT1579
PIN FUNCTIONS
LBO1: This is the open collector output of the low-battery
comparator LB1. This output pulls low when the com-
parator input drops below the threshold voltage. The
LBO1 output voltage is 1V when sinking 5mA, dropping
to under 200mV at 20µA (see curve of Logic Flag Voltage
vs Current in the Typical Performance Characteristics).
This makes the LBO1 pin equally useful in driving both
bipolar and CMOS logic inputs with the addition of an
external pull-up resistor. It is also capable of driving
higher current devices, such as LEDs. This pin is inter-
nally clamped to 7V and – 0.6V (one VBE). If unused, this
pin can be left open circuit. Device operation is unaffected
if this pin is not connected.
LBO2: This is the open collector output of the low-battery
comparator LB2. This output pulls low when the com-
parator input drops below the threshold voltage. The
LBO2 output voltage is 1V when sinking 5mA, dropping
to under 200mV at 20µA (see curve of Logic Flag Voltage
vs Current in the Typical Performance Characteristics).
This makes the LBO2 pin equally useful in driving both
bipolar and CMOS logic inputs with the addition of an
external pull-up resistor. It is also capable of driving
higher current devices, such as LEDs. This pin is
internally clamped to 7V and – 0.6V (one VBE). If unused,
this pin can be left open circuit. Device operation is
unaffected if this pin is not connected.
BLOCK DIAGRAM
VIN1
VIN2
SHDN
SS
BIASCOMP
BIAS CURRENT
CONTROL
1.5V REFERENCE
DROPOUT
DETECT
OUTPUT DRIVER
CONTROL
LBI1 +
LB1
–
LBI2 +
LB2
–
–
E/A
+
WARNING
FLAGS
VOUT
INTERNAL
RESISTOR DIVIDER
FOR FIXED VOLTAGE
DEVICES ONLY
ADJ
BACKUP
DROPOUT
LBO1
LBO2
1579 • BD
11
11 Page | ||
| Páginas | Total 20 Páginas | |
| PDF Descargar | [ Datasheet LT1579CGN-3.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LT1579CGN-3 | 300mA Dual Input Smart Battery Backup Regulator | Linear Technology |
| LT1579CGN-3.3 | 300mA Dual Input Smart Battery Backup Regulator | Linear Technology |
| LT1579CGN-5 | 300mA Dual Input Smart Battery Backup Regulator | Linear Technology |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |