LT1618EMS Ver la hoja de datos (PDF) - Linear Technology
Número de pieza
componentes Descripción
Fabricante
LT1618EMS Datasheet PDF : 16 Pages
| |||
LT1618
TYPICAL PERFOR A CE CHARACTERISTICS
Switching Frequency
1.8
1.7
1.6
1.5
VIN = 18V
1.4
VIN = 1.6V
1.3
1.2
1.1
1.0
– 50 – 25
0 25 50 75
TEMPERATURE (°C)
100 125
1618 G07
Frequency Foldback
1.6
TJ = 25°C
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
0 0.2 0.4 0.6 0.8 1.0 1.2
FEEDBACK PIN VOLTAGE (V)
1618 G08
SHDN Pin Current
50
45
40
TJ = – 50°C
35
30
25
TJ = 25°C
20
15
TJ = 125°C
10
5
0
0
5
10
15
20
SHUTDOWN PIN VOLTAGE (V)
1618 G09
PIN FUNCTIONS (MS/DD)
FB (Pin 1/Pin 1): Feedback Pin. Set the output voltage by
selecting values for R1 and R2 (see Figure 1):
R1=
⎛
R2⎝⎜
VOUT
1.263V
–
⎞
1⎠⎟
ISN (Pin 2/Pin 2): Current Sense (–) Pin. The inverting
input to the current sense amplifier.
ISP (Pin 3/Pin 3): Current Sense (+) Pin. The noninverting
input to the current sense amplifier.
IADJ (Pin 4/Pin 4): Current Sense Adjust Pin. A DC voltage
applied to this pin will reduce the current sense voltage. If
this adjustment is not needed, tie this pin to ground.
GND (Pin 5/Pin 5): Ground Pin. Tie this pin directly to local
ground plane.
NC (Pin 6/NA): No Connection for MS Package.
SW (NA/Pin 6): Switch Pin for DD Package. Connect this
pin to Pin 7.
SW (Pin 7/Pin 7): Switch Pin. This is the collector of the
internal NPN power switch. Minimize the metal trace area
connected to this pin to minimize EMI.
VIN (Pin 8/Pin 8): Input Supply Pin. Bypass this pin with
a capacitor to ground as close to the device as possible.
SHDN (Pin 9/Pin 9): Shutdown Pin. Tie this pin higher
than 1V to turn on the LT1618; tie below 0.3V to turn it off.
VC (Pin 10/Pin 10): Compensation Pin for Error Amplifier.
Connect a series RC from this pin to ground. Typical values
are 2kΩ and 10nF.
Exposed Pad (NA/Pin 11): The Exposed Pad on the DD
package is GND and must be soldered to the PCB GND for
optimum thermal performance.
4
sn1618 1618fas
Share Link: 