LT1931 데이터 시트보기 (PDF) - Linear Technology
부품명
상세내역
일치하는 목록
LT1931 Datasheet PDF : 12 Pages
| |||
TYPICAL PERFOR A CE CHARACTERISTICS
Quiescent Current
7.0
NOT SWITCHING
6.5
6.0
LT1931A
5.5
5.0
4.5
LT1931
4.0
3.5
3.0
–50
–25 0 25 50
TEMPERATURE (°C)
75 100
1931 G01
Current Limit
1.6
1.4
TA = 25°C
1.2
1.0
0.8
0.6
0.4
0.2
0
10 20 30 40 50 60 70 80 90
DUTY CYCLE (%)
1931 G04
Feedback Pin Voltage
–1.28
–1.27
–1.26
–1.25
–1.24
–1.23
–1.22
–50 –25 0
25 50
TEMPERATURE (°C)
75 100
1931 G02
Switch Saturation Voltage
0.45
TA = 25°C
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
0 0.2 0.4 0.6 0.8 1.0 1.2
SWITCH CURRENT (A)
1931 G05
LT1931/LT1931A
Shutdown Pin Current
90
TA = 25°C
80
70
LT1931A
60
50
40
30
LT1931
20
10
0
–10
0
1
2
3
4
5
6
SHDN PIN VOLTAGE (V)
1931 G03
Oscillator Frequency
2.5
2.3
LT1931A
2.1
1.9
1.7
1.5
1.3
LT1931
1.1
0.9
0.7
0.5
–50 –25 0
25 50 75 100
TEMPERATURE (°C)
1931 G06
PI FU CTIO S
SW (Pin 1): Switch Pin. Connect inductor/diode here.
Minimize trace area at this pin to keep EMI down.
GND (Pin 2): Ground. Tie directly to local ground plane.
NFB (Pin 3): Feedback Pin. Reference voltage is –1.255V.
Connect resistive divider tap here. Minimize trace area.
The NFB bias current flows out of the pin. Set R1 and R2
according to:
( ) For
LT1931A:
R1 =
| VOUT | – 1.255
1.255 + 8 • 10–6
R2
SHDN (Pin 4): Shutdown Pin. Tie to 2.4V or more to enable
device. Ground to shut down.
VIN (Pin 5): Input Supply Pin. Must be locally bypassed.
( ) For
LT1931:
R1 =
| VOUT |
1.255 +
– 1.255
4 • 10–6
R2
1931fa
3
Share Link: 