Datasheet

3
LT1930/LT1930A
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Quiescent Current FB Pin Voltage SHDN Pin Current
Current Limit
Switch Saturation Voltage
Oscillator Frequency
SW (Pin 1): Switch Pin. Connect inductor/diode here.
Minimize trace area at this pin to reduce EMI.
GND (Pin 2): Ground. Tie directly to local ground plane.
FB (Pin 3): Feedback Pin. Reference voltage is 1.255V.
Connect resistive divider tap here. Minimize trace area at
FB. Set V
OUT
according to V
OUT
= 1.255V(1 + R1/R2).
UU
U
PI FU CTIO S
SHDN (Pin 4): Shutdown Pin. Tie to 2.4V or more to enable
device. Ground to shut down.
V
IN
(Pin 5): Input Supply Pin. Must be locally bypassed.
TEMPERATURE (°C)
–50 –25
QUIESCENT CURRENT (mA)
50 75
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
1930/A G01
0 25 100
NOT SWITCHING
LT1930A
LT1930
TEMPERATURE (°C)
–50
1.22
FB VOLTAGE (V)
1.23
1.24
1.25
1.26
1.28
–25
02550
1930/A G02
75 100
1.27
SHDN PIN VOLTAGE (V)
0
SHDN PIN CURRENT (µA)
20
30
40
3
5
1930/A G03
10
0
–10
12 4
50
60
70
80
90
6
LT1930A
LT1930
DUTY CYCLE (%)
10
CURRENT LI MIT (A)
0.8
1.2
1930/A G04
0.4
0
3020 5040 7060 9080
1.6
0.6
1.0
0.2
1.4
SWITCH CURRENT (A)
0
0
V
CESAT
(V)
0.05
0.15
0.20
0.25
0.8
0.45
1930/A G05
0.10
0.4 1.2
0.6
0.2 1.0
0.30
0.35
0.40
TEMPERATURE (°C)
–50 –25 0
FREQUENCY (MHz)
2.5
2.3
2.1
1.9
1.7
1.5
1.3
1.1
0.9
0.7
0.5
25 50 75 100
1930/A G06
LT1930
LT1930A