LT1316IS8 查看數據表（PDF） - Linear Technology
零件编号
产品描述 (功能)
生产厂家
LT1316IS8 Datasheet PDF : 16 Pages
| |||
LT1316
APPLICATIONS INFORMATION
VOUT
100mV/DIV
AC COUPLED
IL
100mA/DIV
VOUT
100mV/DIV
AC COUPLED
IL
100mA/DIV
100µs/DIV
1316 F07
Figure 7. Switching Waveforms for the Circuit
Shown in Figure 7 Without C1. The Output Ripple
Voltage is Approximately 140mVP-P
50µs/DIV
1316 F08
Figure 8. By Adding C1, Output Ripple Voltage
is Reduced to Less Than 80mVP-P
Layout/Input Bypassing
The LT1316’s high speed switching mandates careful
attention to PC board layout. Suggested component place-
ment is shown in Figure 9. The input supply must have low
impedance at AC and the input capacitor should be placed
as indicated in the figure. The value of this capacitor
depends on how close the input supply is to the IC. In
situations where the input supply is more than a few
inches away from the IC, a 47µF to 100µF solid tantalum
bypass capacitor is required. If the input supply is close to
the IC, a 1µF ceramic capacitor can be used instead. The
LT1316 switches current in pulses up to 0.5A, so a low
impedance supply must be available. If the power source
(for example, a 2 AA cell battery) is within 1 or 2 inches of
the IC, the battery itself provides bulk capacitance and the
1µF ceramic capacitor acts to smooth voltage spikes at
switch turn-on and turn-off. If the power source is far away
from the IC, inductance in the power source leads results
in high impedance at high frequency. A local high capaci-
tance bypass is then required to restore low impedance at
the IC.
Low-Battery Detector
The LT1316 contains an independent low-battery detector
that remains active when the device is shut down. This
detector, actually a hysteretic comparator, has an open
collector output that can sink up to 500µA. The compara-
tor also operates below the switcher’s undervoltage lock-
out threshold, operating until VIN reaches approximately
1.4V.
10
1
8
2
LT1316
7
3
6L
VIN
RSET
4
5
CIN
GND
D COUT
1316 F09
VOUT
Figure 9. Suggested PC Layout
Share Link: 