Texas Instruments LM3404 Evaluation Boards LM3404HVEVAL/NOPB LM3404HVEVAL/NOPB 사용자 설명서
제품 코드
LM3404HVEVAL/NOPB
ON/OFF
Q1
2N7000 or
equivalent
GND
DIM
BOOT
SW
CS
RON
LM3404/04HV
VIN
D1
L1
C
B
R
SNS
C
F
R
ON
C
IN
V
IN
I
F
VCC
GND
DIM
BOOT
SW
CS
RON
LM3404/04HV
VIN
D1
L1
C
B
R
SNS
C
F
R
ON
C
IN
V
IN
VCC
R
Z
Z1
SNVS465F – OCTOBER 2006 – REVISED MAY 2013
Figure 20. Output Open Circuit Protection
LOW POWER SHUTDOWN
The LM3404/04HV can be placed into a low power state (I
IN-SD
= 90 µA) by grounding the RON pin with a signal-
level MOSFET as shown in
. Low power MOSFETs like the 2N7000, 2N3904, or equivalent are
recommended devices for putting the LM3404/04HV into low power shutdown. Logic gates can also be used to
shut down the LM3404/04HV as long as the logic low voltage is below the over temperature minimum threshold
of 0.3V. Noise filter circuitry on the RON pin can cause a few pulses with longer on-times than normal after RON
is grounded or released. In these cases the OVP/OCP comparator will ensure that the peak inductor or LED
current does not exceed 300 mV / R
shut down the LM3404/04HV as long as the logic low voltage is below the over temperature minimum threshold
of 0.3V. Noise filter circuitry on the RON pin can cause a few pulses with longer on-times than normal after RON
is grounded or released. In these cases the OVP/OCP comparator will ensure that the peak inductor or LED
current does not exceed 300 mV / R
SNS
.
Figure 21. Low Power Shutdown
THERMAL SHUTDOWN
Internal thermal shutdown circuitry is provided to protect the IC in the event that the maximum junction
temperature is exceeded. The threshold for thermal shutdown is 165°C with a 25°C hysteresis (both values
typical). During thermal shutdown the MOSFET and driver are disabled.
temperature is exceeded. The threshold for thermal shutdown is 165°C with a 25°C hysteresis (both values
typical). During thermal shutdown the MOSFET and driver are disabled.
14
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