lt3689-5 Linear Technology Corporation, lt3689-5 Datasheet - Page 4

• Manufacturer Part Number: lt3689-5
• Description: 700ma Step-down Regulator With Power-on Reset And Watchdog Timer
• Manufacturer: Linear Technology Corporation

LT3689/LT3689-5
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Absolute maximum voltage at V
nonrepetitive 1 second transients, and 36V for continuous operation.
Note 3: The LT3689E is guaranteed to meet performance specifi cations
from 0°C to 125°C junction temperature. Specifi cations over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LT3689I is guaranteed over the full –40°C to 125°C operating junction
temperature range. The LT3689H is guaranteed over the full –40°C to
150°C operating junction temperature range. High junction temperatures
degrade operating lifetimes. Operating lifetime is derated at junction
temperatures greater than 125°C.
TYPICAL PERFORMANCE CHARACTERISTICS
ELECTRICAL CHARACTERISTICS
SYMBOL
t
4
junction temperature range, otherwise specifi cations are at T
UV
90
75
70
65
95
85
80
0
Effi ciency, V
T
f = 1MHz
A
= 25°C
0.1
V
IN
PARAMETER
UV Detect to RST Asserted
WDI Input Threshold
WDI Input Pull-Up Current
WDI Input Pulse Width
W/T Threshold Voltage
W/T Input Pull-Down Current
WDE Threshold Voltage
WDO Pull-Up Current (Note 6)
RST Pull-Up Current (Note 6)
0.2
= 32V
LOAD CURRENT (A)
OUT
0.3
V
V
IN
IN
= 5V
= 12V
= 24V
0.4
0.5
IN
and EN/UVLO pins is 60V for
0.6
3689 G01
0.7
75
70
65
90
85
80
0
Effi ciency, V
T
f = 700kHz
CONDITIONS
Step V
A
= 25°C
0.1
The
A
FB
= 25°C. V
0.2
l
from 0.9V to 0.5V
LOAD CURRENT (A)
V
denotes the specifi cations which apply over the full operating
IN
OUT
V
V
0.3
= 32V
IN
IN
Note 4: Current limit is guaranteed by design and/or correlation to static
test. Slope compensation reduces current limit at higher duty cycles.
Note 5: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 150°C when overtemperature protection is active.
Continuous operation above the specifi ed maximum operating junction
temperature may impair device reliability.
Note 6: The output of RST and WDO has a weak pull-up to V
typically 1μA. However, external pull-up resistors may be used when faster
rise times are required or for V
Note 7: Polarity specifi cation for all currents into pins is positive. All
voltages are referenced to GND unless otherwise specifi ed.
Note 8: For the LT3689-5, V
= 3.3V
= 12V
= 24V
IN
0.4
= 12V, V
0.5
OUT
0.6
3689 G02
= 5V, unless otherwise noted. (Note 3)
0.7
OUT
l
l
l
l
l
OH
is set to 5.5V to ensure the switching.
75
60
55
50
80
70
65
higher than V
0
Effi ciency, V
T
f = 1MHz
MIN
–0.6
–0.6
300
0.4
0.4
0.4
A
10
= 25°C
0.1
0.2
–0.85
–0.85
LOAD CURRENT (A)
0.95
OUT
TYP
0.8
2.6
0.8
30
–2
OUT
.
0.3
V
= 1.8V
IN
= 12V
0.4
MAX
1.15
65
1
1
OUT
V
IN
0.5
= 5V
of
0.6
UNITS
3689fa
3689 G03
μA
μA
μA
μA
μs
ns
0.7
V
V
V