LT3688 LINER [Linear Technology], LT3688 Datasheet - Page 4

• Manufacturer Part Number: LT3688
• Description: Dual 800mA Step-Down Switching Regulator with Power-On Reset
• Manufacturer: LINER [Linear Technology]

LT3688
ELECTRICAL CHARACTERISTICS
SYMBOL
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 the V
is 36V for continuous operation.
Note 3: The LT3688 is tested under pulsed load conditions such that
T
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
LT3688I is guaranteed over the full –40°C to 125°C operating junction
temperature range. The LT3688H 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. The junction temperature (T
calculated from the ambient temperature (T
(PD, in Watts) according to the formula:
TYPICAL PERFORMANCE CHARACTERISTICS
4
junction temperature range, otherwise specifi cations are at T
J
= T
T
impedance.
J
A
95
90
85
80
75
70
65
= T
. The LT3688E is guaranteed to meet performance specifi cations
0
Effi ciency, V
A
f
V
SW
IN
+ (PD θ
PARAMETER
RST Pull-Up Current (Note 6)
WDO Pull-Up Current (Note 6)
CONFIG Low Level Input Voltage
CONFIG High Level Input Voltage
CONFIG Pin Voltage When Open
Maximum CONFIG Input Current in Open
State
CONFIG Pin Bias Current
= 12V
= 1MHz
0.2
JA
LOAD CURRENT (A)
), where θ
OUT
0.4
= 5V
0.6
JA
(in °C/W) is the package thermal
0.8
A
3688 G01
IN
, in °C) and power dissipation
, CONFIG and EN/UVLO pins
1
CONDITIONS
V
90
85
80
75
70
65
60
CONFIG
0
Effi ciency, V
J
f
V
, in °C) is
SW
IN
= 0V, V
= 12V
= 1MHz
0.2
The
A
IN
LOAD CURRENT (A)
l
= 25°C. V
denotes the specifi cations which apply over the full operating
OUT
0.4
Note 4: The LT3688 contains circuitry that extends the maximum duty
cycle if the BST voltage is 2V greater than the SW voltage. See the
Applications Information section for more details.
Note 5: Current limit is guaranteed by design and/or correlation to static
test. Slope compensation reduces current limit at higher duty cycles.
Note 6: The outputs of RST and WDO have a weak pull-up to V
typically 2.5μA. However, external pull-up resistors may be used when
faster rise times are required or for V
Note 7: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed the maximum operating junction temperature
when over-temperature protection is active. Continuous operation above
the specifi ed maximum operating junction temperature may impair device
reliability.
Note 8: All currents into pins are positive; all voltages are referenced to
GND unless otherwise specifi ed.
= 3.3V
0.6
IN
= 12V, unless otherwise noted. (Note 3)
0.8
T
3688 G02
A
= 25°C unless otherwise noted.
1
l
l
l
l
MIN
–1.5
–1.5
1.4
85
80
75
70
65
60
55
0
Effi ciency, V
f
V
SW
IN
OH
= 12V
= 500kHz
higher than V
0.2
–2.5
–2.5
0.64
TYP
LOAD CURRENT (A)
OUT
0.4
= 1.8V
BIAS
MAX
0.6
±20
0.2
±1
.
BIAS
0.8
of
3688 G03
UNITS
3688f
μA
μA
μA
μA
1
V
V
V