Datasheet

LTC3766
5
3766fa
For more information www.linear.com/LTC3766
elecTrical characTerisTics
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C. (Note 2) V
IN
= 15V, GND = PGND = 0V, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Oscillator and Phase-Locked Loop
I
FS/SYNC
FS/SYNC Pin Sourcing Current 20 μA
f
HIGH
Oscillator High Frequency Set Point V
FS/SYNC
= V
CC
234 275 316 kHz
Δf (R
FS/SYNC
) Oscillator Resistor Set Accuracy 18.75kΩ < R
FS/SYNC
< 125kΩ
l
–12 12 %
f
PLL(RANGE)
PLL Sync Frequency Range 100 500 kHz
Differential Amplifier
A
DA
Gain 1.5V ≤ V
SOUT
≤ 15V, V
IN
= 20V 0.99 1 1.01 V/V
CMRR
DA
Common Mode Rejection Ratio V
IN
= 20V 75 dB
R
INP
V
S
+
Input Resistance V
IN
= 20V 120 kΩ
R
INM
V
S
–
Input Resistance V
IN
= 20V 160 kΩ
I
OH
Output Sourcing Current V
IN
= 20V, V
S
+
= 5V, V
SOUT
= 2.5V
l
0.8 3.0 mA
V
IN
-V
OHST
Output High Fault Threshold V
S
+
Rising 1.2 1.5 V
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: The LTC3766E is guaranteed to meet specifications from 0°C
to 85°C with specifications over the –40°C to 125°C operating junction
temperature range assured by design, characterization and correlation with
statistical process controls. The LTC3766I is guaranteed over the –40°C to
125°C operating junction temperature range, the LTC3766H is guaranteed
over the –40°C to 150°C operating junction temperature range, and the
LTC3766MP is tested and guaranteed over the –55°C to 150°C operating
junction temperature range. High junction temperatures degrade operating
lifetimes; operating lifetime is derated for junction temperatures greater
than 125°C. Note that the maximum ambient temperature consistent with
these specifications is determined by specific operating conditions in
conjunction with board layout, the rated package thermal impedance and
other environmental factors.
Note 3: T
J
is calculated from the ambient temperature, T
A
, and power
dissipation, P
D
, according to the following formula:
T
J
= T
A
+ (P
D
• θ
JA
°C/W)
where θ
JA
is 95°C/W for the SSOP and 43°C/W for the QFN package.
Note 4: The LTC3766 is tested in a feedback loop that servos V
FB
to a
voltage near the internal 0.6V reference voltage to obtain the specified ITH
voltage (V
ITH
= 1.2V).
Note 5: Operating supply current is measured in test mode. Dynamic
supply current is higher due to the internal gate charge being delivered at
the switching frequency. See Typical Performance Characteristics.
Note 6: The V
IN
Regulator employs an external pass device to produce the
regulated V
CC
output voltage. The LTC3766 is tested using a 2N3904 NPN
transistor as an external pass device.
Note 7: Guaranteed by design.