Datasheet

LTC3245
3
3245fa
For more information www.linear.com/LTC3245
elecTrical characTerisTics
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. This IC has overtemperature protection that is
intended to protect the device during momentary overload conditions.
Junction temperatures will exceed 150°C when overtemperature is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 2: The LTC3245E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 125°C operating junction
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3245I is guaranteed over the
–40°C to 125°C operating junction temperature range. The LTC3245H is
guaranteed over the –40°C to 150°C operating junction temperature range
and the LTC3245MP is tested and guaranteed over the full –55°C to 150°C
operating junction temperature range. High junction temperatures degrade
operating lifetimes; operating lifetime is derated for junction temperatures
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
= 12V, V
OUT
= 5V, C
F LY
= 1µF unless otherwise noted.
greater than 150°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 resistance and
other environmental factors.
Note 3: The junction temperature (T
J
, in °C) is calculated from the ambient
temperature (T
A
, in °C) and power dissipation (P
D
, in Watts) according to
the formula:
T
J
= T
A
+ (P
D
• θ
JA
) where θ
JA
(in °C/W) is the package thermal
impedance.
Note 4: V
OUT
programming range is from 2.5V to 5V. See the
Programming the Output Voltage section for more detail.
Note 5: The maximum operating junction temperature of 150°C must be
followed. Certain combinations of input voltage and output current will
cause the junction temperature to exceed 150°C and must be avoided. See
Thermal Management section for information on calculating maximum
operating conditions.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
VIN
V
IN
Quiescent Current
SEL1 = SEL2 = 0V
V
OUT
Enabled, BURST = 0V
V
OUT
Enabled, BURST = V
IN
Shutdown, V
OUT
= 0V
CP Enabled, Output in Regulation
CP Enabled, Output in Regulation
4
18
20
8
35
40
µA
µA
µA
V
OUT5_BM
Fixed 5V Burst Mode Output Regulation
(OUTS/ADJ Connected to V
OUT
,
BURST = 0V, SEL2 = V
IN
, SEL1 = 0V)
(Note 5)
5V ≤ V
IN
< 38V, I
OUT
≤ 250mA
4V ≤ V
IN
< 5V, I
OUT
≤ 150mA
3.3V ≤ V
IN
< 4V, I
OUT
≤ 75mA
3V ≤ V
IN
< 3.3V, I
OUT
≤ 45mA
l
l
l
l
4.8
4.8
4.8
4.8
5.2
5.2
5.2
5.2
V
V
V
V
V
OUT5_LN
Fixed 5V Low Noise Output Regulation
(OUTS/ADJ Connected to V
OUT
,
BURST = V
IN
, SEL2 = V
IN
, SEL1 = 0V)
(Note 5)
5V ≤ V
IN
< 38V, I
OUT
≤ 200mA
4V ≤ V
IN
< 5V, I
OUT
≤ 120mA
3.3V ≤ V
IN
< 4V, I
OUT
≤ 60mA
3V ≤ V
IN
< 3.3V, I
OUT
≤ 35mA
l
l
l
l
4.8
4.8
4.8
4.8
5.2
5.2
5.2
5.2
V
V
V
V
V
OUT33_BM
Fixed 3.3V Burst Mode Output Regulation
(OUTS/ADJ Connected to V
OUT
,
BURST = 0V, SEL2 = V
IN
, SEL1 = V
IN
)
(Note 5)
5V ≤ V
IN
< 38V, I
OUT
≤ 250mA
4V ≤ V
IN
< 5V, I
OUT
≤ 175mA
3.3V ≤ V
IN
< 4V, I
OUT
≤ 110mA
2.7V ≤ V
IN
< 3.3V, I
OUT
≤ 60mA
l
l
l
l
3.17
3.17
3.17
3.17
3.43
3.43
3.43
3.43
V
V
V
V
V
OUT33_LN
Fixed 3.3V Low Noise Output Regulation
(OUTS/ADJ Connected to V
OUT
,
BURST = V
IN
, SEL2 = V
IN
, SEL1 = V
IN
)
(Note 5)
5V ≤ V
IN
< 38V, I
OUT
≤ 220mA
4V ≤ V
IN
< 5V, I
OUT
≤ 140mA
3.3V ≤ V
IN
< 4V, I
OUT
≤ 90mA
2.7V ≤ V
IN
< 3.3V, I
OUT
≤ 50mA
l
l
l
l
3.17
3.17
3.17
3.17
3.43
3.43
3.43
3.43
V
V
V
V
V
ADJ
OUTS/ADJ Reference Voltage (Note 4) SEL2 = 0V, SEL1 = V
IN
, I
OUT
= 0mA
l
1.176 1.200 1.224 V
R
CL
Load Regulation (Referred to ADJ) SEL2 = 0V, SEL1 = V
IN
0.2 mV/mA
V
PG_RISE
PGOOD Rising Threshold V
OUT
% of Final Regulation Voltage 95 98 %
V
PG_FALL
PGOOD Falling Threshold V
OUT
% of Final Regulation Voltage 88 91 %
V
PG_LOW
PGOOD Output Low Voltage I
PGOOD
= 0.2mA
l
0.1 0.4 V
I
PG_HIGH
PGOOD Output High Leakage V
PGOOD
= 5V –1 0 1 µA
V
LOW
BURST, SEL1, SEL2 Input Voltage
l
0.4 0.9 V
V
HIGH
BURST, SEL1, SEL2 input Voltage
l
1.2 2 V
I
LOW
BURST, SEL1, SEL2 Input Current V
PIN
= 0V –1 0 1 µA
I
HIGH
BURST, SEL1, SEL2 Input Current V
PIN
= 38V 0.5 1 3 µA
I
SHORT_CKT
I
VOUT
Short-Circuit Current V
OUT
= GND 900 mA
R
OUT
Charge Pump Output Impedance 2:1 Step-Down Mode
1:1 Step-Down Mode
1:2 Step-Up Mode (V
IN
= 3.3V)
3
3.5
14
Ω
Ω
Ω
f
OSC
Oscillator Frequency
l
450 500 kHz