LTC3803-5_15 Datasheet, PDF (4/16 Pages) Linear Technology – Constant Frequency Current Mode Flyback DC/DC Controller in ThinSOT

LTC3803-5
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.
Note 2: The LTC3803-5 is tested under pulsed load conditions such
that T_J ≈ T_A. The LTC3803E-5 is guaranteed to meet specifications
from 0°C to 85°C junction temperature. Specifications over the –40°C
to 125°C operating junction temperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3803I-5 is guaranteed over the –40°C to 125°C operating junction
temperature range, the LTC3803H-5 is guaranteed over the –40°C to
150°C operating junction temperature range and the LTC3803MP-5 is
tested and guaranteed over the full –55°C to 150°C operating junction
temperature range. 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.
Junction temperature (T_J) is calculated from the ambient temperature T_A
and the power dissipation P_D in the LTC3803-5 using the formula:
T_J = T_A + (P_D • 230°C/W)
Note 3: High junction temperatures degrade operating lifetimes; operating
lifetime is derated for junction temperatures greater than 125°C.
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 5: The LTC3803-5 is tested in a feedback loop that servos V_FB to the
output of the error amplifier while maintaining I_TH/RUN at the midpoint of
the current limit range.
Note 6: Peak current sense voltage is reduced dependent on duty cycle
and an optional external resistor in series with the SENSE pin (R_SL). For
details, refer to the programmable slope compensation feature in the
Applications Information section.
Note 7: Guaranteed by design.
TYPICAL PERFORMANCE CHARACTERISTICS
Reference Voltage vs Temperature
820
V_CC = 5V
815
810
805
800
795
790
785
780
–60 –30
0 30 60 90
TEMPERATURE (°C)
120 150
38035 G01
Oscillator Frequency
vs Temperature
240
V_CC = 5V
230
220
210
200
190
180
–60 –30
0 30 60 90
TEMPERATURE (°C)
120 150
38035 G04
Reference Voltage
vs Supply Voltage
812
T_A = 25°C
808 ^{VCC ≤ VCLAMP1mA}
804
800
796
792
788
4.0
4.5 5.0 5.5 6.0 6.5 7.0 7.5
V_CC SUPPLY VOLTAGE (V)
38035 G02
Oscillator Frequency
vs Supply Voltage
220 _{TA = 25°C}
215
210
205
200
195
190
185
180
4.0
4.5 5.0 5.5 6.0 6.5 7.0 7.5
V_CC SUPPLY VOLTAGE (V)
38035 G05
4
Reference Voltage
vs V_CC Shunt Regulator Current
812
T_A = 25°C
808
804
800
796
792
788
0
5
10
15
20
25
I_CC (mA)
38035 G03
Oscillator Frequency
vs V_CC Shunt Regulator Current
220 _{TA = 25°C}
215
210
205
200
195
190
185
180
0
5
10
15
20
25
I_CC (mA)
38035 G06
38035fd