LTC3803-5 Datasheet, PDF (3/12 Pages) Linear Technology – Constant Frequency Current Mode Flyback DC/DC Controller in ThinSOT

LTC3803-5
ELECTRICAL CHARACTERISTICS LTC3803H-5: The ● indicates specifications which apply over the full –40°C
to 150°C operating junction temperature range, otherwise specifications are at T_A = 25°C. V_CC = 5V, unless otherwise noted.
(Notes 2, 3)
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX UNITS
V_TURNON
V_TURNOFF
V_HYST
V_CLAMP1mA
V_CLAMP25mA
I_CC
V_ITHSHDN
I_ITHSTART
V_FB
V_CC Turn On Voltage
V_CC Turn Off Voltage
V_CC Hysteresis
V_CC Shunt Regulator Voltage
V_CC Shunt Regulator Voltage
Input DC Supply Current
Normal Operation
Undervoltage
Shutdown Threshold (at I_TH/RUN)
Start-Up Current Source
Regulated Feedback Voltage
g_m
∆V_O(LINE)
∆V_O(LOAD)
Error Amplifier Transconductance
Output Voltage Line Regulation
Output Voltage Load Regulation
I_FB
f_OSC
DC_ON(MIN)
DC_ON(MAX)
t_RISE
t_FALL
V_IMAX
I_SLMAX
t_SFST
V_FB Input Current
Oscillator Frequency
Minimum Switch On Duty Cycle
Maximum Switch On Duty Cycle
Gate Drive Rise Time
Gate Drive Fall Time
Peak Current Sense Voltage
Peak Slope Compensation Output Current
Soft-Start Time
V_TURNON – V_TURNOFF
I_CC = 1mA, V_ITH/RUN = 0V
I_CC = 25mA, V_ITH/RUN = 0V
(Note 4)
V_ITH/RUN = 1.3V
V_CC = V_TURNON – 100mV
V_CC = V_TURNON + 100mV
V_ITH/RUN = 0V
0°C ≤ T_J ≤ 85°C (Note 5)
–40°C ≤ T_J ≤ 150°C (Note 5)
I_TH/RUN Pin Load = ±5µA (Note 5)
V_TURNOFF < V_CC < V_CLAMP (Note 5)
I_TH/RUN Sinking 5µA (Note 5)
I_TH/RUN Sourcing 5µA (Note 5)
(Note 5)
V_ITH/RUN = 1.3V
V_ITH/RUN = 1.3V, V_FB = 0.8V
V_ITH/RUN = 1.3V, V_FB = 0.8V
C_LOAD = 3000pF
C_LOAD = 3000pF
R_SL = 0 (Note 6)
(Note 7)
● 3.9
● 3.2
● 0.05
● 6.2
● 6.3
●
● 0.08
● 0.07
0.788
● 0.780
200
170
70
● 85
4.8
4
0.8
8
8.1
240
40
0.28
0.34
0.800
0.800
333
0.1
3
3
10
200
6.5
80
40
40
100
5
0.7
5.7
V
4.9
V
V
10.4
V
10.7
V
350
100
0.45
1
0.812
0.820
500
50
230
8.5
90
115
µA
µA
V
µA
V
V
µA/V
mV/V
mV/µA
mV/µA
nA
kHz
%
%
ns
ns
mV
µA
ms
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC3803H-5 is guaranteed to meet specifications from –40°C
to 150°C. The LTC3803E-5 is guaranteed to meet specifications from 0°C
to 85°C with specifications over the –40°C to 85°C temperature range
assured by design, characterization and correlation with statistical process
controls.
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 at junction temperatures greater than 125°C is derated to 1000
hours.
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.
38035f
3