LTC3805-5 Linear Technology, LTC3805-5 Datasheet - Page 3

• Manufacturer Part Number: LTC3805-5
• Description: Adjustable Frequency Current Mode Flyback DC/DC Controller
• Manufacturer: Linear Technology

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ELECTRICAL CHARACTERISTICS
SYMBOL
I
V
V
I
V
I
g
ΔV
ΔV
f
DC
DC
f
V
I
I
t
t
t
t
V
I
V
I
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 LTC3805E-5 is guaranteed to meet specifi cations from 0°C to
85°C. Specifi cations over the –40°C to 85°C operating temperature range
are assured by design, characterization and correlation with statistical
process controls. The LTC3805I-5 is guaranteed to meet performance
specifi cations over the –40°C to 125°C operating temperature range.
Note 3: T
dissipation P
temperature range, otherwise specifi cations are at T
CC
RUN(HYST)
FB
OSC
SYNC
SS
FTO
SS(INT)
FTO(INT)
RISE
FALL
SL(MAX)
OC
m
RUNON
RUNOFF
FB
SYNC
I(MAX)
OCT
T
O(LINE)
O(LOAD)
ON(MIN)
ON(MAX)
J
= T
A
J
+ (P
is calculated from the ambient temperature T
D
D
according to the following formula:
• 45°C/W)
PARAMETER
Input DC Supply Current
RUN Turn-On Voltage
RUN Turn-Off Voltage
RUN Hysteresis Current
Regulated Feedback Voltage
V
Error Amplifi er Transconductance
Output Voltage Line Regulation
Output Voltage Load Regulation
Oscillator Frequency
Minimum Switch-On Duty Cycle
Maximum Switch-On Duty Cycle
As a Function of f
Minimum SYNC Amplitude
Soft-Start Current
Fault Timeout Current
Internal Soft-Start Time
Internal Fault Timeout
Gate Drive Rise Time
Gate Drive Fall Time
Peak Current Sense Voltage
Peak Slope Compensation Output
Current
Overcurrent Threshold
Overcurrent Threshold Adjust Current
FB
Input Current
OSC
A
and power
A
= 25°C, V
CONDITIONS
Normal Operation (f
(Note 4)
V
(Micropower Start-Up)
V
V
0°C ≤ T
–40°C ≤ T
–40°C ≤ T
V
I
V
I
I
R
R
f
f
70kHz < f
70kHz < f
No External Capacitor on SSFLT
No External Capacitor on SSFLT
C
C
R
(Note 7)
R
TH
TH
TH
OSC
OSC
RUN
CC
CC
ITH
TURNOFF
LOAD
LOAD
FS
FS
SL
OC
Pin Load = ±5μA (Note 5)
Sinking 5μA (Note 5)
Sourcing 5μA (Note 5)
= 350k
= 36k
= V
= V
= 0 (Note 6)
= 0 (Note 8)
= 1.3V (Note 5)
= 200kHz
= 200kHz
The
< V
= 3000pF
= 3000pF
A
TURNON
TURNON
RUNON
≤ 85°C (E-Grade) (Note 5)
OSC
SYNC
< V
●
A
A
CC
≤ 85°C (E-Grade) (Note 5)
≤ 125°C (I-Grade) (Note 5)
denotes the specifi cations which apply over the full operating
CC
< 700kHz,
= 5V, unless otherwise noted (Note 2).
< 700kHz
+ 100mV
+ 100mV
or V
< V
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 5: The LTC3805-5 is tested in a feedback loop that servos V
output of the error amplifi er while maintaining I
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. For
details, refer to Programmable Slope Compensation in the Applications
Information section.
Note 7: Guaranteed by design.
Note 8: Overcurrent threshold voltage is reduced dependent on an
optional external resistor in series with the OC pin. For details, refer to
Programmable Overcurrent in the Applications Information section.
CLAMP1mA
OSC
CC
< V
= 200kHz)
TURNON
(Note 5)
– 100mV
●
●
●
●
●
●
●
●
1.122
1.092
0.788
0.780
0.780
MIN
70
67
85
85
4
1.207
1.170
0.800
0.800
0.800
LTC3805-5
0.05
TYP
TH
360
333
700
100
100
1.8
4.5
40
20
70
80
–6
30
30
10
10
5
3
3
6
2
at the midpoint of the
1.292
1.248
0.812
0.812
0.812
MAX
133
115
115
5.8
2.9
90
95
9
FB
to the
mV/μA
mV/μA
UNITS
38055fa
mV/V
3
μA/V
kHz
kHz
mV
mV
ms
ms
μA
μA
μA
μA
nA
μA
μA
μA
ns
ns
%
%
%
V
V
V
V
V
V